RubeRad

So mtbers who go tubeless, do they just never change their tires? I get that with good sealant, puncture flats should disappear, so they shouldn't have to take tires off as often as I do, but still, what if they just want to try out a different tire? It seems like due to the hassle&mess of tubeless installation, you put a tire on, and leave it on until it's ready to throw away.

Also, I've crashed my (tubed) hardtail due to underinflation; tire couldn't handle a right turn out of a downhill driveway. I don't think the bead broke, but there was just insufficient rigidity in the tire overall to handle the sideways load. Doesn't that same thing present a problem when running lower tubeless pressures? Or are tubeless-specific tires lower-profile, so the sidewall is not so tall and sideways pressure doesn't have as much leverage?

Right now my do-almost-everything bike is a 60cm crosscheck wearing 700x50 marathon supremes on velocity dyad rims (24mm width). I'm 250lbs. When I 'pump up' the tires, it's 60rear/40front, and it rolls really fast. If for some reason I wanted to convert that setup to tubeless (which I don't think I want to), would it work? Would I just run it at a super-squishy 30/20 or something since I wouldn't have to worry about pinch flats? Or maybe up to 60/40 for low rolling resistance on the road, but drop it for trails?

fietsbob

Not Me. But I Read CX racers trying to go Toobless, Burp all the air out in corners .

The real racers Pros, use glued on Sew ups which have a Tube. UCI legal maxes out at 33mm

RubeRad

Why would UCI enforce a max width -- does it get unsafe (roll-off hazard) if it gets wider?

dsaul

Tubeless specific rims have a bead shelf that the tire bead pops onto upon inflation. This bead shelf mostly alleviates the problem of burping or rolling the tire in a turn, unless you're running stupid low pressures. A tubeless setup on a standard rim will suffer from burping or rolling the tire at low pressure.

dabac

Several of the sealants needs regular topping up anyhow, so if you manage to time your urge to try another tire until "refill time" comes around, there isn't much mess. But I'm sure the size of the task might not look the same to all.
And, along with Dsaul's comments, all rims are not created equal. I've got some Weinmann rims I wouldn't even consider for tubeless. My Stan's though doesn't give any concerns.

Leebo

The mt bike tubeless standard matches the rim to the tire bead. The tires have stiffer sidewalls allowing lower pressure. Usually I just change my tires out in the winter for studded tires. Crosscheck tubeless? maybe. How are you going to seal the rim? Rim tape? I think some people have had good luck with the almotion from schwalbe for tubeless. I'm still waiting for some good tire/rim combinations for good commuter tubeless options.

RubeRad

IF I were to try tubeless (on the CrossCheck or a mtb), I would try this ghetto DIY method with gorilla tape and homebrew sealant.

Willbird

I'm picking up a bike with RS11 wheels, I can't find a pic online but print articles say spoke holes are not drilled through. Billed as tubeless ready, 2014 Cannondale evo. No Rim strips needed :-). They have straight pull spokes.

Kopsis

The intent of the rule is simply to preserve the challenge and character of CX racing. Part of the "sport" of CX is the difficulty of handling a technical off-road course on relatively narrow tires. Whether the rule actually helps the sport or is even needed is open to debate.

RubeRad

I'm trying to picture this; spoke holes not drilled through, no rim strips needed, so the inside of the rim is a solid metal channel? How did the nipples get into the wheel?

Kopsis

Unless you're really clumsy, it's not all that difficult or messy. On narrow tires, you only need to run an ounce or two of sealant (four tablespoons). Let the wheel sit overnight so the sealant collects at the bottom. Break the bead at the top and work down. Once one bead is off the rim, simply pour the sealant out. Wipe down the inside of the tire with a rag, then finish removing.

Mounting (assuming you have the right tools and a properly designed rim/tire combo) isn't any more difficult than mounting clinchers. Sealant goes in after, so there shouldn't be any mess at all.

RubeRad

That makes sense

Darth Lefty 

This is part of the UST standard, which is designed to work like car or motorcycle tires that pop onto the rim without sealant. The wheels have a special interface at the spoke holes, and a special hook edge, and a shallow channel with a deeper section in the middle that helps with seating on inflation. The tires have special construction that includes some features for not having a tube, and some for sealing.

More typical is a "tubeless-ready" wheel with a UST-standard bead and channel, and regular spoke holes, and a strip of tape to simply seal all that stuff; and a "tubeless-ready" tire which has the bead and the construction but needs sealant.

Nice article with details here:
To The Point - UST Rims and Tires - Pinkbike

And more
https://www.schwalbetires.com/tech_info/tubeless_ready

Willbird

I was trying to picture it myself :-)......did not find any images online that gave details :-). The link posted is interesting and helps answer some questions anyway :-)

RubeRad

Ah, that first link shows nipples (or spoke heads?) that screw into the rim.



Darth, that's a good explanation. I never realized before that "true" tubeless doesn't even need sealant, they're just like cars.

Marcus_Ti

Some wheels like Campag use a magnet and a temporary steel thread insert for the nipple...and drop in the valve stem hole...guide into place with the magnet

Looigi

If only.

alcjphil

When I bought my Shamal 2way fit wheels they supplied the temporary steel insert and a magnet to be used in case a spoke needed replacement. I have been running them for the last 4 years without sealant. Using road tubeless tires, they don't lose air any faster than a conventional inner tube

Leebo

Break the bead and pour the sealant out? Not how I do my mt bike stuff. This for some road setup? I never break the bead to add sealant, just unscrew the valve.

RubeRad

we're talking about swapping tires, not just topping up sealant.

Willbird

So as far as lower pressures go, if you ran a latex tube with a tubeless spec tire and rim, could you run the same low pressure as tubeless with sealant ? Weight and ride feel might be similar ?

alcjphil

I suppose that you could, but there would be a far greater chance of pinch flats with any inner tube. Tubeless tires are far less likely to be affected

hig4s

I just watched this, seemed pertinent. https://www.youtube.com/watch?v=Q89N...ZPFn2guv-A2_JT

Willbird

Yes that makes sense about pinch flats, I was overlooking that aspect.

Marcus_Ti

Thing to remember with riding those delicious low pressures tubeless, you won't pinch flat, sure. But in place of killing a $5 tube, you can instead kill a $100-200 rim (depending on make/availability). Which would you rather have?

I say this as someone who has ridden tubeless and needed to dremel my rims due to a speed bump in the dark and bottomed out.