Will a 450 speedo work on a 550?

[mr20turbo]

I have recently acquired a 1977 GS550. Unfortunately it didn't come with a speedometer, and i have no since of speed.

A member is selling a speedo off of a 1980 450l. Is the ratio correct to use on my bike? If not, what speedo gear will have it read correctly?

Thanks in advance,

Adam

[mike-s]

If you don't get a useful answer here may i suggest you hook it up to your bike in combination with a correctly calibrated pushbike speedo (stick a magnet to the front rim or disc carrier with the reed switch mounted on the forkleg, etc). That way you'll get a fairly accurate idea if it works for you or not.

I think the chances are that it'll be the same, if not close, given the fact it's the same manufacturer, similar era bikes and the wheel sizes for 450 & 550's are likely to be the same. Also if the wheel diameter is likely to be the same, why would they bother changing the ratios needed (and thusly the mechanics in the drive and speedo itself).

[mr20turbo]

If you don't get a useful answer here may i suggest you hook it up to your bike in combination with a correctly calibrated pushbike speedo (stick a magnet to the front rim or disc carrier with the reed switch mounted on the forkleg, etc). That way you'll get a fairly accurate idea if it works for you or not.

I think the chances are that it'll be the same, if not close, given the fact it's the same manufacturer, similar era bikes and the wheel sizes for 450 & 550's are likely to be the same. Also if the wheel diameter is likely to be the same, why would they bother changing the ratios needed (and thusly the mechanics in the drive and speedo itself).

that is my line of thinking as well. i just wonder if anyone on the forum has first hand experience with them.

[Nessism]

450 has an 18" wheel but 550 has 19". Not sure if that will make a difference but you might want to check into interchangeability of the speedo drive gear.

[kparkfan]

i have a speedo off a 79 550 that i'll let go for 20.00 shipped.

[chef1366]

It will work. If you can get it to mount it's plug and play.

[Richharr]

450 has an 18" wheel but 550 has 19". Not sure if that will make a difference but you might want to check into interchangeability of the speedo drive gear.

I have 2 gs 450's with 19" wheels