Royal Start Trike Speedometer pickup resiting / replacing

[casarva]

We are currently converting a Royal Star (1996) to a trike with one of our conversion kits. The problem we need to solve is the resiting / replacing of the speedometer pickup which on the bike is fitted to the rear of the swing arm / shaft cowl. As we are removing all this assembly the question is how to retain the existing speedometer (tank mounted). On a previous conversion - A Royal Star Venture - we resorted to a replacement handlebar mounted digital speedo but the customer would prefer to use the original.

Can anyone give me advice on where and ho to re-site the speedo or if there is some modification we have to make. Looking at the speedo pickup on the swingarm the sensor is bevelled and looks to operated buy the make break of the splines on the shaft is this correct?

Thanks in advance

Steve

Casarva Custom Conversions UK

[Flyinfool]

The pickup is operated by counting the gear teeth of the pinion gear as they go by.

You may need to machine a hole in the differential located over the pinion gear to mount the pickup. You may then need to do some recalibration to get the speedometer back to reading correctly. I do not know if it would work to make up a plate that spun at rear tire speed with an appropriate number of holes to get the speedo to read that plate.

[casarva]

The pickup is operated by counting the gear teeth of the pinion gear as they go by.

You may need to machine a hole in the differential located over the pinion gear to mount the pickup. You may then need to do some recalibration to get the speedometer back to reading correctly. I do not know if it would work to make up a plate that spun at rear tire speed with an appropriate number of holes to get the speedo to read that plate.

 

Thanks for the reply. we are replacing the stock tyre with a 225 / 55 16 item. if we make a reluctor ring (like an ABS disc) and mount the existing pickup near it we will have to do some heavy recalibration the speedo as the circumference is much greater than the teel on the shaft spline that it currently picks up on and it would have to be calculated as it depends on the tyre size and if the owner changed that's it would be incorrect which isn't really a good solution. To my mind I think taking it off the engine is going to be the best bet before it goes through the new differential. I wonder if I should think about making a smaller make / break ring on the modded propshaft which is being mated to a Quaife reverse gearbox.... I need to look again.

 

Thanks again for your time and if anyone has any other thoughts its appreciated

Cheers

Steve

[winston66]

as Flyinfool said the pickup counts the teeth on the pinion, against time ,I think the ratio is something like 30 to 9 for one complete revolution of the rear wheel when it is fitted with a standard sized tyre.

I would do the maths and possibly construct a suitable toothed type of signal source to replace the signal that you would get from the pinion gears, if they are not to be used in the rebuild.The new signal source could then probably placed on either the front wheel adjacent to one of the discs, or else perhaps on one of the new rear wheels, or even as a bolt on type of toothed sleeve on the new drive shaft. and also be reusing the original pickup, in the new location.

For calibration purposes do a search on this forum under the heading of, Speedo Healers.

There might be some good and applicable information there.

I have also seen somewhere on this forum a write up where someone made a replacement of a new and calibrated face card for the original speedometer and used that in order to get an accurate read out .

 

I hope that this helps.

 

Cheers, Winston66, Northampton, Western Australia

[angie198]

Hi Casarva I have the same problem with my 1999 Royal star venture I have a digital fitted, The old clock gives fuel reading, but I would like to have it all working if possible, have you found any solutions? could something be mounted on the front wheel? any help would be great thanks...

[casarva]

Hi All

After much.. and i mean much research, there is no straightforward way to replace the existing speedo - Thanks for the suggestions winston66 but it just isn't viable commercially to do i.e. I cant charge the customer for the amount of time and resources it would cost to do.

We had to use a secondary speedo mounted in the centre of the handlebars and picked up off a sensor mounted on the front wheel.

I wonder if there is someone who is able to replace the internals of the existing speedo with those of a secondary unit which then could be picked up from the front wheel? Here's a photo of the trike (sorry about the top box it wasn't our choice and is being replaced!) if you click on it it gets bigger!

 

 

Cheers

Steve