Brake on sprocket?

[Engineer]

I have seen it done in the past but don't see it much anymore, running the brake caliper right on the large sprocket.  Either clearance it to run over the chain, or put it where the chain isn't.

Anybody that has any experience let me know the pros and cons, or your experiences.

Here is what I see so far:

Pros:

No extra brake rotor

lighter

Cons:

Chain lube on brake pads

Adding heat to sprocket/chain

[Nutz4sand]

I agree with all your pros and cons and add:

Con: You wear out the sprocket but the brakes are fine. You STILL gotta spend a lot on a new sprocket AND brake combo. $$$

Same goes the other way. If you happen to wear the brakes out before the sprocket. I see sprockets going first but maybe not.

Now if it was a two piece? But that starts getting bigger and complicated and $$ But you would only have to replace the bad part.

[LiveWire]

I saw one before where it looked like there were plates bolted on each side of the sprocket to make it thicker and the outsides plates could be replaces independent of the sprocket. The sprocket could also be replaced an reuse the plates. I think you would just have to be more careful when lubing. If the chain is dripping lube, it won't be for long since it will fling off. I think you would be more likely to have problems if the chain goes through the caliper.

[fabr]

I have seen it done in the past but don't see it much anymore, running the brake caliper right on the large sprocket.  Either clearance it to run over the chain, or put it where the chain isn't.

Anybody that has any experience let me know the pros and cons, or your experiences.

Here is what I see so far:

Pros:

No extra brake rotor

lighter

Cons:

Chain lube on brake pads

Adding heat to sprocket/chain

Might be fine on a small lightweight lower Hp app but not for what I think you are planning. IMO.

[Engineer]

Thanks, All good points.

The sprocket is .343 thick.  That is probably thicker than most single rotors.  It is gonna take a while to wear that out.  I also noticed that Willwood offers calipers/pads for .38 thick rotors, so that would work, but how thick of rotors is everyone running?  I am guessing if it is off of a bike it will be much thinner.

For braking safety, I am not sure I like a bike sized rear brake on a buggy that is 2-3 times the weight of the bike, not to mention that most of the bikes stopping power comes from the dual brakes on the front......

[Nutz4sand]

Many single rotors  that are thin are on like a quad and stopping one little tire. The back is sorta thin but when braking there is not much weight on the rears usually. (Plus any quad nut will tell you you will replace two or three sets of rear pads to one front. Mostly I am guessing due to the motor still spinning the rear axle? But the two larger tires (normally) likely cause issues too)


You say the sprocket is .343 thick and some rotors are thinner. But if you put brake pads to that material it might go bye bye pretty quick. Even if you blanchard ground the sprocket and heat treated it it may not last anywhere near as long as a sprocket made from better material for the job of a brake disc/sprocket.

 My old POS Kawi powered mini buggy had ONE brake disc on the rear that actually came off the front of the bike the motor did. (early 1980's KZ750 twin cylinder four stroke)  That brake rotor did OK around the little hills of Silver lake and what not. But when we took that thing out to Glamis When I drove it down Oldsmobile hill even with the motor in low gear and revving to high the brake would overheat and fail. I had to go back and forth across the hill to get down it at a safe speed.

As a side note we also had my Honda Pilot to Glamis that trip. Its brakes got warm I am sure but it handled the hills there much better coming down (Kawi rail was MUCH faster going up though!) On that same note at Silver Lake I usually only used the Pilots brakes if someone cut in front of me. Simply swerving back and forth with it scrubbed off speed VERY quick.

Still if you wanted to look into it didn't Harley Davidson put these sprocket/brake combos on some bikes? Might not be the size you need though.

[BDKW1]

Cons..... Abrasive brake dust coating your chain............

[Engineer]

Cons..... Abrasive brake dust coating your chain............

Ewwww.....  That is a pretty big con, plus the chain will sling it everywhere as well.

Many single rotors  that are thin are on like a quad and stopping one little tire. The back is sorta thin but when braking there is not much weight on the rears usually. (Plus any quad nut will tell you you will replace two or three sets of rear pads to one front. Mostly I am guessing due to the motor still spinning the rear axle? But the two larger tires (normally) likely cause issues too)

You say the sprocket is .343 thick and some rotors are thinner. But if you put brake pads to that material it might go bye bye pretty quick. Even if you blanchard ground the sprocket and heat treated it it may not last anywhere near as long as a sprocket made from better material for the job of a brake disc/sprocket.

 My old POS Kawi powered mini buggy had ONE brake disc on the rear that actually came off the front of the bike the motor did. (early 1980's KZ750 twin cylinder four stroke)  That brake rotor did OK around the little hills of Silver lake and what not. But when we took that thing out to Glamis When I drove it down Oldsmobile hill even with the motor in low gear and revving to high the brake would overheat and fail. I had to go back and forth across the hill to get down it at a safe speed.

As a side note we also had my Honda Pilot to Glamis that trip. Its brakes got warm I am sure but it handled the hills there much better coming down (Kawi rail was MUCH faster going up though!) On that same note at Silver Lake I usually only used the Pilots brakes if someone cut in front of me. Simply swerving back and forth with it scrubbed off speed VERY quick.

Still if you wanted to look into it didn't Harley Davidson put these sprocket/brake combos on some bikes? Might not be the size you need though.

I think total vehicle weight plays a greater role than the tires the brake is controlling.  I would agree that the motor pulling on the rear brakes doesn't help either.  But generally when riding lazy the rear brake is the brake of choice.    I know it is for me!

This is exactly what I am worried about.

I am gonna see if willwood or anyone on the net has any resources for figuring braking capacity.  Surely there are formulas: rotor diameter, brake pad area, rotor thickness, vented or non, vehicle weight, mph, etc. to figure what is needed.  Plus there is a big difference between stopping once, ie drag racing, and continuous hard driving.

[LiveWire]

My 2000 Formula Cross with a single non-vented rotor and a 4 piston caliper. It still has the original pads on it. I can also lock them up very easily. So capacity does not seem to be a problem. I can, however, still boil the fluid out of it. Mainly that is from going into corners throttle and brake on. It makes a CVT drive machine come out of the corners harder. I am switching to a vented rotor. Yes, it is heavy. I just want to beat on the brakes and not have them let me down. I thought about making a sandwich of thin rotor, aluminum layer, thin rotor. The aluminum would be laser cut in sort of a many pointed star. So it would be a very thin vented rotor. I decided too much of a PITA. I also thought about machining grooves that would only go half way through and another set on the other side offset half the degrees. Also a PITA.