Inner Tube Sealants, Bike Sizing & T-Type On Non-UDH Frames | Ask GMBN Tech 291

Welcome back to another episode of Ask GMBN Tech, where we try to answer all your complex, scary, niche, and technical questions about mountain bikes and MTB-related tech!
💻 Submit Top Mods, Bike Caves, Rewinds and more to us 👉 upload.gmbn.com/tech
⏱️ Timestamps ⏱️
00:00 - Intro
00:18 - Can you fill innertubes with sealant?
01:58 - Does seat angle change when riding a full-suspension bike?
04:38 - I have 26” non-boost wheels on a single-speed hardtail, can I keep the wheels and replace with 27.5”?
06:11 - Is there much of a difference between downhill and trail bike sizing?
08:27 - Is there any remedy to install a T-Type to a non-UDH frame?
10:54 - I recently purchased a bike and the rotors are not covered by the brake pad surface?
Useful Links:
🛍 NEW MTB Bike Maintenance Book 👉 gmbn.eu/MTBMaintenanceBook
Sign-up to our newsletter 👉 gmbn.eu/newsletter
Do you have a question for us here at GMBN Tech? Ask away in the comments, and be sure to use #AskGMBNTech for a chance to be featured! 👇
Watch more on GMBN Tech...
📹 School Of Shock 👉 • The Ultimate Suspensio...
📹 Watch our Editor’s Choice Playlist 👉 gmbn.tech/editorschoice
📹 Watch our weekly show 👉 gmbn.tech/GMBNTechShow
🎵 Music - licensed by Epidemic Sound 🎵
A Long Goodbye - William Claeson
#AskGMBNTech #GMBNTech #GMBN #MTB #MountainBiking
The Global Mountain Bike Network (GMBN) is the world’s largest and fastest-growing online mountain bike channel and community - and your destination for the best mountain bike content in the world.
GMBN is dedicated to inspiring and unlocking your riding potential. Our videos cater to fans of every mountain bike discipline: from mile-munching cross-country (XC) riders, through adrenaline-fuelled dirt jumpers, gravity-hungry downhillers or aspiring enduro racers, and beyond.
Every day of every month, our ex-pro presenting team are on hand to entertain and inspire you while also providing a uniquely qualified insight into the world of mountain biking. Every week we deliver original daily videos that include:
Adventurous and entertaining features
Mountain bike skills coaching
Technical advice and guidance
Mechanical know-how to keep you rolling
A place for the riding community with our weekly Dirt Shed Show
Thanks to our sponsors:
Canyon Bikes: gmbn.eu/Canyon
Propain Bikes: gmbn.eu/Propain
Orbea Bikes: gmbn.eu/Orbea
Park Tool: gmbn.eu/ParkTool
Smith Helmets & Eyewear: gmbn.eu/Smith
Crankbrothers Pedals: gmbn.eu/crankbros
Shimano Footwear: gmbn.eu/ShimanoShoes
Ergon: gmbn.eu/ergon
Vittoria Tires: gmbn.eu/Vittoria
Reynolds wheels: gmbn.eu/Reynolds
FSA: gmbn.eu/fsa
Topeak: gmbn.eu/topeak
Garmin: gmbn.eu/Garmin
Peaty's Products: gmbn.eu/Peatys
Worx Power Tools: gmbn.eu/Worx
CamelBak: gmbn.eu/CamelBak
Watch our sister channels:
Global Mountain Bike Network - / gmbn
Electric Mountain Bike Network - / embn
Global Cycling Network - / gcn
GCN Tech - / gcntech
GCN Racing - / gcnracing
Global Triathlon Network - / gtn
GMBN Racing - gmbn.eu/GMBNracing
GCN Italia - / gcnitalia
GCN en Espanol - / gcnenespanol
GCN auf Deutsch - / gcnaufdeutsch
GCN en Francais - / gcnenfrancais
GCN Training - / gcntraining

[@gmbntech]

Do you have a question for us here at GMBN Tech? Ask away in the comments, and be sure to use #AskGMBNTech for a chance to be featured! 👇

[@topchoice1621]

I’d like to know if Anna is married?

