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tubeless w/ new UST rims--good plan?

6K views 50 replies 10 participants last post by  krisdrum 
#1 ·
I'm sick of screwing around with all these wheels and tires and since I'm not that good anyway I want to just race cross on one damn set of tires.

So there.

My plan on paper is to get some of those tubeless shimano ultegra wheels and run something like a PDX with sealant at 35-is psi, maybe softer in the front, I weigh 175.

The time I waste dicking around with tubulars, I'm going to spend training.

Good plan??
 
#6 ·
In my limited experience, there will be some trial and error. For the last half of the 2013 season, I ran Stan's Alpha 400 Comp wheels with Clemente MXP tires as my do-everything wheelset. My first race I burped/blew my rear tire off the rim coming down a flyover, but I was running way too high of a pressure. 2nd race was great, no problem. 3rd race I burped again, the front this time, going through some deep ruts running perpendicular to the course. After that I think I finally figured out my pressure (I'm 190ish lbs) and the last 3 races on these wheels went by without a problem. These tires work for 90% of the conditions around here, so I plan on sticking with them for this season.

I don't particularly have the gumption to try getting one started, but it would be great if we had a sticky for the forum for tubless rim and tire combos on how they perform in race situations. Something like: rim, tire, rider weight, F/R tire pressures, scale of 1 to 5 for how they perform. That would take a lot of guess work out of something like this.
 
#10 ·
It's been a while, but I believe I was about 33 in front and 35 in back, though even that might be a bit high. Running lower than that, I felt the squishy feeling from the rear tire when riding across pavement sections to be really unnerving, thought it might just be something I need to get used to.

Are you using the rim strips with the 400s? Or just Stan's tape and sealant?

Although not quite as in depth as you propose, the CXM article I posted in another reply is updated periodically with their trial and error feedback on rim/tire combinations.
Just the tape and sealant.

And thanks for the link. I will check it out.
 
#16 ·
shimano does not recommend alkaline sealant with their tubeless wheelsets.

so... Stan's is out of the question.

Caffe-Latex or OrangeSeal may be alternatives, but I don't know they pH.
 
#19 ·
#22 ·
#23 ·
I can promise you PDX's will not stay on any rim except for a Notubes Iron Cross Disc, when coming around a corner very very hard. You have kind of a chance with 340/400's but they can still roll off, i used those and actually glued the bead to the rim, then they were solid.

If you go the tubeless rim route, i would get actual tubeless tires. Like IRC serac CX, vittora XL or XG TNT, Kenda, Maxxis or Hutchinson.

I have Reynolds R29 XC disc wheels with IRC serac CX's on them and there is no way they are going to burp. We dropped the tires to 10 psi and pulled them around the rim, so that the bead even broke free into the center channel, and they still didn't leak any air.
 
#26 ·
Kenda uses UST (for the UST ones) and SCT (Sealant CompaTible) designations.

Kenda SCT is more like Specialized 2Bliss (and 2BR on the older Captain tubeless compatible)

Specialized has for MTB, UST-specific also

there is a difference between 2Bliss/SCT and UST. They just have the extra butyl layer for the bead and the casing is compatible with sealants. ... the extra butyl layer usually does not require an extra rimstrip.

UST was originally designed to not use sealant. (however, people do use sealant as backup protection for punctures).
 
#27 ·
ok, thanks. I have a guy building up some panceti rims and I'll maybe try the XL tire and figure I can grab my fango tubulars when it's dry and have my bases covered. If I have success with tubeless I hope to phase out the tubulars, though I have said that before.

I used my PDX with tubes in a gravel road sort of event last sunday and got a pinch flat 5k from the finish and rode the thing in on the rim. I doubt a tubular would have flatted and I suspect I could have rode faster on a flat tub, but who knows.
 
#31 ·
I have a set of Rol D'Huez that are tubeless compatible on the way. Got them custom built 24/28 2X front/rear.

From my experience, and my experience is with the mountain market where I've been running tubeless for about 12yrs now. To the point where I make my own sealant, and don't use traditional tubeless tape.

The UST bead is a square type bead, where most tires are a traditional round bead. You shouldn't see any compatibility issues, but there shouldn't be an incentive to explicitly search out something with UST. In the mountain bike world, nearly every tire can be set up tubeless whether they're tubeless ready or not. Wire-bead tires need not apply, but it 'can' be done.

Personally, I'd personally stay away from Ultegra wheels and Shimano hubs in general. They don't use full cartridge sealed bearings and require preload adjustment. If you're wanting something that you don't have to fiddle with, you may look elsewhere.

If you have a disc frame, you have loads of options since you can basically mount any mountain rim onto your hub and set it up. Now as far as a static 35 PSI?? Well, consider your tire and terrain, its not that simple. Different tires with different castings support the tire differently. So you have to kind of "feel" that out as far as finding a point to run as low as possible where you don't have to deal with burps or rim strikes. To add to that, understand WHY a tire won't stay on certain rims. It has to do with bead depth and how the bead grabs and supports the tire. Some rim designs are superior to others..they aren't all the same!

Don't go into it ignorantly, you're talking about one of the most important factors of a bicycle, and you're talking about racing.
 
