Single Disk improvements

[rocketman]

AFter getting my LT I realized just how weak the single disk on my 78 R100/7 was and started looking at options for improving it. Seems it boiled down to several options as list below: (the early airhead disk systems had the cable operated master cylinder, which was under the tank)
1. Replacing the whole front end to go to dual disks was not really cost effective, ($1000) or
2. Rebuilding just the one side to add a lower fork leg to take a second disk wasn't much cheaper or
3. change out the brake line from rubber to braided and/or
4. replace the handgrip with a later model grip with the master cylinder on the handlear ad get rid of the cable portion (since it stretches its not as positive as having the handle operate directly on the master).

The last two are best done at the same time or in stages but it would seem that they are the two things you can do that will give you the most bang for the buck.

What I have done so far on my 78 is replace the brake line with a steel braided one and let me tell you (which is the point of this post) it has made a VAST improvement in the airhead's brake response/feel. It is much more responsive and the feed back much improved. So I'd have to say that if you're looking for the easiest and most cost effective upgrade, I'd say get rid of that old rubber line (which for all I knew was the original 30 year old one, which is why I started looking at options before replacing just that or doing more).
I do think I will now get rid of the cable, which will cost me around $200 or so for the new/used handle and parts for a rebuild (since I won't know the age of the parts) before installing, and considering the improvement with the new hose, I expect that with the cable protion removed I should see equally positive results.

So anyway just thought I'd share, I know there are lots of folks with the old setup who might be interested in my results to date.

RM

 

[BOXERR]

Not sure on your brake setup, but on my 1990 R100GSPD, I have fitted a 6 piston caliper to the original disc, with braided line, and this setup is unreal.

It is a big thing over at ADVrider, and some are using 4 piston calipers as well.
If you are changing out the hand control, something like this maybe a good option.

As I stated though, I have no knowledge of your type of brake system, so this may not be an option.

 

[sumran]

I had similar results when I changed my brake lines. I have been told by folks I respect that I would have gotten a large improvement replacing them with new rubber lines as well.

The factory pads do not have the same stopping power as some of the aftermarket pads. There is always a compromise made between pad life and friction. I will opt for quicker stops and more frequent pad replacement.

A floating rotor should also improve the system, due to improved alignment under braking stress. Costly for me since I have three rotors. I am looking for a set of carriers so that I can get the floating rotors without taking the bike off the road.

 

[Darryl Cainey]

Carriers for sale!

I had similar results when I changed my brake lines. I have been told by folks I respect that I would have gotten a large improvement replacing them with new rubber lines as well.

The factory pads do not have the same stopping power as some of the aftermarket pads. There is always a compromise made between pad life and friction. I will opt for quicker stops and more frequent pad replacement.

A floating rotor should also improve the system, due to improved alignment under braking stress. Costly for me since I have three rotors. I am looking for a set of carriers so that I can get the floating rotors without taking the bike off the road.

I have a set of 1977 BMW Carriers for sale with worn our rotors.

Make an offer?

Darryl

 

[krehmkej]

A PO installed a floating cast iron disc on my '78 /7. This, along with Ferodo pads suggested by Vintage Brake, rebuilt MC and WC, and SS line give OK braking. Considering the vintage, it's acceptable.

 

[rocketman]

Not sure on your brake setup, but on my 1990 R100GSPD, I have fitted a 6 piston caliper to the original disc, with braided line, and this setup is unreal.

It is a big thing over at ADVrider, and some are using 4 piston calipers as well.
If you are changing out the hand control, something like this maybe a good option.

As I stated though, I have no knowledge of your type of brake system, so this may not be an option.

I looked into that as well and if I went to a dual disk setup I would have upgraded the calipers as well, I believe anything after 83 or there abouts used the newer Bremo system, but I have also heard that the fork legs on my 78 are considered better than the later models with dual setup. Can't confirm that though. As I said this seemed like the best bang for the buck, but I couldn't see spending a $1000 on a 30 year old bike I paid $2200 for with (now) 175K on the clock.

I also use EBC brake pads and have since I got the bike back in 99.

RM

 

[JohnnyMoto68]

This is a great thread, and the info is much appreciated. I'd like to replace the pads and the brake line on my '78 R60/7 which also has the single front disc. It's downright scary.

