Fornt Brake Pad Changing on a ChinaDesign brake
by: rcq92130 - Jul 18, 2015 13:11:50 GMT -5
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Post by rcq92130 on Jul 18, 2015 13:11:50 GMT -5
OK, so no one ever accused china engineers of designing Nobel Laureate products. Sometimes they do well (broken clocks are also right twice every day), other times not so much.
Most ChinaScoot's have normal front brakes but some of you will find yourself unlucky enough to have the kind found on this BMS Heritage. They work fine, but when it's brake pad changing time - a job that should be simple & quick - you find the idiotic design to be not so terrific.
If you were not so unlucky as to get these totally stupid ChinaBrake designs, skip all the crap about removing the wheel, just remove the caliper mounting bolts, take the caliper off, put new pads in, put the caliper mounting bolts back in (with blue Locktite!), and finish up in 30 minutes or less. And be glad you were not bad and unlucky.
Otherwise you have to do all of THIS crap!:
Here is the type of brake I'm talking about:
With any NORMAL disk brake there are a pair of bolts that attach the brake caliper to it's mount. Remove the 2 bolts and lift the caliper off. Take out the pads, put new pads in, bolts back on, job done. Half hour.
Here is the problem with these idiotic brakes:
Where the 2 caliper mounting bolts SHOULD be are 2 rubber things (one is black, the other actually a cast metal (grey) part of the caliper with a rubber insert). No bolts. Now the mount - the flat part the has the axle go thru it - has 2 pins sticking out that slide into these rubber cups. The pins are instead of bolts.
OK, so there should be a way to then just slide the caliper off the pins, making the job even easier than removing bolts. Maybe if the 2 black hex head brake pad pins (see here) ...
... are removed, allowing the brake pads to simply fall out, the caliper will then slip outward and off the Mounting Pins. Here the pins are half out:
Here is a pic of the pads themselves (a little uot of order, obviously) showing the holes the black pins go thru to hold the pads in place:
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i57.tinypic.com/2afietl.jpg[/IMG
NOPE. The brake disk, which sticks up into the middle of the caliper, prevents that.
OK, so maybe you can just put the new pads on by slipping them between the caliper & disk without removing anything, then pushing the black pins in and done. Nope. There are springs inside the caliper and it's basically impossible to do the job w/o actually removing the caliper.
So to do a simple brake pad change on this idiotic ChinaDesign you actually have to remove the entire front wheel, dropping the disk out of the caliper so you can get to the pads. Grrrrrrrrr !!!!
OK. Onward and upward. Remove the front axle nut (17mm):
![]()
i57.tinypic.com/2afietl.jpg[/IMG
Pull the axle out from the other side:
The speedometer puck (on the side of the wheel opposite the brake) will just fall out once the axle is withdrawn:
As the axle is fully removed the wheel will just fall down. Don't forget or lose the spacer that goes between the wheel and the brake mount plate:
So now the brake mount is free:
You could, if you wanted, now simply slide the caliper off the mounting pins though there is no need since the brake pad area is not accessible. But it's a good idea to grease the mounting pins, so do so and slide the caliper back onto the greased pins.
Next step is to put new pads in, but first push the piston back ibnto the caliper (it gradually descends as pads get worn, so with (unworn) new pads you need to make room by pushing the piston back into the caliper:
On these tiny ChinaBrakes pushing the piston back is simple (unless you have a lot of dirt and corrosion), but pushing on only 1 piston simply pushes the OTHER piston out. You need to push on BOTH at the same time. Easiest way is to just lay a brake pad in against the pistons and push on the pad. That moves both pistons back together:
If your brakes are corroded and the pistons won't move back you will have to use a small c-clamp to push the pistons back into the caliper.
Time now to start the black pins back in that secure the pads in the caliper. Here is looking inside the caliper, the first pad installed and the 2 pins emerging thru the holes in the pads:
And here is with both new pads installed and the pins all the way in, securing the pads in the caliper. I have a screw driver between the pads to keep them separated in preparation for sliding the wheel and rotor (disk) back into the caliper assembly:
NOTE: on larger brakes you usually should put some "anti-squeal" goop on the backside of the pads (NOT the friction surface) to keep the brakes from making noise when applied. However - maybe because they are so small, ChinaScoot brakes seem to usually not have this problem.
OK, time to put the wheel back on. Start by putting it in place with the brake rotor up inside the caliper and between the 2 new brake pads:
Don't forget the spacer that goes between the wheel and the caliper mount plate.
On the opposite side of the wheel, put the speedometer puck back in place ... GENTLY. The puck has 2 flimsy tabs that fit into slots on the wheel - if you force the puck against the wheel and the tabs are not positioned in the slots you will bend the tabs. result - no speedometer. Rotate the wheen to get the slots in position properly for the tabs.
Slide the axle thru everything until the threaded part is sticking out the opposite side. ALWAYS - without fail !!!! - use blue locktite on the threads before putting the nut back You do NOT want the nut to fall off, and then your front wheel fall off, when you are, like George, scooting along at 75mph:
Tighten the nut. I am sure there is some sort of 'correct" torque; I just ratchet it on about as tight as I can. Do you really think ChinaProductionWorkers properly torque these things when they are made??? Really
OK, job about done. But - remember you pushed the pistons back into the calipers? That means if you pull on the brake lever nothing will happen until the brake fluid has pushed them back against the rotor. You want to do this NOW, not wait till you start to ride and actually need brakes to work. Just squeeze the brake lever a few times till the brakes have normal resistance. No need to bleed the brakes or anything. Just get the pads back into proper position:
One final step. Check the brake fluid level in the reservoir. It might [possibly need a bit more:
Done. Again, if you were not bad all year and were not so unlucky as to get these weird brakes without mounting bolts, ignore all the crap about dropping the wheel.
