Power Meter Connection Problems & Replacing Brake Fluid | GCN Tech Clinic

[@gcntech]

What do you think caused the mystery puncture? 🛞

[@adadinthelifeofacyclist]

I think you're right about it being a combination of tube and tubeless tyre, it appears to be the only possible scenario. During installation there would be a volume of air trapped between the tyre and the tube. As the tube is inflated it will compress the trapped air to nearly the same pressure as the air in the tube. The puncture was a pinch flat, aka snakebite, so only the tube was compromised and the pressure equalised between the tube and the tyre. It's worth keeping an eye on the seal between the rim and the valve as it is an inner tube valve and probably won't seal against the valve hole in the rim as well as a tubeless valve would. Just to make it more fun, although the pressure at the valve dropped during the puncture, the tyre would actually become firmer at the same time!

[@feedbackzaloop]

When in doubt, blame the valve and the way it is glued in.

[@FelixRichardson]

i had a similar when i ran tubelss i found out it was the bead poping and reseating

[@adadinthelifeofacyclist]

Vaguely connected side anecdote: I picked up some bargain second hand deep rim track wheels for my daughter, only used a couple of times as the seller decided he didn't get on with riding on a wooden track. He said he found the track too bouncy. Weird huh? Well, my daughter came to race them and said the tyres were soft. I pumped them up to 200psi (they are rated 215psi) and she said they still felt soft. I had a good look and there appeared to be a very slight bump on the front tyre but the rear seemed fine. So I decided to reglue them. When I removed the tyres I found that the glue had been layered so thickly on the rims that it had sealed the spoke holes and when the tubs were seated there were big pockets of air trapped between the tubs and the rims. Unlike the weird puncture in this week's GCN Tech Show, this air was trapped outside the tyre's pressure sealing so its pressure would be pretty low - a similar order of pressure to a balloon. So the guy was riding around with balloon-like suspension under his tyres and sold all his track stuff because he thought the tracks were bouncy! 🤣🤣🤣

[@imilic8]

probably a tire burp, just like on a MTB 🤔

[@flyt129]

Regarding the thing with the choice of 25-28 or 28-35 tubes I would say that the bigger one might be very slightly more resistant to punctures. As the smaller one would be more strecehd to get to its maximum size the material most probably will be a bit thinner compared to the bigger one that would be at its minumum size and therefore not streched out.

[@gcntech]

Great point! Plus you can fit some fat tyres if needed... after all wider is faster 👉kzbin.info/www/bejne/gnjQXpqZg6qei7M

[@overcookit1433]

It seems a very common opinion that the inner tube has an influence on the puncture resistance, but I am sure the only thing that matters is the tyre. Once a piece of glass has managed to cut the tyre, it does not matter what the wall thickness of the inner tube is like. At least a latex inner tube is more resistant due to its much bigger flexibility. Two years ago, I had Michelin latex inner tubes, and they usually lost about 1 bar per day. It happened that the rear wheel started to loose 1.5 bar per day, the loss rised to 2 bar per day (important thing: the valve insert is not a separate part). After two weeks, I came in the basement, and the rear tyre was flat. Only when I took off the tyre, I found a small piece of wire, it seems it had taken it two weeks to make a hole in the inner tube. I usually inspect the tyres at least every two days, but I simply had not seen that piece of ******* wire.

[@StephenChenney]

A tube that needs to stretch less is likely to be easier to repair should it puncture, because the reduced stretch puts less stress on the repair.

[@edreilly6674]

One other advantage of doing the wheel upgrade first is that you now have two sets of wheels, and you can reprovision your old ones for winter riding.

[@gcntech]

Great point! Do you think winter training wheels are still important in the modern age of disc brakes? We now don't have to worry about the grit and grime wearing down our braking surface

[@edreilly6674]

@@gcntech I agree that disc brakes lessen the need for winter wheels, but when my new wheels come tomorrow(!), I will put some wider, more fun, tires on my stock wheels and save up for an additional cassette and chain on which I can use a wet lube. The weather is getting warmer here (New England), but we still have a sloppy spring ahead.

[@bikeman123]

Since Shimano use mineral oil, which is not hydroscopic unlike dot fluid, so it doesnt attract moisture. As such if its working, leave it alone.

[@shred3005]

I’m 4.5 yrs with the original Shimano mineral oil in my gravel /commuter / adventure Ti bike Ultegra 8000. I’ve been pondering if it’s time to change mineral oil …. still working fine but what’s happening inside ?

[@gcntech]

Great point! A real fit and forget system 🙌

[@sbccbc7471]

​@@shred3005 It might be dirty at this point. You're probably overdue by at least double the duration now.

