How much travel at your front brake lever?

[KEITH KRAUSE]

Help me out guys.
I need you to go get a ruler and measure how much travel you have at the lever.
I'm not allowing for that small 1/8" of slack before the lever actually touches/pushes the piston/cup assembly. And I'm not allowing for a hard squeeze either. Just the amount necessary to stop the bike and compress the forks a little after you push it forward a little with your feet.
So the distance from where contact actually starts until a moderate pull at the lever.
Please be accurate. I'm trying to figure out if I have a problem and need some bikes to compare mine to. Thanks a lot!

[tconroy]

Help me out guys.
I need you to go get a ruler and measure how much travel you have at the lever.
I'm not allowing for that small 1/8" of slack before the lever actually touches/pushes the piston/cup assembly. And I'm not allowing for a hard squeeze either. Just the amount necessary to stop the bike and compress the forks a little after you push it forward a little with your feet.
So the distance from where contact actually starts until a moderate pull at the lever.
Please be accurate. I'm trying to figure out if I have a problem and need some bikes to compare mine to. Thanks a lot!

I have right at 1/2" or a hair over. It's hard to hold the ruler and brake with the bike going forward all at the same time.Plus there is no spongyness at all.With the front wheel proped up off the ground it will stop the wheel solid at 3/16ths of travel. I hope that helps you because you have helped me so much its the least I could do!!!!

[Clone]

4-5mm, I would say next to none. When I grab the brake it is pretty instantaneous. I cannot pull it all the way to the grip and i even have big foamy grips.

[KEITH KRAUSE]

Thanks for the reply. Hard to believe you only have 1/2" travel to reach moderate braking. My travel WAS right at 1" and that was with the pistons sticking too far out because of swelled seals. I found 1" travel was great for feel but I knew it was related to a malfunctioning brake system.
My pads were starting to drag on the rotors and it was because I ran silicone Dot 5 fluid and it swelled the seals. With the pistons not retracting correctly after releasing the lever, it took only that 1" before solid braking took place. I would think 1/2" would suggest you have a brake problem similar or worse than what I had before my seal replacement.
Anyway, to let you all know what's going on now, after replacing the seals with genuine Suzuki and changing the fluid to the "new" 5.1, I now have 1 3/4" of travel before noticable braking takes place. So I've gone from too little to what feels like too much travel. I'm about as sure as I can be that the brakes have been bled correctly. I bled them the same way I always have. The pads and fluid amounts are good too. I run SS lines.
You can imagine, especially after riding the bike awhile with the original problem/lack of travel, the 1 3/4" present travel feels wrong. It doesn't feel spongy, just too much travel to get to solid braking.
So I'm asking anyone out there with a known good front braking system, please measure the travel as I said above and let me know what you've got.
If I do have a travel problem, you would typical blame air in the system but I bled them through an entire 3 reservoirs full AFTER the last bubbles were seen. I can't believe there's air still in there.

[KEITH KRAUSE]

And in case I'm not being clear about what point to measure at...
I'm not talking about the pinch point of the lever, I'm talking about at the end of the lever, where the ball/tip is. What distance does your lever travel before moderate braking force is being applied. Thanks!

[bwringer]

Measured at end of the ball on the end of the lever, my 1983 GS850G brakes engage firmly at 16mm (5/8 inch). Very hard braking might take them to 21mm or 22mm. Stainless brake lines rock. \\/

The brake on the 1990 VX800 also engages firmly at 16mm, and has a slightly harder feel since there's only one (stainless) line and one, more modern dual piston caliper. Hard braking takes it to about 21mm.

Even though the GS weighs about 100 pounds more than the VX, the GS850's dual calipers give more braking power and feel than the VX800's measly single caliper. Neither bike can touch the brakes on a more modern sportbike, but with the stainless lines, the GS brakes are pretty dang good.

[Boondocks]

My lever travel is about the same as Brian's.

I'm sure that you know now that DOT 5 silicone based brake fluid was not a good choice, and is not recommended for use in our bikes. Spongy brakes due to compressibility are only one of the concerns. Since your problems haven't cleared up after switching to DOT 5.1 (Super DOT 4), I would think that the prior use of DOT 5 is responsible. The silicone based DOT 5 is notoriously difficult to remove.

An expert's advice at DOT 3-4 Verses DOT 5. Which brake fluid should I use? states that once DOT 5 is used it is so tenacious that you will never get it out of your system, and recommends not trying to change back to a non-silicone brake fluid.

[SqDancerLynn1]

Try the rubber band trick . Wrap a lg rubber band / cable tie around the lever & handle to lightly apply the brakes. Leave it over night. I usually use a piece of vacuum hose into a sm bottle with some brake fluid in it. submerge the hose, open bleader screw & slowly blead brakes- watch fluid for bubbles

[denydog]

My lever moves one inch before firming up. One and a half inches with a hard pull.

I have the SS braklines, but the cylinder also has to actuate the antidive plumbing and the hydraulic brake light switch, which requires extra lever movement.

[Captk]

Mine travels from 16 - 20 mm and thats from the point where you can feel the brakes actuate to the point wher it's impossible to push the bike.

I have the Anti- Dive gear on mine and changed the fluid about 6 weeks ago as part of routine maintenance.

I've got one of those little brake bleeding kits, which is just a clear line with a one-way valve attached.

The way I was taught to bleed them is like this....

1) Bleed F/Left AD till new fluid shows
2) bleed F/Left Brake - new fluid, no bubbles
3) Bleed F/Right AD till new fluid shows
4) Bleed F/Right Brake - new fluid, no bubbles

In other words you're working from the furtherst point away from the master cylinder to the closest point.

Hope this helps.

