How to fix a broken Bicyle Frame Boss (water bottle, bottom bracket, down tube)

[@germanhugger41]

Can't believe that Cervelo would use such a ridiculous method of retaining a rear brake caliper? Great work as work as always Mr. Hambini...

[@ccmmrrnn]

@Ultranationalist It really shouldn't. This bike obviously gets ridden in the UK winter, is rarely cleaned, and although galvanic corrosion as Hambini mentioned is a thing, it's also easily avoidable (a bit of grease on threads of the bolt periodically, not putting the bike away wet, gentle cleaning as required). Rivnuts can do the job for years; this is a case of neglect. Every carbon frame brand in the world uses similar methods for water bottle bosses. In this case they're using it for the brake mount as there's no way to pass a normal brake calliper bolt and nut all the way through the frame. That said, it would make sense for them to use a stainless steel rivnut and bolt, but they probably choose not to because grams.

[@KimHDRoberts]

@@ccmmrrnn That is a case of poor application of an solution that is adequate for lower stress applications (bottle cages etc.) - where that solution is used appropriately. Rivnuts for securing a rear brake is an exceedingly poor use of that solution (and is why the vast majority of manufacturers would absolutely never use this type of setup).

[@ccmmrrnn]

​@@KimHDRoberts The brake is not secured to the rivnut. It's bolted into the plate (what I called the brake mount) that is secured by the bolt that goes in the rivnut . That plate is supported by a larger part of the frame around the axis of the brake calliper bolt, so it's not cantilevering the bolt that's in the rivnut. Sure it's not ideal and there are better designs, but it's sufficient for Cervelo's design goals with this particular frame (aero). The rivnut failed due to poor maintenance, not due to the design.

[@GK-zr9cq]

The reason Cervlo has that set up is because the brake is mounted to the seat tube due to the aerodynamic design. There is no bridge between the seat stays to mount a brake, so you can't access the back of the bolt. Of course, the implementation of the fastener could have been better, but if not over torqued and kept fairly clean the nut shoukd not fail.

[@KimHDRoberts]

@@GK-zr9cq as I said - a poor implementation. The fact the frame design is at fault just exacerbates exactly how poor. Many aero bikes utilise rim brakes and none do it this badly.

[@bizzehdee]

This is the video that originally brought me to your channel. Bought a PlanetX Pro Carbon 2 years ago, and almost immediately snapped the thread from a bottle cage boss, they wanted nothing to do with fixing it, even though it was under warranty, so i had to just deal with it. This video was in the related videos section on a GCN video a few weeks ago, so clicked it wondering how hard it would actually be. Turns out that it was a piece of piss to drill out and drop a new one in, and cost £8 for the tool with some rivinuts on ebay. Thank you 😁

[@rosomak8244]

You should have put some copper grease on the nut to mitigate the galvanic corrosion.

[@howd500]

Or zinc cromate paste ? but i do use copper or aluminium grease a lot in automotive areas or molycote no plugs intended

[@1crazypj]

@@howd500 It's actually better to use something that would insulate and also prevent oxidation. Titanium is relatively inert but if you add copper grease it can accelerate galvanic corrosion (yes, it surprised me when I found out) Stainless steel into aluminium is particularly bad. Best cheap solution is to get some plumbing Teflon thread sealer from local home supply megastore (B&Q still going in UK? Lowes, Home Despot in USA) NOT PTFE tape although even that would be better than 'dry' assembly

[@howd500]

@@1crazypj Hi thanks for the info in the stainless / Aluminium combintion i have used in the past in sailing applications zinc chromate paste as a barrier thanks for your reply

[@1crazypj]

@@howd500 Cool stuff. Sea sailing is about as bad as you can get for corrosion, probably worse than riding a motorbike in British winter with all the salt they put on roads. (I guess they still do that?) I think Teflon plumbing compound may be easier to get hold of for most people though, I've never seen zinc chromate outside of specialty stores

[@arsaeterna4285]

Yeah, I've been hearing that you need a real physical layer as opposed to a grease I've heard that carbon slowly delaminates over time, even with molecular level contact As a result, the only guarantee is a physical layer of plastic or something

[@drewscreen]

Thank you, this video gives me the extra push to do this repair myself on my wife's bike, a Specialized Crossroads, with a loose aluminum downtube water bottle boss that I need to mount a lock bracket.

[@WiseGuyFTW]

Although I do not have mechanical engineering background but I have just binge-watched almost all of your videos :) and I want to thank you for going into details to explain things. Please do go into technical details I do enjoy that. Your recent video about Shimano BB86 and Scott Bike Case Study was very insightful and one of my favorite videos.

[@Hambini]

Thanks for the feedback! It's always difficult to get the right mix between technical and switching people off.

[@mrfailure93]

Dude, wash your bike!

