1986 GS550L Speedometer Ratio

[krazy_kz]

Hi Folks,

Sorry, I originaly posted this in the wrong area, so I'm reposting here.

I'm pretty excited to find this site! I have a 1986 GS550L (I know the forum is only for up to 1985, but I was hoping to sneak in and not upset anyone too much [-o< )
I'd like to remove the stock speedo and tach and replace them with just an aftermarket mini speedo unit. Does anyone happen to know what the gearing ration is for the speedo on this bike?

Thanks in advance,

Krazy_kz

[krazy_kz]

No takers on this one?

[Einar J Skog]

Hi

You can do the measurement yourself...


10 complete turns of the wheel, multiply with number of turns of the speedo wire
divided with the wheel circumference, then you got your number..


Example
10 x 27,5
_________ = 1,36 Use 1.4
202 cm

Hope you understand my lousy English.

[krazy_kz]

Thanks Einar. I've always wondered how this works! Thanks for the info.

I'm a little confused though. In your example, you came up with 1.4. My choices for aftermarket speedos are 1:1 ratio, 1:2 ratio or 1:2460. Which one would I use in for the number in your example, 1:1?


Thanks.

[Dave8338]

Skog was only giving you an example equation...you need to plug the real numbers into that equation to get your answer. The two variables that you will need to determine are the exact circumference of the wheel (outside measurement of the tire all the way around, use a small rope or string and then use a tapemeasure with a metric reading, usually a cheapo) and number of rotations on the spedo cable end at the speedometer head. Then, do the math and choose the new speedo with the closest aspect ratio.

[krazy_kz]

Dave,
thanks a million!! I got it now.

Best regards,

Krazy_kz

[Dave8338]

No problem...Glad I could help. O

[phantomwerks]

just wondering what you figured out for ratio?
i'm also wanting to buy a mini speedo for my gs.