grips diameter

[mr72]

So, I just replaced the grips on my Triumph.

These are supposed to be for 7/8" bars, and the left one fit fine. I didn't bother to check before I installed them if the left and right were different sizes, figuring that if I attempted to put the throttle-side grip on the left, it would just be way too big and I'd notice. But then the throttle side grip was very difficult to install, I had to heat it up to get it to stretch over the throttle tube.

So I now suspect both grips are 7/8" and I just stretched one. And obviously now the right side grip is literally larger in diameter than the left, since I think they are the same thickness.

I guess I never bothered to check if the Oury grips on my GS are also like this, but a quick check seems to tell me maybe they are the same, the RH grip is 1/8" or so larger in total diameter than the LH grip due to being stretched over the throttle tube.

Am I wrong in expecting motorcycle grips to be made so both sides, when installed, should be the same diameter? And that the throttle size grip should have an appropriately larger inner diameter than the LH side? Or if I'm not entirely wrong, how do I tell whether grips I order are going to be the correct size? The original Triumph grips were obviously made to be the same diameter left/right and to fit the throttle tube.

I am only out about $9 for these not-perfect grips so I'll not mind ordering another pair. Just annoyed that they make them this way.

[Bluesmudge]

If Triumph is the same as Japanese bikes...your assumptions are correct. The OD of both grips should be the same but ID is different to accommodate the different diameters of the left and right handlebar. Once installed you shouldn't be able to tell that the IDs were different.

The grips should hard or impossible to put on dry. There is no way you could ever accidentally put the left hand grip on the throttle side over the throttle tube. I always use an adhesive to first act as a lubricant and then dry to keep the grips in place. Hairspray, Loctite, and actual grip glue all work well.

Some aftermarket grips may require a little trimming of the length. Especially if you have bar end weights and even more especially if you have a throttlemeister type cruise control.

I've always liked Pro Grip brand grips. Made in Italy for $10 - $20 and a wide variety of styles and colors.

[mr72]

I used rubbing alcohol as a lubricant to put them on. The Triumph has sort of an incomplete flange on the end of the throttle tube that made it especially hard to install. Maybe it's just my perception that the RH side one is bigger. But I have a micrometer!

[Bluesmudge]

Maybe your Triumph has a larger or smaller throttle tube than most bikes. It makes sense that not all throttle tubes are identical across all makes and models of motorcycles. If that is true, there can be no "correct" inside diameter for aftermarket grips.
I bet if you purchased OEM Triumph grips they would be the same outside diameter.

FWIW, I always find the throttle side harder to put on because there is more friction to overcome and the tube can move around. The left side is smooth and rigid...you can easily lube it up and jam it on there.

[mr72]

I measured, as much as you can get an accurate measure on a bumpy hand grip. LH is 1.25" and RH is 1.33". The difference is about 1/16". I definitely notice but I really thought it would be a bigger measurable difference. For now I am going to leave it alone, since I am planning to put on heated grips before winter.

But it wasn't all in my head, yet the RH grip must have had a bigger ID than the left because otherwise the difference in OD would be much more. I'm quite sure the throttle tube is thicker than 1/16".