Thursday, June 23, 2011

Some More Great Road Tubeless Tips


I have been using Stan's valves since they came out for road. They have had the rectangular rubber plug at the end. Recently, I actually pulled the valve through the hole into the cavity between the walls of the rim. The only way to extract it was to actually drill out the rubber!

Now, I have noticed that Stans is now shipping valves with round rubber plugs. This seems like a much better design, as I had always had issues with trying to get the bead around the rectangular plug.  Invariably, tightening the nut would cause the rectangle to rotate, making it even more difficult to seat the bead. Frankly, the only problem I have with these valves is their cost. At $8 each, I have yet to see the justification for a valve costing twice as much as an entire tube.


The other day, I had a puncture of my Hutchinson Fusion 3 Tubeless tire. Stan's sealant squirted out until about half my pressure was gone. Re-inflating it was no help as it would continue to leak down to about 50 psi. This would have been fine for an off-road application, but it was marginal for road riding. I was able to complete my ride, albeit cautiously.

Later, I was able to re-inflated it to full psi, only to have the leak re-appear one minute into my next ride. At that point, I did the unthinkable and utilized my spare tube. At the very least, it gave me the opportunity to note the poor ride quality of a tubed tire, something I had not experienced in some time.

The moral of the story is that you need to apply a tire patch to any puncture large enough to visibly leak sealant. Sealant is, at best, a temporary solution.

Rim Joints

For the birthday of a good friend, I decided to upgrade him to road tubeless. Frankly, I was tired of sitting on the side of the road fixing his flats when we rode. Unfortunately, his rims were pinned, not welded. As in the past, I have had trouble sealing these rims. Surprisingly, one of the two sealants I have tried failed to seal the rim. I tried the other and it worked.  The key was continuous air pressure from a compressor while shaking the rim with the joint side down. I did this while immersing the joint in water so I could visually detect the minute leak. I took about two minutes to seal.

Which sealant worked and which did not? Stay tuned to this blog to find out.

Thursday, June 9, 2011

Why Pros Don't Use Tubeless

Lennard Zinn at Velonews is a tireless advocate for road tubeless. This week, he answers a reader's question about the relative lack of road tubeless on the Pro circuit.  It turns out that it comes down to several factors. Pros depend on sponsors, and there really aren't many road tubeless wheel and tire manufacturers out there that are ponying up the sponsorship bucks. Also, they are weight weenies and carbon tubulars will always be lighter than clinchers of any material. He also cites tradition. Frankly, most pro teams are very conservative when it comes to revolutionary new technology. Pros were slow to shift from steel to titanium and carbon as many consumers were using these frames before the pros. LeMond's famous use of aero bars to win in the 1989 Tour de France in the final time trial is another example. Fignon lost because he wasn't interested in the aerodynamics at a time when even recreation riders like myself were using aero bars.

On the other hand, think about what it means to be a pro. On every ride, be it a race or even a training ride, you have a team car following you with not just spare wheels, but entire spare bicycles. It must be nice. Me, I set out on 6-8 hour rides deep into the Colorado Rockies. I could see snow in the middle of summer riding hours away from the nearest bike shop. Do I really want to carry a spare tubular tire? Do I want to make the bet that one will be enough? With tubeless, I carry a spare tube that I can go years without using. Should my spare fail, I can fall back on another rider's tube. I also can't afford to replace an $50-$100 tubular tire should I get a flat.

In conclusion, tubulars are a great option for people who are followed around by a support vehicle. For the rest of us, you can't beat tubeless road tires.