Combining brakes on racer...

[Derrick Adams]

Here's the scenario. Through out this racing season i've had several occasions where i've hit the back brakes coming into a corner and killed the engine on the 250R. At best causing me to have to restart the bike, at worst loosing positions because of it (this happened more than once).

As a result of this issue, I found myself using the front brake more and more while racing to insure that I don't run into the same problem. What this does is actually make me come into corners slower (never good) and can make the bike a little tippy in certain areas because i'm loading the front wheel soo much.

So my first solution to this issue was to just simply remove the front brake and practice that way until I get the hang of it.... But I find it much easier to reach the front brake lever at all times while racing vs. trying to position my foot to hit the rear brake.

So I came up with the idea of switching out the front master cylinder to a Quad unit (designed for 2 calipers) and running a second brake line to the rear brake with an inline adjustable proportioning valve. I could then adjust how much brake pressure I apply to the rear brake while applying full pressure to the front brake. All from the front brake lever.

So let's here your opinions.

[tyman]

sounds like a good idea.... wouldn't see why it wouldn't work.... good luck...

[200xcellent]

I think all you need to do is practice using the rear break only and ALWAYS have at least one finger on the clutch. It will become second nature eventually to grab enough clutch right before you hit that back break then knock it down a gear, give the throttle a stab and dump the clutch. I had to make a conscious effort to do this everytime and it is just habit now.

[88 Turbo Coupe]

Your watching too much F1. lol I would use a brake compound that is hard and not have a tendensy to lockup your rear. If you saw that videao on you tube that someone posted a couple of weeks ago 85 atc race in bridegeport NJ, watch the first corner start. The rider who got second position locked the back brakes , slid sideways and with his momentum bump started his bike. If your not on it hard use the front brakes. Ive stalled but was able to bump start. Most the time. Or you can try removing some of the brake pad from the plate.

[BigGreenMachine]

Yeah I've locked and stalled just fooling around. I don't think intergrated brakes are going to fix the problem. In fact I'd see them restricting you more then solving anything.

I know some Polaris quads use this system and most mags frown on it for performance riding.

[TimSr]

First off, what kind of shape is your clutch basket in? My R was really bad for this, because until I got a billetet basket, it was always getting grooved, and the clutch wouldnt let go enough to keep it from stalling when I locked the brakes.

What I found to combat this situation was to not use the clutch for braking and shifting in corners. Sounds like it would be worse, but if you lock the rears up, as soon as soon as you let off the brake it restarts.

[3leggeddog]

yes,great point tim.derrick i do not like this idea at all.maybe great for somethings,and is a hellofa idea,but man,it's silly.just like usin those brakes in the air,you just practice it.

let's break this down for a moment.you only do this when.......when you holeshot me.what else do you do when you holeshot me...........hit 60 for table tops wde open in 5th gear,over shootin em,and landing on your rear.

so with that said,i think the problem is more you being excited,and not focused,more then just lack of skill,or effort.when i'm trin to ride too hard,mistakes happen.i stalled my bike once this year,when i was in front of brian at smith road.why,cause i was too fast,and looking for him rather then just ridin my own race.

not cuttin on ya just how i see it.!!

[Billy Golightly]

I use the front brakes way more often then the rears anymore just because they are more accessible. When I'm coming into a corner I'm already off to the side and its easier for me to grab the lever instead of the foot pedal. I think you should try maybe changing the way they work. Make the bars operate the back, and the pedal operate the front. Thats what I've been thinking about doing anyways. That might take a little bit of getting use to for hill climbing though

[TrikeKid]

Just work on having a finger or two on the clutch at all times, once you get used to it it will just be automatic, thats what I do off road where how delicately you control the rear tire decides if you can make it over an obstacle.

[ATCWRENCH]

you could always install a rev-tech clutch. never have to wory about stalling again considering they are a auto clutch design that a lot of mxers use to help with cornering on tight tracks

[atctim]

Derrick - this is one of the most innovative ideas I have heard in a while. Some Honda touring bikes started incorporating this in the late 90's. I know the Honda ST1100 was set up this way. A lot of bikers liked it and a lot did not. The one and only problem I see with this is not being able to lock up just the rears to get your slide started going into a corner. Other than that it sounds great. If there was a way to incorporate the foot pedal being rear only and the front handle being both - that would be the hot setup! Let us know how it goes if you decide to do this. Possibly you could find what you needed parts wise off of a wrecked / salvaged Honda ST1100.

Here is a link for more ideas and brainstorming:
http://www.superblackbird.com/lbs.cfm

[ATCWRENCH]

getting the front master to operate the front and rear and have the rear master operate the rear only wouldnt be difficult to set up, finding the parts to make the setup might be.

you would need a Y-shaped fitting that had 2 one way valves just before the 2 lines go into one. reason is, if you didnt have any kind of valve in the fitting and you stomped on the rear brake pedal the fluid would pressurize the caliper first then it would start to pressurize the front master cylinder and front caliper as the excess fluid needs somewhere to go once the rear caliper has pressurized.

you could even set up a metering valve for the rear caliper from the front master cylinder so you can get good usable stopping power from both ends but if you need to lock up the rear end you can still stomp on the rear pedal and override the valve and use full braking pressure from the rear master cylinder.

[atctim]

But if it is a one way valve - how could pressure be released back up to the hand control once pressure was applied from there. there would almost have to be some kind of equalizer that back feeds the hand control in a different route. Like some sort of closed loop or something

[ATCWRENCH]

But if it is a one way valve - how could pressure be released back up to the hand control once pressure was applied from there. there would almost have to be some kind of equalizer that back feeds the hand control in a different route. Like some sort of closed loop or something

the valve would work by pressure both ways, not spring loaded but a free floating ball. both valves will operate the same. when pressure is applied to the rear caliper from the front master the ball in the valve will be pushed into an oblong hole that will still allow fluid to pass around the ball. now since I suggested a metering valve before the Y-valve, the fluid pressure after the metering valve will be considerably less than what the rear master cylinder would be able to obtain. Now when you apply pressure to the rear caliper from the rear master cylinder it will over come the pressure that is generated after the metering valve and push the ball in the valve towards the other side of the valve into a hole that will create a seal that will not allow fluid to transfer back up to the front caliper and master cylinder.

now when no pressure is applied at either end the ball in both valves will relax and allow the fluid to equalize and there will be no pressure on either caliper.

sorry for being windy and complicated

[4cylinders]

hey, antilock hiteck, I'd work on finding a way to keep the rear brake from locking up so easy. maybe different pads, adjustment, or even a different pedal or length. that's what racing is all about, innovation.