Front brake only?

[Manfred2025]

While fabricating my own custom aluminum footpegs I managed to damage my rear brake master cylinder ( Now I've been using my bike braking with the front only. To tell the truth I have not seen any difference in braking distance and if anything I now feel more control of my Raptor (I know it sounds strange). Now, do you guys recommend a rebuild or a new master cylinder? Are there even rebuild kits for our master cylinders?

[Spyke]

I know Jack Shit, so I recommend very little, but you might wanna read http://www.raptorchapter.org.uk/viewtop ... =14&t=3241 and http://www.raptorchapter.org.uk/viewtop ... =14&t=2123 to see what has been said on this subject previously!

It sounds like both rebuild kits and m/cs are available though.

[snapdragon]

Rolling off throttle engine braking is very effective but rear brake is handy at times, can be fixed though

[Red Mist]

Since I don't have the use of my right foot, then I can't use my foot brake. I've actually linked both brakes to the front brake and this set-up works a treat. Most of the braking is on the front but the back brake is applied as well when I pull in the lever. The local bike shop tested the system and said that the distribution is about spot on. This is without the aid of any valves.

Only problem is that all my braking is now on the one system. The danger is that if one brake goes - they all go. Still, that's the way you'rs is at the moment. The other problem is that it's an MOT fail. I'm still saving up for a twin lever set-up which seems to be increasing in price quicker than I can save the money.

[ColleyV12]

My rear brake master cylinder failed, kept locking the rear disc, managed to ride for a while without rear brake, and thought I go used to it. Then kept locking the front up unexpectedly.

Replaced the cylinder with a new one, for the cost, not much point in repairing, now I can balance the brakes properly

Learnt at advanced riders, the difference in one brake to both in stopping difference, quite an eye opener

Worth fixing, brakes are important on a bike

[Shwat]

Ive been without a back brake for about 4 months now. Have to leave it until I have money to get it all sorted.

No accidents or anything near yet, engine braking is more than sufficient most of the time anyway I think

[shedmonkey]

I think the back brake is only good for ballancing the bike going into corners, its useless for anything else. The Guzzi system was back and one front on pedal and one front on hand (or was it the other way round?)

[Manfred2025]

This embarrases me a little bit, but I hope it helps someone: I thought I had busted my rear master cylinder right? (I suspected some aluminum dust had scraped the inside while fabricating my footpegs...) On my footpegs the master cylinder is retained in a near vertical manner. I decided to take it off completely and purged the system while the master cylinder was held in a 45 degree angle, with the ports "facing up". Boom. Rock solid rear brake feel in less than 15 minutes, without sirynge, mighty back or anything! Oh yeah, the caliper was held high, the brake line completely vertical and the purge nut at the highes point. The brake pads were pushed all the way inside the caliper before beginning to purge. I connected some transparent hose to the purge nut with some brake fluid in it. Mind you, that transparent hose was curved up so the brake fluid was always in contact with the purge nut opening. I opened the reservoir, filled with brake fluid and opened the purge nut. Then I pushed the brake pedal, closed the nut, released. Opened the nut, pushed the brake pedal, closed the nut, released brake pedal. I refilled the reservoir as needed and repeated.
It was purged in less time than I used to type this. When no more bubbles or foam was seen on the transparent hose I closed the purge nut definetely. Then installed the caliper back again. I pumped the brake a few times to make the brake pads reach the disk, refilled the reservoir as needed. Then the brake pads made contact and the brake has a perfectly solid feel to it, so no air was trapped inside at all.

Nevertheless being without a back brake for some days was worth it, because now I discovered that I was using it too much and I now think its overuse was a contributing factor on my tank slapper accident (which almost cost me a leg and my life). While braking with the front brakes only I finally felt the same control and confidence on the Raptor as I have with my KTM Duke.

[Manfred2025]

Since I don't have the use of my right foot, then I can't use my foot brake. I've actually linked both brakes to the front brake and this set-up works a treat. Most of the braking is on the front but the back brake is applied as well when I pull in the lever. The local bike shop tested the system and said that the distribution is about spot on. This is without the aid of any valves.

Only problem is that all my braking is now on the one system. The danger is that if one brake goes - they all go. Still, that's the way you'rs is at the moment. The other problem is that it's an MOT fail. I'm still saving up for a twin lever set-up which seems to be increasing in price quicker than I can save the money.

Thank you very much for your input Red Mist. Actually both brakes linked to the front master cylinder is a very interesting idea, the only problems I see with it are what you already mentioned, that a failure would leave you without any brakes at all and that the "distribution" of braking power now depends on the number of disks (two at front), diameter of disks and brake pad friction factor in front and rear. Has your back brake ever locked up with your setup?

[Manfred2025]

Ive been without a back brake for about 4 months now. Have to leave it until I have money to get it all sorted.

No accidents or anything near yet, engine braking is more than sufficient most of the time anyway I think

I agree, totally.

[Manfred2025]

I think the back brake is only good for ballancing the bike going into corners, its useless for anything else. The Guzzi system was back and one front on pedal and one front on hand (or was it the other way round?)

Could you elaborate more on that Guzzi system? Which bike used it?

[shedmonkey]

Most models apparently and yes 1 front disc and the rear opperate from the pedal and the other front from the handlebar its probably a better system for normal use, but if you live on the edge probably what we have is best, more independant control (not that i ride on the edge or anywhere near it ,unless something goes a bit wrong of course)

[Red Mist]

Thank you very much for your input Red Mist. Actually both brakes linked to the front master cylinder is a very interesting idea, the only problems I see with it are what you already mentioned, that a failure would leave you without any brakes at all and that the "distribution" of braking power now depends on the number of disks (two at front), diameter of disks and brake pad friction factor in front and rear. Has your back brake ever locked up with your setup?[/quote]

There is no danger of the back locking up at all. As I said, I had the bike tested on a rolling road and by happy coincidence, the brake distribution is near enough perfect. It may be partly to do with the smaller rear disc but it doesn't do too much. I pull the lever hard in an emergency stop and the front dives but the back stays under control.

I know that the back brake works a bit because I have checked it with the back end off the floor, so it has some effect. I think it works better than just having the front brakes which I have also done for a while before getting the back brake linked up.