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Sprinting(10 posts)

Mar 25, 2001 7:06 AM
What is the best cadence for sprinting!
re: SprintingRobO
Mar 25, 2001 10:05 AM
The faster the better.
re: SprintingKerry Irons
Mar 25, 2001 10:58 AM
You should start your sprint at a cadence no lower than 80 - 90 would be better. You should be able to top out at 140. This gives you a 50% increase in speed without having to shift. If you can't get this kind of rpm, shifting becomes imperative, but each shift causes you to lose a little compared to giving it all you've got. A lot depends on the type of sprint (distance, up/downhill, with/against wind). Obviously, you weren't asking what cadence to reach and hold, as sprinting is a game of ever-increasing speed! Unless you started to early, in which case your speed goes up, plateaus, and then drops, and you most likely lose the sprint.
as high as you can maintain formDog
Mar 25, 2001 1:17 PM
I actually experimented with this on my trainer that has a wattage computer on it. More watts = more power = higher speed.

I assumed that really muscling the cranks at 80 rpm would give the most power. That's how it seems climbing, right? Wrong!

I tried many times, and discovered that the highest wattage (around 1000 for me on this trainer/computer), was when I was spinning the heck out of the cranks, but would then drop off as I lost form.

Sort of like a car engine. Typically, they make a lot of power from higher revs, until the engine just can't suck any more air or the valve train loses it's form. Same thing, sort of.

Mar 27, 2001 6:32 AM

How are you measuring watts? Do you have a "power tap" type devise or does your trainer do it? What ever happened to Power Tap anyway? After Le Tour 1999, when Lance said he used a power measuring device on training rides, I thought everyone would have something like a Power Tap by now. Are they too heavy? I don't even see them advertised any more. (They didn't fit my budget!)

Mar 27, 2001 7:13 AM
Tune was basically going out of business, stopped production, and started looking for a buyer. Graber apparently purchased Tune according to this press release:

While Armstrong and many other European pros swear by the SRM (which is prohibitively expensive for most of us), the Power Tap is incorporated in a heavy rear hub that needs to be specially built into a wheel. While wattage information would be extremely valuable, most amateur racers probably aren't going to spend the money to train/race on a heavy wheel. Well, this one won't, and I build wheels.
Polar S-710 with optional power kit for wattageDG
Apr 11, 2001 9:48 PM
The Polar S-710 will be out soon with an optional power kit to measure wattage. It will be expensive but not as much as the SRM system. Check out the details:

"How The S710 Measures Power:

The system derives wattage from the chain, not from the crank or hub as other models do.
The systems works by measuring two key factors:

Chain Tension - measured using a sensor on the chain stay
Chain Speed - measured using a sensor on the rear pulley

POWER = chain tension X chain speed.

All of the drive force of the bike is transmitted through the chain, allowing the S710 to calculate watts very accurately. The sensor positioned on the rear pulley works magnetically and measures the speed of the chain. The chain stay sensor calculates the tension of the chain by measuring the vibration as it passes over the sensor. (The user will enter one time during set up: chain length, chain weight and the measurement between the bottom bracket axle to the rear wheel axle. A chart in the manual will help provide some standard parameters.)

The system provides a real time readout of Power in watts that is ±5%
Very CoolHap
Apr 12, 2001 5:51 AM
This sounds like a very cool tool. I hope to here from some "Test Pilots" soon.

Mar 27, 2001 4:56 PM
These have wattage output. Anyone know if they're accurate?
Eddie B's pupils at the SD velodrome ...HH
Apr 12, 2001 10:54 AM
... teach new trackies to accelerate out-of-the-seat, not sitting down until their pedaling "gets crazy". The guys who are any good at it don't get crazy until their cadence (if you can call it that) is about twice that of a typical roadie cruise cadence.

Wasn't there a record set a year or two ago, discussed in this forum, where one top trackie cranked over a horsepower for an hour in some phenomenal test? My mind withers!