Disc Brake on Engine's Output Shaft

[FJ1100mjk]

An innovative way to reduce un-sprung weight, and centralize mass.

1992 ATK 604

[FJmonkey]

Neat concept. The rear only provides about 20% of possible braking. A small disc and 2 pot set up just might work on a heavy FJ. How much of the weight do you think would be saved from the rear un-sprung weight?

[red]

Just a consideration here, but if you break the drive chain,
you would lose the rear disk brake, as well as the engine braking.
Hope the front brake can handle the results.

[simi_ed]

I can attest that the front brakes will stop an FJ w/o any rear brake.   Even 2 up, not a problem. I've been riding that way for about 25 years.


Ed

[CutterBill]

What?  You have NO rear brake?  Care to elaborate?
Bill

[ribbert]

....The rear only provides about 20% of possible braking.

...yes, and the harder you brake with the front, the more that figure drops until near enough to zero.

Noel

[FJmonkey]

Yep...

[ribbert]

I don't conciously think about braking but always use both (except for slow full lock turns) but I lost my back brake on a fast ride down a mountain a while back. Obviously the bike could still be slowed but it felt wildly unsettled braking heavily with just the front. So much so I backed off.

Noel

[ribbert]

Yep...

OK, until zero. 

[FJmonkey]

Near enough I think Noel. I rarely use my rear brake in the twisties. My logic for this is predictability when leaned over. When leaned over to turn Left I have easy use of the rear brake. When leaned over to the Right my boot is getting stuffed between the lever and land. I fear that if the suspension is doing what it should and causes my boot to apply more brake than intended then bad stuff might happen. I am not a racer and have no intention of being the fastest in any group for any reason. I also could just be over thinking it, I tend to get wrapped around the axial for this.

[ribbert]

I rarely use my rear brake in the twisties. My logic for this is predictability when leaned over. When leaned over to turn Left I have easy use of the rear brake. When leaned over to the Right my boot is getting stuffed between the lever and land. I fear that if the suspension is doing what it should and causes my boot to apply more brake than intended then bad stuff might happen. I am not a racer and have no intention of being the fastest in any group for any reason. I also could just be over thinking it, I tend to get wrapped around the axial for this.

Mark, tempted as I am to further comment on this subject of corners and braking, I have been down this road before (pun intended) and it didn't end well, I think I'll leave it here.

Noel

[FJ1100mjk]

Mark, tempted as I am to further comment on this subject of corners and braking, I have been down this road before (pun intended) and it didn't end well, I think I'll leave it here.

Noel

We'll, that would be fantastic considering that this post was initiated simply to comment on a unique brake system (and on a dirt bike too), and was hijacked and morphed into personal braking techniques on road bikes.

[ribbert]

Mark, tempted as I am to further comment on this subject of corners and braking, I have been down this road before (pun intended) and it didn't end well, I think I'll leave it here.

Noel

We'll, that would be fantastic considering that this post was initiated simply to comment on a unique brake system (and on a dirt bike too), and was hijacked and morphed into personal braking techniques on road bikes.

Yep, you're right, that's exactly how some of the best, most informative and interesting discussions here come about.

Noel

[simi_ed]

I can attest that the front brakes will stop an FJ w/o any rear brake.   Even 2 up, not a problem. I've been riding that way for about 25 years.


Ed

Sorry Bill, that is not quite accurate. I have a rear brake. I just don't use it.


Ed

[Firehawk068]

Although this seems like an interesting idea for possibly reducing a little unsprung weight, and possibly to tidy up the rear wheel area if you have a show-bike, I honestly don't think it would work very well for anyone that lubes their chain regularly. There would be no way to prevent chain-lube from eventually getting on the brake disc or caliper/pads, rendering them useless................unless of course you had a dry, belt-driven bike.