Saturday, October 31, 2009

SASS meets 650b

I finally got the funds for a wheelset. Since I already have a a rigid Single Speed Bonty Conversion , I wanted to do something to make the SASS unique. My decision was to go with a 650b (27 ½”) wheelset. The SASS has a lot of room for big wheels/tires; the bike comes stock with 2.40 tires. My criteria for the wheels besides 650b, was the rear had to be both disc and rim brakes compatible (needed for a flip flop hub and drilled cog) and the front just disc compatible. I looked around for a wheelset under $500 and found only one; the Stan's NoTubes 355. My other choice was to build a wheel with Velocity Dyad rims and a Shimano Deore or XT hub. I decided on the Stan's wheels, which with ZTR hubs (re-branded WTB Laser-lites). The next decision was tires. I found a bargain on Kenda Nevegal 2.35 and went also for the folding bead.

About a week later the big brown truck showed up with the wheels. Almost all new wheelsets look nice, so I won't bore you the owws and aass. Two issues I had not thought through and they involved the hubs, specifically the rear hub. First the hubs are not easily converted to a solid axle and the freewheel shell is aluminium. After I mounted the rear wheel I found the outside cam QR that came with the wheels, could not hold the wheel in the sliding dropouts. I switched over to a Shimano (interior cam) and it seemed to hold. However, now I didn't trust a QR, so I added a Surly Tuggnut tensioner to be safe; I also later upgraded to a Surly BMX cog with a wider base. I first mounted the tires with tubes and went for a ride; it was like magic. So nice, I realized it was also the weather and trail conditions, not just the new wheels. Still I liked the bigger wheels. For those of you that need to know such things; the bigger wheels fit the SASS frame perfectly and resulted in a 11 1/2" bottom bracket measurment.

Once back home, I got the idea of converting the wheels to tubeless. The Stan's wheels are obviously made to be tubeless, but there are no tubeless 650b tires as of yet. However Stan's has advertised from the beginning, to be a means of converting standard tires and/or rims to tubeless. They sell a spoke tape and rim-strip for this purpose, along with their sealant. The Stan's rims come with their version of spoke tape, and their “Olympic Valve stem”, which is a stand alone valve stem, designed to work with just the spoke tape (no rim strip) . The Stan's web site said most applications using the Stan's rims, work with the spoke tape and Olympic valve. Kenda tires are on the Stan's recommended list, it also recommends wire bead tires, especially for 29er tires, but with the exception of Intense, IRC and Hutchinson (they also recommended to my riding buddy, not to use WTB 29er) tires, most standard tires should work; so I figured the Nevegal's folders should work.

I first tried mounting the tire with soapy water and a floor pump; that did not work. I do not have a compressor, so I went to a gas station and used the tire “pump”. The first station's pump did not have enough air volume to work. I went to another station (across the street), which was a little better. I still had to use the pump is short bursts so it could build up pressure and volume. After 3-4 bursts, the tire sealed enough to start filling up the tire and you could hear the beads snap into the “bead socket”. Okay, that worked, but I still had to pour in some Stan's sealant. I returned to my house, deflated the tire and broke the seal on one side. I then poured in the sealant and took some time nudging the loose tire bead onto the “bench” (the flat area that divides the center spoke groove; Stan's rims have a wider benche than other rims for better sealing). I used my floor pump with about 5-8 quick pumps and the bead sealed; a few more pumps and the bead seated. I mounted the other tire much the same way, using a tube to seat the tire before I poured in the sealant. I pumped both tires up to about 40 psi.

My next ride was at Wilder Ranch; the Eucalyptus and Enchanted loops. This may sound over the top, but I now can not understand why anyone that rides with a rigid fork and can afford them, does not use tubeless tires. The combination of the 650b and tubeless, smoothed out the bumps, holes and roots to a new level; even technical climbing was easier. I have previously tried running standard 26" 2.30 Hutchinson Pythons @ 30 lbs with a rigid fork and front end wallowed badly. There was none of that with the tubeless.With the rolling nature of the 650b and the suppleness of the tubeless, I now have to reset my limits with a rigid fork. Another way to explain it is, it's like the wheels now have a dampener. I'm faster, with a smoother ride, more in control, and climb technical sections with less effort. OH BTW I tried to drill a Shimano BMX cog to mount on a disc hub, but a cobalt drill wouldn't even leave a mark; I have since ordered a Tomi Cog.. Hmm, but you no what? I think I need more riding time. I'll get back to you...But when it comes to mountain bike wheels and tires I am now spoiled. Damn.

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