I need a handbrake for MSVA but neither my donor scooter nor the fiat front end have one. I read on here that Willwood and Hispec so spot calipers,
which they do but they cost £50 and £65. Mini moto calipers cost more like £13. Are they any good? Will one of these be OK as a handbrake for a
220kg 3 wheeled vehicle. It only has to pass MSVA and stop my 3 wheeler rolling down hills.
Edit: What's the difference between front and rear calipers? Are they just handed for the cable run?
[Edited on 22-7-2010 by smart51]
I can't comment on the legallity or the effectivness of using one, but from experience I would have to say most minimoto parts are made in the
far east and are the worst made components I have ever seen. Personally I would never even consider putting something like that on a car I have made.
I know this is Locostbuilders, but out of principle I would rather pay more.
As you can see I have a real hatred to these Chinese import minimotos.
On a more practical issue, what disc width are the mini-moto calipers designed to work on?
Mini moto discs are quite small at 120mm diameter and 3mm thickness. The calliper I've seen has no obstruction for a larger diameter and looks
like it can be shimmed out to fit my scooter's 240mm by 5mm thick rear disc.
The problem with the Wilwood and Hispec parts is that their minimum thickness versions are 1/4" or 6.35mm.
what about a mechanical caliper from a mountain bike?
link
The pads on these things are tiny, but the size is only really there to handle the heat, which as a parking brake it will not see.
The quality of bike parts can be quite good, and the weight will be super low. A heavily loaded tandem might get up to 250-300kg, and have these as
their main brakes, so perhaps not ridiculous.
Have you considered using the handbrake on the front wheels. I say this because then you get a larger diameter disk, and a pair of calipers (instead
of 1) all of which will help.
Just thoughts,
Matt
With single rear wheel with hardly any weight on it you are going to be hard pushed to get an effective and brake working on the rear. You really need a hand brake working on the front wheels.
quote:
Originally posted by matt_gsxr
what about a mechanical caliper from a mountain bike?
link
The pads on these things are tiny, but the size is only really there to handle the heat, which as a parking brake it will not see.
The quality of bike parts can be quite good, and the weight will be super low. A heavily loaded tandem might get up to 250-300kg, and have these as their main brakes, so perhaps not ridiculous.
Have you considered using the handbrake on the front wheels. I say this because then you get a larger diameter disk, and a pair of calipers (instead of 1) all of which will help.
Just thoughts,
Matt
That's a good point BT. My 3 wheeler will have a weight distribution of 40% to the rear so in order to achieve a handbrake force of 18% of the
vehicle's mass, I need 45% brake effort of the mass on the rear wheel, or 54kg of hand brake force. Working it out, that means a hand brake
lever force of 5.1kg.
Assuming the brake doesn't lock up I think 5.1kg is a realistic figure. Locking up 2 wheels on the foot brake test is acceptable in lieu of
meeting the 50% required foot brake "efficiency". Is locking the handbrake acceptable in the same way?