Machine the clamp or buy new a one?....

I recently got a nice set of pro taper bars (thanks to a fellow tt member), but the idiot that I am (no news here), I totally forgot that the 400 top triple clamp is a once piece set up for the clamp and the bar mounting brackets... yeah I know, not too smart.

Now, I am at the point where I have three options and would like your opinion/advice.

-first, would be to "bore" out the current mounting brackets to the 7/8th size

-second, to machine the brackets off to create a smooth/flat triple clamp, then drill the holes for some pro taper mounts

-third, buy a new clamp.

I have access to a professional machine shop so the maching job would be good but I wonder about structural intergrity and all that business. But I don't have the cash right now for a new triple clamp.

What do you guys think?


you can actually get an adapter that raises the bar slightly and changes the 7/8' mount to a 1 1/8' mount. I used to have the moose racing set on my old bike and it was fairly cheap. I'd recommend it for sure.

I bought a used upper triple clamp for 1 1/8 bars on ebay for $30. Good luck!!

Thanks greentyler, that seems the best way to go! eBay is good too, just got to be more patient to wait for the good deals and right stuff


Just buy the univeral riser adapters, they can be had for 20-30 bucks or maybe even cheaper. If you have access to a machine shop, you could probably make your own without much trouble as well.

Well, this just shows that I didn't do my research on this because there are clearly a lot of products out there for this topic... which is good.

In any case, Thanks for the help.


If you have access to a machine shop don't waste your money on those adapters. Just have the 7/8 clamps milled off, then drill them for the pro Taper clamps. I manage a CNC shop and have done this before It will not change the structural integrity.

If you look at the underside of the top clamp, you'll see that there would not be enough material to bolt bar clamps to should you mill off the existing clamp/riser. Similarly, the center to center distance between the bolts in the bar clamps is too close to allow the clamp to be bored out to 1 1/8.

the center to center distance between the bolts in the bar clamps is too close to allow the clamp to be bored out to 1 1/8.

thats exactly what i was thinking.

I have a 99 yz400f also! Are you saying that 7/8's bars won't fit the factory top clamp? I have a set of protaper 7 8's on the way right now, Am I going to need a new top clamp to?

Captaincaveman, sorry for the mix up, I was talking about oversized bars which are actually 1 and 1/8 inches. The factory 7/8th will fit right in the oem mounts :)

Gray- That was my concern too that there isn't a lot of material under to make a good base for some other mountin devices. The boring would of taken an eightth of an inch from the radius, thats too much like you mentioned.

BTW - will an early 426 fork fit on the 99 400s?


when i bought my 400 it had the adapters on it from stock to pro tapers. It worked fine but raised the bar mount up. I bought a used upper pro taper mount off ebay to lower it back down. at 5'6" it felt like i was riding with ape hangers. we put those mounts and bars on a friend of mine's bike, he is 6'1" and he loves them and we have had no problems with them.

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