The speedo ratio at the head will be the same, they vary only at the drive gearbox (wheel) end.

 

Thanks Slinky

Thanks for taking the time to respond Slinky.
This helps, I have an opportunity to buy a brand new speedo for a fraction of the price.
Thanks again.
Ride safe.
Mike T.

 

Slinky is right about the speedo and drive, a Bonnie America or T100 speedo will work on a Thrux, the difference in frt wheel diameter is taken care of by a different ratio in the drive at the hub.
FYI there are a lot of speedos that will work. The ratio is 2240:60, most Japanese bikes are that ratio, lots of after market speedos out there.The main other ratios available are 1:1 and 2:1., Harleys seem to have used all three ratios at various times. The Bonnie America speedo is quite large, may obstruct your vision tucked in on a Thrux and it won't fit in the hole next to your tach.What's wrong with the one you have?

 

speedo swap

Good morning 6T,
Thanks for the response and sharing the technical info. That is good to know. And yes, after doing some online research I dismissed the Bonnie America speedo for exactly the reason you mentioned..it is huge, much too large. Saw one on youtube.
Searching on here I found that Yamaha XS 650 speedos are a perfect swap and Mike's XS site has some nice small ones at a great price. That is the way I plan to go.
...as for what happened to the original....?...I suspect it is embedded into the side of what ever the previous owner hit. I bought a crashed 2005 Thruxton with just over 5000 miles on it that I've been slowly (due to lack of US currency) putting back together. Actually I am into it a little deeper than I thought I'd be..I had to replace the frame as the stem was twisted on the bottom, (love eBay!). Front end was trashed. Hoping to get on the road this spring. Searching for headlight and brackets, front pegs, clutch lever, speedo (but you know that) and a nice black cowl with the checkered flag pattern which would keep me from painting the yellow one I have. All of these remaining pieces I suspect will be aftermarket as I've no luck seeing any bargains out there..damn, OEM is outragou$.
Getting anxious, the bike runs great, (on blocks), sounds smooth and strong! ...then I can start my other bike project!

...good luck tomorrow Canada vs US hockey! ..
Thanks again!
Mike

 

I don't know how you're going to put any speedometer on the stock sender and expect it to be somewhat accurate, but if you figure it out, please post up.

*rolls eyes*

(I just kill me...)

Good luck with the project.