corvette front brakes on trike rear?

[Holeyroller]

I am building a trike with Ultra glide components...99 frame, 08 motor and trans, o6 ultra front end with 08 plastics, I purchased a rear end complete from a Tri Glide that was coupled into a swing arm with panard bar. It is minus the entire brake system and the reverse motor. I am using C6 corvette front wheels and have resplined some chevy axles to fit the rearend. I want to use the front calipers and rotors off a c6 Corvette, but wonder if the rear brake cylinder will put out enough pressure to make them work properly.

Anybody out there that can address this? So far I have been told at most every turn that this is not gonna work, but it is coming together...I have purchased an o7 fx starter with the idea of using it for a reverse motor....thoughts?

[1550vt]

In short....NO.

But (there is always a but), if you will get me the piston diameter in mm and tell me how many pistons per caliper and if they are fixed or opposed....I can tell you for sure.

With the Ultra frame, you are stuck with the stock rear 5/8 master cylinder and it will not properly operate anything more than a pair of 30mm-32mm 4-piston opposed calipers.

Since you have a custom build here, you may want to go to the trouble of mounting a larger MC, but I am pretty sure that 5/8 will not be adequate for a pair of Corvette calipers and I would guess it would have to be close to a 7/8 or an inch.

Failing all else...I can tell you how to get brakes on the thing using the existing 5/8 MC if you want me to.

[Nauga Mok]

As 1550 hints at, but doesn't say, it isn't a question of pressure, but volume. The master cylinder must have enough volume to fill the caliper cylinders, THEN develop the pressure for it to work. The cylinders in the calipers will need "X" ammount of fluid to make full contact with the rotors before they can develop the pressure. With just a 5/8" diameter master cylinder, it may not have the volume to activate the calipers. You may need to increase the bore of the master cylinder or maybe find smaller calipers from maybe an earlier 'Vett or maybe one of the smaller Chevys that use the same size rotor. Several different ways to atack the problem, so keep an open mind. Also keep in mind the old addage of "if a little is good a whole lot is better" doesn't apply -- the master must match the calipers in volume. Get the master too big, it won't develop the pressure needed to stop the trike. The laws of hydraulics can get strange, but basically keeping the master as small as possible & still actuate the brakes at about 1/3 to 1/2 pedal stroke is the secret.

NM

[1550vt]

Right Nauga. I even went so far as to try and figure out how to make GM metric calipers (small single piston) work with the 5/8, but the volume of the caliper piston is simply too large.

I have searched high-and-low for a larger MC that would mount like the stock 5/8 on the dresser....but to no avail. The sport bike and Sporster riders have options as those master cylinders mount differently and a 3/4 can be had easily....but not for a bagger.

It's either bastardize the MC mounting and operating configuration (adding forward controls is one way), or go with smaller volume calipers and thin rotors. There are many calipers of the right size that will work with the 5/8, but I doubt very seriously a pair of Corvette calipers will fit the category. I prefer the radially mounted ones off the front of modern era crotch-rockets.

I have a master cylinder ratio-chart that already has the math worked-out to indicate what size calipers can be used with what size MC....and by size, I mean volume.

[1550vt]

Holey....don't give-up on us. Like you, I have had plenty of people tell me I couldn't do something....but that always made me do it anyway. You can get some good brakes on this thing, you just may not be able to use those Vette calipers.

[Holeyroller]

Hey VT2550...
I just ressurected the trike project which has set in the shop for nearly 2 years. I have mounted the calipers. I think they look pretty good. I was thinking of sleeving the bore and using smaller pistons. I am an aerospace machinist with access to equipment. I know that I dont need that much brake....but want to use them. I want to know how you'd do it. I can shoot you an email...I cant figure out to add a pic to this post.