Need for speed (accuracy)

[DannoXYZ]

Yeah, simple enough to swap guts. Lots of options on used market now, wow! It's been over 20-yrs since I last looked at ST1100 dash and they were quite pricey at time. Wonders of internet shopping!

Probably best option: https://www.ebay.co.uk/itm/176343685002 £19.99 new!

Wow, ancient tech, it uses mechanical odo instead of stepper motor!

One thing that can be done while you've got it apart is to replace bulbs with LED versions.

 

[jfheath]

Brother has recently done this. Swapped out a European clock for a Uk mph clock.

No other changes need to be made. Same cable, same gear on wheel. But we knew that - we checked the part numbers.

Only thing to watch out for is the mileage. It's illegal to change to a a unit that shows a lower mileage than actual. It will be picked up at MOT. Suggest taking a photo side by side before the change with the km unit in situ and with the mph unit held in shot
and a second photo with the mph unit fitted and the kmh unit held in shot. Have the camera show the date as well.

Your MOT records will show km. You will need to ensure that future records show the mph odometer reading and that the record shows miles.

 

[Uncle Phil]

IIRC, weren't the ST1100 police model speedometers calibrated accurately?
Swapping out the whole unit is easy enough.
If the 'new' unit has lower mileage, the old electric 'drill' in reverse will eventually run it up.
Over here you buy cheap electric drills from Walmart, knowing they only last about 1,000 miles in reverse.

 

[DannoXYZ]

It’s even possible to pull off or spread end cap of odometer slightly. This frees up individual digits and you can turn each one to proper number to match real mileage on bike.

 

[Larry Fine]

I'm not sure, but you can probably disassemble the gauge housing and swap the odometer itself.

 

[DannoXYZ]

I'm not sure, but you can probably disassemble the gauge housing and swap the odometer itself.

Certainly easy to do. But don’t we get into whole km vs miles gearing thing? Looks like wht/blk gearset is part of odometer. Driven by take-off shaft from speedo cable.

 

[Larry Fine]

Certainly easy to do. But don’t we get into whole km vs miles gearing thing? Looks like wht/blk gearset is part of odometer. Driven by take-off shaft from speedo cable.

I was actually comparing swapping odometers between two MPH-reading (or two KPH-reading) speedos as opposed to spinning them with a drill.

I'm thinking about swapping odometers between the OEM speedo on my '01 1100 and the calibrated police speedo I bought a while back.

The speedo cable rotates at the same revolutions-per-speed/distance with either MPH or KPH , so the difference must be built into the odometer itself.

The speedometer needle points in the same direction for a given speed, regardless of the printed number, so the odometer must be what is geared differently.

You would have to compare each gear in the drive pathway to see where the difference in the gear ratio is located, and see if they can be swapped.