[@jbratt]

Evan V ...and take that rear wheel off!

[@romka_ind]

And use some protective solution. Or your sweat will eat your bars :)

[@onlymeok]

It looks like it was fished out of the canal.

[@zPtrck]

Comments are very helpful, 1. Copper grease can prevent that to happen again. 2. Very clean demonstration but you need to clean your bike man. 3. This Channel is good.

[@mmusic9194]

Hi! Question-i have scott addict R1 2009 crame. Front carbon hanger broke. I would file it down to nice round shape like seat tube. Can I drill holes in to seat tube and use alu braze on hanger and use rivets or its better use clamp on hanger? thanks 🙏

[@mikemelbrooks]

I have used a little superglue "Cyanoacrylate adhesive" to stop a rivnut from turning, If you feed the glue in like you would soldering or brazing ( surface tension ) you can often remove the fixing bolt.

[@Hambini]

I've never tried that but I might give it a go next time.

[@seasky6101]

Yes i will put superglue too for extra power

[@jonathantatler]

If you drill at a slight angle it helps stop the rivnut turning but will continue to cut even if the rivnut spins. I prefer the epoxy method, it helps secure it without stresses and also helps reduce galvanic corrosion.

[@txm100]

Why no grease on the bolt? That's inviting the same problem again..

[@AirCrash1]

not unless the grease has a metal like copper in it......thread science 101 No amount of grease is going to stop metal on metal contact when the bolt is tightened. Greases help prevent corrosion of the non metal to metal parts of the thread but they don't help with the part of the thread where there is metal to metal contact.....Also see thread science 101 Only the first few threads are actually holding the fastener together(metal to metal contact) the rest of the thread just sits there(some parts metal to metal some parts not)

[@MartinTeerly]

I love you showing every possible reason why people should stay away from carbon 💪🏻

[@bizzehdee]

The aluminium rivnut failed, not the carbon frame...

[@tonyhussey3610]

I agree it’s just a poorly executed fastening method, nothing wrong with Carbon.

[@MartinTeerly]

@@tonyhussey3610 yeah ? And what's good about it ?

[@tonyhussey3610]

Marcin Terlecki You can’t be serious..you actually believe carbon fibre is a pointless bike material...yes the material can be misused by poor design or assembly but to totally dismiss the material is ridiculous. #Steel is Real or Flat Earther comes to mind...

[@MartinTeerly]

@@tonyhussey3610 yes pal I'm a flat earth believer 🥺

[@albertralphmiguel1657]

Just want to know what size of the rivnut need for cable guide under the bottom bracket? Thanks

[@Hambini]

M5

[@albertralphmiguel1657]

@@Hambini but mines is smaller than the watter bottles rivnuts

[@Hambini]

Unusual if it's m4

[@dyzoly]

Please tell me that they didn't use a rivnut on the front brake also...

[@jdodd1258]

What if the rivnut doesn't move, just the thread has been stripped? Would it be best to tap it out? Currently dealing with this problem at the bottom bracket cable guide. Thank you!

[@Hambini]

Jude Dodd I would drill it out. I would not tap it out!

[@jdodd1258]

Thank You

[@196hasnain]

helicoils?

[@NoFretBrettCSSMBFF]

'Cheat'... Epoxy the Guide's Bolt into the stripped RivNut (if it is a simple CableHolder and NOT a CableSTOP)...

[@adttrdat2212]

I still ❤ you hambini!

[@niezbo]

Just wonder. Wouldn't be possible to user steel rivnut with steel bolt? Finding adequate steel bolt shouldn't be a problem, and at the end would prevent corrosion, right?

[@zaahierstanley955]

How does one remove a m5 seat post Allen key bolt that is damaged and the allen key has no grip ? Thank you

[@ccmmrrnn]

Either use a hacksaw or cutting disc to cut a slot in the damaged head of the bolt so that you can get a flat head screwdriver in there, or if you can't get at the head you can remove it with an extractor bit available from a hardware store. Failing that you can completely drill it out but you'll probably have to say goodbye to your seatpost clamp. KZbin search for how to remove a stripped bolt.

[@johnchilton3975]

Has a different electrical charge??

[@Bari_Khan_CEng_CMarEng]

Nobility of materials/metals/alloys

[@johnchilton3975]

My point was that the different metals do not have a different electrical charge. Electrical charge is electrical charge (either positive or negative). Overall the metals are neutral, and are so when they are put together. The effect discussed here is complex but put simply, when two dissimilar metals are touching in a way that allows charge to move, then a voltage is set up between them. I am being 'picky' about the physics, that is all.

[@Bari_Khan_CEng_CMarEng]

@@johnchilton3975 Yes for sure, but Mr. Hambini did explain it simply enough - or as you allude, a cell is created, and that is effected by ref. to the Galvanic series.