[@justsayin3600]

#AskGMBNTech If I use a Cascade link that increases travel by 8mm. How can a stock shock still work properly if say, you have a 150mm stock shock, put a Cascade link increasing the travel 8mm to 158. How does that work? Also, if I buy a new shock should I buy a 155 or 160mm shock for the Cascade link?

[@BrianLizard]

#AskGMBNTech I have a number of older bikes (road, commuter, TT) without tubeless. We have a puncture vine here in Idaho called "Goatheads." You WILL puncture your tube on regular intervals without extra protection. Like sometimes once a week, so plan on being late for work and having to buy tubes in bulk. I now put "Stan's" sealant in my tubes (removable valve core) and I can literally ride for years without a puncture! Highly recommend sealant in tubes if you don't have tubeless already.

[@tamholt3494]

I can highly recommend the Slime inner tubes. I once had a 30mm m3 bolt stabbed through my tire and it was NOT a clean little cut like glass would make. This was a nasty punch through but the slime was still able to seal the hole and left me with enough air in the tire to limp home. Another time on a different bike I had it seal up so fast I didn't even notice I had a puncture until a week later.

[@Bob_Shy_132]

I had a tire explode on me today. Went to stock up on food. Loaded my backpack with items and went outside to grab the bike to ride home and POW! Carcass split in three pieces! Walking home in 92 degrre heat 5.5 miles wasn't too much fun.

[@smithandshortdogs]

I don't think sealant designed for tires will work in tube. There is a memory somewhere in the back of my head from watching a manufacturer saying that the elasticity of the tube stops most sealants working. Slime worked because it was specifically designed for tubes and had something that looked like large cotton filaments in it that plugged the most of the hole before the green stuff finished the work.

[@johnsonjay60]

I've ran sealant in tubes on a bike that wouldn't take tubeless. Many pinch flats, but that worked.

[@justinh7099]

Was the tube stuck to the tire after a bunch of punctures?

[@metalwheelz]

With the pad not fitting the disc problem, I've seen quite a few "made in China" e-bikes come in the shop with this problem straight from production. The danger is that as the pads wear, the tops of the pads that do not contact the rotor form a non-worn shelf that eventually will contact each other above the rotor. This will prevent the pads from contacting the rotor, thus, there will eventually be no braking power (even before the pads are worn out). This can happen rather suddenly and unexpectantly.

[@fernandoguerrero2895]

I have used slime sealant for years! Highly recommended if you are not using tubeless tires. It is very effective and keeps everything cleaner than tubeless sealant.

[@resurrectorbikerepair454]

In regard to the brake pad not matching up completely with the rotor, if they are Shimano brakes, there are narrow and wide rotors available. The wide rotors are generally for brakes that use the B05S brake pads. The narrow rotors are for pretty much everything else. The outer diameter of the rotor is the same but the inner diameter of the actual braking surface is different. The narrow pads with a wide rotor are no problem but the wide pads with a narrow rotor can cause issues. Shimano has great compatibility charts available, although they can be a bit difficult to understand at first.

[@a8f235]

Tires have become so much better at puncture protection over the years, that's something I've noticed as I've been away from mountainbiking for 8 years. I remember punctures was just very common, and now I have had *_ZERO_* punctures in 2 years. Filling a tube with sealant sounds like a meme or a t-shirt in my mind lol. Maybe fill it up with a lot of sealant and blam you got a ghetto cushcore setup 😅

[@hawgietonight]

It is easy to think that tubeless is somewhat ubiquitous but the reality is that many Sunday Warriors are running rim and tire combos that are not tubeless. Or have the rim so deformed that it cannot seal. At the shop when we can't get the combo to seal or are having problems with unusual leakage, we recommend a tube with sealant. Most are very happy with the solution to the extent that when they come back for new tires, automatically ask to reuse and refill the tube. And of course, there are extremes. I've had several times when somebody couldn't stand the normal tubeless leakage. It isn't that they couldn't pump up the tire a bit every week, it was just seen as a defect in their eyes. The best solution was a tube with sealant. So far no complaints.