[@jamesmckenzie3532]

You still can get contamination in the fluid. You need to test the fluid in the system and replace if it is contaminated. Otherwise, you are slowly damaging parts and the calipers. If you had to replace the pads due to "wet" contamination, best to flush the system. Same as you would do for your automobile.

[@cb6866]

Thanks Alex and Dr O. and crew...Ideal gas law ? Atmospheric pressure ?

[@Lerainier]

Thanks for your answer! Off to the local bike shop then!

[@jamesmckenzie3532]

Here's the key to when you need to flush your fluid: Contamination. If you had to replace your pads, time to "bleed/flush" your lines. Also, if you get "squishy" time to bleed/flush. Otherwise, it's best to leave the fluid alone. Oh, change pads, bleed.

[@staypufft80]

Yep, the m8100 outer plates do rust, can confirm. Sram, no trouble at all.

[@_J.F_]

Unless it is absolutely bone dry outside, which it very rarely is this time of year, I always wipe the chain when I come back from a ride, and reapply a fresh helping of lubricant. I know some people say not to do this but I once forgot to do it, and didn't go for a ride for several days after, and there were visible signs of surface rust on the plates. The rust did come off with a good amount of cleaning but I much prefer to simply wipe the chain, reapply lube, and not have to worry about rust regardless of when I go on my next ride.

[@festerofest4374]

I always wipe the chain down after a ride. Then I use my air compressor to blow out any fine grit and dust that I can, then re-lube. A clean chain is a happy chain.

[@cherriagana]

How about the pop beeing the tubeless hooks popping in the channel. When using innertubes with a tubeless (ready?) tire the bead might not have been seated correctly.

[@LindseyH24]

Even the older 11sp ultegra level chains rusted after chain cleaning. Haven't had the issue with the dura-ace level chains, with the same prep (mineral turpentine, methylated spirits)

[@vapyd3999]

I have a '19 Scultura 400 and am about to put slightly used dura-ace C35s on them, first real change other than saddle, but feel the same as the last question now that my route has changed and now includes a few short inclines that I love to get out of the saddle and power up.

[@gcntech]

Interesting! It might be the bars themselves rather than the full frame?

[@iancalland5934]

I wash my bike then use me leaf blower to dry drivetrain and chain then add squirt lube to rollers then put some between fingers and run chain through them to ensure outside of chain is oated

[@overcookit1433]

Concerning the different sized tyres on front and rear, I also do so: on my summer bike 20mm (which become 21.75mm) on the DT Swiss ARC Dicut 80mm front wheel, and 23mm on the rear wheel (HED Trispoke or HED 3D disc wheel), as well as on my actual used bike, 21.75mm from a 23 mm Goodyear Eagle F1 in front, and a 23.5mm from a 25mm Goodyear Eagle F1 Supersport on the rear, both on a set of Shamal HPW Titanium with 13C rims. As it is quite advisable to have a higher pressure in the narrower tyre, I put in 7bar, and on the rear 6bar, so there is no higher rolling resistance of the narrower tyre, this would only be the case if I used the same pressure front and rear. This is already quite comfortable for me (139 lbs).

[@ltsw06]

Hey GCN Tech Team! Any tips on how to prevent tubeless sealant from clogging up valves? A number of reviews point towards Silca Tubeless Sealant but I find it dries incredibly quickly making it a pain to maintain.

[@feedbackzaloop]

Regarding bendy bikes, it may also be the case of not being used to unstable racing geometry, since we talk first road bike. Getting out of the saddle and shifting body weight forward changes the dynamics a lot.

[@gcntech]

That's an interesting point! racing bikes can be a different feeling 😵‍💫 Did you hear what Josh Poertner had to say about frame flex? 👉kzbin.info/www/bejne/qnWZknuqbbGgj9U - Very interesting 🤔

[@feedbackzaloop]

@@gcntech when it comes to frame stiffness, Tour Magazine is my primary source of information. I believe Josh mentioned them too😉

[@edromero7985]

#askgcntech I suggest and would like to see a video on the dynamic and static forces on spoked wheels. I'm sure Olie will do a great job nerding out on this. It could answer a question I've been having with my LBS on which side of the rear wheel is more stressed, left or right? Jobst Brandt in his book "The Bycicle Wheel" say the right side, page 35. There are many insights in this book (trying and soldering does nothing to add strength; it's not Stiffness, but strength that really matters......) Finally you could cover why carbon spokes can be a better choice, which I'm sure most don't understand......thanks for all you do to educate!! This is THE best cycling show with great presenters, racing news and tech information!!!!