[@omerfurtun4115]

Hey great video, I just discovered this. I have the same problem with my seat post bottle cage rivnuts. Any help would be appreciated! Mine were loose so I tried pulling the rivnuts out, but I may have wiggled it a bit to get them out, causing a tiny chip on one hole (it's like a slight Q shape now). If I take the original expanded rivnuts that I took out, I am able to put them back in the holes without too much hassle. I'm thinking maybe the holes were enlarged a bit. Everything is out though. Just left with these holes. I think the rivnuts weren't corroded too badly as yours, but they must have come loose with vibration over time. I can't find anybody who seems confident in fixing this. I'm not experienced with epoxy but I can follow instructions quite well. Should I try (bigger) rivnuts or some epoxy? What type of epoxy should I go for? Or any other suggestions?

[@Hambini]

Hi Oemer, I would try a rivnut that has a longer compression area, so it will fill out the damage in straight bit of the "Q". It's not heavily loaded so epoxy should do the job.

[@firesurfer]

kzbin.info/www/bejne/jmPWqqZ-qNyInas is what you are looking for. use a standard gun.

[@lobuxracer]

@@firesurfer Now that's a brilliant piece of engineering! Not sure why it should be relegated to composites, the advantages in a blind application are clear regardless of material. If you have access to the backside, using a washer of the same material as the rivnut works well too and avoids the problems seen in the video.

[@yurysun4727]

Hi Sir Hambini, any suggestion, how shud and can i prevent and care for my Aluminium Frame from corrosion? , i mean the inner tubes of the frame, by any chance, shud i spray the inner tubes in the frame with wd 40?

[@shoos9315]

Thanks for shearing

[@almondchristopher]

Brilliant video, one question about rivnut’s, how strong are they? If I wanted to add disc brakes to an older carbon bike would I be able to attach them with rivnuts? Thanks

[@michaelpidsadny2379]

The older carbon frame probably isn't reinforced in that area for disc brakes, like how a disc specific frame isn,t reinforced in the right areas for a rim braking setup.

[@TimInertiatic]

Old post..but NO! Frames and forks are specifically strengthened for use with disc brakes

[@michaelpidsadny2379]

@@TimInertiatic thanks!:)

[@elephantcup]

"Job complete". Not sure I'd agree with that. Your part failed due to galvanic corrosion. My initial thought watching this video was surprise that a very smart engineer such as yourself who rides his bike in such wet hostile conditions would have allowed that to happen in the first place. I'm referring to the lack of any dielectric compound smeared on the threads prior to assembly to mitigate that corrosion. Clearly an issue evidenced by the corrosion that you pointed out on your handlebar clamp. Why not take all of those fasteners off, use a brass wire wheel and brush to get them back to bare metal (or just replace them...), smear well with grease, dielectric compound or anti-seize and keep it from happening again? Waterproof grease liberally applied is probably best in your climate. Your bike is a ticking time-bomb of part failure. How bad would it suck for your handlebar to snap off while you're riding due to fastener failure? Anyway, thanks for the #nerdporn.

[@Hambini]

Thanks for the comment. This problem is rife in the Aero industry where I work. I've tried most of the suggestions in your comment and they have mixed results. Granted, they slow the rate down but on the whole the stuff gets washed off or the threading inevitably contacts between fixings. It's not the surface area so much that causes the corrosion it's the electrical joint.

[@Ammi6543]

@@Hambini Have you tried PTFE tape on the bolt? It probably isn't perfect because there will still be some parts of the threads that cut through the tape and make contact, but there should be far less contact and threrefore far less corrosion sticking the two parts together.

[@Hambini]

@@Ammi6543 I've never found it to work as the threads cut the tape and you always get some metal to metal contact.

[@rosomak8244]

@@Hambini This is a much more widespread issue in the marine industry. Another method is to provide some "fodder" for the corrosion to be eaten preferable to the metal you want to protect. In this case: copper grease would be helpful.

[@KamikazeCommie501]

How long would that last? That fix especially looks like it with break again the first time you brake.

[@wseto09]

Preventive is the best medicine for any nut or bolt seizure on any bike parts. You're right rosomak. Copper grease from automotive place or if possible hardware store. It will also prevent the dreaded cold fusion of nuts and bolts or when there's contact between metal / aluminum / titanium or steel for seatposts and bottom brackets. Of course carbon grease for carbon to steel / aluminum contacts.

[@elkat_bori_pr7791]

Curious to me your saddle possition!

