Tubeless Blues

Chazmo said:
rim tape? I dunno, Jeremy.

Am I wrong about the cutouts? Look closely at the bigger picture. Are those not trapezoids? Is this not common with fat tire wheels?

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Yes, cutouts are common in fat tire rims, but I've always assumed those rims were for tubes. And I see the trapezoids, but are they all the way through? Also much larger the individual openings I'm used to seeing in fattie rims. Seems like that would put a huge burden on both the rim tape and the remaining metal.
 
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Mr. Coffee said:
What I'm noticing is this:



That doesn't look like a trapezoidal cutout to me.

99 percent of the tubeless issues I have had have either been from poor rim tape installation or the valves. Even bike shops with competent techs might take a couple of tries to get the rim tape installation just right on a wheel, especially a rim they haven't worked with before.

Valve placement is tricky because having the lock nut either too tight or too loose results in sealant leaking. Also some pumps (Lezyne) are really efficient at unscrewing the lock nuts when you remove the pump. My least bad solution for this is to have two or three lock nuts on each valve to keep it in place. I might also consider weak threadlocker on the nuts but haven't gone that far yet.
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One thing I got right every time is rim tape. I used the DT-Swiss as it has a little stretch, and it was pretty easy to get right. But valves were a battle. But don't use lock-tite, or it is a battle to get the nut off the threads are so fine that anything in them makes it super hard to remove (dont ask me how I know this) but two nuts work pretty well.
 
Stefan Mikes said:
A fat bike rim is huge. If it were solid then it would weigh (figuratively speaking) tons :) Therefore, a fat bike rim has trapezoidal cut-outs to reduce the weight.
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FYI, mine doesn’t have the cutouts, but that’s what I thought… pretty common.
 
I just want to mention a fat bike rim with cut-outs easily holds a thin TPU tube so why shouldn't it hold a good rim tape?
 
Stefan Mikes said:
A fat bike rim is huge. If it were solid then it would weigh (figuratively speaking) tons :) Therefore, a fat bike rim has trapezoidal cut-outs to reduce the weight.
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Understood. My mistake was in thinking that the cutouts forced them to use tubes. Apparently not.
 
Stefan Mikes said:
Please watch this video first:

Ollie said, among others, something like that: 'So you have installed tubeless on your first wheel easily and then you try to do it with the second wheel...' :D
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I hadn't known the Bike Farmer to swear until a customer talked him into installing tubeless tires. I believe he calls them a custom hack. He says bike mechanics often refuse to perform custom hacks because they aren't worth the hassle.
 
The cost of tubeless can be high. Luckily, we had tubeless rims already. After a year or so working out my bigs, they work pretty well, but we ride all of the time. I have been using Peety's sealent, it seems fine, but last winter I had several cuts that would not seal or would keep leaking even a little. So I wonder if I should change brands for winter? But it does nto seem to dry out and is easy to clean compared to most. It's more like stans, but you can use CO2.it can also make a lump of the fiber they use and plug the valve at this base a little bit. When I took a tire apart, I finally saw what was blocking the air from coming out of the valve, a little ball of the sealant and fiber.
 
For all of the caterwauling about how awful tubeless is, I'd guess that seventy percent of the cyclists I see around are riding tubeless. Probably the big exception is road cyclists on very skinny tires with very skinny wheels and high tire pressures.

Especially for bigger tires the weight savings from tubeless can be quite dramatic and make it like you are riding a much zippier bike. And the fact that you can fix 99 percent of punctures without removing your wheel or tire.
 
You do have to replace the sealant often and if you pop the rim seal on a mountain trail, you'll be very lucky to get it back on.
All my friends carry two spare innertubes and boy can it be messy getting them in.
Ive had lots of success in the past with car emergency sealant cans.
 
Is sealant significantly lighter than water? Or do people just put in a fraction of what sealant companies recommend?

I'm not sure the claims of weight savings hold water, or air, unless you assume everybody with tubes buys the cheapest, heaviest tube available.

My lighter bike has Pirelli 700x30 tires which I guess are probably considered skinny by anybody not riding a road bike, though any roadie with a nice bike more than a few years old would consider them chunky. These come in a tubeless ready version and a tube-only version.

260g Pirelli P Race Zero (tubed version)
36g TPU tube w valve stem
296g total weight

335.0g Pirelli P Race Zero TLR
52.5g sealant (interpolated from Stans recommendations for 28 and 32 tires)
7.5g valve stem (5-10g range)
395g total weight.

Same scenario plays out on my bike with 27.5x2.xx tires. There aren't many tires made in both tubeless ready and tube only versions (outside of road tires), but where there are the TLR versions incur a substantial weight penalty.

But yes, if you have a bigger tire and you use the extra thick 'puncture resistant' butyl tubes then you probably could save a lot of weight by switching to tubeless. Pretty good chance your wallet is just a tad lighter as well.

None of that is to minimize the puncture sealing advantage. But when compared to a modern tpu tube I don't see a weight advantage, and the comfort and rolling resistance advantages are not nearly as B&W as typically portrayed.
 
For the fat tire riders out there, I am considering getting studded tires for next winter’s trail riding. I think I’d stand a chance on thin ice, although I’ve already learned my lessons many times on my old 2+” MTB so I’m hesitant to even brave it…. Anyway, I’m not sure I’ll do this, but my question is is there any advantage/disadvantage to going tubeless with studded fat (4”) tires? There’s a potential that I’d ride at lower pressure than the 35-40psi that I have always used with Fättie’s tubed RST tires (which have been terrific, by the way). Does lower pressure (say under 20psi) work better with tubeless or tubed?

@Chargeride do you drop pressure when you’re riding in sand, etc..? Just looking for some experienced opinions.
 
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BlackHand said:
Is sealant significantly lighter than water? Or do people just put in a fraction of what sealant companies recommend?

I'm not sure the claims of weight savings hold water, or air, unless you assume everybody with tubes buys the cheapest, heaviest tube available.
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I'm running fatter tires than that, and generally I'd say that with any 30mm tire or skinnier tubeless is of very questionable utility. The whole system works better at lower tire pressures on the average.

The weight savings can be dramatic for not just fat tires but even big 29x3 tires.

Oh, and generally the sealant "dries out" not by evaporation but because the sealant reacts with oxygen over time. That's part of the magic of the system the sealant tends to stay liquid until exposed to the air -- like when the tire is leaking.

 
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