Carbon Rims advice - Hookless or not when tubeless + setup experience?

[Jerryno]

The title says it all - carbon rims - hookless or not when tubeless?

Hookless rims should be stronger, but setting up tubeless is more difficult. How well do they hold on and how often you need to pump them?

Which rim width is the way to go and which tire are you using? What pressure can you run safely without burping?

Any experience with how to setup them is also welcomed!

[Vipassana]

I've set up several sets of tubeless tires on hookless rims.  I've found them to be as easy or easier than their traditional hook rims.  Hit them with a compressor, tire seats instantly, shake around to get the fluid on the beads.  Repeat as necessary. 

With hook rims, I've had trouble getting the tire bead to fully seat resulting in a tire that wobbles or isn't fully round.

I'm running the 30mm hookless as are 3 of my riding partners and we run everything from 2.1 to 2.4 tires on out XC race bikes.  Almost no issues.  Only one of us has had issues with burping and I think that's because he runs super low pressures.  His Continental tires have been prone to leaking through the bead and sidewalls too so maybe they are the root of the issue.  The rest of us run Schwable or Specialized with no complications.

One last bit of advice with ANY tubeless setup: if the tire arrives folded, unfold it several days prior to mounting to let the bead straighten out.  On really rough/tight folded tires, I will use a tube to expand them out for a day or two before mounting.  This makes the seating MUCH easier.  Also, do yourself a favor and get access to a high volume airpump or compressor.  That also makes it about 100x easier to seat them for the first time.  I'll even pull valve core out to help with the initial seating, then add the fluid and replace the core and air it back up.

[Vipassana]

Also, speaking on your "Is 30mm too much?" question, is the 30mm internal or external?  My 30mm are external with a ~25.5mm internal width.

Many of the rim manufacturers are going to wider rims for all applications.  The idea behind this is that the wider rim allows the tire sidewall to be better supported resulting in less movement during cornering (which leads to burping).  Here is a good read on the subject:
http://www.pinkbike.com/news/Tech-Tuesday--Wider-Rims-Are-Better-and-Why-Tubeless-Tires-Burp-.html

I would think 2.1 is just fine for 30mm, but I'm not really sure.  I've see it done with fine results.

[Jerryno]

The 30mm that I was thinking about are external: http://www.xmcarbonspeed.com/Productinfo.asp?f=1294 with 26mm internal width.
Thanks for the info, your's have also a little bit thicker walls (internal 25.5) - thats probably also better.. I'll keep looking for the best rims.

[Patrick C.]

+1 for hookless.  I also have the 30 mm external width hookless rims.  No problems getting Schwalbe RoRos or Continental X-Kings to seat and hold air.  I agree that a compressor is required for initially seating a new tire, but you really can seat them with a floor pump once the tires are "in shape".

[carbonazza]

he runs super low pressures

What is a super low pressure?
I have 30mm rims too, but I think I could do better/lower than 1.8 bar / 26 PSI.
How could we test the limit?

[lexicon]

35mm carbon hookless + Rocket Rons 2.25. No issues They set into place with a good pop and I run nice low pressures, no burping issues whatsoever.

Your question isn't about exactly about technique to achieve tubeless, I realize, but for completeness here I'll mention this: Soapy water. Don't even try to seat a tire tubeless without spreading lots of soap suds around all edges. I was actually battling for a while until I remembered that - hit it with the suds and bam - instant seating!

Then do the big "Stan's Shake", rest horizontally on a bucket or box for a while, shake, flip, repeat. Apply soapy water around the sidewalls and rim edge, and the valve stem to monitor for leaks. Shake sealant into leaky areas. I find a few repetitions of that result in perfectly performing tubeless conversions.

[MTB2223]

On what pressure do have the tires when doing the big "Stan's Shake"?

[lexicon]

Pretty firm, but not crazy high. It may take more to seat the beads but for sealing things up I find 30 psi or so works - enough pressure to force sealant everywhere, without being crazy high.

[frankR]

I run 2015 Specialized Roval Control SL. 22mm inner width hookless (specialized was the first to market on beadhook-less carbon rims if I am not mistaken). They are similar spec to the light bicycle wheels.

Currently I hVe mounted  Maxxis Ikon 2.35 F/R 19/21psi with Stans. Awesome setup. Great all around performance: light weight, fast rolling, compliant/comfortable, and excellent traction. A little loose on some trails but all I need for 99% of what I ride.

I love the beadhookless design. Strong and low weight. Slightly more difficult to mount tires. The RaRa 2.25 I was running before were a challenge to mount. The Ikons are relatively easy.

I think its obvious wider beadhookless rims run tubeless are the way to go.

[bxcc]

Just weighing in with what I've got in case it helps.
Nextie 35 outer / 29 inner hooked rims.
Bontrager XR3's 2.35f 2.2r
One wrap of gorilla tape
2oz of Bontrager sealant

Setting up tubeless has been easy and issue free. I've had 2 flats in 2 years. One was due to a rock strike and put a hole in the sidewall. No rim damage. The other was a broken valve stem. As far as rim width goes, I don't want to go back to anything narrower than this. I would like to try some 40's (outer).