[@Millicente]

Appreciate the answer! Thanks!

[@gcntech]

Thanks for dropping a question 🙌 The tech Clinic is all about the community!

[@andieymi]

Looking at lower end SPD pedals for road bike bikepacking (for the walkable shoes). Need an even wider Q-factor than the jump from road to MTB pedals. Should I just get Shimamo 520s with 16-20mm spacers or go for the SQLab 511? #askgcntech

[@mipko]

I have cheap 7 year old MTB which I used as city roundabout or for occasional trip to the woods. That bike have base shimano hydraulic disk breaks and I never once changed the oil in it... I do change pads, rotors and bleed the system as needed, but d I never once changed the oil in it and it works perfectly fine. However I have SRAM system and I do change fluid in it on bi-anual basis as dot fluid is fussy.

[@gcntech]

Mineral oil is very good, great to hear that you've got a fit and forget system! Have disc brakes been a game changer for you?

[@mipko]

@@gcntech They have been game changing for whole industry... They gave us comfy road bikes as we can fit much wider tires and MTB with incredible strong breaks. And to these days I am shocked how reliable and good are even the cheapest hydraulic disk breaks. Yeh they are bit more expensive and bit more fussy, but so much nicer and better to use that it is worth the tradeoff for me.

[@johntheconnor8721]

Hi Prof. Oli and friend. I run tubular tyres at crit races. I’d like to run them on the road but loath the idea of carrying a while tyre with me if i get a flat. Could i run tubeless sealant inside my tubular tyres?

[@jlfd26]

#askgcntech. Regarding power zeroing. If I keep my bike in a cooler environment (or warmer) than what I will be riding should I wait a few km before zeroing the power meter. I have a crank based power meter if that changes anything Thanks

[@MD001]

#askgcntech Hey GCN, a question regarding seatposts: I am building up a custom bike with a seattube diameter for 31.6 mm seatposts, would you recommend sticking with a 31.6mm seatpost or would I be better served in terms of comfort using a shim to adapt the frame to use a seatpost with 27.2 mm diameter? Looking forward to hearing your thoughts, thanks!

[@apuldram]

Haven’t you guys ever gone to your bike (the next day) and found it flat… but when you pumped it up there was no problem and went on for weeks? Thinking inner-tubes here, but would appear more probable with tubeless.

[@2.old4this]

Help Guru Masters…. Need to send my carbon frame off for repair, (Giant Defy Advanced 2022 - 1x seat stay damaged on flight) I’ve never stripped a bike with partial-internal cables. Advice please. Love the show and enjoy the banter between Alex and his side-kick. #Askgcntech

[@davidheathfield5040]

I’m buying a bike with mechanical Tektro MD510 disk brakes. I want to swap the 10 speed groupset out but keep the brake callipers. Can I use any old rim brake groupset, do I need a specific pull ratio for the brake cable?

[@DanTuber]

How much is the allotted time and does it vary?

[@festerofest4374]

We will never know what the allotted time is, I suspect!!

[@DanTuber]

Then how will we know if we get short changed? @@festerofest4374

[@Arthur-ns4yh]

I found that 105 level chains do rust when used with wax whereas upper level chains dont and some cheaper KMC don't either. I guess that is up to material used

[@user-gg6gl2su3p]

Hi Dr. Ollie Bridgewood (the chain waxing guru) and Alex. Greetings from Qatar, Im contemplating trying to waxing my chain, is it advisable to do so living in a dusty/desert. Wont the wax attract more dirt/sand which normally comes with the wind.. looking forward to your input.. thanks! PS: missing gcn plus😢

[@gerrymcbride6429]

I live in the UAE and all of my chains have been waxed for some time now, no issues for me whatsoever.

[@eddiewards123]

Complete opposite to what you think! For dry/dusty environments, waxing is the best. Wax doesnt attract anywhere near as much as a wet lube would (subsequently becoming a grinding paste). Wax doesn't hold up as well in wet conditions, so I think in Qatar you'll be much more suited to waxing!

[@emmabird9745]

#askgcntech In your last answer viz the frame/wheel stiffness, Alex said that the spokes might have lost some tension. If that might be the case wouldn't having the spokes retensioned/trued be a good first step?

[@blabla5604]

#askgcntech Hi Alex and Olli, I have a question regarding sun screen. Currently, most sun screens use octocrylene or similar chemicals. Recent studies have shown that these products could possibly cause cancer (because they decompose to benzophenone). Hawaii has banned the use of these sun screens because they interfere with marine life. An alternative is sun screens with titanium dioxide. How do these hold up in a high sweat environment like cycling? Thanks in advance for your answer!

