For those of you who have changed to 12 or 13 wheels how did you correct your speedo? Mine is now -5 or so MPH. Is there a new cable/gear that can be used to remedy?

 

well, I don't see anyone with a quick and easy solution

these guys say they can do it

Custom Calibrate Smiths and British Jaeger Speedometers as Required For Tire, Trans. and/or Gearing Changes

http://nisonger.com/index.htm

they advertise in many classic car mags like Classic Motorsports

in NY state

I've just learned what the conversion is and live with it as I'm thinking this won't be cheap. But since my odo' is also busted having the speedo' rebuilt is on my wish list for someday.

 

As far as I know, the only _real_ fix is to re-gear the speedo so that it is calibrated to the circumference of the wheel/tire combo.

For some reason I have speedometersolutions.com bookmarked. I think I was planning on getting an adapter to be able to run an aftermarket gauge with the stock Mini speedo cable, but ultimately decided to use the stock Smiths gauge. You might try to contact them and see what they can do for you.

And BTW, I have 12" wheels but the tire circumference is very close to the stock 10" tires, so my speedo is almost dead-nuts on. If your speedo is off then it's due to the tire circumference, not the wheel size. A smaller sidewall will fix that problem. I'm assuming you don't want to change tires to fix this issue.

Hope it helps,
Jeff

 

Thanks for the links and info. Might just deal with it for now. Have been considering a 1275/manual conversion from my 998/auto, so might Make more sense to wait since there isn't a plug n play solution.

I understand that overall diameter is really the key. When I switched from 10s to 13s I couldn't find a tire size that was close to the 175/65/10s. The typical 13" tires run on Minis have about a 1" bigger overall diameter. At least that I could find on the typical mini sites and golf cart tires stores.

 

Yes, sounds like a typical problem. Somehow my MIni's previous owner found some Yokohama 12" that are nearly identical to the 10" circumference. In the next 6 months I'm going to be in the market for some new sneakers and I will likely have the same problem that you do (although I won't be going with 13" wheels).

Let us know if you do come up with a solution and I'll do the same.

 

This thread makes me chuckle ... my speedo is in kilometers. I'm always running the math to approximate mph.

 

i'm using a GPS based speedo in my mini. no need to re-calibrate