[@howd500]

Does Titanium react with alu? i would imagine it does

[@firesurfer]

'' Study of the Galvanic Series suggests that steel and aluminum are reasonably compatible; but, if titanium and aluminum contact, the aluminum, as the anode, will corrode. The bolt, where it contacts the aluminum, will not corrode because it is now the cathode. The aluminum plate in contact with the bolt may corrode, but only slightly because of the minor difference in their electro-potentials and the large anode-to-cathode area ratio.'' www.accuratescrew.com/asm-technical-info/material-compatibility-selection-data/ I have lightly edited it because it was a generic statement. I couldn't find the picture it was referring to perhaps because it was deleted by my ad blocker. As a practical matter, using silicone grease on the bolt and/or fitting should isolate the two parts. Some have recommened loctite, but that is not good because it is a conductor. They make a dielectric grease but that is just silicone grease. Any dielectic silicone grease will do. Regular cleaning is much more effective. (1or 2 times a year)

[@paulhawkins6415]

You need a sacrificial anode to stop the corrosion, there is so much crap on your bike that you could place it anywhere and there would be an electrical connection ;) I cant believe a five thousand pound bike has such a rubish fixing for the brake. Rivnuts are utter crap, any vibration and they come loose or damage whatever they are fixed to. The fixing for the caliper should have been embedded in the matrix of the frame when the bike was made, not crimped on as an afterthought! Anyway keep up the good work.

[@Hambini]

Dirt = the hambini electrical conductor of choice!

[@paulhawkins6415]

I wish my ******* was as dirty as your bike. Gender left unassigned to prevent triggering of snowflakes.

[@Rob-xe4lo]

Shocking rear brake fixture, no wonder my local bike shop stopped selling cervelo's..

[@Dude_42069]

Thanks for the video i learned a lot from it. Would you think that a stainless steel or titanium frame would be more resistant to that kind of failure.

[@Hambini]

Yes, you could have the insert as an integrated part of the frame and it would not corrode in stainless steel or titanium.

[@NoFretBrettCSSMBFF]

Especially if you utilize Bolts of similar materials... SS with SS... Ti with Ti...

[@joeottsoulbikes415]

Do you not use any anti-seize compound on your bolts to try and reduce the corrosion? I've always found that the Park Tool ASC-1 compound does a pretty good job at reducing corrosion between aluminum and titanium interfaces and if reapplied during a yearly overhaul can help reduce the acceleration that your bodies sweat can have on that corrosion.

[@RabidMortal1]

FWIW, given the possible damage to the carbon, Cervelo might replace the frame for you. Last year Cervelo replaced my bike when a single tiny rivet broke off of one of the cable tensioners. Guess they couldn't rule out that the downtube was compromised and decided to give me a new frame.

[@MADTASS]

Alternatively, if your a Cheap Skate like me, Slot the Riv Nut in the Hole, put a Nut on a Wheel Skewer, Screw the Wheel Skewer into the Riv Nut and then Tighten the Nut on the Skewer towards the Frame, worked a treat when i had a loose Riv Nut on my Merida. I use a Bit of Cloth so as not to mark the Frame in any way.

[@metiks111]

i like this kind of mechanics who do full on repais, not just some parts swap

[@byronwellburn]

Have you washed it yet?

[@howd500]

Why don't they use the hexagonal rivnuts rather than the round ones with lines?

[@ColinWatters]

Before gluing in the new nut you must clean out any penetrating oil that may have got in there. Use something like Methylated spirit on an ear bud.

[@pgn666]

I LOVE but why not to clean the bike when you inserting new bosses ore reinstall break calliper. The contact point between the frame and the break hanger filled with junk is gone damage you frame in that area and result in loose break calliper and less precise/string breaking.

[@neilstoddart00001]

Good to see carbon frame repairs, I bet there are many bridges jobs out there. Have you seen the UV setting adhesive? It's derived from dentisty. If you have, what's your take on this as an adhesive for repair or mounting bosses?

[@MFKR696]

In my experience, UV-hardened epoxies are nowhere near as strong as chemically-catalyzed epoxies. I know you probably didn't want an answer from me, but just be happy you got an answer lol.

[@cosmaflorin20031]

I like to watch your video. It's nicer to work on your bike if is clean. I had the same problem on my road frame and I solved it in the same way.

[@Sudipto17Kolkata]

Many of the commentators here are missing one important point - this video is not about how the problem could have been avoided and what the guy should have done in the first place etc. It is simply about how you fix the problem, if and when it happens. It is not about "please advise me how not to get a broken rivnut in my bike". Those who want to say that should consider creating their own videos on the subject.

[@Hambini]

I think you are spot on with your comment

[@Geeraffe]

just a note on alignment for the rivnut might be good ? I would be concerned if the nut was off centre a touch and then affecting the calliper. Otherwise nice video please make more.

[@Hambini]

Thanks for the feedback.

[@Hambini]

ThankyoU!

[@branes2000]

Odd that the Ti bolt is so long. That's the original presumably? I can't see why it's so long when the rivnut thread seems so short - surely a shorter (steel) bolt would be better?