[@Michael_Rega]

My KMC X10 chain has suffered from the rust on the outer plate while using hot wax

[@gcntech]

Will you still be waxing the chain? How's your maintenance regime? We've got a great video on Jus that if needed 👉kzbin.info/www/bejne/aofShX-Fi9xleg

[@Michael_Rega]

@@gcntech Yes I will because I can feel the improvement with the wax on the chain in the cranks, but just looks like crap with the rust spots on the outer plates. I think I be upgrading the chain to titanium-carbon-nitrade coating to help prevent this, but I will continue to wax the chain.

[@KlumpatschSchneider]

Had the same problem. Switched to KMC X10 EPT (EcoProTeQ) which is designed to withstand rust. Made all the difference. I live in northern Germany, so the weather is comparable to that in the UK. One thing that is hardly mentioned when switching to wax is that one has also has to choose a different kind of chain than before. There are different options from KMC an Connex as far as I know.

[@KlumpatschSchneider]

Had the same problem. Switched to KMC X10 EPT (EcoProTeQ) which is designed to withstand rust. Made all the difference. I live in northern Germany, so the weather is comparable to that in the UK. One thing that is hardly mentioned when switching to wax is that one has also has to choose a different kind of chain than before. There are different options from KMC an Connex as far as I know. Maybe this is an information worth sharing on tech clinic?@@gcntech

[@foxy1706]

i have had 11 speed KMC, sram and shimano chains and all have rust issue at some point. im quiet good for cleaning water off chain after ride and even have mini low power blower to dry it off (very handy to clean out bolt heads but not powerfull enough to drive water into bearings) ive just resorted the winter riding needs wet lube in ireland. still clean chain after ride so dont build up gunk and except system wont look as clean as it does with waxing

[@gcntech]

Wax is great but if you live somewhere that's wet, classic wet lube might be the better option. Do you think you would change to wax in summer?

[@oplkfdhgk]

kmc ept is the best. been riding in rain and snow for like a year. no issues and yes i have waxed chain.

[@foxy1706]

@@gcntech for the commuter probably not even if good conditions as faff of checking conditions and changing. the summer and even winter weekend bike does and will continue to have wax as its rarely out in horrible conditions. and rigorously cleaned if it is as have the time. With every day irish weather the commuter takes a beating most the year so want simplicity and a solution that doesnt create a new issue of rusty chain

[@neilbuckley5796]

I hot wax, also top up with CeramicSpeed all conditions wax, it’s brilliant, never had a rust issue.

[@noptimized]

Re: Flexy bike If you can, try to borrow someone’s higher-end wheels for a test ride. It’s typically not too difficult to find a compatible match if you know a few other cyclists. Five minutes up a hill and you’ll have a good sense of what difference wheels could make.

[@gcntech]

That's a great idea! Kit sharing is a great way to get to know what upgrades you need 🙌 Do you think that carbon wheels are going to make a big difference?

[@eloann]

Hey, gearing question : amateur road bike riders want/need easier gears than pros and that is somewhat catered to by cassettes with a wider range, but at the expense of bigger jumps between gears and with the smaller sprockets acting as glorified spacers. Why don't we see more cassette with an easier top gear? Are there any good options out there?

[@dtsybulskyi]

Not completely related to your question, but you might want to try smaller chainrings instead. For pro cyclists smallest cassette cogs are only really useful when pedaling downhill (my guess), so unless you're into fast descending, you might change chainring to smaller ones, and then use compact cassette, that still would allow for comfortable climbing :-)

[@eloann]

@@dtsybulskyi Yup I actually got GRX 48-31 on my new bike which should work great with an 11-32 cassette. I bet most consumers would rather be safe than faster down a mountain 😅

[@danielt91]

Hey, CGN Team, I was wondering if cycling in an aero position is beneficial when there is a strong TAIL wind. Should I still be holding the aero position or should I stand as upright as possible? I'm also interested in a video that talks about deep section wheels when riding in windy conditions. I feel like unless the wind is coming either straight at me or straight behind me, the deep wheels will actually slow me more compared to some shallower ones. :)

[@JeffPatry-od8ik]

#askgcntech I have a carbon ENVE fork on my road bike. I don’t have a torque wrench for use in tightening the thru axel. Is the a rule of thumb on not over tightening so I don’t damage the threads, or conversely make it too loose so the axel backs out from vibration?

[@sbccbc7471]

The way I do it, I choke the hex wrench so that I don't have a lot of leverage to work with to prevent accidentally applying too much torque. I tighten till it's snug. Apply a constant tightening force until you can't tighten any further with that same amount of force. If in doubt, have an LBS mechanic show you how.