[KEITH KRAUSE]

OK. Thanks for those replies. I've got 1 3/4" to solid braking.
I have to think it's the silicone. I suppose it could be air, I mean, you can't actually see inside the parts, but I've never had a problem bleeding air out before.
I had the parts completely taken apart, trying to remove any silicone residue. I did read that article and will re-read it. The only parts that could still have any residue would be the brake lines. For the lines, the only thing I could think of to do was to flush some contact cleaner through them that leaves no residue itself. I followed that with fresh fluid. Per that article, it said some solvents could leave a residue as bad as the silicone. That's why I decided on the contact cleaner. I had to try something that seemed "clean".
How exactly does any very small amount of silicone left inside cause excessive travel??? I don't get it.
If that's the case, I guess I'd have to go back to silicone and possibly live with replacing my seals sooner than normal. All because there's some tiny amount of silicone still sticking to my lines?
Odd thing is, I used silicone since 1980. I had absolutely no problems and had the original caliper piston seals in there until 1999. Then, as part of my restoration, I replaced the seals with genuine Suzuki seals about 6 years ago. Awhile back, the pistons started sticking and it appears it was due to the silicone swelling the seals. The pistons couldn't retract. I saw no evidence of corrosion or wear in the bores or any problems with either piston, so I have to believe the seals were the problem. Now I have this excessive travel. The other strange thing that's not jiving with you guys is that as the dragging/sticking got worse, the lever travel lessened. At 1" I had to fix it. I know I had more than that before the problem. Now you guys say you have even less than me. I'm totally confused here.
I'll re-read that atricle. Any other help on what you would do or have heard of is appreciated.

[waterman]

Keith, have you inspected your master cylinder for blockage? If I understand correctly, you have noticed that the brake lever requires less travel to activate and the brakes are sticking or seem that the brake pads are not retracting. I question whether it is the brake caliber piston seal swelling or it is a blocked return hole in your master cylinder. I struggled with non retracting, locking pads until I cleared the small brake fluid orifice in the master cylinder. The symptoms were similar, very little brake level travel and locking brakes. After the fix it seemed as if the brakes were weak since I was used to the short lever travel.

Before I had fixed the problem I would bleed a little fluid out of calipers before each ride. My lever travel would increase and the brakes didn't seem so sensitive. Check to see if after you apply brakes and let off if you still have pressure in calipers by opening bleeder screws. If fluid spuirts out, I would suspect master cylinder needs attention.

I have had good luck bleeding brakes by loosening the master cylinder banjo nut connection. It seems that the air will collect at this higher elevation. To do it just squeeze lever while cracking bolt until fluid comes out. Yes it does make a mess. Good luck.

[Boondocks]

OK. Thanks for those replies. I've got 1 3/4" to solid braking.
I have to think it's the silicone. I suppose it could be air, I mean, you can't actually see inside the parts, but I've never had a problem bleeding air out before.
I had the parts completely taken apart, trying to remove any silicone residue. I did read that article and will re-read it. The only parts that could still have any residue would be the brake lines. For the lines, the only thing I could think of to do was to flush some contact cleaner through them that leaves no residue itself. I followed that with fresh fluid. Per that article, it said some solvents could leave a residue as bad as the silicone. That's why I decided on the contact cleaner. I had to try something that seemed "clean".
How exactly does any very small amount of silicone left inside cause excessive travel??? I don't get it.
If that's the case, I guess I'd have to go back to silicone and possibly live with replacing my seals sooner than normal. All because there's some tiny amount of silicone still sticking to my lines?
Odd thing is, I used silicone since 1980. I had absolutely no problems and had the original caliper piston seals in there until 1999. Then, as part of my restoration, I replaced the seals with genuine Suzuki seals about 6 years ago. Awhile back, the pistons started sticking and it appears it was due to the silicone swelling the seals. The pistons couldn't retract. I saw no evidence of corrosion or wear in the bores or any problems with either piston, so I have to believe the seals were the problem. Now I have this excessive travel. The other strange thing that's not jiving with you guys is that as the dragging/sticking got worse, the lever travel lessened. At 1" I had to fix it. I know I had more than that before the problem. Now you guys say you have even less than me. I'm totally confused here.
I'll re-read that atricle. Any other help on what you would do or have heard of is appreciated.

If you don't have stainless steel brake lines, your lever travel will be greater due to the expansion of the OEM rubber lines. If brake components are dragging/sticking, they are not returning to the fully relaxed position, in effect being partially "on" all the time. Thus it would seem that less lever travel would be required when brake components are starting from an "almost on" position. The sticking parts are typically caused by fluid contamination or air pressure in the lines.

DOT 5 sometimes gets blamed for seal damage, but it is usually caused by contamination of the brake fluid. The article at DOT 5 Silicone Brake Fluid Warning has some interesting contributions about contamination. Contact cleaner that I have used is mostly alcohol. According to the link, flushing with alcohol can cause problems. Flushing should be done only with DOT 3 or DOT 4.

The article at Understanding Brake Fluid is one of the best.

There are also interesting articles at DOT 3 vs. DOT 5 Brake Fluid and
Brake Fluid Does Wear Out

[flyingace]

If you're still collecting samples, I have box stock lines and hardware with 1 inch of lever travel before braking begins.

[Metal Jim]

Brake bleeding.

Keep in mind also that aftermarket handlebars car create new high points in the system that could be difficult to purge air from. If your master cylinder outlet is angled up, count on air in the pocket. You can always pull your master cylinder off the bar (leave hydraulics connected) and straighten out the line as best you can for optimum gravity bleed or in worst case, wet build from the caliper up. Keep on tapping, one bubble is enough to affect feel. There is no "give" in hydraulic fluid (for our purposes), so feel is an issue of containment. Given stainless lines, something else is getting out of the way.