Hitchcocks Forum

I suspect that the erratic movement of my speedo is due partly to the fact that the drive is from the front wheel. The needle swings at every bump in the road as the cable flexes. Has anyone successfully adapted the drive to the rear wheel? I know some of the early twins had this arrangement.

Pete, all Redditch bikes had speedos driven from the rear wheel. I'm not sure it's the road bumps that are causing the problem, I wonder if perhaps the inner (drive) cable is a bit too long? Perhaps you could ask our Hosts to check the length and measure yours? If it needs shortening I use a cutting disc in a Dremel very carefully!

REgards, Mark

I've had erratic speedos before (2, 3 and 4 wheelers). Each and every time it was caused by 'snatch'. The inner cable would catch somewhere on the outer cable. The speedo drive would wind up the inner cable until there was enough tension to over come the restriction and 'snatch', the needle goes mental. I simple greased the inner cable along its entire length. The I re-routed it to avoided sharp turns. The end result is a happy speedo.

Hi Pete,



my Redditch/AVL hybrid has a later Indian Bullet rear wheel modified to take the speedo drive gearbox. It's just a question of filing/carefully grinding out the two slots for the speedo drive (copy the ones on the front wheel) and trimming down the the outer spindle spacer to compensate for the thickness of the speedo drive casting where the rear wheel spindle passes through. You might also have to open out the spindle hole a little for it to pass through freely. If you've done it properly, once everything is tightened up the drive gearbox stays put when the back wheel rotates, and nothing binds up. You then need at least a 54" drive cable with the correct end for the Indian speedo, ebay will have these if our hosts don't.



A.

Just a thought, it's not a proper chronometric is it? The first time I came across one, I thought it was broken, jumping up and down it was!

Thanks Adrian, I was hoping that would be the way to do it. I have access to a lathe so it should be straightforward.
Mark and Barry, I've checked all those points already but thanks for replying.

No Scaly, nothing so exotic 😐

Front wheel speedo drives are more accurate than rear; less tire deflection, slippage, growth and wear than rear wheels.


DONT over lube the drive gear box!


Take out the inner cable, inspect it for any significant kinks? If it has Bin-it, otherwise clean it, lightly grease the inner and make sure that the inner passes freely through the outer,and turns freely throughout. Any kinks or tight spots in the outer will initiate flutter of the needle.


How old is the speedo? Std RE issue? They are cheap "quality" (oxymoron) items, not the most accurate to begin with and are subject to wear and dry seizing. Flutter will get worse as the speedo head inner gubbins wear. It does not take too long for the Speedo reading will slowly get higher, 30% out is not uncommon and most are at least 10% off from the outset!


Accuracy? My bog std 2003 Bullet cruises at at an indicated 140 kph (sweeping from 120-160) LOL and I still get passed by Lorry's...

I really don't think the cause of your erratic speedo is down to it being driven by the front wheel. It's far more likely to be caused by a sticking cable. A front wheel cable is much shorter and potentially has a much cleaner run than a rear wheel driven cable, which also has to cope with similar suspension movement to that you believe is causing the problem.

"jumping up and down it was!"



Strangely enough, Yoda's exact same reaction that was...



Pete, my only reason for going back to a rear-mounted speedo drive was to make the bike look a little bit more Redditch-y. Being able to treat it to a chronometric was nice, though.



A note to anyone tempted to fit a genuine chronometric to an Indian Bullet in place of the factory item, make sure the inner cable protrudes by no more than 9mm at the speedo end, or it can damage the internals.



A.