Originally Posted by Beemerboff
At present I have the stock set up with a braided line and DP 620 GG sintered pads , which I bought on Ebay for $20-
They were advertised as HH but it says GG on the pad.
No problem , they are a mile in front of the Galfer Greens , and they were supposed to be GG too.
With this set up I can lock the front wheel with a good hard squeeze , and I dont really need much more, but when Guy announced his sensibly priced adapter for big callipers I thought I would upgrade a little, and get up to date two finger braking at a reasonable cost.
Last time I was in Churchill Dismantles all the callipers were $25.00 but they now have a new sales manager and he is as stupid as the guys at Show and Go - $250- for one second hand calliper , with no pads or hose.
The reason for going with the Tokico six piston is to keep the M/C - caliper ratio as close to stock as possible , as IMHO this is the critical part of the exercise.
If Ray Potter was still working I could have got my M.C. sleeved to 11 or 12 mm which would have made the two piston viable , but with a 13mm MC the Tokico six piston is the only one I would fit
I have a 11mm on my twin disc R75/7 and it works really well , no problems with excessive pull etc so I have no problems with high ratios.
Good stuff here Boffo,
Hydraulic ratios are seldom understood by folks switching bits and pieces around. I'm a bit confused by some of what you've suggested re. keeping piston ratios as close to stock as possible. As you won't realise any braking improvement until you increase your master cylinder vs. slave cylinder piston ratios. ie: reduce the m/c swept area or increse the slave cyls swept area. You seem to be aware of this when mentioning your intention to sleeve your MC down to 11 or 12mm. Did I miss something?
I've got a 4-pot Brembo from my wrecked 1150GS doing duty on my GS/PD and it's provides a noticable improvement over the stock two pot Brembo. Easy to fit, too, simply required filing a bit off the caliper's boss to centre it on the GS/PD's disc (0.125" iirc). Currently running whatever the 1150 was using for pads, which I believe were stock BMW bits.
Having said all that, with the stock set up I could howl the front tire at any speed the bike was capable of if I gripped it tightly enough. All you're doing with a fancier brake is easing the effort it takes to howl the tire - so you're not actually getting any greater ultimate breaking force.
The tire's the final factor in the braking force equation, as I'm sure you know.