Brakes

[olddog]

Just a Question on brakes, I have a 1983 R65 single disc and would like to know if fitting a second disc to improve braking is worth all the hassle.
The original disc was replaced with a cast one to try and improve the braking by the previous owner, the braking is not what you would call good. I have had front drums that were better, It does not instill confidence in an emergency braking stop, would fitting a floating disc help any or should I bite the bullet and fit the second disc + lines + master cylinder this is all going to cost heaps of money that I don't really want to spend if it is going to be for little gain........Thanks....Peter

[montmil]

Pete, I would likely question the replacement rotor work done by the PO. The single front disc setup on both my R65s, 1981 and 1983, are superb stoppers using OEM bits.

You're correct about the expense of going twin. Even going with a new BMW OEM rotor would be less expensive than upgrading to dual discs. Lots of bucks and you'll still not have an established baseline for performance comparisons. IMHO, stay single...  8-)

Monte

[Bob_Roller]

I would remove the caliper, and check the condition of the pads, they may be just 'glazed', and a little 'roughing ' up with some sandpaper, may improve your braking .

Try doing a brake bleed, and see if there is any air in the system .

Do you still have the OEM ATE rubber brake lines ?

If so you may want to consider replacing them, braided stainless lines don't cost an appreciable amount more than OEM, I myself wouldn't go back to standard rubber lines again .

If you go this far, as to replacing the lines, you may want to remove the master cylinder from the right handlebar grip, and take it apart, have a look at the cylinder wall, and condition of the 'cup' seal on the piston, they may need some work as well .

[Semper Gumby]

Hi olddog,

Is you bike a nekkid R65?  Or is it loaded down with stuff (Fairing, bags , top case etc.)

I remember when the Henna Red LS came out.  It had those dual Brembos and I was immediatly smitten with *brake envy*.

Of course I was at the time riding a clapped out 1975 CB550 Honda in 1983-4 with one rather weak disc.  

[drewboid]

My fiance rides the R65 - small hands and not a lot of hand strength. I added the second disk and all her stops became much shorter with more control. I'm convinced that it makes enough of a difference to be worth doing.
Cutting costs - you may not need to change the master cylinder. I originally did not and although the lever moved further it worked for her. I could get the lever to just touch the grip if I used all my strength. I have since changed to the larger diameter master cylinder because the original was leaking. She did not notice the difference but I could no longer force the lever back to the grip.
Do change to SS braided brake lines.
Rather than using a splitter I ran a new line from the bleed valve hole across the top of the fender to the second caliper. Less fluid and length of line and you can bleed the brakes through the second caliper.  It also makes for an easy change back if decide the second caliper is not worth it - just disconnect the new line and reinstall the bleed screw. There are many ways you can make this work - this one works for me.   YMMV

[olddog]

Thanks to all for the reply,s .... I have replaced the brake line with a braided unit, flushed the system with new fluid, and will look at the pads for glazing at the weekend, if this shows no improvement I will fit new pads and if need be a new O E M disc. I also note that there is a slight pumping and vibration evident on moderate brake application, so may have a warped disc will set up a dial guage and have a look at that as well..........Again thanks...............Peter