Monday, July 25, 2011

Contador Punches Spectator

This doesn't have much to do with tires, but I liked this picture. Remember, cycling is the only major sport where spectators are actually allowed on the field of play!

Wednesday, July 20, 2011

Tension Adjustments On Tubeless Wheels

I recently heard from some readers across the pond at Strada Hand Built Wheels. They wrote me the following:

Hi Jason

We have just built our first pair of wheels using the NoTubes ZTR Alpha. We
had some issues getting the tension right as when the tyre air pressure is increased to riding levels the spoke tension drops away as it compresses the rim. Increasing the tension further just stretches the alloy round the spokes holes.... Any advice on building with these or can you refer us to anyone with experience please?

Kind regards,


Jonathan Day

Web: Strada Hand Built Wheels

Not having noticed such a problem, I forwarded his comments to Velonews's esteemed technical editor and tubeless expert, Lennard Zinn. He was kind enough to reply:

I haven't checked spoke tension on the A340s since putting road tires on them. At 28psi with 'cross tires it wasn't an issue.But yes, we always notice a decrease in spoke tension with tire inflation. Eaton, for instance, builds the rear wheels off dish so that when the tire is inflated the dish is correct.

Lennard Zinn

Eventually, I heard back from Jonathan over at Strada:

Here are photos [above] from recent builds including these ZTR Alpha rims onto our own label hubs. These were built for a light climber who wanted to try a tubeless setup. He completed the Marmotte 2011 on them which is great. Getting the spoke tension right is tricky and we have decided to sell them only with a new pair of Hutchinson Fusion 3 tyres fitted so we can tune them with the tyres on to ensure the best finish.

To be honest, I still don't know what to make of the whole spoke tension issue. I have now converted at least eight different road wheels to tubeless over the last five years, but none of them have had any spoke tension issues. I have a Park Tools professional truing stand at home, and I like to keep my wheels true within a fraction of a millimeter, so I think I would notice if it screwed up any of my wheels. That said, I trust experts mechanics like Lennard Zinn and professional wheel builders like Jonathan at Strada. If they say it is happening, I believe them. Fortunately, it does seem that this problem, where it arises, is surmountable.

Sunday, July 10, 2011

Mounting Difficult Tires

A reader asks:

I'm trying to switch to a tubeless Hutchison Fusion 3 on a Campy 2-way Shamal rim...I'm finding it difficult to mount (tips??)...but I look forward to the ride.

Assuming your problem is mounting, not inflation, here is what I would suggest: 

Mount opposite the valve first, you don't need it getting in the way and taking up valuable bead. Remember, the tire bead needs to be in the low point of the rim, so it can't hurt to pinch the tire a little. You should always be able to get one bead on first. Then push the other bead on to the tire up until near the valve. Hold that in place with one hand (As a right handed guy, I use my left hand to hold the bead in place), then, with the other hand, push as much of the bead on as possible. You should always be able to get all but about 10 inches on by hand without much work. Next, insert a strong, plastic tire lever about an inch past where the bead is no longer mounted. I use the blue, Park tools levers. Holding the other side with your left hand, push the bead over the rim with your right. Without removing the lever, move it over another inch, and repeat. It will be a challenge, especially with a brand new tire.

Often, just unsticking the lever will cause it to slide several inches, instead of just one. Be conservative and just do an inch at a time. Once you have the bead inside the rim within a few inches of the valve and almost have the full bead seated, you can often just roll the tire with the palm of your hand and it snaps into place. Finally, you will need to push the valve up into the tire so that he bead can be seated between it and the rim as you screw the nut down.

Remember, I read all the comments, so be sure to let me know how it works for you!