First, there is the alignment of brake pads on the rims. The brake pads need to be resting entirely within the brake track on the rim, and not be touching the tires. The idea is to maximize the contact area between the brake pad and tires, for maximum braking power.
After the alignment is set, the toe-in needs to be set. Toe in means that the front part of the brake pad will contact the rim just slightly before the rear of the brake pad. This will largely eliminate any squealing during braking. A toe in amount of 0.5mm is probably sufficient. However, setting this toe-in is tricky as the brake pad will move about during the alignment. Too much toe in is also not ideal, as it will create a spongy feeling at the brake levers due to excessive flexing of the brake pads.
A simple and clear illustration about the toe-in on brake pads.
While shopping online, I came across this Tacx Brake Shoe Tuner that was designed to simplify the alignment of brake pads. It is really simple to use, as shown below.
Usage method as shown on the box
Turn the black knob to clamp the tool on the rim
The tool flexes to cater to different rim widths
As seen on my Wheelsport rims. Does not work if you can't fit it between the spokes!
Set the top edge of the tool so that it goes over the rim, and into the small groove between the tire and the rim.
Align the brake pad flat and against the top edge of the tool. The front side of the tool is thinner, so that when the brake pad is set against the tool, the toe-in will be set at the same time. Once this is done, just tighten the brake pad holder. Simple!
However, the brake pad is set about 2mm below the top of the rim brake track. This is due to the lip of the tool which is rather thick.
This causes the bottom of the brake pad to be unused as it cannot contact the rim at all.
On the bright side, the toe-in setting is perfect! As seen from the picture, the front of the brake pad is touching the rim, but the rear is still about 0.5-1.0 mm away.
Due to the unsuitable alignment of the brake pad to the rim, I can't really use this tool for these wheels. However, it is noted that Wheelsport rims have narrower brake tracks that some other wheels. Kinetix Comp wheels have a wider brake track (confirmed by actual inspection/comparison), and this tool would be perfect for those wheels. It would most likely be suitable for most, if not all full sized wheels.
Overall, I would recommend this tool as the brake pad setting is made really easy. Clamp on the tool, and align the brake pads to the top edge. Tighten the brake pad holder and it is done! Perfect alignment and toe-in all done at the same time.
The only thing to take note is that not all rims can use this tool properly. It is not suitable for rims with narrow brake tracks such as Wheelsport wheels.
Try deflating your tyre so that the tool can slide up a little further.
ReplyDeleteOr chamfer bottom edge of pad with a Stanley Knife. I never feel happy with brake pads right on top edge of braking surface.
ReplyDeleteOr chamfer bottom edge of pad with a Stanley Knife. I never feel happy with brake pads right on top edge of braking surface.
ReplyDeleteI think I'll 3d print my own tool so that it is a thinner height and more curvature for 20 inch rims. Do you know if the vertical direction also has a slope or is it parallel with the rim? Because the angle of the pad will change slightly when you squeeze the brake.
ReplyDeleteProbably best to have a slight angle in the vertical direction, so that it contacts the rim perfectly flat. How much angle will depend on how big the gap you usually set.
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