[@alexislifecycle]

Thanks @gmbntech, Anna and Neil. I guess I have to change my frame now.

[@Autonomous_17]

its not worth it, I got the xx sl and feels the same as my slx mech grouppset

[@alexislifecycle]

@@Autonomous_17 it was impulse buy because of the sale. Ugh, now I am regretting it. Sigh

[@VFXBishop]

Big proponent of inner tube specific sealant when you can't set your wheels up tubeless. The only times I've had punctures on tubes that have stopped me are when I've had no sealant in them.

[@TroyKasper]

I forgot I had a tube in, thinking it was tubeless and added sealant, didn't realize the mistake until I went to change out the tire and there's a tube...ooops. haha

[@123moof]

Another possibility for the pads being larger than the rotor is that some low end brakes, like Shimano MT-200 have wider pads than what you find on the higher end models and have specified compatibility only to rotors with a wider braking surface. If so, the solution is to buy the correct rotors, which thankfully are the low-end cheap ones (though heavy).

[@Mansemouse]

I use Orange Sealant in the tubes of my off road disability buggy. Before I used the sealant I got two punctures in the first two weeks but since using the sealant and five years of riding (including going wearing out the tread of two pairs of knobbly tyres!) I haven’t had one flat. However when my tyres were found it was obvious that the sealant had saved my tyres multiple times! If it's good enough for BMX riders it's good enough for my four wheel off road disability buggy! #AskGMBNTech

[@nodigisfreeride]

#AskGMBNTech how different is the rear triangle of the current tyee to the previous tyee? And if it's not too different, is there a chance to use the newer one on the old frame?

[@OldDocThedan]

We leave in a few days for a tour in Norway. Taking steel frames w/ S&S couplers. These beasts have gotten us all over hell and back. Plenty of countries. Plenty of trains. Ferries. All the usual gibberish that comes with such fun. They run V-brakes. So it’s hard to find a tubeless rim that works w/ a rim brake. There are times I’m wishing for our other tubeless bikes. But it’s rare. And so- before each trip I put Stan’s or slime into tubes. And it’s nearly always a good answer. Plus- tubeless seating can be a puzzle now and then. So I’m glad I’m not searching out a compressor on the fringes of Nairobi.

[@derekcraig3617]

they're steel frames. braze on disc brake mounts to modernize your bikes

[@OldDocThedan]

@@derekcraig3617 That’s easy enough but then presents its own issues. I even build the wheels w/ disc hubs incase later down the road…. But if I did that- it means I need to pull the rotors off when packing the bikes. It’s too cramped and odd the way it all stuffs in. Rotors would bend. And so that’s more time fiddling w/ the bikes to prep them to pedal. So… do I want tubeless? How bad is the time to build/pack each bike? Centerlocks would require a specific tool to remove the rotor. I should have laced up 6 bolt hubs eh?

[@Autonomous_17]

I got lucky my frame had udh because I didnt see transmission coming but now that I installed the xx sl on my bike, I can say its all bullocks and feels the same as my slx groupset. make it make sense that a 200$ groupset feels as crisp as a 2500$ grouppset wont even shift well underload which everyone was bragging about. the setup was done with the utmost care and while it shift perfectly it does not do it under load so basically you still have to let go just as its always been.

[@rustybunny351]

#ASKGMBNTECH I have a 29inch 2023 Rocky Mountain altitude aluminium can I put a 27.5 wheel in the back and use the ride 9 adjustment to counter the geo change?

[@patoberli]

Dear #askgmbntech, regarding the inner tube sealant. On my city bike I once had a tiny hole, so that the tire was slowly but continuously loosing air. I already once had fixed a hole and suspected that I didn't do a clean fix with the repair patch. Anyway, from Muc-off there is/was an inner tire sealant at that time for the prize of about two quality tubes. As I'm a bit lazy and hate to fix rear tire punctures, I decided to try it out. It immediately fixed the tiny hole and I was able to use the tube for two more years, before I caught a real big double hole thanks to a nail, which then couldn't anymore be sealed. On the positive side, there was barely any mess, maybe not enough sealant was left.

