Barlow Pass Tubeless

[CMiller]

I have a Stan's Iron Cross wheelset that I am hoping to get some road use off, but don't want to mess with the 45 PSI restriction for the rim. Contacted Stan's and they really don't recommend going over 45 PSI ever. Ever. I'll listen!

Setting a wide road tire tubeless seems like it could be a good option. I am hoping to hear anyone's experience running the Compass Barlow Pass 700 x 38 tires tubeless.

Specifically, what PSI did you end up with for your weight? I'm 165 + 20 pound bike, and want to make sure these would run under the 45 psi limit safely with my weight.

Thanks!

[bironi]

I'll bet you'd get a few responses here:

seattlerando@googlegroups.com

[one60]

while the iron cross rim is not a true road rim I'd suggest confirming with Stan's that its safe to run a tire designed for road clincher rim in a tubeless/UST format at the intended pressures.

Clincher road tires are not safe for use in on tubeless ready road rims due to the higher pressures the bead must endure. Not sure what the threshold pressure might be for the combo you are considering but wouldn't want you to take an unnecessary risk.

[linkedrecoverie]

one60's point takes precedence, but I've got 20 pounds on you, and 45 psi is the upper limit for me on those tires (I have tubes on Open Pros); I usually run them closer to 35 psi.

[doomridesout]

Many have had luck converting big fat road slicks that are not explicitly tubeless, especially those tires, in the 650b community.
I am of two minds-- I would NEVER run anything not explicitly tubeless ready for road tubeless, but for mountain bikes, the whole thing got started as 'ghetto tubeless' and conversions seemed to make it OK, probably because of the lower pressures required.
I think it all comes down to an equation of pressure, volume, and the types of impacts the tire will sustain, and a 'burp' is a definite catastrophic event, and I can't pretend like I know that equation, so I say NO WAY to stuff that's on the fringe. Reading about people converting anything not marked explicitly as tubeless for road use gives me chills.

[doomridesout]

Many have had luck converting big fat road slicks that are not explicitly tubeless, especially those tires, in the 650b community.
I am of two minds-- I would NEVER run anything not explicitly tubeless ready for road tubeless, but for mountain bikes, the whole thing got started as 'ghetto tubeless' and conversions seemed to make it OK, probably because of the lower pressures required.
I think it all comes down to an equation of pressure, volume, and the types of impacts the tire will sustain, and a 'burp' is a definite catastrophic event, and I can't pretend like I know that equation, so I say NO WAY to stuff that's on the fringe. Reading about people converting anything not marked explicitly as tubeless for road use gives me chills.

[HillDancer]

...Setting a wide road tire tubeless seems like it could be a good option...
It is.

No mention if this is a disc brake equipped application or rim brake. If rim brake, only narrow rims are available; too bad. If disc braked, now a lightweight, appropriate width rim can be used. I ran the non-tubeless specific 38mm Pari-Moto in 650b, tubeless, on a 34mm internal width carbon (http://www.derbyrims.com/technical-specs---faq-s.html) tubeless ready rim, 34psi rear/29psi front (average), 210lb rider & bike combined. The Pari-Moto was/is made by Panaracer, with the same aramid fiber bead, and casing like the tire you want to use.

The key to success for safety is the rim, and the same key applies for realizing greater performance potential from a wide tire. I suggest not skimping on the rim.

[sandyrs]

It is.

No mention if this is a disc brake equipped application or rim brake. If rim brake, only narrow rims are available; too bad. If disc braked, now a lightweight, appropriate width rim can be used. I ran the non-tubeless specific 38mm Pari-Moto in 650b, tubeless, on a 34mm internal width carbon (http://www.derbyrims.com/technical-specs---faq-s.html) tubeless ready rim, 34psi rear/29psi front (average), 210lb rider & bike combined. The Pari-Moto was/is made by Panaracer, with the same aramid fiber bead, and casing like the tire you want to use.

The key to success for safety is the rim, and the same key applies for realizing greater performance potential from a wide tire. I suggest not skimping on the rim.

The Stan's Iron Cross rim is disc-only.

[saab2000]

The Stan's Iron Cross rim is disc-only.

Correct. I have a set. There is no brake track.


Not a fan of the 45 PSI limitation but I run some Ruffy Tuffys and some Michelin Jets at higher pressure with no issue but I run them with tubes, not tubeless.

I cannot comment on the tubeless limitation. If I rode the bike more I'd probably eventually replace them. I would like to try tubeless for the gravel bike someday, but not this day.

[Dustin]

The psi limit in stans rims does not apply when using tubes.

I have the new 650b 42mm compass tires set up tubeless on wtb Kom rims, 40 psi rear and 35 in the front. Amazing. Thinking of rebuilding the wheels with wider carbon rims so I can go lower on the psi while retaining sidewall stability.

I have a 700c bike with Barlow pass tires and have been really tempted, but don't like the rim brake options.

[CMiller]

Hey all, I really appreciate the help and hearing personal accounts. Stan's got back to me extremely quickly!


"The Iron Cross was designed as a dedicated CX race rim, with light weight prioritized over the ability to run high pressures (a rim designed to hold high pressures will require a little more structure in the extrusion and will be a little heavier) and the max pressure for the rim is the labeled 45psi whether you are tubeless or using tubes.

With regard to those particular tires: no tire tire should ever be run tubeless above 40psi unless it is specifically labeled for tubeless use. Provided you keep it under 40psi (which should be more than enough given the volume of those tires) they should work great."

[Dustin]

I stand corrected on the stans with tubes thing!

[one60]

Thanks for sharing the information from Stan's re road tubeless tires versus clinchers...

its easy to see why someone might think a clincher could be substituted for a tubeless tire but important to understand its an unsafe choice.

Since this is a valuable insight, is there a good method for sharing this information for the larger cycling community that might search paceline for info on such topics?

A sticky? (whatever that is) or a new thread as a PSA??