[@Hambini]

I think they just buy a box of bolts and use them everywhere on the bike. Cost saving or parts rationalization

[@nickhumphrey4833]

I love your videos Hambini best technical vids on the web but bloody hell the clearance between your tyre and frame is miniscule. Don't go gravel riding !

[@TimInertiatic]

It's an aero road bike!

[@stibra101]

What happened to all videos from last 2 years? Please upload them to Vimeo for example.

[@mrnobody9821]

stibra101 Probably temporary...hope so.

[@mrnobody9821]

He states in his website due to bereavement his orders will be delayed so I’m guessing someone in his family has passed, probably made the videos private to quiet things down for the time being.

[@clivewilliams3661]

If the set Rivnut pulled out the hole created was then bigger than the correct sized hole for a new Rivnut so that it is unlikely to be as secure (if at all) as originally. The best thing to do is to use a larger say, M6 Rivnut and bolt or fully coat the Rivnut and hole with epoxy, set the nut and leave the epoxy to set and hopefully there will be enough interference to stop the new Rivnut pulling out. Also, one of the complications here is that the titanium bolt is too long. The threads project too far through the set Rivnut and will clog with corrosion from the Rivnut or any crud floating about, when that happens the bolt will bind up and probably spin the Rivnut, never mind that its a waste of a bolt length and adds weight. Ideally, only 1 thread should be showing at the base of the Rivnut internally, which means that the bolt has maximum thread engagement without the possibility of clogged threads. Personally, I use Alusteel Rivnuts as they have greater mechanical strength and you can set them with higher torque for better holding power and there is less likelihood of galvanic corrosion. Also with steel threads the threads are less likely to strip or the bolt pull out after repetitive assemblies, a dab of anti-seize grease is sufficient to ensure no problem unscrewing the bolt.

[@villangmail]

Do you have any plans to make 68mm english threaded bottom brackets? I am thinking of upgrading my track bike to a sram omnium or sugino 75 DD, and want to avoid press fit bottom brackets. Anyways, thank you for the epic content, keep it up!

[@Hambini]

villan hi I'm afraid I have no plans to make any threaded bottom bracket

[@howd500]

Why not lightly clamp the rivnut in the vice an use a socket? just an idea love the channel

[@georgehugh3455]

Nice video. I am skeptical, however, about the ability to effectively hold the round and minute protruding rivnut rim while drilling the core out. Of course, losing some depth of paint around it helps, but still....

[@Hambini]

You are 100% right, it's not easy but it is aluminium so you physically deform the metal to stop it turning. With steel that would be a different ball game altogether.

[@bagafatcat]

loctite freeze on tire and rim, nice going m8

[@jonathan___4684]

Just curious, why is that bad?

[@NoFretBrettCSSMBFF]

I do not know much about Loctite Freeze... If it is like PB Blaster, there is a definite #NotGoodForFrictionBrakingSurfaces quality to it...

[@NoFretBrettCSSMBFF]

It May *STOP* the *Brakes* from *SQUEALING!!!* ... but (inadvertently?) the Rider may end up *SCREAMING* Even *LOUDER* and *LONGER* ...

[@graememorrison333]

Great video, but my case is slightly worse than yours. My water bottle rivnut has popped clean out from the downtube and taken a bit of cf with it - leaving a ragged 1cm diam hole. (Bottle cage now kept steady with zip-tie.) What I'd like to know (and how to do it) is whether to fill the hole with epoxy putty, or the trickier but maybe stronger solution of bonding layers of cf around the hole before drilling through them risking tearing, and then squeezing in a new rivnut. Obviously you shot this last year, but can i suggest that you treat yourself to a decent winter bike with mudguards and everything?! Even pro racers don't care what they look like when riding/training in shit conditions.

[@Hambini]

you could try some body filler and fibre glass. If it's only for the water bottle, the load is not high so it will probalby take the load. Alternatively, fibre glass and epoxy will definitely take the load.

[@graememorrison333]

@@Hambini Cool! Will look into that. Thanks for replying too. Just found your channel - its v infomative (and dryly funny!)

[@mekore]

thats the way cervelo attach a rear caliper??? crazy

[@karlstine2065]

A weeks worth of dirt?

[@NoFretBrettCSSMBFF]

Yes... or less than *ONE Hour* Worth of GravelGrinding (in less than ideal conditions)...

[@NoFretBrettCSSMBFF]

... and ... a Week Ago, the Dirt was Acquired... a Month from now, it might get cleaned...

[@waynosfotos]

Normally the manufacturer put a fibreglass piece in the frame to act as a barrier to stop the galvanic corrosion. I wonder if Cervelo did? I have a S5 and the rear brake is a bit of a poor design and the bracket acts like a lever when braking. I know it is about being aero. But I now don’t buy aero bikes as they have these special parts which can be a pain.

