Wilsons Sandbox

Posted: **Thu Dec 11, 2003 2:36 pm**

> From: "Stuart Mumford" > Subject: RE: RE: Group purchase - Galfer 320mm disk > The kit I heard about does indeed involve a different (twin piston) caliper. > However, you have to wonder, with our spaghetti-like 38mm forks and a big > single disc and a better caliper, will the fork flex be out of the realm of > controllability?

Mike announced development of this brake kit on the list a while ago... Pay attention, folks! However, I thought he was planning on sticking with the stock rotor diameter and adapting the twin-piston caliper. I don't think I was able to lock up the front wheel like Stu, but with an EBC stock-size rotor and TufStop pads, I had very solid braking power. Considering that the stock rotor is 260 mm, going to a 320 may be overkill, especially with our forks. Watch that thing in the rocks, too. What we really need is an intermediate kit... With the KLX forks on my bike, I bought an EBC oversize kit with a floating 280mm rotor and caliper bracket for $150. If they made that for the KLR, it would be just the ticket. I'm running a KX caliper, which I suspect has smaller pistons than the KLX caliper, and I've only had a slight degredation in braking over the old setup. If I adapted the KLR caliper, or once I get the KLX caliper, I suspect it will be very strong. Krokko -- Dr. J. Christopher Krok John Lucas Adaptive Wind Tunnel Caltech MS 205-45, Pasadena, CA 91125

Posted: **Mon Dec 15, 2003 10:54 am**

> From: "Mike T" > Subject: RE: Re: Kawasaki Canada doesn't know about the doohickey ???? > > Dang! To loose a buyer due to this balancer adjuster issue has got to get be > made known to Kawasaki.

It's not the "issue" that lost a buyer, it's the hype.

> and the brake upgrade, which is awaiting Big Cee input (no rush).

Huh? My input was that my stock brakes were great with an EBC aftermarket rotor and TufStop organic pads, but that if EBC made their MX Oversize kit for the KLR, it would be the ticket. Now, I have a KLX front end, so I have no relevant input. Krokko -- Dr. J. Christopher Krok John Lucas Adaptive Wind Tunnel Caltech MS 205-45, Pasadena, CA 91125

Posted: **Tue Apr 13, 2004 5:57 pm**

> From: Devon > Subject: Re: Re: brake systems > > It makes the brakes far less tolerant of air bubbles, misfitment of > pads, and misalignment of calipers. If everything else is properly set > up you will still be able to pull the lever back to the bar, but the > front will be locked after 1/2 or 2/3 travel, with warm tires on clean, > dry pavement.

Maybe not. Even with everything else worked out, the caliper piston still has to move some small distance (due to seal flex?) to put the pads in hard contact with the rotor. With a smaller master cylinder piston, you'll have to move the lever further to begin generating braking force.

> The pressure you are capable of generating, yes. But the pressure > applied to the pads is dependant on MC size AND caliper piston size. > > Works just like gearing. The MC piston surface area is the countershaft > sprocket, the total caliper piston area is the rear sprocket.

Um, that's exactly what I was describing. In this case, the master is the same, so the pressure on the pads is dependent on the caliper piston size. Krokko -- Dr. J. Christopher Krok John Lucas Adaptive Wind Tunnel Caltech MS 205-45, Pasadena, CA 91125

Posted: **Tue Apr 13, 2004 7:00 pm**

On the subject of master cylinder size... I experimented with master cyclinder size on my 1992 BMW R100RT when I upgraded the calipers from 2-piston (Airhead) Brembos to 4-piston (Oilhead) Brembos. The extra system volume of the 4-piston calipers put the brake lever easily against the handlegrip with the stock 13mm master cylinder. I thought I didn't have all of the air out of it. I changed it to 15mm and the lever would not bottom, though it would come close if squeezed mightily. The brakes were very responsive and progressive. I could hold the brakes at a rolling slide where the front tire was singing loudly, but the wheel was still moving enough to maintain directional control and stability. Obviously I could lock it as well, but what's the point in that? I didn't have enough front tire traction (or hair on my ass) to do a stoppie. I tried a 16mm and it was too far the other way. The lever felt much firmer, but it took more force to stop and the feel was not as progressive and controllable. From this I learned that there is an optimum size for each hardware setup. I imagine that the 15mm would have been too big for the stock 2-piston calipers even though it was the best of the bunch for the 4-piston calipers. More is not always better and the sweet spot is usually in the middle somewhere. Lee / Colbert, GA USA

Posted: **Tue Apr 13, 2004 7:21 pm**

stingray@... wrote:

>> From: Devon >>Subject: Re: Re: brake systems >> >>It makes the brakes far less tolerant of air bubbles, misfitment of >>pads, and misalignment of calipers. If everything else is properly set >>up you will still be able to pull the lever back to the bar, but the >>front will be locked after 1/2 or 2/3 travel, with warm tires on clean, >>dry pavement. >> >> > >Maybe not. Even with everything else worked out, the caliper piston >still has to move some small distance (due to seal flex?) to put the >pads in hard contact with the rotor. With a smaller master cylinder >piston, you'll have to move the lever further to begin generating >braking force. >

When I did the dual rotor setup on my SR500, it was just like Lee described with the lever going back to the bar. I bled, bled, and bled some more. Used a Mityvac. Finally asked around and the guy at vintagebrake.com said that's exactly how it would feel with the setup I had. And to go ride it and see how it worked rather than making decisions sitting in the garage. Ended up being a lighter touch, and more progressive than the brakes on my buddy's '97 900SS. I doubled the caliper piston area, and though I had a very soft lever, the brakes are excellent. Laughably, ridiculously good for a 34hp air-cooled single. -- Devon Brooklyn, NY A15-Z '01 KLR650 '81 SR500 cafe racer "The truth's not too popular these days....." Arnold Schwarzenneger, in The Running Man

Posted: **Wed Apr 14, 2004 10:47 am**

> > I doubled the caliper piston area, and though I had a very soft lever, > the brakes are excellent. Laughably, ridiculously good for a 34hp > air-cooled single.

