Topic: CB750K 'Sport Tourer'

[knottedknickers]

So with the Cognito Moto hub, you can't run the stock speedo drive. I knew that when I started this build, but I'm still thinking there's got to be a way to use it! Stubborn, I am...
The other day I stumbled on this:

and,

Anyone want to tell my why something like that wouldn't work? Or am I going to run into serious 'ratio' issues? If the stock ratio is 2240:60 on a 19" wheel, is there any way to calculate a different ratio? Or, to ask the question another way: is there any chance of rigging the speedo drive unit to run off a different 'surface' (e.g., rear sprocket [as above], rim of front brake disk)?

I'm just brainstorming right now, so any input would be welcome!

[slikwilli420]

British bikes run the speedo off the rear. I just picked up some Rickman CR kit parts and the the wheels have a snout that takes a stock Honda speedo, except it has been bored out to take a bigger axle. It runs on the right side with the disc. I suppose you could rig one to be the spacer from your drum hub to swingarm. Probably be pretty easy to bore one out on a lathe. Mine is cracked from my kit so I will be doing the same on a stock Honda unit.

[754]

Are you running disc on rear, we could try to do what Willi suggested.. the el cheapo trick is...bicycle speedo..

[knottedknickers]

Are you running disc on rear, we could try to do what Willi suggested.. the el cheapo trick is...bicycle speedo..

Thanks for the replies. I read about the Rickman rear speedo drive, but couldn't find any info on it. No rear disc--just two up front. I found a new VDO X1 bicycle speedo at a garage sale last year for $2, so that's my fall-back. I've also got a GPS that I could stick somewhere... But I'd like to figure out a way to keep the stock speedo, even just for the odometer. I'll keep thinking around it.