Quick aftermarket speedometer question

[musicman]

I'm fairly sure the answer to this is "yes", but I figured I'd ask just to be sure. The speedo's that MikesXS say they are calibrated for a 19" wheel, my bike having a 19" front wheel means one of those speedo's would work on my '79 550e right? I wasn't sure if the speedo drive would have the same ratio but google tells me most of the early jap bikes used the same ratio. I e-mailed MikesXS but they won't respond, might be busy for the holidays.

I can't also help but wonder if they actually calibrate the speedo's, or if the 2:1 ratio is just correct. If 2:1 is right for my bike that opens up a lot of different options for me as well. I took my cluster apart and cut the ears off my speedo but I can't for the life of me find any paint or primer that will adhere to that orange plastic, and it still looks goofy.

[Steve]

Can't tell you the numbers for the ratio, but 2:1 doesn't sound quite right. I think it's the other ratio.

.

[musicman]

Dime city list their speedo's as 60mph @ 2240rpm, but my guess is it's the same, hmmm

[Steve]

Yep, those would be the numbers.

I knew the 2:1 did not sound right.

.

[Road Rash]

You want the 2240 rpm/60 mph flavor. They ARE two different speedos. Use the 2:1 and it's gonna be off.

[musicman]

Sweet, thanks guys!

[MisterCinders]

Yes. 2:1 will run too fast, giving you inaccurately high MPH and odometer readings.

[Biggie]

the exact ratio for most japanese 80's bikes is 1.4:1