Yeah, but you _doubled_ the brakes, right? Even at half as much pressure in the system, you'd still get the same amount of braking. What I'm saying about the KLR system is that the stock setup (even with braided line) can bring the lever close to the grip, and going to a small master will only make it go farther, and you might not be able to generate the same amount of pressure as before when it bottoms. I'm not sure I agree 100% that lever travel is easier to modulate than pressure... I think there's a happy medium there, too. On rough terrain, I'm already moving around enough; it's nice to have resistance in the brake lever to work against. Might just be a matter of what you're used to. The KLX master I found has an "11" cast into the body on the cylinder, so I'm guessing that it's an 11mm. The stock one looks like it has a "1/2" cast on its cylinder (hard to see behind the guard), so that should be a 12.7mm. The difference in piston area is 95 sq mm vs 127 sq mm, which is pretty signifigant. Just have to wait for a pressure switch bolt, and I'll hook it up and see how it works with the KX caliper. The KLX cylinder also has a shorty lever with an adjustable reach... Could be nice. Krokko -- Dr. J. Christopher Krok John Lucas Adaptive Wind Tunnel Caltech MS 205-45, Pasadena, CA 91125

Posted: **Wed Apr 14, 2004 11:20 am**

stingray@... wrote:

>>I doubled the caliper piston area, and though I had a very soft lever, >>the brakes are excellent. Laughably, ridiculously good for a 34hp >>air-cooled single. >> >> > >Yeah, but you _doubled_ the brakes, right? Even at half as much >pressure in the system, you'd still get the same amount of braking. >

I'm told the best bang-for-the-buck setup for an SR500 is ONE lightweight aftermarket rotor, one caliper, stainless line, and an 11mm master cylinder.

> >What I'm saying about the KLR system is that the stock setup (even with >braided line) can bring the lever close to the grip, and going to a >small master will only make it go farther, and you might not be able to >generate the same amount of pressure as before when it bottoms. >

That makes me wonder if your caliper bracket isn't bent. As you got down to the last 1mm of pads, did you get a firmer lever? With a stainless line, and all else stock, I couldn't pull the lever more than 1/2 to the lever. I could make the tire howl on dry pavement, and just lock it with a four-finger death grip. If the caliper was misaligned, by even 1-2 degrees, this would require a lot more pad movement to get full contact with the rotor.

> >I'm not sure I agree 100% that lever travel is easier to modulate than >pressure... I think there's a happy medium there, too. On rough >terrain, I'm already moving around enough; it's nice to have resistance >in the brake lever to work against. Might just be a matter of what >you're used to. > >The KLX master I found has an "11" cast into the body on the cylinder, >so I'm guessing that it's an 11mm. The stock one looks like it has a >"1/2" cast on its cylinder (hard to see behind the guard), so that >should be a 12.7mm. The difference in piston area is 95 sq mm vs 127 sq >mm, which is pretty signifigant. Just have to wait for a pressure >switch bolt, and I'll hook it up and see how it works with the KX >caliper. > >The KLX cylinder also has a shorty lever with an adjustable reach... >Could be nice. >

Which KLX is that off of? I want one. Devon

Posted: **Fri Sep 03, 2004 6:21 am**

One of the highly recommended mods for our KLRs is to improve the front brake. I can lock up the front wheel on my A18 on the street. It does require a healthy squeeze. I'm wondering if Kawasaki improved that recently. The KLR's braking seems linear and adequate. Not great, just OK. But I don't see the need to improve it - yet. Not a big guy, I'm only 168 pounds - maybe that makes a difference...? Mike

Posted: **Fri Sep 03, 2004 6:57 am**

--- In DSN_klr650@yahoogroups.com, "Mike Frey" wrote:

> One of the highly recommended mods for our KLRs is to improve the front > brake. > > I can lock up the front wheel on my A18 on the street. It does require a > healthy squeeze. I'm wondering if Kawasaki improved that recently.

The KLR's

> braking seems linear and adequate. Not great, just OK. But I don't

see the

> need to improve it - yet. > > Not a big guy, I'm only 168 pounds - maybe that makes a difference...? > > Mike

I agree, I have no troubles, it is bit weak, but so is the traction on DOT knobbies. Drive accordanly and no problems. Not a traveler so the brakes are fine for me. Dooden A15 Green Ape (still waiting to leave to the woods)

Posted: **Fri Sep 03, 2004 7:20 am**

Add 40 lbs of body fat, 20 lbs of tools, spare tubes, 30 lbs of luggage/rain gear/cloths/dry socks, a street oriented front tire THEN see if you can lock the front tire.

--- In DSN_klr650@yahoogroups.com, "Mike Frey" wrote: > One of the highly recommended mods for our KLRs is to improve the front > brake. > > I can lock up the front wheel on my A18 on the street. It does require a > healthy squeeze. I'm wondering if Kawasaki improved that recently. The KLR's > braking seems linear and adequate. Not great, just OK. But I don't see the > need to improve it - yet. > > Not a big guy, I'm only 168 pounds - maybe that makes a difference...? > > Mike

Wilsons Sandbox

pilot screw / idle mixture screw????????

front brakes

front brakes

front brakes

front brakes

front brakes

front brakes

front brakes

front brakes

front brakes

front brakes