[@Hambini]

I don't think cervelo put the fibreglass in, if they did, it wasn't there when the rivnut failed. I agree, the special parts are a PITA

[@sidshel4428]

hi not to be to critical. you ride your bike in the winter and don't maintain it. I saw the one when you changed the rusted head set bearings. as an owner of any bike you have to clean and maintain on a regular basis and not wait until its rusted or broken. a simple clean and lube or grease its worth it in the end. its a bit of fussing around ; however for me it brings a certain amount of satisfaction. the rivnut would have lasted if you cleaned the bike . so my real point or question is if you ride in the winter and don't want to be bothered to clean and maintain your bike why on earth ride an expensive bicycle ? you could buy something nice as your winter bike and still be able to stay in shape and go 30 klm / hour . and finally I saw the comments and your answers to as why you do not put grease around the head set bearings. in my humble opinion grease keeps the moisture out even though it attracts dirt. that's why i do regular maintenance on my bikes. and yes i have one for the winter which is like your aero bike a project in the making which maybe i will finish by next winter. and does grease really hurt carbon fiber. they do paint the bikes for protection and yes I am careful not to get any grease on my carbon fork because i have heard its bad for the carbon fiber. you are dammed if you do and dammed if you don't. there must be something one could use thats not going to react with carbon fiber. other wise I do enjoy your videos thanks

[@sidshel4428]

i did check around seems like most manufactures say bike grease is ok . auto grease may have some acid which is no good. trek says no problem with their bikes. use grease and wipe up the extra grease should be ok. no harsh cleaners

[@jen3800]

i grease all my bolts before install. is that wrong? i also smear a light coating of grease into my booties for waterproofing. ugly, but it works in Canada in the winter

[@Hambini]

Greasing is a good idea. If you want to be really pedantic, it's worth running a tap or a die through any aluminium parts as they inevitably end up with some surface corrosion. Then the grease will stop the galvanic corrosion (or certainly reduce it).

[@Hambini]

Greasing your bolts is fine. It will make the thread engagement better

[@evanchan7207]

dude you are the man...

[@garysanderson4932]

grease all bolts will help stop galvanic corrosion

[@Yonok2009]

Now you can wash your bike ---please !!!

[@5davi524]

@Hambini Unreal that you use an S5 with Di2 as a commuter

[@Hambini]

5davi5 in summer I commute on the time machine!

[@5davi524]

I'm feeling a bit jealous :) I have a 12 year old Bianchi 928L that has only seen rain twice, it's my Summer bike. Oh by the way, keep up the great videos.

[@danfuerthgillis4483]

Another lightweight bike weenie lol I see a lot of these fools needing a 7 kg aero bike to ride 40 km. My $250 GMC Denali is cleaned after every long ride. Look at his bike that is disgusting and its obvious this fool has no idea how to maintain bikes lol. If I give him my 14 kg GMC Denali this guy would pass out in 10 minutes.

[@DeepakKumar-lv4te]

@@danfuerthgillis4483 so mr bike expert, what actual difference would it make cleaning the frame?

[@danfuerthgillis4483]

@@DeepakKumar-lv4te First rule of bike frames is to keep it clean even on carbon bikes. The more shit you leave on it the more shit will fly off into the metal components and cause issues later on. Britain ( I mean the country still owned by the Opium cartel family) is very rainy so it’s quite obvious that he does not give a “Shit” about cleaning his bikes.

[@rorixaviertolentino3610]

The bike is begging to be cleaned. Sir Hambini, can you make a technical video shed light on various frame materials like steel (Fe) vs Ti vs Al vs composite in ride quality and damping capacities?

[@Hambini]

Will add it to the list!

[@AmazingChinaToday]

That seems like a very poor design, there are significant forces on the brake bolt. The frame should have an embedded piece of metal that is part of the carbon fiber construction, not a drilled-in afterthought.

[@prowlertf34]

Hambini you need to put your S5 in ISO.

[@pf465]

2:07 You were gonna what? Did I hear that correctly?

[@Cynyr]

why does everyone use round rivnuts... right right, round holes are easier to machine, but they make hex and square ones. That way even if things go sideways later you can at least get the fasteners out.

[@Hambini]

Pass, I don't know why they don't bond directly into the frameshell. it's what they do in aero

[@chrisbowman2030]

From what I see, there is no problem with the titanium screw and the aluminium rivnut. Here we have two problems: No.1) The aluminium rivnut is corroded away due to a galvanic reaction with the carbon. No.2) The bike is filthy as heck. This is no dirt from a week of commuting. This is solid patina, built up over months without any cleaning. The dirt together with moisture leads to corrosion like this. I always check if rivnuts on my bikes are properly sealed with paint. If not I just seal it with super glue. It's also a good idea to use weak loctite on screws, because it seals the thread. And yes, I am engineer.

