Sunday, March 10, 2013

The rubber hits the road, if I can get it to hold air

I'm just about ready for my first training ride with the Racing Greyhounds. All I need is some air.

I have to say right up front I love my Stan's NoTubes. I converted two bikes to tubeless last year - my Giant Anthem X 29er 2 (Schwalbe Racing Ralph tires/Giant S-XC29-2 rims), and my wife's 26" Giant Anthem X1 (Kenda Nevegal/Mavic 117 rims). It only took about an hour to convert both bikes, including drilling out the valve holes per the instructions and installing the rim strips. I used an air compressor to get the beads to seat initially - I'm not sure how you get air in fast enough to seat the beads with a floor pump.

Both bikes ran great all summer - no flats, minimal air loss between rides, and I never even had to add more sealant. Perfect! I didn't notice that the wheels felt lighter, but I did notice that my bike really responded well to lower tire pressures - 25psi front, 30 rear and I'm a Clydesdale. Lots of grip, better suspension feel in long fast sweepers, and it never felt mushy or like I was losing much straight line speed due to low pressures.

So last night when I started to change my worn out rear tire, I thought I'd have it done in 10-15 minutes and have plenty of time to put in some time on the trainer. I was wrong! After 2 hours of coating me, the garage floor, and everything else in the area with Stan's Sealant, I gave up. I'm sure it's not the fault of the tires, the rims, or the NoTubes conversion - I was using the same rim, same make/model tire, same technique. The only thing I can think of is that it's about 50 degrees colder than when I did the job last summer, maybe the rubber is stiffer and not as compliant?

I also noticed I wasn't getting much air into the tires using the presta-schraeder adapter and the standard schraeder value chuck on the compressor. The presta core just wasn't getting enough force on the valve in the schraeder chuck to open it all the way. And the one time the tire actually beaded, I let all the air out when the valve core came off with the adapter. So the adapter (which works great for bike pumps and CO2 cartridges) had to go. One trip to Home Depot later:

  • Workforce Dual Foot Inflator and Gauge
  • 1/4" Male NPT compressor barb
  • 1/4" Male NPT to 1/8" hose barb (would have liked a female version, but Home Depot was out)
  • 1/4" NPT Union (no need if you get the female version of the 1/8" hose barb)
  • Short piece of 1/8" hose and Presta/Schraeder pump head (scavenged from an old floor pump)
  • Hose clamp
  • Teflon tape
I'm not recommending you actually go out and make something like this. You should go buy Park Tool's very nice shop inflator, even if it does cost 4-5 times as much as my homemade version. If you do make one of these, you're on your own - don't come complaining to me with your remaining fingers if something goes wrong.

I do recommend getting a good air pressure gauge if you're running pressures this low - the gauges on my floor pumps were pretty inaccurate and inconsistent this low in the range. If you're off by a pound or two on a 110 psi road tire, no big deal. A pound or two at 25 psi makes a big difference! This SKS gauge from REI works well for me


The whole point of getting the bike ready NOW is that tomorrow (Saturday) is my first planned ride with the Greyhounds. Livonia to Ann Arbor, do some hill repeats, stop at Zingerman's Deli to regroup/refuel, then back to Livonia. 50+ miles. On mountain bikes. In March. I don't think I had 50 miles total on in March last year. Next week, the regular Tuesday road and Wednesday mountain bike training rides start up. Daylight saving time starts this weekend, so there's more light in the evening to ride. Time to get out of the basement!

Race season is coming.


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