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http://velonews.competitor.com/2010/10/cyclocross/technical-qa-with-lennard-zinn-getting-those-cross-tires-on-right_101235

  • By Lennard Zinn
  • Published Nov. 1, 2011
  • Updated Nov. 29, 2011 at 11:55 AM EST

This photo was taken of a protester at the Occupy Wall Street protest in New York City. Apparently, he feels that the bike maintenance skills of the protesters and onlookers are not up to snuff. Can’t have anything to do with history…
Lennard

Q. Dear Lennard,
At our club meeting tonight, a discussion came up about different pedals and the potential to deliver more power over a wider platform. As an example, would a wider pedal platform like a Dura-Ace allow a rider to deliver more power than a Speedplay pedal? Is there any correlation to platform size and power transfer? Does this make sense?
— Gifford

A. Dear Gifford,
My education is in physics, and I was always taught to approach questions like this by evaluating them at the limits. Certainly when you approach the lower limit of pedal size, it would seem to affect power output, since when the pedal becomes vanishingly small, you don’t have enough area to push on effectively. But when you approach the upper limit, that of infinite pedal platform area, it clearly makes no difference. Whether you have a 4-inch by 4-inch platform, a 4-foot by 4-foot one, or a 4-mile by 4-mile pedal platform, you’re not going to be able to produce any more power with one than the other based on platform size.

Speedplay founder Richard Bryne gives this more complete answer:
“The short answer is no, you cannot deliver more power through a wider pedal platform. Size is not the answer. Using this logic, a bigger chain would also deliver more power.

Given that the rider’s shoe provides adequate support, platform size is not the issue that affects performance or comfort. The two issues that affect pedal performance are the lateral stability of the system and the lack of play in the pedal/cleat connection. A stable and tight shoe-to-pedal interface is what top riders demand.

I evaluate the robustness of a pedal system’s connection by snapping the shoe into the pedal (on a bike) by hand. Then, with both hands I grab the shoe and check its stability by forcibly tilting the shoe sole upward and downward. Then I feel for any fore/aft or vertical slop in the connection. The tighter the shoe/pedal connection, the more efficient the power transfer of the system. This by-hand test method is also a great way to check if your cleat/pedal components are worn out beyond their useful service life.

A firm shoe/pedal connection will ensure optimal power transfer and provide more comfort on long rides. And although it is hard to describe, a play-free connection provides a more connected-to-the-bike feeling that simply makes you feel more secure and makes riding more enjoyable.”

Speedplay pedals

So you can take this answer back to your club and hang your hat on it, Gifford.
— Lennard

Q. Dear Lennard,
For those of us who have adopted your recommended technique of using Belgian tubular tape to more firmly affix tubular cyclocross tires to rims, what happens when it comes time to remove a tire (either to replace/repair a worn or punctured tire or to do end-of-season maintenance)? More specifically, should one attempt to remove the tire from the tubular tape/rim combination or endeavor to keep the tire and tape intact and remove this combination from the bare rim? And, if the tire is to be reused/reglued, how should that process be undertaken?
— John

A.Dear John,
Just start removing the tire. Usually the tape stays on the rim, but not always. Then peel it off of whichever one it stuck to.
— Lennard

Q. Dear Lennard,
I recently came across your article on gluing tubular tires for cross where you mention the way they tend to separate from carbon rims much more fully than on alloy rims. Does this hold true for road tubulars as well, or does the higher pressure mitigate the risk? I run 46mm Reynolds carbon wheels (DV3K) with Open Corsa 25mm tires. I weigh about 100kg and usually run 130psi rear & 120psi front… would there be any advantage to or would you recommend I use the ‘Belgian tape’ method you described in your cross article on my road setup or would it just be entirely overkill? I should say that, while I haven’t been on tubulars long, I haven’t had any issues previously, but it’s certainly not something I’d like to stumble upon at high speeds and learn the hard way. Thanks for any advice & keep up the awesome work!
— Troy

A.Dear Troy,
Yes, it applies. But the high pressure and better fit to the rim means that you can get a secure glue job without problem.