[@isbemorph]

all you people whining about using grease you just dont get that its a small aluminum nut and very hard bolt, meaning you can only torque it very little, by feel generally, and it just must hold the caliper no matter what as brakes are important. Using grease you risk over torquing, stripping threads or that the bolt would come loose. I actually in such low torque application use special wax based clear paint which acts like a glue, but it melts from alcohol or heat, so no problem undoing the bolts.

[@NoFretBrettCSSMBFF]

Not quite correct... Lubed Threads *ALLOWS* More Accurate *Tension* on the Bolt (for the exact same 'Torque' Readings that are often specified from the manufacturers)... 'TENSION' is what is required on Bolts - NOT 'Friction' that hinders application of the necessary Tension...

[@isbemorph]

@@NoFretBrettCSSMBFF , ​ i agree but who uses a torque wrench for such small bolts? i'd be afraid of stripping threads or cracking the frame and rather go by feel and some thread lock. But for cars sure i generally lube, eg i was retorquing headbolts on a motorcycle and lubed all the nuts before tightening to the specs, dont know if it stopped the leak yet tho.

[@NoFretBrettCSSMBFF]

ThreadLocker 'acts' as a 'lubricant' (when tightening)... So, (I understand that) We Agree...

[@cesarfabiantejada2474]

Step 1. Clean what you are going to work on! I think you should have cleaned the parts with acohol (after washing the whole bike) and use epoxy to preven rust and movement of the piece you are installing.

[@AndrewSmith-cd5zf]

Ok so its a commuter - we get that but breaking a boss on a filthy bike to clean one component is a bit naff. Why not leave it alone - happy and filthy. On my commuter I will wash the critical components at either end of the ride (often just with the water bottle and a rag) or the hose at home so that the drive parts work smoothly and last longer ( quality 60 - 90 seconds ).

[@pskonejott2568]

Thanks for sharing

[@jonnyflanders1229]

Great informative video keep it up!

[@jonnyflanders1229]

PS, clean ya bike 😂

[@Hambini]

I aim to please. As for cleaning my bike, I might take it to the local car wash.

[@aaronpaterson7582]

please jet wash this bike.

[@ap6584]

Could you point me towards a suitable epoxy? Everything I've tried hasn't been strong enough and I've always had to use the rivnut gun.

[@Hambini]

Henkel

[@NoFretBrettCSSMBFF]

Added Suggestions; - Remove RearWheel (to have more room to work, as it appears that the 'axis' of the RivNut was too close to tangent with the wheel, and the additional width of the tool making it appear to be simply added hassle and interference)... - Add a touch of Epoxy to RivNut/Frame (for less likelyhood of this situation occurring again, and 'fill in' the voids that occur when removing broken RivNut - additionally handy if you want to touch up the paint). (This may also make 'Removal of a previously Spinning RivNut' - unnecessary.) - Anti-Seize on Threads (for Better Initial Tension, Less Corrosion, Easier Removal)... - Steel or Titanium Bike Frames (are less likely to have these issues)...

[@cup_and_cone]

Ridiculous cost cutting by Cervelo going with rivnuts. They should have used a tapped piece of aluminum bonded into the carbon for that design.

[@Hambini]

welcome to the bike industry!

[@MFKR696]

If you think that's bad, you should see what KHS is doing. My local bike shop stopped carrying them because they almost went under due to warranty work. They're so bad that I brought my old seat-post in because the friction ribs at the top got stripped out, and they just handed me another one from under the counter for free. It's almost like they were expecting me lol.

[@c.g.c2067]

Seems to me that the rear caliper nut problem is due to poor maintenance

[@BIGDO13]

well done.. also yes, that Cervelo is filthy.. lol.. filthiness is for Felt's man, not Cervelo's...

[@mototarka]

Putting some thick lube on prevents or delays galvanic corrosion for some time...

[@batbawls]

Your commute looks brutal. I certainly hope the S5 isn't 'the good bike' :)

[@Hambini]

I have 2 bikes. a Time machine when it's not windy and daylight and the S5 for all other conditions.

[@ronbelleza5588]

Hambini basically a crap bike for crap condition

[@onsight-records]

Titanium screw on alloy part is not a good combo....

[@Metal-Possum]

Aluminium and carbon don't mix either. A lot of carbon-wrapped aluminium products have a layer of tissue between them to prevent this.

[@markr5132]

carbon is porous, why not coat with resin & paint the surface; Less moisture absorbson and less galvanic corrosion with AL. p.s. Great channel and info except for the issue I mentioned.

[@tomthompson7400]

lol , grab the tool with a pair of old pliers , that will help make it really nice for future use.

