79 850GN - Front Tire and Rim Size?

[Goose]

Anyone know the correct spec for the front tire on my 79 850? Also, how would I know if the front rim is the right size? My speedo is off - reads high. At 65 my speedo shows about 75...

Thanks!

[Piston720]

Good Morning
The front tire is a 100-90/19, I use a 110-90/19 and do not have any issues.
Just for information sake I also run a 130-90/17 on the rear, and have done so for many years.

[tas850g]

Good Morning
The front tire is a 100-90/19, I use a 110-90/19 and do not have any issues.
Just for information sake I also run a 130-90/17 on the rear, and have done so for many years.

I run the 100-90/19 on front and the 120-90/17 on the rear. I've been told by a very knowledgeable guy you can run a 130 on the back as Piston does this with no problems.

[Goose]

Hmm... I've got a 100-90/19 on the front, so it's not that that's throwing off the speedo... Wait a minute, the speedo is driven off the front wheel, right?

[tas850g]

the speedo drive is on the front left side of the wheel.

[Goose]

Yeah, that's what I thought. And thank you for sparing me the walk back out to the lot to look...

So, now I'm wondering, why the hell is my speedo so far off?

[tas850g]

That i don't know. As someone mentioned in another thread, could be the speedo drive, the cable, or something within the speedometer its self. I'm sure you'll get more recommendations over the course of the day(s).

[Goose]

Yeah, I hope so. I know that something "bad" happened to the front end of this bike in it's past. Most likely a low side slide for life by the looks of the gauge cluster and right front fork. I don't believe the speedo was replaced, but could there have been something swapped out in the guts? Or down near the front wheel?

Insert big sigh here.