[@magysoeldner6074]

Hello, I want to share my wahoo kickr with my girlfriend, who is 7 cm smaller than me, without us having to change bikes on it for each indoor ride. I thought, if we buy a cheap bike that is slightly small for me (I am currently riding a 52 cm frame, so maybe 50/51 cm), we could keep this one on the permanent setup and each of us only has to adjust the seat post for riding in the virtual worlds. Plus: On nice winter days we could ride outdoors without having to dismount any bike from the kickr first. It's apparent, the bike fit cannot be 100% ideal for both of us but on the other hand we only ride about 500 KM each in one winter season. What is your opinion on this? Do you think it is a budget friendly solution that will make us happy or do you recommend a different setup? Thank you for your dedication to this channel. I like watching it a lot and really appreciate the pragmatic advice!

[@PeterRamzy]

#askgcntech Hello Alex and Ollie and the rest of the GCN team. I recently hit a milestone and completed my first ever century ride. My question is how much difference does an aero bike make when you are a heavier rider? I did the century with my friend who is much thinner than I am but noticed something weird, I would pass him during the headwinds but he would pass me in the climbs. I associated the difference to bike and aerodynamics but as a larger rider, wouldn't cause more drag then my thinner friend who rode with me? As a reference, I was riding a cervelo s3 and he was riding a supersix evo.

[@masterwu22]

#askgcntech Hello all, obviously, it is never a good idea to support a carbon frame by clamping it with any amount of force (especially on the top tube). However, would it be safe to hang the bike from the top tube. I am wondering if it okay to use my rear bike rack to support my carbon frame and don't want to risk it cracking. Thanks!

[@jsmith84]

#askgcntech hello gurus, I currently ride a Cervelo Soloist with 28mm tires. I have been debating trying to get into the cyclocross scene later in the year and maybe some gravel rides this summer. What, if any, issues would arise if I added 33mm tires to my current bike instead of buying a new one(the soloist can have up to 34mm tires)? Would I be at a significant disadvantage vs a full gravel or cyclocross bike? Thanks!

[@kuri8015]

#askgcntech Question: Alex and Nigel... Can I use a tube (tpu or butyl) on a hookless rim if I have a puncture on my tubeless set up?

[@sbccbc7471]

Yes you can, but always respect the lower maximum pressure limit. Don't forget to track down the sharp debris stuck in the tire.

[@kuri8015]

Question: Alex and Nigel... Can I use a tube (tpu or butyl) on a hookless rim if I have a puncture on my tubeless set up?

[@gcntech]

Great question remember to use #askgcntech so the team can pick this one one 👌

[@kolerezegnee3620]

I guess that on low pressure it would work, but if i were you i would get hooked rims for the roadbike.

[@bikeman123]

Yes of course. You may have trouble removing the tubeless valve without pliers though.

[@saxon1376]

#askgcntech , Really helpful content guys , If your running hookless wheels and you puncture and you have to fit an inner tube what pressure should you run that inner tube . Bit worried about putting 100 psi in an inner tube in a hookless rim . Please help

[@sbccbc7471]

Always respect the lower maximum pressure limit, whether it's the tire or the wheel. If you're on ZIPP wheels, never exceed 73 PSI as printed on the wheel.

[@pnyholm]

Funny puncture- it could be that the rim and tire is tubeless ready, and was not fully seated when the ride started. then the bunny hop made the tire seat properly?

[@gcntech]

Ooooo interesting idea 💡 We're loving all this detective work 🕵

[@Mo.Jo.MTB_101]

#askgcntech Hi Alex, Olli and Manon I'm new to road riding (have been MTBing for about 20 years) and I'm riding my dads old Scott Sppedster S1 my question is would there be a noticeable upgrade in shifting performance if I changed the Ultegra 6700 to a 105 7000 groupset? Thanks for your answer and love your show Mo

[@mcnugget6169]

#ASKGCNTECH Hello! How do I know when to change the sealant in my tubeless tyre? Thx

[@romanluu]

#askgcntech Hey guys, great show, as a newcomer to the sport I always learn a lot. I have the Triban RC 520 (from Decathlon) which comes with a quick release system. However, I am thinking of upgrading the wheels in the near future and was checking out some options, but a lot of them are thru-axle only. I was thus wondering, how difficult is it to convert a QR bike to thru-axle? Is it even possible/practical? Thanks in advance!

