my front brake sucks

[MrSelfdestruct]

I've had my GS on the road for a few months now and in that time i've never really been impressed with it's braking ability. I've changed to stainless lines, fresh fluid, new pads, and my 3400lb Audi can still out-brake my bike. I noticed the other day that it is due to quite a lot of caliper flex. And it's not the bushings in the caliper that are bad, it's the actual metal flexing. I see that a lot of you guys with newer GS's (mine's a '78) have slotted/drilled rotors which don't look like they're 3/4 of an inch thick cast iron, and two pot calipers. (my rear brake is two pot, why is my front only one) Basically what I want to know is: Are the newer style of brakes a direct bolt on swap for my old bike, and if they are, is there any braking benefit? If not i'll likely make some adapters and fit a six-pot from an older sportbike when my GS goes under the knife this winter. Thanks for any help. Oh, here is the bike in question.

 

[Macmatic]

Edit: I just looked at the 1978 GS750 diagrams and the calipers are quite a bit different but your problem sounds exactly the same. I doubt your actual calipers are flexing (I thought mine were too) but you're probably getting movement from the worn pins and bores. Suzuki calls them axles.

Do a search for "twinpot" and you'll find many discussions of brake upgrades.

I have the same problem with flexing brakes. When bleeding with the calipers off the bike and clamps holding in the pistons I'd have a rock hard brake lever but back to squish once they were on the bike. The problem is the caliper slide pin bores in the caliper carriers, the "bushing" surface is the aluminum of the carrier itself and they wear before the steel pins.

As an experiment I worked my brake lever with one caliper off and clamped and one on the stock carrier. Then I installed a carrier of a GS450 with 9,000mi that showed much less wear in the bores. The result was a much improved lever feel with the GS450 carrier (Same as GS750/700 Left carrier).

Unfortunately these parts are not available from Suzuki and the best option I've come up with is to have someone drill out those bores and install a bronze bushing sized to fit the pins. I haven't priced this out but it's probably half way to a real "twinpot" upgrade.

Good luck whatever you do.


/\/\ac

 

[Big T]

Your 78 single disc indeed lacks braking power.

I upgraded mine with Dan's adapters and Ninja calipers and the difference is incredible.

6 pots are probably too wide for your wire wheels

Seach for Kawasaki twinpot and you'll find that thread.

You'll need

1. Dual brake forks or lowers
2. 2 larger discs
3. The correct calipers
4. The adapter kit from Dan

 

[posplayr]

Your in luck............

http://www.thegsresources.com/_forum/showthread.php?t=140253

http://www.thegsresources.com/_forum/showthread.php?t=160203

 

[tkent02]

Just putting on the brakes from a 1980 or later dual brake GS will help a lot, with good pads and lines. Not like a modern bike, but pretty good. Certainly good enough to get all the braking traction the tires have to offer with a finger or two. Once you get the dual brake forks, it all just bolts together. I'm sure the twin pot conversion works a lot better.

 

[MrSelfdestruct]

Thanks for the replies. I don't plan on going to a dual rotor setup because that would require a new front wheel and I don't want to get that far into it. If I understand right I'm looking for a cbr600 f3 front rotor that I will need to re-drill, and a ninja twin-pot caliper + adapter. Is there anything special about ninja calipers or can I use, say, an fzr600 caliper? Those are 4-pots and a little cheaper than ninjas. Of course the adapter would be different. How about master cylinders? Will my stock one work or will that need to be switched too?

 

[Big T]

Isn't your front hub drilled on both sides for rotors?

You don't need to change your master cylinder

You can use any caliper that's thin enough if you're going to make your own adapter, The Ninja ones are just tried and true

 

[MrSelfdestruct]

i'll have to check but I'm 90% sure it's only drilled on one side.

 

[SqDancerLynn1]

The wheel should be drilled on both sides for a disk, you may need to clean the threads.
Would also need to change both the lower fork tubes to one's from a dual disk, 1980 up GS setup.
The caliper is positioned different between single and dual disk, the single disk is larger
Not mandatory? depending on the size of your master cyl you may need to up grade it.

 

[salty_monk]

+1. The wheel should be drilled both sides. May be hidden under a black cover. You may need to run a tap in them to tap them out to full depth (Suzuki left about 50% of them tapped short it seems).

I may have some of the aluminum lower legs in black for dual rotor setup. You can transplant the rest from what you have I believe.

 

[MrSelfdestruct]

interesting. I remember the black cover, but not the holes. At any rate, i'm not looking to be able to do stoppies, I'd just like to be able to do a proper panic-stop if the occasion should arise. can I get away with just an upgraded single rotor setup? If not I may be hitting up salty_monk for those lowers in a few weeks. Thanks everyone for the help.