Brake caliper upgrade?
#11
Join Date: Dec 2008
Location: Summit, Mississippi
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You should be able to lock the wheel with whatever you have on there, no matter who made it. Some folks use both ends to stop a bike and others rely mostly on the fronts as a matter of habit. I am one of those that rarely ever touches the rear unless at a signal light or something just to hold the bike. I am also one of those that has "swapped ends" with a bike because I hit the rears too hard.
On the fronts...whatever caliper you install on the front has to be balanced with the correct volume master cylinder. It's a thing called brake ratio. Too large of an MC will make the lever hard to pull and reduce braking power. Too small a MC will surely make the lever softer, but will increase travel and if too small, may lock the caliper before you want to....which is not good at all. The major brake component manufacturers will specify what size MC you need for that particular caliper you are considering. I think most of them are designed to work with the stock HD MC, but you need to know and be sure that is what you have on your bike. Many modern-day crotch-rockets have adjustable MC's to fine tune the brakes, but you generally don't need to go this far on a Harley. It doesn't matter if it has 2, 4 or 6-pistons....the caliper volume has to match the MC volume to deliver the right brake ratio, which should be in the high-teens for a front brake. Rears are more like 8 to 10. You want "feel" in the front brake, but the rears can be more wooden. The rotor diameter certainly comes in to play also, but the whole thing boils down to how you want your brakes to feel. You do not want the fronts to be wooden...you need some "sponge" in there so they don't grab when least expected.
I would simply talk to the people that I planned to buy the caliper from and see what size MC they recommend.
As an aside and certainly not a recommendation......I have never had any problems with the stock HD brakes. The pads can make a big difference even when running the old-style single piston calipers. BUT....the aftermarket calipers can be much more attractive, just don't buy them for their looks alone. Shiny, expensive chrome calipers won't stop you on looks alone and the pad cost and availability needs to be considered. I try to run parts that I can find in any Harley Dealership, because most of my riding is on long trips and I do not want to be broke-down in the desert 2,000 miles from home and not be able to find parts to get me home.
On the fronts...whatever caliper you install on the front has to be balanced with the correct volume master cylinder. It's a thing called brake ratio. Too large of an MC will make the lever hard to pull and reduce braking power. Too small a MC will surely make the lever softer, but will increase travel and if too small, may lock the caliper before you want to....which is not good at all. The major brake component manufacturers will specify what size MC you need for that particular caliper you are considering. I think most of them are designed to work with the stock HD MC, but you need to know and be sure that is what you have on your bike. Many modern-day crotch-rockets have adjustable MC's to fine tune the brakes, but you generally don't need to go this far on a Harley. It doesn't matter if it has 2, 4 or 6-pistons....the caliper volume has to match the MC volume to deliver the right brake ratio, which should be in the high-teens for a front brake. Rears are more like 8 to 10. You want "feel" in the front brake, but the rears can be more wooden. The rotor diameter certainly comes in to play also, but the whole thing boils down to how you want your brakes to feel. You do not want the fronts to be wooden...you need some "sponge" in there so they don't grab when least expected.
I would simply talk to the people that I planned to buy the caliper from and see what size MC they recommend.
As an aside and certainly not a recommendation......I have never had any problems with the stock HD brakes. The pads can make a big difference even when running the old-style single piston calipers. BUT....the aftermarket calipers can be much more attractive, just don't buy them for their looks alone. Shiny, expensive chrome calipers won't stop you on looks alone and the pad cost and availability needs to be considered. I try to run parts that I can find in any Harley Dealership, because most of my riding is on long trips and I do not want to be broke-down in the desert 2,000 miles from home and not be able to find parts to get me home.
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