[@sbccbc7471]

I'm sorry to say, it's impossible. Disc brake road bikes have different hub spacing standards. Open-dropout (quick-release) (usually found on more affordable road bikes and early-stage higher-end disc brake road bikes) Front: 9 x 100 mm Rear: 10 x 135 mm Closed dropout (thru-axle) (the current road disc brake standard) Front: 12 x 100 mm Rear: 12 x 142 mm Your only option with this bike is a wheelset (factory-built or custom-configured) with a hubset that can be converted for use with thru-axle road framesets in the future, such as a wheelset with DT Swiss 350 Disc (just change the hubs' end caps).

[@michaellynch1132]

Regarding the wheels, you could try just re-truing the wheels, it could be that the spokes are just loose in sections. If you still have issues, you can upgrade wheels but you don't have to break the bank. Regarding when to replace fluid in your brakes, you should also take into consideration how often you ride each of your bikes. I recently learned the hard way that not riding hydraulics can make them more prone to leakage and that can be much more expensive than just a drain and replace as you will need to pay for new pads at the least if you do it at home and rotor cleaning if you take it to a mechanic. If you are letting your bike sit, go out and flex your brakes a couple of times each month. Time well spent. $$

[@JonCannings]

I wonder if that mystery puncture was like what Alex said, a presta valve core, had the locking part of the pin undone, and through a one in a million chance, the impact meant the the rubber seal inside the valve pin, became momentarily put of place and a whoooooosh of air escaped. If it was a schrader valve, no idea!

[@gcntech]

People still use schrader valves 😵‍💫 Only joking! Thanks Jon, you're a master at these puzzles 🙌

[@jazznroll5]

#askgcntech Hello guys. I want to upgrade my tyres and i am between 2 options. Option A is 1mm narrower than my rim width so really aero and option B is 1mm wider than my rim. However, option B has 3 watts less rolling resistanse for the pair at the same pressure. What would you choose ?

[@lipegps]

#askgcntech Hey guys, i have road bike with shimano 105 11s 11-32 and my wife has a road bike with sram rival 11s 11-28. It's possible to share a smart trainer with same cassette or need to switch cassette/free hub every time?

[@Dhungerf60]

Here is my explanation to the tire tube that made a pop sound, lost pressure but was OK. I believe that the tube was twisted inside of the tire when it was installed, when the rider bunny hopped, it straightened itself out thus dropping in pressure because the volume has now increased.

[@trothaksharkpuncher1059]

I don't think this can be the answer since the tire went from 7.5 barg to 1 barg. This corresponds to the volume increasing by a factor of four. I don't think the bike would have been rideable with a tube that twisted. Valve failure is the only thing that makes sense to me.

[@Photoguti]

#askgcntech I have a Specialized Tarmac SL6 with Tiagra group set and alloy wheels, is it better to change the group set to 12-speed mechanical 105 or to change the wheels to carbon fiber to improve both weight and performance?

[@neilbuckley5796]

Wheels every time.

[@eddiewards123]

Second vote for wheels, biggest bang for your buck I'd say. Groupset isn't too bad of an option, but will unlikely add much noticeable difference. You may have crisper gearing and more gears to select, but wont change how the ride feels. Wheels will be more noticeable with comfort/speed changes.

[@a1white]

I’d go with wheels too. It’s doubtful if 2 extra ratios will make your bike faster but lighter/stiffer wheels will.

[@peterdobos1606]

The Zwift monsters! The deadly duo, the watt wunderkids...look so unassuming nerding away in front of their laptops.

[@gcntech]

The Watt Wunderkids... we like that! 👌

[@adoj105]

#askgcntech I'm interested in transitioning to waxing my chains. My question is if I do this, how do I keep my chain performing well over a long trip where I won't be able to re-wax the chain? I'm planning on doing the GDMBR in the USA late summer and will be out on the trail for about 2 months. Is there a good strategy for this or should I just stick with a traditional lube for a trip like this? Thanks

[@Macca8884.5]

Hi l would run 2 chains wax them in silca and you will get about 300 km out of it then add super secret to it then u will get about 200 km before toping it up again until you hit 1500kms then replace the chain with second chain

[@FKnoph]

#askgcntech Salutations, tech gurus! I have been looking into setting up my bike tubeless, but have run into a problem. According to Silca's tyre pressure calculator, I should run 90psi in the front and 80psi in the back. However, this is above the generally accepted limit of 72psi for tubeless tyres. What would be the solution to this? I prefer not to change the width of the tyres on my Canyon Aeroad (25mm front and 28mm back). Ride on! Fredrik

[@user-cx2bk6pm2f]

"can I run tubes in my tubeless tires for added protection"... whaaaaaa???? 🤣This chap sorely needs your advice.

[@colincampbell8311]

When to change fluid? Well, sometime after changing to disc brakes, which I have no plans to do.