Don’t use Jantex (a.k.a. “Belgian”) gluing tape on a road tubular. It’s probably less secure, with higher rolling resistance.
— Lennard

Q. Dear Lennard,
I have a set of seldom-used Mavic Cosmic Carbones. The current tires were glued about 6 years ago. They have at best a couple hundred miles. How long are the tires good for? How long is the glue good for? Should I pull the tires off and glue new ones on?
— Mike

A.Dear Mike,
At least re-glue those tires. And if the base tape or tread peels off of the tire during removal and mounting, then the tires are done, too.
— Lennard

Q. Dear Lennard,
Based in part on your review of their Alpha wheelset and your road tubeless advocacy, I have decided to make the jump to road tubeless using Stan’s Alpha 340 rims.

The mechanic at my LBS built me a rear wheel using my existing 28-hole Powertap SL+ in a two-cross pattern on both drive and non-drive sides. The spokes were double-butted round Wheelsmith 2.0, attached with alloy nipples. Tension was set to Stan’s recommended 95 kg.

I mounted a Hutchinson Intensive tire using Stan’s yellow tape and two ounces of their sealant and took off down the road. After about 10 miles of smooth pavement, the wheel’s non-drive-side spokes had lost almost all tension.

Here’s my question: assuming my friendly mechanic (who’s built hundreds of wheels) proceeded correctly, is there anything about that rim / tire / hub combo that might have caused the spokes to become untensioned so quickly? Have you noticed tubeless tire installation affecting spoke tension? Any advice about building the wheel so it stays nice and stout?
— Eric

A. Dear Eric,
If anything, the tire pressure is lower on a road tubeless tire than a road clincher, so that does not affect it any more than a standard clincher. All tires, when pumped, reduce spoke tension somewhat. He should have used DT ProLock nipples and, to even out the tension more (and his tension in general may be a bit low), he maybe ought to have laced it radially on the drive side; the two-cross should have been fine on the non-drive side.
— Lennard

Q. Dear Lennard,
I also am a fan of tubeless wheels and have used tubeless wheels and tires for over a year. I have two Dura Ace C24 carbon wrap wheelsets. I use the Effetto Mariposa Caffelatex sealant. When I change the tires, I have had to scrape out the old sealant to be able to mount the new tires. Is there any way to remove the old sealant that is safe for the wheel other than manually scraping it away? I have used the recommended amount of sealant for a road tire.
— Ed

A.Dear Ed,
Finish Line pink bike cleaner works great.
— Lennard

Q. Dear Lennard,
I’ve been a devotee of tubeless tires for a few years now, but have to admit that I am falling out of love. As I follow your ongoing discussion of tubeless technologies and praise, I have to wonder if anyone else is having problems with tires. I suppose it could be the wheelset I’m riding, but the failures I’m having are coming solely from the tires I have been riding. Currently, I am riding a pair of NoTubes Alpha 340 rims built with Ultegra hubs (3x, 32°) and have previously ridden Shimano Dura Ace 7850 SL. I rode through two sets of Hutchinson Fusion Tubeless tires on the Shimanos — all the way down to the casing — after thousands of miles with a grand total of one flat. I recently built up the NoTubes with Hutchinson Intensive Tubeless tires and haven’t had a flat, but have replaced both original tires as they developed splits through the rubber down to the casing. I’m about to replace one replacement Fusion 2 since it has developed a split as well. Below is an overview of the tire failures, all on the NoTubes wheels. To date I have 1,129 miles on the wheels. Again, I never had a problem with the Shimano wheelset.

Any thoughts? Any other reports of Hutchinson tires splitting?

  • Intensive (rear) – massive splits next to rim parallel to braking surface
  • Intensive (front) – split up the middle of the tire along the casting seam
  • Fusion 2 (front) – split up the middle of the tire along the casting seam

— Justin

A.Dear Justin,
Actually, this is the first I’ve heard of it, but now lots of us have heard your experience.
— Lennard

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Lennard Zinn

Lennard Zinn

Our longtime technical writer joined VeloNews in 1987. He is also a framebuilder, a former U.S. National Team rider, and author of many bicycle books, including Zinn and the Art of Mountain Bike Maintenance and Zinn and the Art of Road Bike Maintenance, as well as Zinn and the Art of Triathlon Bikes and Zinn's Cycling Primer: Maintenance Tips and Skill Building for Cyclists. He holds a Bachelor’s degree in physics from Colorado College. Readers can send brief technical questions to Ask LZ.

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