[atrokz]

This article says Steve Smith was running two valve stems during his victory this past weekend...
http://www.pinkbike.com/news/devinci-wilson-carbon-steve-smith-interbike-2012.html

Exactly.

We're not comparing ourselves to pros here. They need it for the reasons I stated. Because they blow **** up. That was the question and it has been answered, not 'why do we need it', because we probably don't.

Here's PB's POD. Something probably more than a few of us 200lb+ guys have done

 

[Transcend]

Lelandjt maybe isn't a wc pro, but he isn't exactly slow, either. I'm sure he's hit a berm at 25mph before. He is little, so maybe that's the difference...

Watch Sam Hill corner. Than watch pretty much anyone else corner. That's why those guys cannot run tubeless. They will literally tear a tire from the bead and burp it, no matter what interface you put on their rims. Tube + tubeless tire is a simple, effective setup many racers on the WC are using.

 

[slyfink]

Tube + tubeless tire is a simple, effective setup many racers on the WC are using.

then why don't we see more pictures of it?!

 

[BrayDownhill]

Tube + tubeless tire is a simple, effective setup many racers on the WC are using.

This is what I often wonder about, Im no world cup racer but have terrible trouble burping tubeless on the DH bike running around the 25psi mark. However I have run tubes in a tubeless tyre on a tubeless rim (823s) and pinched the tube and ended up with a completely flat tyre.

Are people running that set up but glueing rims / sealing valve holes so that when the tube goes the tubeless set up affords a secondary backup? Or what else are people doing as redundancy?

I've had better success running tubeless front setups but on steeper tracks like Mozine singletracks and champery steep runs the fronts burp aswell as the weight transfer is much higher on the steeper trails

 

[atrokz]

This is what I often wonder about, Im no world cup racer but have terrible trouble burping tubeless on the DH bike running around the 25psi mark. However I have run tubes in a tubeless tyre on a tubeless rim (823s) and pinched the tube and ended up with a completely flat tyre.

Are people running that set up but glueing rims / sealing valve holes so that when the tube goes the tubeless set up affords a secondary backup? Or what else are people doing as redundancy?

I've had better success running tubeless front setups but on steeper tracks like Mozine singletracks and champery steep runs the fronts burp aswell as the weight transfer is much higher on the steeper trails

Are you sealing the valve stem? I would assume it would leak out of there quite fast if unsealed.

 

[Lelandjt]

What pressures are you guys running with your UST set-up? I'm a big guy (240lbs before gear), running standard Maxxis DH tires (non-UST) w/ Stans and EX823s at 30f/35r PSI and hardly ever burp....
I wouldn't call myself slow but I'm nowhere near WC speeds... Either way I doubt most of you guys are either.

I weight 165 and run 29/34psi with 2.7" non-UST Minions and Stan's. The factory guys seem to all run mid to high 20s. They get better traction at those pressures for sure but you and I would go through too many rims to be worth it. I know you weigh a lot more than me but I've experimented and put big dents in rims at even 1psi less.

I think it's great that attention is being paid to this aspect of bikes as this is the only part that has given me problems in the last few years. If anyone else here has changed a motorcycle tire you know how much tighter the fit is. More work to change but a more secure bead/rim interface with a big shelf the bead sits on. Kinda like UST and Notubes but tighter fitting.

 

[atrokz]

^ Anyone who remembers those older Tioga DH rims, and has ever tried mounting a set of Michelin DH tires on them, will probably agree that there's a thing as too tight!