Projects HARLEY SPEEDOMETER

I'm thinking of using a repro Harley speedo in my project and I've found some that might work. what do I need to do to use one on my Turbo 350? It's a mechanical type with a 2:1 ratio.....Bob

 

The proper speedo gear is a crap shoot. Too damned many variables. But they are cheap, just try what you think will work and go from there. You are likely to never get it right on but close is cool if you know how it reads.

 

Don't you want a 1:1?

 

1:1 ratios are harder to find. Also what would be the advantage of it over a 2:1 version?

 

It'll read right. In the dim recess of my memory, I had to get a 1:1 for my Panhead, it had a 2:1 and was 1/2 off. I've got a 1:1 "police Special " for the roadster. If you need a different one, repops are around $70. A wide variety of face designs, and ratios. Easy. JP Cycles, one source.

 

This is mine.

 

The 2:1 and 1:1 Harley speedometers are calibrated to show one mile with 720 turns of the wheel per mile (this is based on the typical 90/90-19 front tire that's used). So a 1:1 ratio would mean 720 cable turns per mile, the 2:1 would mean 1440 turns. American automotive speedos are generally calibrated for 1000 cable turns per mile, so in both cases you'll need to 'correct' the ratio to get a reasonably accurate reading. You'll need to know your tire size and rear axle ratio, at that point you can calculate what speedo gears you need in the transmission to get reasonably close.

A 1:1 speedo will probably be the better choice as it's 'closer' on a percentage basis. It will also be more likely to read 'fast' rather than 'slow'.

There's all kinds of repo and aftermarket speedo available for Harleys, you shouldn't have any problem finding something that will work. Stay away from the 2240:60 ratio speedos, those are roughly a 37:1 ratio and will be impossible to correct.

 

Thanks to you guys for all the good info but I have one more question; What did you guys use for a cable or am I looking at a custom cable and if so where to get one? Thanks again......Bob

 

IIRC, Harley used two different sized cable nuts at the speedo end over the years and one was a 'standard' size. I'm not so sure that the repos will have that as they now sell 'adaptor' nuts for some of these applications. If you need a custom cable, most any speedo shop can build you one.

 

I have that exact speedo, it was $25.00 at the swap
It is a 2 to 1 and I just went to evil bay and found the company that makes a converter. I bolted it to the trans (turbo 400) and the then normal cable to speedo.
Sorry no pics at this time,,,