biker_reject
Over 1,000 Posts
Is this possible without too much hassle? I'm thinking of using a CBR600 master cylinder with my stock CB 750 caliper and buying a ss brake line. This should work, right?
Modern brake master mated to stock caliper?
- Thread starter biker_reject
- Start date
Barkingmadspeedshop
Sell the many to fund the few
Yes it will work.
killian101
Been Around the Block
are we talking a radial MC? If so, should be ok. Could be wrong
Gage Werke Composites
Been Around the Block
Worked for my twin disc conversion on my cb450. I used a modern yamaha raptor master cylinder/lever. It had everything integrated into one package. Worked great.
surffly
Over 1,000 Posts
It will not just work.
You need to know more things before an answer can be given
There is a ratio in brake systems that needs to be maintained.
This is a ration between the caliper and the master
This changes when talking about single and dual disc set ups.
You need to look at the size of the master and the size of the caliper.
Then look them up on a chart....vintage brake has a great chart to use and helps to tell you what the different ratios will give you.
You need to understand what mods will do to the bike and how they effect the system.
Im assuming that you think that a modern master will be better and improve your brakes...
Its good to see that you want better brakes but we need to know more.
what year bike?
Im running a CBRF3 master with 32mm twin piston OEM honda calipers on my F
plan to run a DOHC 750 master with dual discs on my K.
You need to know more things before an answer can be given
There is a ratio in brake systems that needs to be maintained.
This is a ration between the caliper and the master
This changes when talking about single and dual disc set ups.
You need to look at the size of the master and the size of the caliper.
Then look them up on a chart....vintage brake has a great chart to use and helps to tell you what the different ratios will give you.
You need to understand what mods will do to the bike and how they effect the system.
Im assuming that you think that a modern master will be better and improve your brakes...
Its good to see that you want better brakes but we need to know more.
what year bike?
Im running a CBRF3 master with 32mm twin piston OEM honda calipers on my F
plan to run a DOHC 750 master with dual discs on my K.
Barkingmadspeedshop
Sell the many to fund the few
It will Just work. If it works well or not is a diffrent story.
Bozz
Coast to Coast
Yes, you can swap MC around with Calipers, if you are careful.
We are talking about hydraulics here, so fluid volume, relative piston sizes, and the like are the relevant facts.
Start with the caliper(s).
Find out what the diameter of the stock MC was with that caliper.
(this was usually stamped in the casting of the MC, something like 8mm or 10mm or 14mm or some such)
With this knowledge you can use any modern MC with the same diameter piston.
If the numbers match you are good to go.
I have heard of people using a *slightly* larger MC bore than the calipers had in stock trim successfully, but that's where it can get tricky.
Inside the stock calipers is a rubber seal (o-ring) that is designed to retain its seal under specific pressure loads.
A larger than stock MC piston will generate higher pressures and potentially result in a seal/caliper failure.
Brake failure is to be avoided in my book at all costs.
So I guess the short answer is the same as above:
Yes, it can be done, but pay attention to the details!
Cheers.
We are talking about hydraulics here, so fluid volume, relative piston sizes, and the like are the relevant facts.
Start with the caliper(s).
Find out what the diameter of the stock MC was with that caliper.
(this was usually stamped in the casting of the MC, something like 8mm or 10mm or 14mm or some such)
With this knowledge you can use any modern MC with the same diameter piston.
If the numbers match you are good to go.
I have heard of people using a *slightly* larger MC bore than the calipers had in stock trim successfully, but that's where it can get tricky.
Inside the stock calipers is a rubber seal (o-ring) that is designed to retain its seal under specific pressure loads.
A larger than stock MC piston will generate higher pressures and potentially result in a seal/caliper failure.
Brake failure is to be avoided in my book at all costs.
So I guess the short answer is the same as above:
Yes, it can be done, but pay attention to the details!
Cheers.
biker_reject
Over 1,000 Posts
My problem is in finding a decent original MC. I've gone through 3, none of which I could dismantle. Either the pistons are frozen in the bores, or the pins are frozen into the lever perches. I ended up beating the shit out two of these things. I thought, the hell with it, just find a modern master.
surffly
Over 1,000 Posts
biker_reject said:
Honestly If you have gone through three there is something wrong. Ive rebuilt a few Honda masters and only ever thrown one out, and that one looked like it was stored underwater....
If you are just buying $5 ebay ones then i bet you will have a harder time getting them apart. takes time and some chemical/heat help at points.
Well we still dont have the info to actually help....
What year is the bike?
what brake set up do you have right now? IE sizes and number of calipers.
biker_reject
Over 1,000 Posts
Yep, they were all from fleabay and they were not $5.00 Ha! I even boiled one. No result. I've seen these reconditioned ones on ebay that look pretty good. You guys may have seen these? I would've purchased one but I really want adjustable CRG type levers on my bike but I don't see any apps to fit vintage perches.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=120754935654&viewitem=&sspagename=STRK%3AMEWAX%3AIT
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=120754935654&viewitem=&sspagename=STRK%3AMEWAX%3AIT
Barkingmadspeedshop
Sell the many to fund the few
Ever try putting it in an ultrasonic cleaner? I have a 5 gal one and its great for taking ceased shit apart.
biker_reject
Over 1,000 Posts
I started out to pull the caliper of the '79 CB 750 DOHC, but got sidetracked on the Buell (it's so damn pretty not to mess with), and then ended up pulling the airbox and carbs off the '75 KZ 400! Suddenly, the weekend was over. I'll get it tonight if I my little kids don't follow me into the garage. "Daddy, what doing???"
bikeboy
Over 1,000 Posts
Hey guys, just some food for thought. While I was upgrading the bol d'or, I came across the chart mentioned earlier at vintagebrake.com, and thought "I could probably do something with that". So I did. I made an Excel document using the info and put it in a more user-friendly format. Mainly because it didn't include the set-up I was working with.
Anyway, I've attached a zipped version. At the bottom it explains that ratios in the 27:1 range-2 finger power brakes, feeling some line and/or caliper flex. 23:1 is at the other end of the spectrum-firm. Ratios lower than 20:1 can result a feel so "wooden" as to have a toggle switch effect: nothing happens until the wheel locks. So the ratios to shoot for are around 27:1 ratio.
To use it, you put in the diameter of the pistons in col. A, (total) number of pistons in B, then read across the line to your master cylinder diameter to find the ratio. I've filled it with vintagebrakes data, but you can change any row and it will re-calculate. You can therefore use it to find the optimum ratio by finding the closest fit to 27.
Oh, I should also put in some sort of disclaimer that this is a guide only, and I take no responsibility for anything
Might also put this in the Brakes forum? Someone might find it useful?
cheers
ian
Anyway, I've attached a zipped version. At the bottom it explains that ratios in the 27:1 range-2 finger power brakes, feeling some line and/or caliper flex. 23:1 is at the other end of the spectrum-firm. Ratios lower than 20:1 can result a feel so "wooden" as to have a toggle switch effect: nothing happens until the wheel locks. So the ratios to shoot for are around 27:1 ratio.
To use it, you put in the diameter of the pistons in col. A, (total) number of pistons in B, then read across the line to your master cylinder diameter to find the ratio. I've filled it with vintagebrakes data, but you can change any row and it will re-calculate. You can therefore use it to find the optimum ratio by finding the closest fit to 27.
Oh, I should also put in some sort of disclaimer that this is a guide only, and I take no responsibility for anything
Might also put this in the Brakes forum? Someone might find it useful?
cheers
ian