Test your brakes for normal operation before riding. And slow down. Deer are in the road everywhere!
Most ChinaScoot's have normal front brakes but some of you will find yourself unlucky enough to have the kind found on this BMS Heritage. They work fine, but when it's brake pad changing time - a job that should be simple & quick - you find the idiotic design to be not so terrific.
If you were not so unlucky as to get these totally stupid ChinaBrake designs, skip all the crap about removing the wheel, just remove the caliper mounting bolts, take the caliper off, put new pads in, put the caliper mounting bolts back in (with blue Locktite!), and finish up in 30 minutes or less. And be glad you were not bad and unlucky.
Otherwise you have to do all of THIS crap!:
Here is the type of brake I'm talking about:
With any NORMAL disk brake there are a pair of bolts that attach the brake caliper to it's mount. Remove the 2 bolts and lift the caliper off. Take out the pads, put new pads in, bolts back on, job done. Half hour.
Here is the problem with these idiotic brakes:
Where the 2 caliper mounting bolts SHOULD be are 2 rubber things (one is black, the other actually a cast metal (grey) part of the caliper with a rubber insert). No bolts. Now the mount - the flat part the has the axle go thru it - has 2 pins sticking out that slide into these rubber cups. The pins are instead of bolts.
OK, so there should be a way to then just slide the caliper off the pins, making the job even easier than removing bolts. Maybe if the 2 black hex head brake pad pins (see here) ...
... are removed, allowing the brake pads to simply fall out, the caliper will then slip outward and off the Mounting Pins. Here the pins are half out:
Here is a pic of the pads themselves (a little uot of order, obviously) showing the holes the black pins go thru to hold the pads in place:
NOPE. The brake disk, which sticks up into the middle of the caliper, prevents that.
OK, so maybe you can just put the new pads on by slipping them between the caliper & disk without removing anything, then pushing the black pins in and done. Nope. There are springs inside the caliper and it's basically impossible to do the job w/o actually removing the caliper.
So to do a simple brake pad change on this idiotic ChinaDesign you actually have to remove the entire front wheel, dropping the disk out of the caliper so you can get to the pads. Grrrrrrrrr !!!!
OK. Onward and upward. Remove the front axle nut (17mm):
Pull the axle out from the other side:
The speedometer puck (on the side of the wheel opposite the brake) will just fall out once the axle is withdrawn:
As the axle is fully removed the wheel will just fall down. Don't forget or lose the spacer that goes between the wheel and the brake mount plate:
So now the brake mount is free:
You could, if you wanted, now simply slide the caliper off the mounting pins though there is no need since the brake pad area is not accessible. But it's a good idea to grease the mounting pins, so do so and slide the caliper back onto the greased pins.
Next step is to put new pads in, but first push the piston back ibnto the caliper (it gradually descends as pads get worn, so with (unworn) new pads you need to make room by pushing the piston back into the caliper:
On these tiny ChinaBrakes pushing the piston back is simple (unless you have a lot of dirt and corrosion), but pushing on only 1 piston simply pushes the OTHER piston out. You need to push on BOTH at the same time. Easiest way is to just lay a brake pad in against the pistons and push on the pad. That moves both pistons back together:
If your brakes are corroded and the pistons won't move back you will have to use a small c-clamp to push the pistons back into the caliper.
Time now to start the black pins back in that secure the pads in the caliper. Here is looking inside the caliper, the first pad installed and the 2 pins emerging thru the holes in the pads:
And here is with both new pads installed and the pins all the way in, securing the pads in the caliper. I have a screw driver between the pads to keep them separated in preparation for sliding the wheel and rotor (disk) back into the caliper assembly:
NOTE: on larger brakes you usually should put some "anti-squeal" goop on the backside of the pads (NOT the friction surface) to keep the brakes from making noise when applied. However - maybe because they are so small, ChinaScoot brakes seem to usually not have this problem.
OK, time to put the wheel back on. Start by putting it in place with the brake rotor up inside the caliper and between the 2 new brake pads:
Don't forget the spacer that goes between the wheel and the caliper mount plate.
On the opposite side of the wheel, put the speedometer puck back in place ... GENTLY. The puck has 2 flimsy tabs that fit into slots on the wheel - if you force the puck against the wheel and the tabs are not positioned in the slots you will bend the tabs. result - no speedometer. Rotate the wheen to get the slots in position properly for the tabs.
Slide the axle thru everything until the threaded part is sticking out the opposite side. ALWAYS - without fail !!!! - use blue locktite on the threads before putting the nut back You do NOT want the nut to fall off, and then your front wheel fall off, when you are, like George, scooting along at 75mph:
Tighten the nut. I am sure there is some sort of 'correct" torque; I just ratchet it on about as tight as I can. Do you really think ChinaProductionWorkers properly torque these things when they are made??? Really
OK, job about done. But - remember you pushed the pistons back into the calipers? That means if you pull on the brake lever nothing will happen until the brake fluid has pushed them back against the rotor. You want to do this NOW, not wait till you start to ride and actually need brakes to work. Just squeeze the brake lever a few times till the brakes have normal resistance. No need to bleed the brakes or anything. Just get the pads back into proper position:
One final step. Check the brake fluid level in the reservoir. It might [possibly need a bit more:
Done. Again, if you were not bad all year and were not so unlucky as to get these weird brakes without mounting bolts, ignore all the crap about dropping the wheel.
Test your brakes for normal operation before riding. And slow down. Deer are in the road everywhere!
