I've been looking on ebay at a vintage Sears speedometer that I am planning on putting on a 24" muscle bike project. I noticed that the speedometer is actually made for a 20" bike. I know that will make the reading inaccurate, in one way or the other. Does anyone know if that can be adjusted to work with a 24" wheel? Or if there is a formula I can use to calculate the actual mileage?
Analog Speedometer Question
- Thread starter JoeyMac
- Start date
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If you just want to know mileage you could use the ratio of the two different wheel sizes and multiply it times the mileage reading from the 20" unit. I think the ratio would be about .83 (20/24) :?:
You will never get an accurate reading either way. If you have ever used a digital speedometer, they have diferent settings for say 26 inch rims. a 26 by 1.5 tire will need to have a code entered that is different than a tire 26 by 1.75 and so on. Its really the tire size on the wheel that makes the diference. You have one for 24 inch wheels but it doesnt say what size tire its for. Just ask anyone thats ever changed the tire size on their car or truck. Because I travelled in my truck the same route a lot with my stock tire size, I knew they exact mileage of certain points, Then I put bigger tires on the same rims and my odometer was off by 1/10 of every mile. The old analog speedos were never truly accurate either, they were much more of a novelty item.
