Backcut Transmission Gears

[latheboy]

After a few hours scouring thru old threads I must ask....

Where can I send out my transmission to get the gears undercut?

Anyone have an idea what this may cost?

This place does cycles, maybe they would do my R.

http://www.aperaceparts.com/transmissions.html

[morse250r]

dave moore racing

[86 Quad R]

Originally posted by morse250r
dave moore racing

X's 2

or contact Tim @ Titan Racing Inc

[gandgracing]

I went with WCR (Whitaker Custom Racing). Did a good job but customer service wasn't very good.

[atvmxr]

arent backcutting and undercutting 2 different things?

and why would you need this on a TRX, it already shifts so damn good. just wondering?

[latheboy]

I understand backcutting and undercutting to mean the same thing-- to undercut the dogs on the gears so when they are engaged with each other, the undercut angles hold the gears together. (see the photos in the link i originally posted) A friend of mine had this done to his 450r, and it is basically impossible to miss a shift. If 2 undercut dogs come together, they will engage.
I agree, my 250r does shift very nicley, but i plan on building a 60hp+ engine, and I would hate to unleash that kind of power on 2 gears that are not fully engaged with one another.

[Honda 250r 001]

What does this usually cost to get done? Do they do all gears? Looks like a nice mod to me im thinking about getting this done for just peace of mind.

[gandgracing]

At my first climb with the Puma I got to the top of the first breaker, let of the throttle and then stabbed it again and second gear came through the left case. When you let off the throttle the gears will seperate some and slam back together when you gas it. Undercutting holds them together in gear.

[Honda 250r 001]

Originally posted by gandgracing
At my first climb with the Puma I got to the top of the first breaker, let of the throttle and then stabbed it again and second gear came through the left case. When you let off the throttle the gears will seperate some and slam back together when you gas it. Undercutting holds them together in gear.

not only does it keep it it gear, the gear it selfs keeps its self in place, so the shift fork is not doing that job, so its not wearing on the fork as much, resulting in a longer lasting tranny.

[latheboy]

Just from riding a 450r with cut gears...there is no way to half shift it. It just seems to shift more postively. I would say its worth it if you have higher hp.

I am sure that you need to cut every gear in the transmission that dogs with another gear. For my application, I would need both sides of the dogs cut. This would make the angles effective for both upshifts and downshifts. I do downshift hard sometimes coming into the corner on the ice oval....

I am wondering what it will cost also.