Sunday, September 20, 2009

More on tires and wheels and such

Today I finally got out on the updated carbon bike. The core of the ride was 32.63 miles in 1:57:32 - or a bit over 16.8 mph, with a total ride of 42 miles. That's pretty good for me, riding solo, on a breezy day. And the route was as hilly as its possible to find around here (although this isn't very hilly).

Initial impressions of the SRAM group. All parts worked correctly. The brakes do have enough modulation for my taste, along with good stopping power. The shifters shift reliably, as do the derailers (Force has replaced the Campy front derailer). The chain and cassette don't seem loud, although they are a bit louder than Campy when cross chained.

The grip around the base of the levers felt good; my initial impression was that it was better than Campy (due in part to its greater width). The end of the hoods have a larger and more pronounce hump than Campy. I like to ride with my palm on the hump with Campy, but all the weight is concentrated on the tall nub with the SRAM shifters. Overall, I was having more Ulnar nerve issues today than usual - but I'll need more rides to determine if this is related to SRAM shifters, or something else. Going forward, I may put on a longer stem to compensate for not riding on the shifter nub.

Overall, I'd say that the tires lived up to expectations - but I have to qualify it for now because the wheels are also new. The tubeless ride is definitely smoother riding - with this being most obvious on sharp-edged bumps. Its not quite like a high-quality tubular, but it's clearly a step up from an open tubular.

One other observation re the tires: They are very nicely concentric on the rims. Recently, I was using some Michelin Pro3Race on test wheels while building the rear-wheel fairing on a tri bike. It was almost scary how far from concentric these (expensive) tires are - so much so that I took them off and remounted them just to make sure that the beads were seated properly. Of course, when testing for clearances, this makes a great worst case example. But while riding, concentric tires roll more smoothly with less rolling resistance. So, again, I am impressed with the concentricity of the Hutchinson tubeless tires (based on a sample of 2).

While my time today was good, I suspect that it had more to do with my current conditioning and a need to burn off psychic energy. I'm sure, at least for now, that the wheels weren't really doing their job.

There is a nice downhill run where I test my rollout. My usual wheels are either an older pair of Campy Zonda (with the steel spokes rather than aluminum), or some MA3's laced up to Record hubs. With these wheels, no one out-rolls me, and I pass up many folks going down this hill.

The Easton EA70s were clearly not competitive going down this hill. I don't know whether this is seal drag, drag in the rachet of the freehub, or a bearing issue. Note that these wheels didn't even have a mile on them when I started this morning - and less than seven miles when I reached the coasting hill. Its entirely possible that the issue is just one of breaking in the bearing seals. Subjectively, the wheels felt as if they were rolling better towards the end of the ride. Guess I'll have post further on this issue after I get a few hundred miles on these wheels.

Over all, I enjoyed this mornings ride. With the gears working correctly, I could better enjoy the ride and the handling of my frame and fork. This really is a nice frame, and handles beautifully. Today was a super morning to enjoy it. It was still a little dark when I started and about 54 degrees. By the time I got home it was 65 degrees, sunny with blue sky.

And that's a wrap for today.


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