Why not Disk Brakes on Front of Fork?
12-25-09, 12:18 AM
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Why not Disk Brakes on Front of Fork?
Just wondering, why aren't disk brakes mounted on the front of forks instead of the rear?
I haven't used them before, but was just looking around at them and... well it seems like when the brake clamps down on that disk you'd get a torque that would tend to push the wheel down and out the dropouts.
Having the brake on the front of the forks should instead pull the wheel up and into the dropouts more solidly... right?
I haven't used them before, but was just looking around at them and... well it seems like when the brake clamps down on that disk you'd get a torque that would tend to push the wheel down and out the dropouts.
Having the brake on the front of the forks should instead pull the wheel up and into the dropouts more solidly... right?
12-25-09, 12:46 AM
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My guess is that with the current configuration caliper forces push on the fork instead of forces pulling on the fork. In the case of IS mounting tabs they are less prone to stress that would tear them off and with post mount style forks the hardware used to fasten the caliper to the fork has less stress since everything is being pushed together instead of being pulled apart. Also it looks cleaner if the caliper is behind the fork and it is also prone to less damage since it is shielded by the fork leg.
12-25-09, 12:49 AM
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Yes, that is a concern and a very good reason to never get rid of the 'lawyer lips' on the fork if it will be used with disc brakes mounted in the rear position. See this site for more details:
https://www.ne.jp/asahi/julesandjames...ase/index.html
Other solutions would be to change the direction of the dropout opening so it is angled forward rather than straight down or even toward the back.
https://www.ne.jp/asahi/julesandjames...ase/index.html
Other solutions would be to change the direction of the dropout opening so it is angled forward rather than straight down or even toward the back.
12-25-09, 12:51 AM
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My guess is that with the current configuration caliper forces push on the fork instead of forces pulling on the fork. In the case of IS mounting tabs they are less prone to stress that would tear them off and with post mount style forks the hardware used to fasten the caliper to the fork has less stress since everything is being pushed together instead of being pulled apart. Also it looks cleaner if the caliper is behind the fork and it is also prone to less damage since it is shielded by the fork leg.
12-25-09, 03:10 AM
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Cotic Roadrat https://www.cotic.co.uk/product/bikes/roadrat/flat_bar/
12-25-09, 03:28 AM
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Yes, caliper looks weird on the front of forks.
Cotic Roadrat https://www.cotic.co.uk/product/bikes/roadrat/flat_bar/
Cotic Roadrat https://www.cotic.co.uk/product/bikes/roadrat/flat_bar/
12-25-09, 12:53 PM
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A lot of the design came from the motorcycle market where calipers are mounted behind the stanchion tubes. Although motorcycles have a much more positive axle-attachment. The actual force pushing the wheel downward inline with the fork-tubes is a sine function of the caliper-to-axle angle relative to fork-tube angle. The closer you place the caliper to the fork-tubes, the less this force is.
