Tyre Liners, Gear Charts & Tough Carbon Wheels | GCN Tech Clinic

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I'm happy with a mechanical groupset, rim brakes, and tires with TPU inner tubes. It saves a lot of inconvenience.

If you rode down the staircase of death and no one died, surely that means it wasn’t the staircase of death? Maybe just ‘stair case of a bit scary?

Rim strength doesn’t prevent snake bite flats. That’s from running with the air pressure too low.

I have have some carbon wheels for my fat bike that I took bike packing through Utah, Nevada, and California. Between myself, the bike and all the stuff it was right around 300 lbs and these took a beating without a complaint. 5 years later they're still true and roll great. The aluminum gravel bike wheels which have never had anywhere near that load have developed a wobble in front, these wheels also are a pain to get sealed tubeless I really regret getting these wheels.

OMG I remember that carbon wheel test video. Kudos to Alex for having the courage! I almost couldn't watch 🤣

3 Tips For Crits. 1. WCS Ritchey Race Comp Slicks 25c 215 grams per Tyre. Ultra Grippy, On Par With Conti & Pirelli Tyres Excellent Rolling Resistance. 2. TPU inner Tubes 36Grams per tube like Olly said, dont bother with tubeless and sealant. The sealant will weigh more than the TPU inner tube. 3. Waxed Chain, BananaWax Drag & Friction Reduction Racing Chain Wax or Silca Secret Chain Wax or any Silca Wax is better than any oil. You want Lightness, and Reliability.

Big fan of TPU tubes with 25mm German Conti clincher tyres. Sealant is great until a total failure where it's a messy pain.

Going for the next tougher 'type' of wheel (or other components) is a great strategy for people who are hard on gear and/or clydesdales. Gravel parts for road. MTB parts for gravel for example. As Ollie said, not usually as light but stronger.

Re: car tyres being tubeless and not requiring sealant, I suspect they do actually slowly leak air, but: The pressure is half that of a bike tyre so slower/less leakage anyway. The circumference is a lot less so much less tyre/wheel interface over which to lose air. And finally, there's a comparatively huge volume of air in a car tyre, so a slow leakage can take months to become apparent.

Wax / Lube ? on a 600 k brevet there is typically an overnight stop where drop bags are. A prefixed chain with quick link "presto chango" is another option.

I would say bring a Second waxed chain for the wax lube chain question

Maybe I’ve been lucky, but I have a set of carbon Roval SL CX wheels that I’ve had since 2015 and have ridden at least 75,000 km on. Both have been rebuilt (new hubs to accommodate new thru axel standards and going from 11 to 12 speed), but the rims are still perfect. It probably helps that these are technically 29er wheels designed for cross country and I run them on an all-road bike (almost never on dirt or gravel) but I’ve been amazed by the longevity.

Re: running tubeless bike tyres without sealant, I find that after initial tubeless set-up with sealant, once the tyre is sealed to the rim, even when the sealant has dried out, the seal remains good. I've often found that upon puncturing out on the road, the inside of the tyre has become dry. Not a problem though, because I always carry spare tubes anyway, for if I get a puncture which won't seal. But effectively, I'd been running the tyre without sealant.

I believe the tubeless setup that did not require sealant were UST wheels/tire. They had a specific bead/rim shape. I had UST wheels/tires on a couple of bikes. Rode hundreds of miles without sealant. Carried a tube. Shame that it did not become a standard.

#askgcntech Pogacar has been using deep section Enve wheels and Vingegaard has been using the Cervelo aero frame with shallower wheels. Assuming both bikes weigh the same, which set up is likely to have better aerodynamics. All rounder frame with deep wheels or aero frame with shallow wheels.

To further stress the argument made: Tubeless tires without sealant will probably not even work cause they lose air a lot… For example, I run Schwalbe Pro One‘s in the TLE version and they don’t hold any air without sealant. If you spray the sidewall with soapy mixture before putting the sealant, you can see bubbles popping out all over the sidewall!

Strength of a wheel isn’t just in the material. It’s also spoke pattern. 1 cross, 2 cross, 3 cross, 4 cross differ in weight and strength. So if you see a competitive cyclist turn a wheel into rotini, check the spoke pattern before arriving at any conclusions. Quite often, those rims are minimally laced for weight savings.

Good advice regarding using more rugged or gravel wheels for bigger and stronger riders. But if you're referring to puncture protection, the tire size may be as or more critical than the wheel. But if it's wheel damage you're worried about, then it's absolutely critical you also choose a name brand wheel and one made with authentic carbon fibre and with consistent manufacturing quality. Some of the Amazon and AliExpress type wheels are made with "non-standard" / non-licemsed carbon fibre, which is the lowest of quality and often blended with nylon, polyester and/or fibre glass, all to save money, but at the expense of reliability, durability and notably, also safety. Also some brands like Zipp will replace a broken wheel "no questions asked" and most legit brands will honor their extensive warranty... something the online, knockoff brands won't. BTW - unlike aluminum which will fail almost immediately and visibility, carbon wheels may take some time to make the results of misuse evident. So the "stair stunt" might not result in catestropic failure right away, but if damaged, then failure will happen, but when you least expect it. I certainly hope the wheels you used for the stair stunt weren't sold or given to anyone.

I'm 100% in favor of TPU tubes on bikes. I've got them installed in both wheels on my daily driver. They're lighter than the very heavy old rubber tubes I used (56 g vs 166 g, and yes I know lightweight rubber tubes exist). They have the very simple installation process of tubes with the weight savings of tubeless. I've also never "burped" a tire with tubes.