However, I don't know if sintered pads are good or bad? Organic? Kevlar? I don't know what the old bikes like vs. what's out there now...or what would be my best bet for a general around-town brake pad. Not touring here...just cruising around.

Are there any recommendations of brand names for the pads and the lines?

Thanks much...

 

[rocketman]

This is a great thread, and the info is much appreciated. I'd like to replace the pads and the brake line on my '78 R60/7 which also has the single front disc. It's downright scary.

However, I don't know if sintered pads are good or bad? Organic? Kevlar? I don't know what the old bikes like vs. what's out there now...or what would be my best bet for a general around-town brake pad. Not touring here...just cruising around.

Are there any recommendations of brand names for the pads and the lines?

Thanks much...

From my research I'd say the EBC pads and floating rotor with stainless lines and moving the master cylinder to the handle bars seem to be the most cost effective mods. Dual disks if you can find a front end for under $500 would give you the best results with the Bremo brake setup. A full mod can cost over $1000, which is why I went with the stainless line first and then plan on the move of the master cylinder next then floating disk. That way I can spread the cost over time and get improved braking with each mod. ans still stay within my $500 budget.

I would add that if you can find a handlebar mounted cylinder and replace that at the same time as the line, so that you don't have to buy a new line when you move the cylinder since it will be a longer line so you wind up buying two, though you could probably sell the shorter one and recoup some of your money.

Not sure of the brand of the steel line I used, but not sure brand is as important with that item as the pad brand/composition.

RM

 

[sgborgstrom]

I'm pondering the various conversions that are out there for my '92 GSPD. In my case the cost is softened somewhat by the fact that my OEM disc is worn out and needs to be replaced ($326 at Chicago BMW/list @$408).

I've had good results using pads by EBC. One thing to think about is what your style of riding is. Those fancy-pants "high performance" pads don't always work so well in regular street riding situations and from personal experience can be downright dangerous when wet...

 

[R100RS]

Not sure on your brake setup, but on my 1990 R100GSPD, I have fitted a 6 piston caliper to the original disc, with braided line, and this setup is unreal.

That setup requires Brembo caliper forks..

 

[JohnnyMoto68]

Well, I decided to move up to dual disc brakes. In a flash of brilliance I decided that I should just buy a different bike that has dual discs up front. Much easier than scrounging for a front end.

So I'm picking up a '77 R100S. Has dual fronts. I am going to immediately replace the pads, and will go to stainless front lines, and I'd like to go with a handlebar mounted reservoir and get rid of the cable / under-the-tank system. I've seen bits and pieces in the forum on how to proceed, but I'm looking for a definitive answer on how to approach.

I reckon I need an entire new front handlebar assembly for the right hand side to go with the handlebar mounted reservoir, no? Can anyone make recommendations on what year / bike are my best candidates to go after? Thanks much!

BTW - the bike is wicked cool. Red smoke. I feel like Steve McQueen.

 

[AnnapolisAirhead]

Rocketman, great post.

My neighbor has a 78 R100/7 that he converted to dual disks. He road my bike and couldn't believe the difference in braking. Mine is amazing--sheer dumb luck, I can assure you...I am learning here. I have an 83 R100 and swapped out the brake lines with SS braided (it came with duals) and a handle bar mounted MC. I replaced the piston in the MC for the same reasons I've done most systems on the bike: it say for 8 years without starting.

Here are the differences between his brakes and mine:

I have SS braided lines, bled completely (he has rubber lines still, but bled completely).
Brembo calipers (his has something else, whatever came on a 78 /7 (ate??)
Both have handle bar mounted MC

Not too sure about the pads on either. After reading your post, I'm thinking that its the ss braided hoses that have the biggest impact. Mine are lined with a tough nylon core that doesn't flex, therefore I reason that all energy developed by the hydraulic action of squeezing the brake is transferred directly to the caliper--whereas rubber (less rigid) hoses may absorb a lot of that energy, resulting in somewhat mushy brakes.

I dunno...but its interesting.

 

[NEALART]

On my /6 I used Ferodo pads and the bike stopped very well.

http://tinyurl.com/6ezx57