R100GS PD - Simple guidelines for better braking

ikkje

ikkje

Active member
UKGSer Subscriber
Joined
Jun 17, 2013
Messages
192
Reaction score
336
Location
Cumbria
The useless nature of the front brakes on R100GS's are well documented and in spite of this, I have my own experience to share as it might be useful for others. Knowing what I do now, I would have saved a huge amount of time and not an an insubstantial sum of money by following these solutions.

The bike already had a 300mm Conversion which was great (made by ABM) - So if you need this as your starting point then yes it will cost you.

I split the calliper and first mistake - the pistons are ceramic and very easy to damage which I indeed did. So blow them out with compressed air, even a foot pump has sufficient power to do this I had to spend £70 odd quid at Motorworks for replacement stainless pistons. I completed the rebuild with new seals etc, etc and repaired a damaged thread etc.

Next problem - bleeding the brakes. It was just impossible to bleed the brakes and I even ended up taking it to a local mechanic who ... also failed to bleed them and charged me for the privilege! On the forum you read all sorts of solutions from holding the calliper up high, to clamping the lever over night - none of these worked, The solution? Stahlbuss bleed valves (http://www.stahlbus.com/info/en/products/description). Not cheap and especially so when the damn Brembo calliper has two on it, but these one way valves make bleeding as simple as a a very simple thing.

Finally - pads ........ After all this I was still less than happy with the brake, so I tried EBC pads, ..... then Ferodo's ....... and still not enamoured. The solution came in form of Lucas TRW Sintered pads which I bought from Louis Moto in Germany (https://www.louis.de/artikel/lucas-...kar/10044701?filter_bike_id=1454&list=1293057) Expensive but finally, finally I have the power and feel that I was after and I am, believe it or not, able to use two fingers most of the time.
 
ikkje said:
The useless nature of the front brakes on R100GS's are well documented and in spite of this, I have my own experience to share as it might be useful for others. Knowing what I do now, I would have saved a huge amount of time and not an an insubstantial sum of money by following these solutions.

The bike already had a 300mm Conversion which was great (made by ABM) - So if you need this as your starting point then yes it will cost you.

I split the calliper and first mistake - the pistons are ceramic and very easy to damage which I indeed did. So blow them out with compressed air, even a foot pump has sufficient power to do this I had to spend £70 odd quid at Motorworks for replacement stainless pistons. I completed the rebuild with new seals etc, etc and repaired a damaged thread etc.

Next problem - bleeding the brakes. It was just impossible to bleed the brakes and I even ended up taking it to a local mechanic who ... also failed to bleed them and charged me for the privilege! On the forum you read all sorts of solutions from holding the calliper up high, to clamping the lever over night - none of these worked, The solution? Stahlbuss bleed valves (http://www.stahlbus.com/info/en/products/description). Not cheap and especially so when the damn Brembo calliper has two on it, but these one way valves make bleeding as simple as a a very simple thing.

Finally - pads ........ After all this I was still less than happy with the brake, so I tried EBC pads, ..... then Ferodo's ....... and still not enamoured. The solution came in form of Lucas TRW Sintered pads which I bought from Louis Moto in Germany (https://www.louis.de/artikel/lucas-...kar/10044701?filter_bike_id=1454&list=1293057) Expensive but finally, finally I have the power and feel that I was after and I am, believe it or not, able to use two fingers most of the time.
Click to expand...


I am currently making an adapter to use a modern Gs caliper on the front, I am using a grinder a hacksaw and a file to make it, as that's what I have, only doing it an hour at a time!

Mr Farmer has the same caliper on his PD,


http://www.advrider.com/forums/showthread.php?t=983242&page=2

I never have any problem bleeding the front, I converted my R80Rt, to twin discs, and it vacuume bled up no bother, even though it runs through both calipers to the one bleed nipple!
 
I've sourced a brembo 4 pot, but as yet have done zilch with it (Think this one was from a K1100RS from memory). Now that I've more or less got a good set up, it'll take some time before I start trying to find someone to mill the faces for me.

Cumbria (well Kendal) is just drying up enough to go out for a ride
 
Speedbleeders work fine for me, as do EBC HH 100 Pads.
If you have to replace / re sleeve the master cylinder go to 11 mm - Guzzi used one with two similar 48 mm calipers, but they are still OK with a single 48 mm.

If you do the maths there isn't much around that gives a better ratio than the 48mm Brembo, so changing to a four or six pot is mainly cosmetic - it wont work any better than a well set up 48mm.
 
1989 R100GS-PD. I improved my front brake in stages.

1. Stainless steel braided brake line.

2. EBC Pro-Lite floating disc.

3. Brembo 4-pot caliper from a K1100 bike.

After bleeding, clamp the lever to the twist grip and leave overnight as this forces every last scrap of air out. Result? A half decent front brake and far, far better than the original one.
 
