The drive for my c15 (2:1) speedo has a piece of cable stuck in it and I've tried everything I can think of to get it out. Is there anyone that does spares for the drives these days or is it a case of sourcing a whole drive. Presumably the teeth on the cogs differ depending on the ratio's so I can't just get any ratio and replace the driveshaft in my drive.
They can be dismantled but it does involve damaging the rivets holding the retainer for the drive gear. I have stripped and rebuilt them in the past - the last one I did was for a BSA Bantam which had a 10:19 drive ratio and these are almost impossible to replace.
2:1 drive ones are common and many after market ones are available including some cheap Indian copies. What ever you get make sure the drive will fit over the axle and also check if the cable exits above or below the swing arm.
I would be tempted to remove the cable from yours - strip it if you need to. If you are careful the 4 rivets can be punched out and reused. The end cap holding the output gear can be a pain to remove but can be done. Finally I have not found anyone who sells spares for them.
Google Gagg and Son, they advertise in OBM.
Thanks Both, I'll try Gaggs and I'll have a look around the Stafford show this year as I'm in no rush with the bike still in bits. Backstop would be a replica replacement, not ideal but at least they are available.
Just had a look at Rupert Ratio and wondering if a 2:1 ratio drive is right for your C15 ? If its a 1600 revs speedo a 2:1 drive seems to be best fit for a 18"wheel with 3.5" tyre ( as on a B40 Star)
(So if you have C15 star on 17" wheels you may find you over impress yourself with your speed !!)
Rupert Ratio indicates a 19:10 drive as the best fit for a 17" wheel with 3.5" tyre or a 18" with a 3" tyre.
If you know it reads ok then no probs. Otherwise consider if its possible to re-fettle to the better ratio. I presume Gaggs will know better than I on whats possible.
I've always taken the indicated speed as an approximation with the old speedometers!
Thanks Hoogerbooger, there's a 19:10 just come onto fleabay today and for difference in speed can't see it will make much difference