[@seasky6101]

this bike looks so dirty and bad shape corrosion all over and the 1:21 stem in front can see it too.

[@WiseGuyFTW]

Did you buy a new bike yet ?

[@Hambini]

yep. I did

[@WiseGuyFTW]

Would be interesting to know about your thoughts, especially around what you considered and why ? I am myself looking for a first proper road bike these days and I like to learn about things to help me decide. My primary objective at the moment is to train for "Vätternrundan" which is one of the longest (300 km) bike event here in Sweden. I might get into triathlons at some point later on and therefore I am thinking about getting an Aero bike for training and shorter events.

[@Hambini]

For an Aero road bike. The Cervelo S5 with the double hole seat post is a good option. Alternatively Yoeleo and Hongfu are wworth a punt. The critical thing is the rider position not so much the frame shape.

[@____________________________.x]

Isn't that classed as a crappy Engineering design in the first place? Normally on carbon fibre assemblies, mounting nuts or studs are welded to a perforated steel disk, the carbon fibre is then bonded to the disk making the nut or stud an integral part of the frame. Compression nuts are really for steel plates, where there is some mutual deformation to hold it in place.

[@velociraptor2544]

I usually wrap around rivet simple nylon thread with some glue, that makes perfect insulation from carbon.

[@AirCrash1]

(a) You don't get galvanic corrosion with carbon (b) no amount of nylon tape will prevent the thread on a metal fastener from biting through when it is tightened. Nylon/Silicon tapes around thread are to stop liquids and gases from escaping between the threads NOT to stop metal to metal contact.

[@bobstevens9040]

Note to self : Never buy a Cervelo.

[@realnutteruk1]

I'm not a happy bunny.... there was clearly damage to the carbon composite around the failed rivnut, yet you failed to address this.... It's your brakes, man! (ok, so it's only the back, mostly useless, one). But FFS laminate in some new cloth to reinforce the hole!!!

[@MF-jo6jt]

borenco.nl/nl/artnr/10230100210a2/blindklinkmoer-vk-rvs-a2-m-10-x-21 These are stainless steel and they have groove's so it won't spin easy Also very important you have to apply a rivnut that krimps over the thickness of your material if its to long its loose if to short you wil damage the carbon

[@pawelciesla5047]

I guess carbon aluminum potential difference is much bigger problem. This is totally unacceptable in aerospace industry.

[@mickoholland1]

Those fuckin riv nuts give me anxiety, had a Cannondale in 05-07 and i must of replaced the waterbottle riv nuts half a dozen times on the bastard.

[@sentimentalkills]

titanium bike with titanium bolts. problem solved

[@Hambini]

This would work

[@swolebro]

I was thinking titanium rivnuts would be a sufficient amount of overkill, but you're right, it's probably better to ditch the Cervelo entirely and upgrade to a full blown titanium frameset.

[@campodma1]

@@swolebro My Litespeed Titanium comes with Aluminum Rivnuts. Have had this Issue 2x Already Mainly on the Downtube Bosses.

@@swolebro i don't think Titanium is soft enough to manufacture rivnuts - they need to be soft to be able to expand. Titanium is - well - not very soft... ;)

[@NoFretBrettCSSMBFF]

@ sciencing.com/top-10-strongest-metals-earth-2595.html

[@scottrider7271]

I have some nuts, not sure if they are 'riv' though.. ..hehe

[@5argetech56]

Aluminum Seat Post Frozen inside steel frame...... You can destroy a seat tube taking it out!

[@meneldil7604]

the other way around is worse

[@firesurfer]

Do they make titanium rivnuts? This may be a better solution. You may need a hydraulic gun. These things are expensive, try to find someone that will lend you one or do it for you. edit: I just found this item. RIVNUT SFC for CF material. www.boellhoff.com/gb-en/products-and-services/special-fasteners/blind-rivet-nuts-rivnut.php kzbin.info/www/bejne/jmPWqqZ-qNyInas

[@Pushyhog]

Really dirty. Keep your bike clean. Or maybe that’s not your bike. I’ll always stick with aluminum rivnuts/kit/gun/ebay.

[@Pushyhog]

Squeeze your gun handle a lil’ when removing gun thread shank.

[@VAX1970]

JB Weld would sort that out

[@ycmgxekwa]

Just keep your bike clean.

[@harrickvharrick3957]

That is some rubbish engineering from a to z! Galvanic effects between different metals are a well-known and a understood fact. It therefore makes no sense whatsoever to use two or three different types of metal to mount one single part onto a frame whatsoever. Why use a titanium bolt on an aluminium nut? Besides they must be completely rubbish in the first place if they break in two 'invariably' when you try to unscrew the bolt. And they aren't mounted into the frame well either of they start spinning with it or get loose - I'd say they are badly designed only for that fact alone !