Jackshaft disc brake??

Jeff

How did you do this? Just mount the rotor to the backside.......?

image.jpg
 
Ok cool. Does the bolt pattern on the rotor match up to the 3 holes on the mini hub or do I have to fab up an adapter?
 
I figured that...! Lol. Would you happen to have a pic of how you mounted your caliper so I can at least get an idea? My email is [email protected]

Did you use a 160 rotor and the post that came with it?

Thanks Jeff!
 
I heard the jack shaft disk brakes can be touchy aka have a hard bite

i seen some de tune the caliper or even cutting up an existing rotor to a smaller diameter helps
 
Question......Should I have the front brake and the jackshaft brake isolated? Or, a better question, can I have both brakes on a dual lever? I'm only asking because one less brake lever is one less thing cluttering up my bars.....
 
My understanding is the jackshaft mounted brakes are MUCH stronger due to the gearing advantage so it might be difficult to balance them on a single lever.
But I really have no idea. Just a guess.
 
scotto- said:
Here's a few pics of mine Mike......to give you some ideas











hope this helps
Click to expand...
Please forgive my ignorance, but I can't wrap my mind around how a brake on the jackshaft can stop the wheels from turning, and brake the bike. HELP! and where can I get that engine & jackshaft mount!?
 
maciver02 said:
Please forgive my ignorance, but I can't wrap my mind around how a brake on the jackshaft can stop the wheels from turning, and brake the bike. HELP! and where can I get that engine & jackshaft mount!?
Click to expand...

The chain is connected to the jackshaft and the rear wheel. Stop the jackshaft from turning, stop the chain. Stop the chain, stop the rear wheel.
 
greaser_monkey_87 said:
The chain is connected to the jackshaft and the rear wheel. Stop the jackshaft from turning, stop the chain. Stop the chain, stop the rear wheel.
Click to expand...

I guess I'm still missing something - how is this superior? To me it seems that a jackshaft brake simply moves the braking action further from the wheel, which is the thing we want to stop originally. Is it to do with the torque? Is it just bonus style points to have a disc brake on the jackshaft?
 
A brake works the same as a gear. The larger the gear, the more force is applied. The larger the brake, the more braking force. Gears affect each other in relation, i.e changing one gear affects how much force other gears in a series can apply. The same is true of brakes. A brake can apply more force to a smaller wheel or, in this case, the jackshaft. The jackshaft being smaller than the wheel allows the disc brake to apply far more braking force than it could if attached to the wheel.
 
It is just an extra brake. It is not taking the place of the other brakes. It will slow the engine, thereby slowing the clutch and disengaging it quicker. And yes, it looks cool and is really not hard to do, especially when you have the parts laying around....
 
My understanding is that having the disc brake on the jackshaft allows it to have much more braking power. Therefore, I plan on having a motorcycle drum in front, which I believe will allow more than adequate braking power for normal stops at the speeds I like to cruise, and the jackshaft disc brake for emergency stops only.
 
maciver02 said:
Please forgive my ignorance, but I can't wrap my mind around how a brake on the jackshaft can stop the wheels from turning, and brake the bike. HELP! and where can I get that engine & jackshaft mount!?
Click to expand...

In a nutshell......the rear wheel (sprocket) is driven directly by a chain from the jack shaft. You stop the shaft from turning, the rear wheel also stops turning which is braking to the rear wheel.

On my 212cc bike, the engine itself does most of the rear braking with it's compression when you let off the throttle. The jack shaft brake is just there if I need just a little more braking power in certain situations while racing.

The front brake of course is used for most of your stopping power as far as all vehicles are concerned.

Here are a few more shots of the j-shaft brake on my 212cc bike.....





 
My jackshaft brake is very sensitive and it would work great but I have a spring loaded chain tensioner and it puts great stress on the chain tensioner.
 
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