Back cut trans. gears????

[nukldrgr]

Why do they back cut trans. gears for racing?Can I put a back cut trans. in my street bike?What effect will it have on shifting and durability?Thanks for the feed back;Mike...

[Nessism]

Under racing condition back cutting the gears will add a measure of assurance the bike won't pop out of gear. Pretty useless for a street bike unless you are a drug runner and power shift all the time.

[jed.only]

back cut on the face/rear of the gear? or back cut on the teeth/drive?

if the former, id say reciprocating weight, if the latter, i have no idea, but Nessism's theory sounds feasible.

[first timer]

it's not the gears the that are back cut but the dogs (the fingers that stick out from the side of the gears) that are back cut (dove tail cut). Like said above it provides posotive shifting, making it harder for the gears to pop out. It's only really good in high Hp and racing situations.

as take from ape racing's website


What exactly is undercutting?
The transmission gears lock together with a series of "dogs' or "dogs and slots" The photo below shows several of the dogs engaged together so that both gears turn together. Under hard use, the gears can began to separate until the dogs become disengaged, this causes the transmission to jump out of gear.
Now notice in the above photo the dogs that are in the circle. They both have angles cut on them where they meet. This causes them to lock together. They cannot separate without first backing up to unload the angles. This is an undercut. On APE transmissions, all of the dogs get these precise angle cuts.

[SqDancerLynn1]

Back cutting the gear dogs can also save a worn transmission

[jed.only]

ah, ive seen that before. dog-ring type. i dont know why i didnt add that up. some serious roadracers (cages) use dog-ring type transmissions.

[trippivot]

Why do they back cut trans. gears for racing?Can I put a back cut trans. in my street bike?What effect will it have on shifting and durability?Thanks for the feed back;Mike...

the "back cut" on the engagement dogs actually pushes the 2 gears together under load, instead of them popping away from each other under load.(hence bikes jumping out of 2nd gear)

1st,4th,5th,gear cutting is not necessary. 2 and 3rd get worked on a street type performance modification.