[@ChrisGuarraia]

#AskGCNTech Hey, Ollie and Phineas. What is the temperature range for melting wax for chains? Silca's new chain waxing system (heater and hanger) specs a temperature range of 75-125°F with the top end for use with the chain stripping wafer (looks delicious, but fun fact: no). I'm using an old chocolate/candy melter and measured the temperature at its two settings-warm and melt-with a digital thermometer. The temperature range is 140-180°F. Am I degrading the wax and losing its optimal performance if I am above 125°F? Thanks for the great channel! Ride on, mates!

[@lason999]

The puncture issue - I believe that during the bunny hop landing there must have been a significant pressure spike because of an impact, and the valve must have let the air out. As Ollie said, maybe it wasn't entirely colsed or simply was faulty.

[@gcntech]

Good bit of detective skills 🕵

[@SteevyTable]

This would be my vote too, although I bet if it's a lower quality valve it doesn't even have to be faulty. I've had tubless valves not quite seated right in the rim before, and it would hold great up to 60 psi or so, but anything above that it would start leaking until to got down to 25 or 30psi. Similar idea of the valve core just isn't up to holding the higher pressures properly instead of a rim/valve interface.

[@lason999]

I would generally agree. It might have been properly closed and still leak some air when pushed with enough pressure even if we talk about set up with a regular inner tube like in this case.

[@gerrymcbride6429]

The poster asked about changing the hydraulic "lines" not the "fluid"

[@user-cx2bk6pm2f]

Hydraulic brake fluid... use motorcycle schedules as a guide. BMW motorcycles use mineral oil. Honda motorcycles use DOT fluid. Both brands suggest yearly changes, or 12,000 miles. I tend to think this is a conservative schedule due to safety. I've had no problem going more than two years on both motorcycles and bicycles.

[@julianallen515]

Based on GP Lama's latest info I would recommend that the viewer who asked about his 9100 pwoermeter connects only to the left side reading as the right is wildly inaccurate.

[@leslie7922]

My disc brake bleed screw seized up so it was bloody tough to replace the fruid 😭😭😭😭

[@user-cx2bk6pm2f]

Frame/wheels flexing during a climb... per Josh Poertner's comment, is it not established that MAX stiffness is likely not the best thing? He said this is an area that needs to be studied but some bike experts believe that a certain type and amount of flex may actually benefit a climb. Before upgrading, collect some data. Is the flex slowing you down?? Who knows. Your flexy bike may be the fastest climber in the group. 😀

[@mt5150e]

The mysterious puncture issue is one I’ve had a couple of times. No idea how but tyre deflates after a big bump and then mysteriously re-inflates…..

[@DeeKay1900]

Considering that the new wheel sponsor offers a new set of carbon wheels for less than $600 I wonder why they did not mention the Elite wheels?

[@ollybooth6138]

#askgcntech how do I avoid getting water in my rims during cleaning? Thanks

[@sbccbc7471]

There's no preventing it. Many rims have at least one hole for water drainage purposes, so once you're done cleaning, just orient the wheels so that the drainage hole is at the bottom, facing towards the wall when you lean them.

[@ollybooth6138]

@@sbccbc7471 thank you

[@DEAR7340]

#askgcntech - Is there a good resource, for determining whether the tire your are buying and installing is going to fit your frame, once installed? I asked my local bike shop how I could avoid making an expensive mistake, since different manufacturer tires will vary in the *measured* sidewall width, versus the width printed on the box. I am told that the internal width of the tubeless rim "shoulders" are also a factor in actual sidewall width. Local bike response: "Nope! It's just the risk you have to take."

[@sbccbc7471]

Yes, internal rim width does affect tire width even with the same tire. I've mounted my 25 mm Maxxis on a wheel with a 17 mm internal rim width to see how little clearance I have left, only to find I have less than 4 mm of it, too little to be compatible. When it was on 15 mm, then it's OK and this is the widest my previous frameset can take. In the shops I've worked at, sometimes there are new tires that are already out of the box, so I get to install them for actual tire width checks before installing them for real. Sometimes I do note them down in my phone based on the tires I've mounted onto various internal rim widths in the past, so I have a tiny database of my own. The response you got, sounds a little like a "Don't know, don't care" kind of attitude.

