Wednesday, August 23, 2017

Going Tubeless for Absolute N00bs

There's a running joke in the local women's cyclocross scene regarding my riding style: I'm like a bull, strong but completely lacking in grace. This came about after numerous pinch flats and a fellow racer suggesting that maybe I should learn how to ride (she put it more graciously . . . I think she used the word "floating"). But I proved last year that if there is a rock, root, or sharp drop-off from pavement to dirt I will find it, bottom out, and pinch flat by riding the least graceful possible line. This is one of my opportunity areas this season; I'm working on it.

But while I'm working on my ability to float around the course while bleeding out of my eyeballs from the effort of producing my modest wattage, I also switched to a tubeless set-up. The bike I bought last year (2016 Specialized Crux) came with tubeless-ready wheels and tires. So last November I went to my LBS, bought some Stan's NoTubes sealant and valve stems, and headed to my basement shop to set myself up for a pinch-flat-free existence.

Four hours (and four days, TBH) later I was ready to pull my hair out.
These instructions . . . are not very helpful.
The only thing I've experienced in home bike maintenance more frustrating that trying to seat tubeless tires is internal cable routing. I have ultimately figured both of those things out. But as I've just mounted new tubeless tires for the season (I've been running tubes in the off season), I'd like to share what I've learned through hard-earned experience (and through asking friends on Facebook).

I'm assuming that you already have tubeless-ready rims. Tubeless rims are designed with an extra secure interface for the tire beads so they'll hook in as securely as possible. They also need to be prepped with special rim tape to keep air from leaking through and to get the beads of the tires as close to the edge of the rim tape as possible. If you don't have tubeless-ready rims, there are conversion kits and ways to DIY them. I've never tried either, and your mileage may vary. My bike came with tubeless ready wheels, and these are the steps I followed to mount them (successfully) this second time around.

  1. Stretch the tires. When you get new tires, they come all folded up, right? We need the beads to lock into the rims as tightly as possible, and folds in the beads will prevent that. So before you add sealant or soapy water or do any inflating, first put the tires on the rims and let them sit there for at least 24 hours. I go a step further and put them on the rims with CX tubes (fatter than road tubes in them) with relatively high pressure (60-80 PSI) overnight. Inflating tubes in the tires will get one side of the beads to seat in the rims right away, and will stretch the tires out so they'll lock into place more easily. I speak from experience when I say that taking the step of stretching the tires before you do anything will save time and frustration. And sealant. After letting the tires sit like that overnight, unseat one side of the tire and remove the tube. Note: Be very careful if you're using tire levers to remove your tires! If you slip with the tire lever, you can damage the rim strip and ruin the interface between rim strip, tire bead, and rim!
  2. Install valve stems. Use a pair of pliers to screw the nut on as tightly as possible. That will pull the rubber part of the valve stem deep into the rim and help plug the valve stem hole more completely. These are a pain in the butt to get out, though.
  3. Add sealant. If possible, hang the tire so it's suspended with the valve stem at the bottom. Seat most of the tire bead around the rim but leave a gap down at the bottom where the valve stem is. Pour sealant into that gap (directly into the tire) then carefully turn the tire so the valve stem is at the top and finish installing the tire on the rim. I get the big bottle of Stan's NoTubes sealant, but they also sell a smaller bottle (theoretically enough for two tires, but I'm skeptical) designed for putting sealant in through a removable valve core. If you want to go that route, you remove the valve core (there's a special tool for that, but you can use a pair of pliers if you're careful) and squirt the sealant in through the valve stem. Having the valve core out also makes inflation easier, because more air can get in through the valve stem than through the valve core. Which brings us to . . .
  4. Inflate. This is where stretching the tire should pay off. Ideally, you use an air compressor for this step (you'll need valve adapters, probably), or one of these double-barreled floor pumps designed for seating tubeless tires. I've seen people recommend using a CO2 cartridge to quickly seat tubeless tires, but CO2 gets really cold inside the tire. It can freeze and break the beads (although that's the method advocated on the packaging of my Hutchinson tires, so maybe it varies by tire bead material). If all you have is a track pump, remove the valve core and pump as fast as you can. The principle here is to get as much air into the tire as quickly as possible so the tire expands all over and the beads push into place. If you're having trouble with this step, try using some soapy water (dish soap works fine) with a rag and wet down both sides of the tire. Not sure if it's lubrication that makes this work or if the surfactant in the soap changes how much air can escape, but it's a common trick to get tire beads to seat. Soapy water will also show you where air is escaping. I've also been able to sort of pull the beads into the rim with one hand to help ease the beads into place, but that only works if there are a few gaps. If none of these tricks work, I recommend walking away and having a drink or two then coming back and trying again. Or giving up and finding a new sport. If this ever turns into a blog about curling, you'll know what happened.
  5. Spin, slosh, and shake. Once the beads have seated, you need to shake the wheel around so the sealant sloshes into all the nooks and crannies. Shake the tire in every direction you can think of. Hold it in front of you like a steering wheel and push and pull it vigorously. Steer it side to side. Lay it on its side and spin it, then flip and repeat. Bounce it up and down. If you're losing air mostly out of one side, let the tire rest horizontally, that side down, so the sealant has time to flow into that side of the wheel and seal all the holes. At this point, I would lay them both horizontally (cardboard boxes work well for this purpose, so that the cassette/disc/end caps of hubs have a place to sit) and walk away for a while. Come back after a couple of hours and flip them over. Leave them overnight. Go to sleep and pray that they still have air in them when you wake up.
  6. Ride and check. The next day, assuming they still have air, inflate them to a little higher pressure than you'll normally ride them and go for a short spin. Check the air pressure carefully (digital gauge helps) before and after your ride.
Talking to a teammate/ex-mechanic, it seems like some tires hold air a little better than others, probably down to casing material; a more supple casing will deform better and give a smoother, grippier ride, but it will also be more porous. I had a helluva time getting my Specialized Tracers to hold air last season, but the Hutchinson Toros I'm running this season were no sweat. I'm probably better at the tubeless process, but I think the tires are easier, too.

If you're still having trouble with the tubeless thing, you can always just run tubes with some sealant in them. Or you can take them to your local bike shop and have them install them for you (although that costs more). If you have any questions, leave them in the comments below and I'll try to get back to you. Or visit my Facebook page and ask there! Good luck!

Update (8/29/2017): A teammate of mine (whose cross racing palmares are extensive) offered these extra tips:

  1. Unless you really know what you're doing, don't try ghetto tubeless. Get tubeless-ready rims and tubeless tires. I know people who have made it work, but if you're an absolute n00b you probably won't and it will just frustrate you and drive you nuts.
  2. Ride your wheels right after you first get them to seat and inflate. That sloshes the sealant around and lets you know right away if they're holding air (or not).
  3. Eric seconds the recommendation for the Bontrager Flash Charger pump (one of the double-barreled floor pumps) and recommends using an air blow gun with a right-angle Presta chuck (often called a "crack pipe" adapter) if you have access to your own air compressor.
Additional note: I know that tubulars are better. They are also more expensive. Please don't leave comments explaining to me why tubeless is worth it because tubulars are so much better. This post wasn't for you.

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