[@mattd5136]

Tube+sealant in a non-tubeless wheel? Yes please! I would love love love if my cargo bike was tubeless compatible but sadly without rebuilding the wheels with compatible rims and replacing tyres the existing kit simply won't seal. I tried :( So the easy answer is to shoot a load of sealant in through the valve and enjoy life. Not all tubeless sealants work with tubes - ranging from not really to fail. Stans works in a pinch but Effetto Mariposa Caffélatex is my absolute goto favourite for tubes. I just wish I could get a tube loaded with Silca Ultimate to test out ... that stuff works so incredibly well it'll clog a hole bigger than a valve stem.

[@porroco]

Hello, cant find t type xo transmision with 34T chain ring for my 160e, is there any optional flattop chain ring to look out there please

[@user-qz5bk6lr6e]

on a engwe e26 can you use tubeless tyres?

[@TivonSanders]

I've used Slime Sealants for my commutes with my bike, and Slime worked very well at sealing very small punctures. Anything like glass or a thorn would render the tube useless unless you had a patch kit, so it's kind of hit and miss with Slime.

[@jonathansanchez1305]

Inner tubes allow for quick change or swap of tires..

[@tim__sadler]

#askgmbntech - so much tech progression in our lovely sport (got to love Owen's Eurobike coverage) - but why are we still stuck with the same seat/seatpost head designs? Yeah there are some subtle differences in approach, but it seems like this is ripe for a bit of a redesign?

[@Packo808]

What's the trail of the person on the red bike (about 7:30 in)?

[@thomashayden4522]

We use gallons of True Goo in tubes. It works great for thorns and such. Not all wheels are tubeless compatible.

[@Locklannnn]

the argument for slime tubes btw its a cheaper alternative to tubeless that works with heaps of wheels sizes and tyre sizes its pretty good for commuter bikes

[@grummbeerbauer3527]

#AskGMBNTech I bought my first hardtail MTB in 2022. I did a bit of research before, so I knew I was getting good components and I specifically wanted a 2by drivetrain. Alas, I was not aware of different axle standards and didn't notice that it is still using quick release instead of through axis/boost. Since the cheap Shimano hubs on the wheels (or rather the freewheel) have gone bad already twice now, I was trying to get a new set of wheels with better hubs when on sale. Alas, they are hard to find (in particular in combination with microspline), the market only has throughaxle/boost, so you actually have to go to a custom wheel builder. But then the price of the wheels is just too high compared to the price of the bike. So the bike seems to be a bit of a dead end. I still like the bike overall, what should I do? Choke up the money for the wheels? Buy a new frame, fork and dropper and salvage the remaining parts (XT 2x12 drive train and XT brakes, mainly) and build a new bike? That would not save much if at all. Or sell it off (in the current market for pennies...) and buy something new? Or just keep buying new rear hubs/freewheels and replace them about once a year?

[@trickyrickymtb5622]

I'm all about tpu at the minute, most of the benefits of tubeless, with out the mess

[@jiriperoutka239]

#askgmbntech My red Ergon GA3 grips have become "sticky" after two years of almost everday riding. Most of the time I ride in my gloves, I wash the bike regularly, including the grips - using dedicated Muck off bike cleaner. I rinse the bike with clean water afterwards. Especially the first ride after the wash-up the gloves almost feel like glued to them, the grips attract lots of dirt. Is it time to buy a set of fresh ones?

[@rupedog]

Slime make sealant u can put in any tube, not just pre filled ones. It's horrific stuff because like tubeless sealant it dries out over time, but then u cant clean it out and replace it, so u have to fit a new tube, and it clogs valve very easily. Hate working on bikes with slime tubes

[@Christok-wc1ik]

#AskGMBNTech Can I fit a 250x75 coil shock on my canyon torque with 250x70?

