O/T...look away-bike ???

[choprods]

got a dumb question....Im mostly about cars so there is a lot about motorcycles that buying them didnt teach me.
I am putting together a bike and want to know something that I am afraid may result in embarassing me!
I am at the point wher I am trying to finish the brakes[front] and I was wondering if any bike has had-OR ever came with brakes that were both operated by the same -ONE-master cylinder both back and front simultaneously. I never saw this -but that dont mean it can't be......
Could it possible be set up with a proportioning valve etc to adjust a suitable bias of the frt and rear?
My main idea for doing that is that the Master and brake lever are hideous lookin as they sit.
OK BASHING MAY NOW BEGIN! http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[Curly]

I've seen it done exactly as you described with the addition of a resivoir to hold the extra fluid that will be used to operate both sets of brakes. These were on show bikes and trikes. Trikes make more sense as they have dynamics closer to that of a car.

The problem is that with the ever-changing forces (cornering, road conditions, etc) and the light weight of a MC it becomes difficult if not impossible to get the bias correct for all conditions that you will see. Brake too hard at one end or the other while going into a corner on a bumpy road and if you brake the same exact way on a smooth road going from stop light to stop light you'll quickly see the difference.

I started out on dirtbikes and raced MX for a few years and I used the front brake way more than the rear and still do even on a HD bagger. I will say that in loose gravel I use the rear brake and try not to touch the front. If you run a biased/single M/C setup how do you compensate for this momentary change in road conditions?

There are two kind of riders out there...ones who have fallen and those that will fall...Don't fall "by design" http://www.jalopyjournal.com/ubbthreads/images/graemlins/frown.gif

[Bass]

I think the best solution to this problem, if you are concerned about looks, is to use a Hurst Airheart bar-mounted master cylinder.

They still look pretty vintage and have a cool ribbed cover. I have one I can take a pic of for you if you'd like.

I don't think it would be too much trouble to adapt the Hurst m/c to use the stock front caliper(s) on your bike.

Trying to combine the master cylinders for front and rear seems like more trouble than it's worth.

[D Picasso]

if you want to be really tricky, use a cable-operated Moto Guzzi master cylinder.

hide it under the tank and watch folks try to figure out why your hydraulic brakes have no bar-mounted MC.

[disastron13]

Can be done without a proportioning valve, friend for years has run a 750 Duc with single disc f & r, the smaller size of the rear disc is the "proportion".
Used a double banjo bolt in the m/c, a Honda part, with braided hoses, one to the f brake caliper and one to the r.
Check the bore diameter of the Hurst m/c to see if it is compatible with your caliper...

[flatshoebox]

Ya can't do bitchin burnout that way! What were ya thinkin'?? http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[CTFuzz]

Lots of bikes work just that way......Honda Gold wings for one. Rear brake lever(foot operated) works the front AND rear brakes and front lever(hand operated) works the front only(two disc in front). BMW uses a cable to m/c set up for the front brakes on some of there bikes, but it ain't cheap! Good idea for a project, keep it going.......

[choprods]

I just saw a slick small alum master [for a bar mount[front] it was off a new Confederate custom motorcycle.Its on ebay for 39 dollars no res..............I may try to buy it and polis it some more and conform to the known laws of physics.!

[marq]

Yep the best dual setup to use is a motoguzzi they were the first and had it for years ,not only that they work real well far better than thier honda,bmw counterparts not only that but someone over there must have an old scrap motoguzzi california they dont want.Most bikers over here remove them because they like to have complete control of their braking system but my mate Roger owns a motoguzzi repair place and swears by them..........Marq

[choprods]

IF I WERE TO......use what I have what would it work like?I have a stock Harley frt and rear calipers/stock 11-1/2 rotors and a stock REAR Harley master cyl. if it were all plumbed up as one system what would it work like JUST AS THAT WITH NO BIAS ADJUSTMENT? http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif?

[BigDdy31]

Chop, I have some Harley experience as well as brit bike and (safety/depenability wise) I just can't see that set up working without some kind of proportioning and that just sounds like a pain in the neck to work out.

Keep in mind though, I'm a bit of a wuss when it comes to my bike brakes, as opposed to cars, just because there is no steel cage around me if my experiment in modification goes awry somehow.

I'll be seein' a buddy of mine tomorrow that is much more experienced with this kind of thing than I so I will ask if he has any suggestions.

Big Daddy Eric

[burndup]

What happens when your white-lining thru traffic to get up to the line at the red light... You wanna keep revving your engine to make your presence between the cars known... but you gotta stop eventually nad wanna be simultaneously slowing down as well as revving...? Just one good reason for divorced brakes...

Or, if you're braking hard, and in dire need of coming to a complete stop... you hit slippery shit and your rear locks up good and your front is losing traction... well, you need to keep that rear locked up and let off the front quite a bit in order to not be doing a bit of bleeding a second later...

I wouldnt mess with it man. Build it primarily to be able to be ridden all day long... if certain parts look a little dorky to acheive that, so what, its worth it. If you can swing making it look entirely kickass at he same time, good for you!

my $0.02
-J

[timebandit]

When I took my MC drivers license years ago my teacher told me to just forget the rear brake totally. Its only good for holding the bike still when eating a hot dog at the snack bar he said. His point was that 90% of the brake effect is on the front wheel, and you will only make things worse if you are using both brakes in a emergency situation. A blocked rear wheel wont do you any good.
I guess he was taking about modern bikes with twin floating discs tho...

[Flat Ernie]

[ QUOTE ]
my teacher told me to just forget the rear brake totally

[/ QUOTE ]

This "truism" isn't wholly accurate. To begin with, bike brakes, as already pointed out, are more important at different times in different riding conditions.

The other problem with that statement, is it doesn't apply as well to rigid bikes as it does to fully suspended bikes whose rear suspension unloads under braking & has more noticeable weight shift towards the front. That's why hardtail chopper riders can get away with ONLY a back brake...the braking dynamics aren't the same as yer girly Honda nighthawk... http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif

[D Picasso]

not only that, but old cable-operated brakes better have a little help from the rears, especially with, say, a BSA conical brake setup.

I want to see a chopper running 4-leading-shoe brakes off a Suzuki GT750 someday. that I'd respect.

[hatch]

I am a human proportioning valve....I will never trust science to do that for me when I'm on a bike....I don't think it's possible.

[choprods]

Ill prob- use the handlebar mount for the frt seperate from the back.
Thanks for the help y'all-I had a stock black latemodel Harley master and its too fuckin ugly to be cool....... http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[hellcatchoppers]

just chuck the fronts your fine with backs

[Flat Ernie]

[ QUOTE ]
had a stock black latemodel Harley master and its too fuckin ugly to be cool

[/ QUOTE ]

Try sandblasting it - sort-of cast texture - better than factory black


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