I have a 90cc kid quad ( an IPC Pitviper 90 ), that I decided to put some better brakes on the rear. Here is what I did: It now has a Polaris break lever/Caliper mounted on the Left side handlebar, it also has a Front brake master cylender from a Polaris utility quad now on the rear disc. I made a 1/4" inside diamiter hydrolic hose for the brake line.
Here is my issue, I figured if this front brake caliper will help stop a 700lb Polaris utility quad it will easily lock up the rear end of this little 190lb atv. Well, guess what? It don't, I have bled it, and it's tight as a drum at the lever but it just doesn't grab like I thought it would. Now the caliper and brake pads are brand new so, could that be the problem? Do they have to wear some before they grab well? For ATV pads these pads are very large and touch allot of surface area of the disk. Are the OEM Polaris pads not very good? Are there after market pads that will grab better? Is my hose inside diameter to large or to small? I mean the brakes work exactly as they should, they just don't have the stopping power I thought they would.
Any ideas?
What do you all think?

 

I'm no hydraulic expert, but I am inclined to think a 1/4" inside diameter hose may be a little large for brake line.The bore of the master cylinder may be having a hard time filling that much hose,hence your less than grabby brakes. Also,that much inside surface area may be allowing more hose swell when you squeeze on the handle,which greatly reduces brake effectiveness. I may be way off base on this one,but I'm going by my years of experience in auto mechanics,even the lines on a car aren't that big, and they stop fine.Just a suggestion,maybe try a temporary,small diameter metal line to the caliper to see how it grabs then.Or a combination,rubber line to the frame,steel line to the caliper,only use rubber where flex is needed,less rubber,less pressure loss. Hope this is some help.