What is my axle size?

[ShoeDr]

Hey guys! I did search but came up empty handed. I'm looking to bolt on a side mount license plate holder. What size axle do I have on a 1979 GS550L? Also, if you have any leads in a seller let me know.

[chuckycheese]

25mm?

I'm pretty sure it's 25mm but I didn't understand the other things you mentioned.

[ShoeDr]

The side mount license plate holders I'm finding for sale are 3/4", 7/8" or 1". I just need to know which one I should go with. Also looking for a seller that anyone on here would recommend.

[Larry D]

If the axle is indeed 25mm....that's 0.984"
Inches and these GS's don't go well together though.

[Steve]

I'm pretty sure it's 25mm ...

I am under the impression that it's less than that, as I use a wrench that is about 25mm to turn the nut. I would think that the axle itself might be in the 19mm range, but I am not close enough to one of my bikes to measure it. If it is a 19mm axle, that is real close to 3/4".

ShoeDr, I have no idea where you live or will be riding your bike, but be aware that the officers in some areas are enforcing every little thing they can find, if they happen to stop you for anything. Most laws call for the license plate to be mounted horizontally. They may not stop you for just that, if they stop you for anything else, they will be happy to add that to the list of infractions.

.

[bwringer]

The rear axle diameter is 17mm on most GS models, but I don't have a GS550 handy to check. The axle nut usually takes a 24mm wrench.

[chuckycheese]

Oooooooops!

Yeah, Steve, I think I made a mistake and it's really 17mm. As far as the license plate mounting rules, that would be legal in California, as far as I know; but if there's money to be made in changing that, I'm sure they'll do it.

[Steve]

OK, I'll go with the 17mm axle, I was just trying to remember what size wrench I have used and how much smaller the axle would be than the wrench.

I brought up the plate orientation bit because I saw something in a 'tuner' magazine that somebody got a ticket for having a non-horizontal plate. Seems one of the custom touches they do to small trucks is to set the plate at an angle in the tail gate. It gets expensive when you do that, then have to undo it to satisfy the law (that you ignored in the first place).

[ShoeDr]

Thanks for the replies guys!