Axle clutch?

I’ve run Horstman Axle clutches for years in dirt sprint outlaw. Love them and virtually indestructible with proper Maint. Problem has been that they are not produced anymore, there are places that have some parts and/ or guys that have stock piled them like myself. Overall they are #1 in my book!
 
They work quite well but you have to readjust your slip with any gear changes and make major weight changes going from small to large tracks. Many run a Birky J/S that will have a fixed ratio so you wont readjust with a gear change. They are a wet clutch and much like a axle clutch. You can go with a dry clutch as well but the Birky is less maintenance other than changing oil regularly.jmo
 

Phiddy

Member
Most dirt tracks aren't big enough and don't run a gear ratio where they can be efficient. The axle spins too slow. If you have lotsa powa you will burn it up if you slip it any. That was my experience with a pair of open reedjets and an SMC.
066.JPG
 

spincycle

Member
Most dirt tracks aren't big enough and don't run a gear ratio where they can be efficient. The axle spins too slow. If you have lotsa powa you will burn it up if you slip it any. That was my experience with a pair of open reedjets and an SMC.
View attachment 6892
ive got a stroker sudam 131 with dual carbs, biggest track I run on is 1/6th, most frequently I run 1/8th's....
 

Jim46

Member
Birky with a Jack shaft , get a hand full of drive gears, go to any track you want
, use a Bully shaft in your jacket shaft , ( before final assembly, install a driver, then cut flats where the Alan cut the shaft
 

Phiddy

Member
ive got a stroker sudam 131 with dual carbs, biggest track I run on is 1/6th, most frequently I run 1/8th's....


If I had the setup you just described, I would use a Bully 4 disc. Birkey is a very nice clutch, but it seems parts are harder to find for them. Or, maybe I just don't know where to look?
 

spincycle

Member
If I had the setup you just described, I would use a Bully 4 disc. Birkey is a very nice clutch, but it seems parts are harder to find for them. Or, maybe I just don't know where to look?
i think that's the direction I'm gonna go, 2019 was my first year with the big 2 stroke, was using a bully 3 disc on the secondary side of jackshaft, was going through friction discs a lot quicker than I expected...:)
 

Phiddy

Member
That is the good thing about the Birkey. Keep it full of oil, change it every few races, and check it after the season. Solid clutch.
 
Need parts call Kevin he always has rebuild parts. As long as you keep the oil clean you should be able to get at least 20 shows out of it. If you need to put new springs any kart shop should have them if you're in a jam.
 

Phiddy

Member
Need parts call Kevin he always has rebuild parts. As long as you keep the oil clean you should be able to get at least 20 shows out of it. If you need to put new springs any kart shop should have them if you're in a jam.
Kevin is not always available, and I understand that. They use the springs same as a Bully right?
 
Top