[@_Zane__]

Tried to change the wifes bike to tubless, kept leaking at the rim joint on 1 rim, even tried wider than normal tape.. gave up and just put the tube back in 😂

[@laurentp89]

JB weld the seam, and sand it flush

[@_Zane__]

@@laurentp89hmm, will the epoxy hold up with rim flexing?

[@laurentp89]

@@_Zane__ I've done this to a few rims, for my own and a few friends', and haven't had any problems. One was used for a at least couple of years after the fix

[@_Zane__]

@@laurentp89 ah cool thanks, I'll give it a try if I decide to convert it again 🤣

[@richardpolidore1702]

Green slime welded tire, tube and wheel together. Had to cut off tire and tube.

[@jamesh2881]

#AskGMBNTech "How much noise is your suspension supposed to make".

[@CanonFirefly]

Pretty sure your channel sponsors sell sealant explicitly for putting in tubes. Agree though, why?

[@natanaeltzul1-248]

#ASKGMBMTECH Does all weather lube require degreaser to clean the drivetrain or could you clean it with water and enough elbow grease? I live in the tropical country of belize where it is mostly dry and wet season doesnt rain enough for me to need a full wet lube. I want to know before i get all weather lube because from my knowledge, its a blend of wax and oil. It would really hel because it wont attract as much dirt while being protected from the rain. Thank you so much and cheers.

[@JoshuaRussell-pi9bt]

#AskGMBNTech, I have a Commencal Meta SX V4, it has a shock with 230 eye-to-eye and a 62.5 stroke. would it work to use a shock with a 65 mm stroke, because some brands(like Fox) don't make coil shocks of the right size.

[@BigManRoloh]

@@JoshuaRussell-pi9bt no

[@briangong007]

5dev has since discontinured the Yeti non UDH to T Typer adapter.

[@45graham45]

I tried the slime tubes years ago. It was rubbish. I still got a puncture & it made a complete gooey mess so I had to bin the tybe & spend ages cleaning the tyre. Useless.

[@johnssmith4005]

#AskGMBNTech has anyone ever tried to put a suspension seatpost on a full suspension bike , would that make it better or worse comfort wise ?

[@BillyBoblovesthedirt]

This is a weird video. I ran silicone sealant in my bike and even my dirt bike tubes for years. Never had a flat tyre. When I went to replace my tyres on my MTB I found I had dozens of holes that had been filled by the silicone slime and no, it hadn’t made a mess in the tyre. Even if it had???? So what. I currently have non tubeless Maxxis Hookworms on my MTB with slime in tubes. Why wouldn’t I ??? Also why wouldn’t I use it in my Dirt Bike??? This stuff has been used in tubes since the early 80’s.

[@tbull1545]

how in 2024 are we still asking if we can fill inner tubes will sealant? yes been doing for decades b4 tubeless was even a thought. literally slimes whole ad campaign

[@kenmoum162]

#askgmbntech My 7 y.o. wheels will NOT work tubeless. I've tried all the hacks. But I ride in AZ where everything has thorns, so I use various tube sealants. Nothing works better than Multiseal brand, but lately I've been using Slime. I have had tubes with as many as 30 thorn punctures still hold air. I do not recommend using tubeless sealant, it seals punctures, but makes a huge mess as Neal mentioned.

[@fud1376]

I'll never go Tubeless.Too messy and doesn't last long.I use a Kevlar style strip on the inside of the tyre,and haven't had a puncture in years...Ha!

[@lashay-z2i]

Blackout 2 is what I want for early American fourth of July Christmas. 🍓🌺

[@mountaincruiser817]

The way Anna looks at Neal in these video's, she really adores this guy…….one way love is painful dough. 😅

[@shrinkingshrimp]

Stop the elitist bs. Many entry level bikes do not come with tubeless ready wheels still to this day. If you are running tubes and you are not after marginal gains (and I'm pretty sure you are not if you run tubes...), then Slime works great on smaller punctures.

[@user-fw7zf8ze3t]

I like on this one how Neil has answered the questions but Anna still feels the need to chime in just to prove a point. It would be cool to see more of these shows without her as who ever she does it with they always seem like awkward interactions and the other presenter uncomfortable