#32 ·
Yes, shimano is still old fashion with their bearings. But they aren't exactly known to be unreliable

Pressure... Also depends on your weight.

I just use Stan's formula as a starting point: your weight divided by 7
Add 2 for the rear
minus 1 for the front


That means around 30 psi rear & 27 psi front
 
#33 ·
Very true about reliability. I can't argue that....just not a fan. I have 4 bikes, and my girlfriend has 3. The more stuff that's maintenance-free, the better! And not much is more annoying than feeling that play in the hub.

That equation is really a baseline if I'm not mistaken. It's worth a shot, but you have to consider the suppleness of the tire! Also heavy, saddle-planted riders will not find good results from that (like my girlfrind...well not the heavy part, but I swear she has a saddle magnet in those buns!)

She'll probably see this later, she snoops my stuff :p
I sleep better on the couch anyways, her farting doesn't keep me awake! :p
 
#34 ·
Like I said... It is a STARTING point using Stan's formula

To get 35 psi in the rear, you would have to weigh 230 lbs
 
#35 ·
So I ended up with a guy building me up some Pacenti sl23 on some 32 spoke ultegra hubs I already owned. I applied a layer of the stans tape and the PDX's went on way easy. My compressor is on the fritz and the floor pump did not work, so I'm sort of in limbo until it comes back from Home Depot repair.

Is one layer of taper generally enough? I put the tape on then installed the valve next, is that the correct way?

If the PDX do not work out, what would be a good reliable muddy day sort of option that still rolls ok, the Michelin mud perhaps?
 
#36 ·
If I were to make a suggestion, don't use Stan's tape. It has weak adhesive, and if you get bubbles you will eventually end up with sealant that creeps under and into the rim and out the spoke holes (non-UST rim).

My suggestion is Gorilla tape. It has a much stronger adhesive, better seal and in my opinion it grabs the tire better. On top of that, its significantly cheaper and easier to work with. Also it is what ENVE exclusively uses/recommends on their rims.

I've been using tubeless pretty much exclusively since 2002 with my first pair of XM819s. It had already been out for a while, but the new tech skepticism kept me from earlier adoption.

I've been using it for a few years now, and to me..it's superior in every way, and if the chance that you dislike it....you have nice little roll of good utility tape for various uses.

Also, there is more to UST than an "extra layer of butyl rubber" The tires are thicker, yes, and subsequently heavier. More to the point, the definable difference between Tubeless-ready and UST is the bead. Rather than go into a long spiel that people will inevitably take as my opinion because they have their own preconceived notion of fact....

Pink bike says it best.
To The Point - UST Rims and Tires - Pinkbike
 
#42 ·
I have several wheel sets that I'm running tubeless with CX tires. The rims are Mavic CXP 22s and Velocity A23s. None of these are tubeless-specific rims. I've never had issues with any of them while racing or while riding my CX bike off-road on moderately rough mountain bike trails. The tires I've used are Mich Mud 2s, Kenda Happy Mediums, and Continental Speed Kings (none of which are tubeless-specific tires). I typically run 24-28 PSI (I weigh around 185). The key, I think, is to build up the inside of the rim channel with strapping tape, Gorilla tape, and/or Stan's rim strips enough that the tire's bead doesn't want to slide back down into the rim channel. I also put in quite a bit of Stan's sealant initially (1.5 cups per tire) and then let the inflated tire 'cure' for several days, turning it from one side to the other every time I think about it. We have a lot of mesquite, cactus, and rocks in my region so the tires get abused quite a bit. IMHO, tubeless is the only way to go :)
 
#43 ·
This is a great post with plenty of good advice. I've run Mud 2 tubeless with A23 and a rubber rim strip, and I had no burping issues around 32 psi. I did, however, rip a sidewall. :(

Let me just add two things:

1) Once you get the tubeless setup up inflated, go out and ride it around the block, do some bunnyhops, off the curb, etc. This will help get the sidewalls sealed up, because you're sloshing around the sealant.

2) The Clement clinchers have little ridges on the bead, and I think that makes it difficult to seal in some situations. For ANY tubeless setup, it won't hurt to apply a couple coats of Mastik to the tire bead, a couple to the rim hook, and let it dry for 30 minutes or so, before mounting. Inflate and when you've checked both sides 360deg for proper seating, you can either add sealant through the valve or, even better, let the setup cure overnight first.
 
#48 ·
I rode the tubeless this week in a rooty rocky MTB training race, running the Conti mud tires (the new tubeless model) with some sealant and maybe 25 psi. They felt soft but took some big hits without burping and the wheels held up great. I really like the ride and traction of this setup so far Bicycle frame Tire Bicycle wheel Bicycles--Equipment and supplies Helmet
 
#49 · (Edited)
I rode the tubeless this week in a rooty rocky MTB training race, running the Conti mud tires (the new tubeless model) with some sealant and maybe 25 psi. They felt soft but took some big hits without burping and the wheels held up great. I really like the ride and traction of this setup so far
Nice, what was the final set-up? Shimano Tubeless wheels? Which sealant?

Are these the tires?
 
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