I've picked up a Pashley no.33 cargo trike which I plan to turn into a coffee bike. Are these single pivot or dual pivot caliper brakes? They aren't particularly effective and I wondered if anyone had any suggestions on what I could change them to?
Single pivot rim brake calipers. They are also mounted in a "reverse cable" orientation, which is relatively uncommon.
Start by swapping out the shoes for new ones - I see one is cracked and they look to be plastic which flexes. Use Kool Stop brand brake pads or similar quality. These longer pads could be used on newer dual-pivot calipers too if you swap them later. There are other good brands too, apparently swiss stop is similar.
Also - your rims are steel and textured. It may be beneficial to rebuild the wheels onto aluminium rims. Steel rims are rubbish for braking in the wet. The texturing will help, but it will rip up brake pads fairly quickly.
For a successful caliper swap, your new calipers will need to have
- the same width (to span the tyre)
- the same height from pads up to the central-mounting bolt (to reach the rim)
- A central mount bolt that does the same as your current calipers. More modern calipers will use a recessed hex socket into a Chicago-nut. You may have to get creative and use some high-tensile rated bolts.
- Some way to have the cable come in from "below" Normally the cable enters the caliper from above and is clamped at the lower arm. Yours are reversed.
There is no chance this bike can use any other brakes like V brakes, U brakes, Cantilever, or disks. I suspect that band and roller brakes won't suit either, and coaster brakes only activate with pedalling backward so no good on front wheels. You're stuck with calipers.
If you can't figure out a way to get reverse-entry on the cables on better calipers, you might have to run the full housing around the front of the cargo area and into the caliper from above. That would likely be safer than faffing with pulleys or noodles to reverse direction 180 degrees. A noodle might be good for getting 90 degree bends neatly, though it allows a join where water might enter.