[@savagepro9060]

When should you replace brake fluid? The moment you depart from rim brakes

[@montrose252]

Replace hydraulic fluid with rim brake cables! Hhahaha

[@JCoe-mh8rt]

Maybe that pop sound was a tire bead that hadn't set correctly until they missed the bunny hop and jarred it...🤷

[@endcensorship874]

About the guy who missed a bunny 🐰 hop and punctured/not punctured; the answer is rather simple. We are all allotted one miracle in life. You don’t know when it will happen. For me, it was narrowly missing a car running a red light in the crosswalk. Whew, close call. For this individual, it’s the non-punctured tube on that missed bunny 🐰 hop. Take your miracle and call it a day.

[@keithmedia]

Whose idea was it to put the saddle right there in the middle? I think Owen

[@edromero7985]

....the "pop" could have been a fold in the tube unfolding under increased pressure

[@sbccbc7471]

It's always the sound of the bead being seated, but I always pre-inflate the tube just enough to hold its shape.

[@user-cx2bk6pm2f]

Durace power meter... Left-Right connection problems are the least of your worries. Shimano are known to be off, wayyyy off. GPlama has talked to Shimano about this, and the response isn't promising. From what I understand, Shimano doesn't acknowledge the problem, and so, I would not count on their meter readings being fixed anytime soon. Get a different meter.

[@baldomantova8466]

Never!!!!! I still use rim brakes! 😂😂😂

[@donbethel7675]

I feel the TPU tubes are far superior to tubeless in so many ways. Here in 2024 there is no need for anyone to suffer the woe's of the price, weight and trouble of dealing with tubeless nonsense. First, dealing with the extra time, energy and effort of get the right size rim (width), and tire, to even set it up. And if you don't get it right, you might need assistance, being a compressor, or extra pricey pump. Second, the weight of tire and sealant is more or equal in most cases. Third, The rolling resistance is slightly better with tubeless, and pinch flats are no longer a thing, however, so slight the advantage, it might not be worth the switch. Forth, The Price! With online availability the TPU is a no brainer. Starting at $1.99 a tube, you can't beat it. Not to mention, most people that ride tubeless carry a spare tube. Fifth, Your only maintenance is in the event of a flat, where as, Tubeless is a yearly , if not sooner thing, regardless of the miles you ride. So if you have more than one bike, Then you may be switching out sealant after only about a couple thousand miles. With that said, I have always felt that tubeless was a fad, and the bike industry was reaching. I mean cars tires don't have sealant, so the seal of the tire must be of high tolerance. I don't thing you can achieve that type of control with a rim that is able to fit a bike.

[@bikeman123]

Can even get a butyl tube for less than £4.99 in the uk. TPU tubes are twice that.

[@bikeman123]

Cars tend to carry a tubeless repair canister, that's why they don't need sealant in the tyre. Only one of my bikes is currently tubeless and it's a godsend. I ran without sealant for a few rides, until I realised, so tolerances are fine.

[@donbethel7675]

Aliexpress my guy. They have them all day long. And I live in Hawaii.@@bikeman123

[@wspmjw]

The answer to replacing hydraulic fluid is never on my mechanical disk system...

[@davidlau2467]

To the user with the 'flexing bike'. You've probably gotten alot stronger for your current bike, so just upgrade to a new, stiffer bike & wheels. GCN wouldn't say so because they are now conscious of the need to be value minded. 😂

[@Jari1973]

Waxed chain rust solution.. sell your bike.. and walk 😁

[@Garfie1d73]

There is absolutely no need to change mineral oil on a yearly basis. You do not even tell us where you got that from. Don't give any advice when you don't know what you are talking about. And you didn't mention the most important point: You have to differ between D.O.T. and mineral oil. Shows me - once again - that CGN ist not the right place for seeking professional advice. Thumbs down.

[@dougpence3862]

Replace the brake, not the fluid. Mechanical rules

[@ZenEndurance]

There needs to be a campaign to educate cyclists that TPU inner tubes don't stop punctures whatsoever. I've noticed there's constant talk of using TPU with no sealant. Or I guess don't tell them if it's a race and you want to up your chances of winning.

[@timoma6620]

Do you wanna use TPUs with sealant? I myself am very satisfied with my Tubolitos

[@feedbackzaloop]

TPU is a tube just like butyl or latex. Sealant won't do anything for or against puncuring a tube. As Alex said, once it's punctured, it's punctured. Not to mention most of sealant formulations are compatible with tyre rubber compound, not inner tube compound and may dissolve it at seams.

[@timoma6620]

@@feedbackzaloop that's what I'm saying, not sure about sealant in TPUs. Pretty sure a product developed for that use case doesn't exist

[@feedbackzaloop]

@@timoma6620 yep, the original comment is nonsensical. These "educators" should learn the basics themselves first before preaching in favor of some campaign.

[@veganpotterthevegan]

Who thinks TPU tubes stop puntures?😂