Speedo repair or adjustment

[Tdi Guy]

After restoring my 88 IIa I need to do some speedo adjust ment with the larger tires. I remember reading about this on a web site THe Series Shed which I dont think works anymore. Are there any other writeups on this topic or how to sites?

[daveb]

After restoring my 88 IIa I need to do some speedo adjust ment with the larger tires. I remember reading about this on a web site THe Series Shed which I dont think works anymore. Are there any other writeups on this topic or how to sites?

hi

I think you would need to change the spring in the speedo. I've taken a few of them apart and it is essentially a magnet that is directly driven by the speedo cable at about a gazillion rpm. the magnetic force tries to spin the needle but the needle is on a coiled spring so that it can't go all the way around. calibration according to the lindsay porter book is by magnetizing or demagnetizing the magnet. go figure...

oh, nissongers in NY. they will rebuild and calbirate for you and if you give thm your tire circumference I think that is how it is done.

rgrds
dave in dc

[Jeff Aronson]

I've seen a formula for converting speedo readings when you switch from 15 to 16 inch wheels. In my memory, the conversion factor is 16%; however, I would not trust my memory when a policeman stops you for speeding. Well, you could speed in a Series Rover in a 35 mph zone!

When I changed my wheel sizes, I installed a speedometer for 16 wheels from Rovers North. When it died recently, I returned it to RN for repair via Nisonger and it was returned quickly.

Jeff