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R100/7 brake upgrade

C

CAPTCARL

Guest
I bent up my front forks on my 1978 R100/7 and now I want to upgrade to the duel disc setup. I had the tubes and axle straightend by the Frame Man and I bought a used right side slider and caliper for the duel disc setup. I need to buy the 2nd rotor and the master cylinder for this setup. My question is, can I upgrade to the master cylinder that mounts on the handle bars and get away from the "under the tank" model. I priced a new duel disc "under the tank" master cylinder and it was around $300 .... Ouch... I miss riding this bike but want it to be safer before I ride it again... Carl
 
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I'm pretty sure you can upgrade to the handlebar MC. Going from single to dual disk requires some consideration for the piston size in the MC. I can't really keep it straight, but there are issues with how much volume of brake fluid you're having to move, how much motion in the lever for stopping action, etc. Hopefully someone can chime in about what should be done in order to end up with a good front brake. I think Oak may have discussed this in an Airmail article...if I can find it, I'll repost.

Kurt in S.A.
 
captcarl said:
I priced a new duel disc "under the tank" master cylinder and it was around $300 .... Ouch... I miss riding this bike but want it to be safer before I ride it again... Carl
Click to expand...
So... get a handlebar-mounted dual disk master cylinder. Wuzza problem?

OBTW... you might want to invest in some stainless steel brake lines and some GOOD brake pads before you spring for the new master cylinder. BIG difference.
 
flash412 said:
OBTW... you might want to invest in some stainless steel brake lines and some GOOD brake pads before you spring for the new master cylinder. BIG difference.
Click to expand...
Be careful with these steel lines...they can do serious damage to paint if they get up against the fender. Some people get them coated in clear plastice or maybe one can get some clear shrinktube and do the same thing.

Personally, I'm OK with the rubber lines. One thing that the rubber lines will let you know is when they are failing, as in they will bulge at the weak spot in the tube. You won't be able to see that with the stainless lines. To some degree, the brake lines are replacement items, due to the internal damage the years of water, ozone, etc., does to them. I replaced my rubber line after about 20 years. I guess I'm good for another 20!!!

Kurt in S.A.
 
20774 said:
Be careful with these steel lines...they can do serious damage to paint if they get up against the fender. Some people get them coated in clear plastice or maybe one can get some clear shrinktube and do the same thing.

Personally, I'm OK with the rubber lines. One thing that the rubber lines will let you know is when they are failing, as in they will bulge at the weak spot in the tube. You won't be able to see that with the stainless lines. To some degree, the brake lines are replacement items, due to the internal damage the years of water, ozone, etc., does to them. I replaced my rubber line after about 20 years. I guess I'm good for another 20!!!

Kurt in S.A.
Click to expand...

BMW doesn't require as frequent brake bleeds with their new Stalhflex lines. The time to bleeds is doubled.
 
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20774 said:
Be careful with these steel lines...they can do serious damage to paint if they get up against the fender.
Click to expand...
The ones I have seen that were made within the past decade or so are made with plastic tubing (in the color of your choice) on the outside.
 
My choice would be to stay with the under-tank system... it's a bit of work to change the fluids but I just don't like the looks of the handlebar system.

As for bleeding... check out http://www.speedbleeder.com/ . I have been running their valves on my dual disc /7 for 2 years and they work great. Flushing new fluid through the system takes about 5 minutes... for both calipers.

I'm running the SS lines as well and I had a problem with them hitting the fender until I readjusted them on the master cylinder to twist slightly to the outside... no more chaffing.
 
CanadaDan, Did you do the upgrade on your /7 to duel disk? If so, did you install the new master cylinder? I have tried the stainless line and rebuilt the caliper and new EBC pads and the bike still will not stop. I do not trust it. Thats why I am doing the upgrade. After riding new tech stuff I don't like the feel of the old brakes.
I do not know much about the bar mounted Master Cylinder. Do I need new throttle controls also. Should I look in the used market for the it. Carl
 
captcarl said:
CanadaDan, Did you do the upgrade on your /7 to duel disk? If so, did you install the new master cylinder? I have tried the stainless line and rebuilt the caliper and new EBC pads and the bike still will not stop. I do not trust it. Thats why I am doing the upgrade. After riding new tech stuff I don't like the feel of the old brakes.
I do not know much about the bar mounted Master Cylinder. Do I need new throttle controls also. Should I look in the used market for the it. Carl
Click to expand...

Sorry... mine came like this in 77.

For used parts I have seen a few /7's parted out on eBay in the last couple of years. For some the sum of the parts is more than the whole. Keep your eyes peeled... the hard part will be the right fork tube if they are parting out a wreck... hard part to trust for a wreck. Make sure you absolutly trust and know what you are buying.

Don't know anything about the hand controls for the bar cylinder setup. I was just commenting that the LACK of a plastic fluid resevoir sitting on my handlebars appeals to my sense of asthetic.

Best of luck with the conversion... well worth the effort in my opinion.
 
keep in mind

Your brakes can be "upgraded": quality pads (EBC, DP), stainless lines (rec: Spiegler, you can use their web-site to "custom design" lines for ANYTHING, and protective plastic is standard), iron rotors, and the H-bar mc w/ revised ratios - cover the typical fixs.

but do keep in mind, it IS a 26 year old system / technology when disc brakes were relatively new to the mc market, and manufacturers opted to be REEEAAALY conservative. ATE brakes can be significantly improved, but won't match what's available on a contemporary motorbike. Brakes today are AWE inspiring.
 
vanzen said:
...Brakes today are AWE inspiring.
Click to expand...

That's the truth... I flipped a brand new Buell thumper arse over bars in the required training course a few years back... apparently brakes on a Buell with 100km on them are MUCH stickier than a 30 year old airhead :doh
 
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