I converted to a Brembo 4 pot caliper and changed to a steel braided line from Motorworks.
The whole job took 20 minutes including bleeding and as DrFarkoff can testify, i'm prone to bouts ofvridiculous incompetence. The difference was incredible.
 
i put a 4-pot brembo on my PD - waste of time and money.
 
Which was kind of my point in starting this - its easy to spend quite a lot for very little improvement and as Beemberbof says, what's there is going to be as good as anything ...... as long as you optimise the set up. Its also clear that different routes work for different people and I suppose the end result can be calculated as successful when you have a set up that suits you, stops you and that you're confident in. For me, other that my incompetent stuff ups, it was the sintered pads that have tipped things in the right direction.
 
ikkje said:
as Beemberbof says, what's there is going to be as good as anything ...... as long as you optimise the set up.
Click to expand...

that is not my experience.

a 320mm disc conversion, or a billet 6-pot will markedly improve braking. i mean, it won't be remotely like a modern bike, but it will be just about good enough IMO. as opposed to the standard setup, which is woeful at best and dangerously inadequate for any kind of spirited riding whatever you do to it. how bmw thought that it was ok to market a bike with that setup in the mid 90s is beyond my comprehension :confused:
 
I allways have a few 4 pot brembos of verry late bickes if any body needs one with good pads !, I allso have a adapter for fiting a 4-6 or 8 pot caliper with 40mm mounting on for the standard disc wich is now surplus as i swaped my forks
 

Attachments

  • IMG_5473.jpg
    IMG_5473.jpg
    68.8 KB · Views: 778
  • IMG_4315.jpg
    IMG_4315.jpg
    50.8 KB · Views: 913
cookie said:
that is not my experience.

a 320mm disc conversion, or a billet 6-pot will markedly improve braking. i mean, it won't be remotely like a modern bike, but it will be just about good enough IMO. as opposed to the standard setup, which is woeful at best and dangerously inadequate for any kind of spirited riding whatever you do to it. how bmw thought that it was ok to market a bike with that setup in the mid 90s is beyond my comprehension :confused:
Click to expand...

It's a shame they never cast the lugs on the other fork. Then it would be easy to upgrade, at least from dire to a bit scary!

Anybody ever get the lugs welded to the other side?

I am hoping that replacing the calliper with the more modern 4 pot, that it will improve the feel, in the same way as adding another calliper did to the R80rt, using the original master cylinder,

I would like an adapter to fit a larger disc, from a modern bike, but I don't know anyone with the tools and skills to produce one!
 
A 4 pot does improve the feel a bit, but does nothing for the stopping power.
 
cookie said:
A 4 pot does improve the feel a bit, but does nothing for the stopping power.
Click to expand...

I did consider, swapping the forks 180 degrees, getting the two tabs welded on the fork without, and using the single disc and calliper from the R80rt, the disc looks the same disc, and the calliper looks like a mirror image of the Gs calliper, the 180 degree swap would be so that the brake is forcing the lug into the fork, rather than trying to rip the lug from the fork,

Might have to look further into it, when the 4 pot disappoints me!
 
Which way round the calliper is is not the problem, although that one is meant to be fitted the other way around due to the odd sized pistons. I think the smaller one is meant to lead. Or is it the other way around?
 
320mm disc, 4 pot caliper, braided line gave adequate braking for spirited riding. If I get another GSPD I would do this mod straight away.

Improving the brakes is fine to a certain level but stopping power is going to be limited by the adhesion limits of the skinny front tyre. Improved braking will also be affected by the condition of the front suspension. Like all modifications the next weakest link gets highlighted but can usually be fixed by a liberal application of $$$$ :eek:
 
Six pot

I actually have a six pot on my GS, and it is no better than the 48 mm twin pot Brembo.
Both have HH sintered pads.
Disk is a cheap Kyoto from Wemoto which works better than OEM.
And , FWIW, modern rubber/ fabric hoses are stiffer than a plastic tube covered with a bit braided SS - next time you pass a 120 ton excavator have a look and see what the hoses are made off - they will be rubber and they have had to come a long way to cope with the stresses on modern construction.equipment .

The PO of my G/S had fitted a larger disk and a four pot.
It started drawing air, and I refitted the original small 42 mm Brembo twin pot.
It actually works better than the four pot - it has a better wipe pattern and the pads in it, EBC hh 100's, must suit the aftermarket disk better than the pads in the four pot.
 
i've done quite a lot of work on a friends g/s. he has the standard disc + a 6-pot. i've tried it and it's definitely way better than the standard setup. i couldn't say why that is so, and the fact is i expected it to be poor, but it isn't :nenau

i could say almost the same thing about the siebenrock kit i fitted to it too, but it absolutely flies with that as well :cool:
 
So the conclusion is......... that one size very definitely doesn't fit all and that everyone seems to have their own route. As I said, I am now pleasantly impressed with the set up I have (though in comparison to my previous KTM950, its still rubbish) and can live with it for fear of going backwards in going forwards, if you know what I'm rambling about. Thanks for all the interesting comments and its a great forum
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
You must log in or register to reply here.


Back
Top Bottom