Speedo re calibration question

[Charlie]

I am looking at dropping a ZRX front end on to my Zed, but as the Rex runs a 17" front wheel and the Zed a 19", it's gonna throw my speedo reading out quite a bit.

I have a Rex speedo drive and I am trying to keep the Zed clocks if at all possible, cos even though I am changing the Zed about, I still want to keep the classic look. Clocks are a very important part of that (to me at least)

So - has anyone encountered a place that can maybe recalibrate Zed clocks, or even found an alternative workaround ?

The possibility of maybe dropping Zephyr or even ZRX clocks into a Zed clock casing intrigues me a little, but I need to try and get hold of something to check out the possibility of making it work ...

[PAULJAC47]

Might be worth just trying it out,Zed clocks are optimistic to say the least,might even be more accurate?

[jonhunt]

Mine are at least 10 mph out. I wondered why it took me so long to work the first time I rode it in😀

[bunnysZ]

I HAVE A ZX7 FRONT END ON MINE, speedo is accurate uptill about 70/75 mph, and shakes about a bit then.

[Charlie]

I have a set of mint original clocks - they are more or less accurate on a 19" front wheel, but I run aftermarket clocks for reasons even I cant work out.

The pattern clocks are already optimistically over reading, that gap gets greater once above 60....

Having 'em read yet another 10% or so over lol will (make em illegal for one thing) make them pointless.

I would be stunned if they could be recalibrated, but it was worth asking.

I guess I will be stuck with stock clocks that are inaccurate or trying to graft a speedo from a 17" wheeled bike into a Zed case .....

So, no problem there then

[needaz1100r]

[quote="Charlie"]I have a set of mint original clocks - they are more or less accurate on a 19" front wheel, but I run aftermarket clocks for reasons even I cant work out.

The pattern clocks are already optimistically over reading, that gap gets greater once above 60....

Having 'em read yet another 10% or so over lol will (make em illegal for one thing) make them pointless.

I would be stunned if they could be recalibrated, but it was worth asking.

I guess I will be stuck with stock clocks that are inaccurate or trying to graft a speedo from a 17" wheeled bike into a Zed case .....



I believe, from some research I did to fit the correct speedo to a Harley, that all Japanese speedos are geared to 2240:60, i.e. they read 60MPH (or KMH, doesn't matter, the point is they re all the same) at 2240RPM of the cable.

So the gearing change for different wheels is in the speedo drive at the wheel, which makes sense, much easier to have a different speedo drive for each application than a multitude of different speedo heads.

I'd suggest trying to fit the 17" wheel speedo drive.

[Charlie]

Thanks Mark, that is interesting.

I am going with the ZRX speedo drive anyway to fit on the thicker ZRX axle. The job itself is still WIP, so I will inform how it ends up

[Big Fluff]

If you need some bespoke custom faces making up for your conversion just let me know and I'll make you a set to any colour or design you like!
Standard looking or wild.... your choice.

Regards, Will

[Charlie]

I am liking that proposal - thanks Will