New Rotors and Pads...

Hello!

I just put on new rotors, brake pads, and stainless brakes lines on my 1982 xj750! It is stopping a lot better than before, it is solid! But, one thing I notice is that that right rotor is grabbing a bit more the the left. (There is more brake material on the right side.) After doing hard stops, you can also feel a 20 to 30 degree difference in temparature between the two. (It's never too hot, I can always touch it without burning me)

So, any suggestions? Anyone had this problem?

Thanks!

 

Did you rebuild the calipers and master cylinder? On the surface, I'd say you've got a caliper hanging up.

 

Is it possible that there might be a little air left in the system on the side that is hanging up? If there is, then with the brakes getting hot the air is expanding and causing it to grab a little more.
Just a thought.

 

You say there is more material on the right hand pads. Do you mean one set is new and one worn, if so maybe different makes/specs?

I would think having new, matching pads all round might go some way to address your issues.

Fitz asks a pertinent question though - have you rebuilt the calipers? If not then you ought to do to get the best out of your upgrade.

 

not just to make the most of the upgrade.

To keep a caliper from hanging up. THEY DO THAT when they're 30 years old and then you suddenly start putting them through heat cycles and expecting them to work like when they were young.

We replace "perfectly good" original brake lines because 30 years far exceeds the recommended 4-year lifespan and we're not stupid, we can do the math.

The original caliper and master cylinder seals had a TWO YEAR recommended lifespan. Why should they be expected to perform as they did when new? THEY AIN'T GONNA, especially the caliper seals (that heat thing again.)

SO

If you didn't rebuild your master cylinder and calipers, then you didn't do a complete rebuild on the brakes.

You wanna see 18? 19?

Fix the brakes. You have much bigger things (like trucks) to worry about; you'll NEED those brakes.

 

pads rotors + lines ain't gonna make a bit of difference if the calipers don't work right....

 

Alright, I'm going to now! Just keep the money flowing. :/ But, on the brighter side of things, considering what I paid for new rotors, and for the medical bills of medical bills, this saves the money, and my life.

I hope I didn't screw up my new rotor, only had 10 miles on it to bed the brakes.

 

Ohhhh! Do you guys know of any how to's for rebuilds of the master cylinder and the calipers?

It is much appreciated!

Thanks!

 

Use the "Search" feature.

There are "How-to's" galore.

When you set about doing the Brakes, ... replace the Brake Lines with Stainless-wrapped Brake Lines.

 

Talking of braking performance, mine seem a bit wooden...

I rebuilt the calipers with new seals, re-built the m/cyl and fitted braided steel lines. All this was two or three years ago when I built the bike.

Whilst the brakes are adequate, I do find I have to use the back one too to stop quickly (something I don't usually do on my other bikes).

One thing I have noticed is that the discs seem a little glazed with some kind of dark deposit - perhaps some new pads would be in order as these may be contaminated from sitting around with other parts prior to the build.

 

I know there is supposed to be some pad material on the rotors, adhesion is one of the ways the bike stops. I would check to see if your rotors are getting hot, the hotter they are, the longer it takes to stop.

And on a side note, it is very important to use the rear brake all of the time! It only accounts for ten or twenty percent of braking power, but in a panic stop, you need be in the habbit of using it correctly! If you're not used to it, it is very easy to lock the rear wheel!

 

Using, or not, the back brake is a matter of personal preference. Brakes on modern bikes are so good that the back brake is not required at all. If you watch Moto GP riders for example, very few of them ever touch the back brake - Nicky Hayden being the only exception I can think of.

The only time it is really useful is to keep the bike level mid-corner if a little speed needs to be lost whilst keeping fore and aft balance... If used under heavy braking there is always a good chance of locking it up and throwing the bike off line. You'd be surprised just how hard you can use the front brake safely, once you've allowed a split second to load the forks.

 

Well, that's not what the Ohio department of public safety thinks. I took motorcycle safety classes, and I was taught to always use the rear brake. That is what I'll do. I'm no pro, but I believe in the way I was taught. And the front can do a lot of stopping power, but one day you may need the 20 feet you got from the rear brake...

Not a risk I will take!

 

I went on an advanced bike course a few years ago and we only used the front. You can virtually stop in 20 feet from 60mph on the front alone - doing this your rear wheel will be off the ground anyway - so no rear brake required. To do this, of course, it helps if you know you are about to apply the anchors - ie you've looked ahead and decided your braking point.

In theory the best way to avoid an obstacle (eg if a car pulls out in front of you and stops across your intended path) is to quickly lose speed then let the brakes off again and steer around it. Like all theories, you may not have too much time to think about it in practice. In those conditions you don't want to be reaching for the back brake lever, as you'll stomp on it and you will lock up.

However, as I said, it's a matter of personal preference and plenty on here may disagree with me, including Ohio Dept of Public Safety.

Ride your bike in the way you want to, main thing is to be able to stop in time whichever method you choose.

Ride safe...

 

And if you don't have ABS on the front...or you're on gravel / ice /wet etc...you'll lose the front end........the best the rear can do is offer some stabilty to your braking....remember, "accidents" and "emergencies" are usually due to someone's error, lack of anticipation, poor observation, speed, drink etc. etc.

 

Yes! And I'm not trying to say that you are wrong NigeW! It's just what I am comfertable with! I don't think I have the stones to brake so hard that my back wheel is off the ground! And I always ride safe! I just always use the rear brake, and mostly the front!

 

You should ride as if the Bike didn't have brakes!
Be in control at all times.
Once you exceed 35mph; you're at the mercy of Vector Forces.
A Gross 16 Sq. In. of Tire "Contact Patch" isn't much of a Friction Patch to offset the Inertia.

This Web Site and the Book "Twist of the Wrist" by Keith Code present solid information for understanding -->> Speed Control - Emergency Braking - and Staged Braking to fast-stopping without Loss of Control.

http://www.webbikeworld.com/Motorcycle- ... g-tips.htm

 

...and believe me, the last person you want to meet up with is
VECTOR FORCES 8O 8O :roll:

 

Took an orbital sander to the discs (outside surface only) to clean 'em up - result, much better braking.

 

NigeW .. reads like you've got contaminated pads,oil? my rotors only have used pad dust on 'em.

 

I think you're right. They were old pads that came with the bike... must order some new ones.