# Track Cycling: Velodrome Racing and Training Area - Gear Inch Calculator

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View Full Version : Gear Inch Calculator

CafeRacer
01-24-09, 09:18 PM
I need a gear inch calculater that also tells me speed for a specific RPM. The one on fixedgearfever.com works awesome but doesnt go high enough. There used to be a really good one online but I cant find it.

Cheers.

jmio
01-24-09, 11:43 PM
look at the barenuckle applet on the fixed gear forum. It's on one of the stickies I believe

canflyboy
01-25-09, 12:16 AM

CafeRacer
01-25-09, 01:29 PM
Thats a pretty cool program but it doesnt go high enough. I need somthing that goes up past 200 RPM

queerpunk
01-25-09, 01:57 PM
Thats a pretty cool program but it doesnt go high enough. I need somthing that goes up past 200 RPM

Since the RPM:speed ratio is constant you can just figure out the speed change that 10rpm creates, and then do the addition.

For example, I plugged in 50x15, 167.5 cranks, and 700cx23. I observe that for every 10rpm the speed increases 2.6 mph. Though 160 rpm is the max (and gives me 41.7 mph), I can calculate that at 210 rpm, my speed will be 41.7 + (5 X 2.6) = 54.7.

Inconvenient if you want to look at several different gear combinations or whatever, but all the data is there.

testtube
01-26-09, 10:57 AM
Thats a pretty cool program but it doesnt go high enough. I need somthing that goes up past 200 RPM

How high should it go? Let me know and I'll adjust it for you... You must have hamster legs!

Recycle
01-26-09, 03:20 PM
Tyr this one: http://www.jbarrm.com/cycal/cycal.html

testtube
01-26-09, 11:38 PM
How high should it go? Let me know and I'll adjust it for you... You must have hamster legs!

Ok, I bumped up the top rpm in Rabbit to 240. I figure that's more than adequate... If any one has requests for Rabbit PM me.

Ichi-Go
01-27-09, 06:28 AM
Is it really possible to hit 240 or even 210 rpm?

CafeRacer
01-28-09, 12:47 PM
If your a sprinter 210 is fairly attainable on rollers or on the track behind a motor. Coming off a big hill you can train the legs to go even faster.

The upgrades to the Rabbit work perfectly, Thanks a bunch for making my post training session math work easier!