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

11 replies to this topic
  • Yz400Flyer

Posted July 28, 2007 - 06:21 PM


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?


  • greentyler

Posted July 28, 2007 - 06:24 PM


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.

  • crazyal426

Posted July 28, 2007 - 06:30 PM


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

  • Yz400Flyer

Posted July 28, 2007 - 06:31 PM


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


  • cowboyona426

Posted July 28, 2007 - 07:39 PM


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.

  • Yz400Flyer

Posted July 28, 2007 - 08:44 PM


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.


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  • ThompsonV311

Posted July 28, 2007 - 09:35 PM


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.

  • grayracer513

Posted July 28, 2007 - 09:37 PM


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.

  • greentyler

Posted July 29, 2007 - 02:40 AM


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.

  • captaincaveman

Posted July 29, 2007 - 04:49 AM


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?

  • Yz400Flyer

Posted July 29, 2007 - 05:49 AM


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?


  • jayh300

Posted July 29, 2007 - 06:20 AM


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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