More tubeless blowoff discussion

[weiwentg]

Someone wrote to Lennard Zinn on Velonews (https://www.velonews.com/2020/01/technical-faq/technical-faq-specialized-turbo-2bliss-tire-blowoff_503717) about a 28mm Specialized S-Works Turbo 2Bliss blowing off his 21.3mm internal diameter Hunt rim.

The response seems very odd to me: Specialized claimed that this tire can’t be used on hooked rims with over a 17mm internal diameter rim if mounted tubeless, and that it can’t be used with an inner tube on hooked rims over 21mm ID. They say it can’t be used on hookless rims at all.

Their response contained a line that this tire was designed to ETRTO standards. They said the issue doesn’t affect other models of this tire, just the 28mm version. They don’t seem to have explained why this is the case.

***!? Discuss.

Consider also: the Roval CL50 (https://www.specialized.com/us/en/roval-cl-50-disc-wheelset/p/155548?color=230247-155548) has an ID of 20.3mm, so it can’t take that tire tubeless. When they redo the 25mm version of this tire to ETRTO standards, are we expecting that it won’t mount to that wheel set at all?

[bigbill]

I'm pretty sure my use of tubeless tires on my road bike have increased the size of the bald spot on the back of my head.

[R3awak3n]

Personally, I will not use tubeless unless tire can be kept under 70psi. For some this is a 28mm tire, for others its a 32mm or even 35mm.

[R3awak3n]

Personally, I will not use tubeless unless tire can be kept under 70psi. For some this is a 28mm tire, for others its a 32mm or even 35mm.

I did notice that spesh has their max pressure for tubeless a lot higher than other companies.

[Clean39T]

Hmm, 25mm Conti GP5K-TL at 55-65psi on my HED Ardennes Black SL have been glorious....... I go a little firmer for climbing days, a little softer for easy flattish days. 193-lbs. YMMV.

Sent from my Pixel 2 XL using Tapatalk

[weiwentg]

Personally, I will not use tubeless unless tire can be kept under 70psi. For some this is a 28mm tire, for others its a 32mm or even 35mm.

Specialized did say in their response that 80 PSI was the max. However, maybe that's irrelevant. Even if the rider didn't exceed the max PSI, the fact is that the 28mm S-Works Turbo 2Bliss tires can't be mounted tubeless on many current rims. They will mount as tubeless on my old Pacenti SL23s, or I think on many current Fulcrum or Shimano wheelsets, or on DT Swiss' performance road line of wheels. They aren't approved for tubeless on my Boyd Altamonts (19.86mm ID), on DT Swiss' endurance road wheels (19mm ID), or probably a lot of other current wheels that you'd think could accommodate tubeless.

They apparently shouldn't be used at all on those Hunts, or on DT Swiss' cross road or gravel road wheels, or Boyd's carbon 36mm road disc wheels, or a bunch of others that you wouldn't think would cause a 28mm tubeless tire to explode.