That’s a common thing with TPU tubes. It is generally said that you should not use a same TPU tube with different tires as the tube takes the shape of the first tire. But we can assume that for similar-section tires, this should not be a big deal.
I agree. It’s much easier to set up a TPU tube in Braus rim as we can apply more force on it without being afraid of pinching it 
I also switched to a TPU inner tube on my G36 (braus rim + KG ultimate tire + new schlumpf hub disc 32h)
I received a pair: 97g and 112g.
Switching from a 29" butyl inner tube to a 36" TPU inner tube does have an impact on wheel building.
I measured the spoke tension only on the disc side with my parktool tensiometer:
I also noticed that the wheel had shifted slightly to the non-disc side.
I think the tube induces a force that goes from the rim to the hub. This force is probably correlated with pressure, and is greater with a 29" tube (for the same pressure). I don’t know if this force can modify the rim’s external diameter… and the tire’s fit on the rim…
Carbon’s not known for being very compressible, so this feels unlikely!
Tension on my spokes drop from, say, 120kgf to 90kgf, after inflating a tire. That’s a 30kgf change. The only way all the spokes lose tension is if they shorten, which means the rim compressed (or shifted to one side and the other side tightened/lengthened).
With the Young’s modulus of stainless steel of 190GPa, we can calculate a 2mm diameter steel spoke’s change in length given the kgf change.
Strain = 30kg * 9.8m/s^2 / 190GPa / cross section area
Cross section area = pi * (1mm)^2 = 3.14e-6 m^2
Strain = 0.00049
Thus, elongation of 0.00049 * 360mm = 0.17mm
That means the rim diameter is getting compressed by about 2 * 0.17mm = 0.34mm
If the rim is stronger and stiffer, then it will compress less. If it compresses less, then we will measure less change in spoke tension. Doesn’t really matter what material, but more in the design+material. We can have super stiff and strong aluminum rim, or super weak carbon rim; or the other way around.
I agree the tube/air will compress the rim. It would be interesting, but I doubt the type of tube would have a significant effect. If you were to inflate inly a tube, how much pressure can it withstand before popping [or at the shape/volume inside the tire]?
If it is 2 psi, then the pressure on the rim would be 2 psi less than the air pressure in the tube. If TPU is stiffer than the butyl tube, and withstands 3psi by itself, then there would be 1psi less pressure on the rim.
Hello everyone,
Currently in the process of building a 36" and had carbon questions.
Does someone make one that’s reliable/good yet? I’ve bought from light bicycle in the past and love their rims on my 29 and 26. Are they good and available?
TPU tubes, where can I get the 36" one? And is it well reviewed?
I think you should read this thread you replied to for info about the Braus rim and the thread about the Nextie Nextie 36" carbon rim and make your own jugement.
Light bicycle does not make a 36" yet.
Tpu Tubes:
36er TPU tubes!
Can be ordered directly from
TRENTASEI//36® TPU INNER TUBES – 36pollici.it
Well… They are in the process of making one. They just need a bit of time to complete the project
Yes, they are! I ride one for the last month and they are truly amazing. I don’t think I will ever go back to Butyl tubes. Light and puncture-proof 
Any news from LightBicycle?
Also just for the record, I’m reporting yet another blowout for my friend. He’s using an NR Lite on a Nextie rim, no exact pressure gauge read but should be less than 40 psi.
Sadly no news. I have just send a new message to investigate about the situation 
I also checked - off the back of this thread revival.
Got this:
Hi Felix,
Sorry for the late reply. I can update you tomorrow. I am checking with our engineer team, they can reply tomorrow.
Just got the same email. Wow. This looks like an exciting time to be alive!
I hope they let us order just 1… and I hope it isn’t super £££
Cc @Elias
I LOVE that information!!
I won’t build a 36er now though, not until there is more choice in tires. As far as I know there is currently 3-4 different 36er tires, and all seem quite bulky (1250 g for the king georges ultimate, which should be the “lightest”).
I usually ride my 29er with a “schawlbe thunder burt 29” Tubeless Easy Souple Super Ground SnakeSkin Addix Speed E-25" Yes, that is a way too long name for a tire, which is 625 g. If adapted on a 36er, it should be between 775 g (if proportional to the diameter) and 1200 g (if proportional to the cube of the diameter). In my opinion, it is somewhere between simple and square (tread should be simple and sides square), so between 775 and 965 g. Using a G-one speed base should be even lighter
All that to say that now we should contact a company such as schwalbe for a good 36er tire in order to go with those probably gorgeous rims.
I won’t do it though, I cannot afford yet another new high end uni. This message might have to go on another topic, you can move it if you think you should.
That would be the dream option. If I had a spare £500,000 kicking around to invest that would be the worst business decision I could make - but a nice tyre would be fun.
Granted 36er tyres are heavy when compared to other wheel sizes. But with a TPU tube and the lightest tyre available now the wheel will just feel like a nippy 29er.
The trouble with them making this rim is once you try a non-aluminium 36er, you want all 36” wheels to become carbon rimmed ones 
Then imagine getting possibly 300 g (maybe even up to 500) less with another tire… But yeah, I get that it would cost way to much money.
I already have the problem with my 29ers. Currently, my road uni has a really light tire combined with a carbon rim, and my muni has a really heavy tire with an aluminium rim. And everytime I am not going offroad, I basically hate my muni wheel (love it in the mud though). Thankfully I am planning on replacing this uni with one equipped with a carbon rim…
As said by Felix, this would cost a lot. I have sent an email to Vee Tire months back but go no reply. Roger also told us a few times he has asked his manufacturer to make lighter and more modern tires. But no luck there, too. 
Yeah, I totally get that it must be hard as hell and cost way too much to develop a new tire for a few hundred persons (at most, including very tall cyclists).
But I have to say that I am a bit suprised by the choice of design of the 36er tires, it almost looks like they are made backwards (holes in a thick tread instead of studs on a thinner tread)
I guess it is the old way of doing things…
With a combination of the larger BSD (Bead Seated Diameter) and taller side of the new version Nextie rim, it should prevent the current 36" tires from blowing off. The standard 36" rim BSD is 787mm. I guess the question would be, will all 36" tires fit on the larger 789mm BSD rim?
Which new version of the Nextie rim are you talking about? The drawing I have sent is the new LightBicycle rim. Have I missed a new version of the Nextie rim? 
