Mechanical disc brakes?

[13brv3]

Thanks. I'll stash that link in case I go hydraulic.
Rusty

[13brv3]

As a follow up, I replaced the Azusa brake shoes even though the originals looked near perfect. As expected, there was no improvement. Aside from the lack of holding power, there's also a significant pulsation and squeak. I suspect there is enough play in the wheel and drum holes that the machined drums are not centered. I may need to loosen the wheel bolts and then try to tap them into alignment if that's the case. I still think the best I can hope for is less pulsation. I can almost guarantee some form of disc brakes are in my near future. I'm still pretty tempted to try the bicycle brakes.

Cheers,
Rusty

[Tony4aro]

The idea of modern bike disk brakes is interesting. I know some people may say they are just too light to work... but the reality is... we are using 1970's mini-bike brakes now. (Azusa) I have a Specialized Turbo Levo (Proper E-MTN bike) and the brakes on it are awesome !!

So... some things to consider.
1) Yes they are light... but on a down hill bike... they are being used HARD for the entire way down the trail. We only need a little braking power to slow us down. So, I don't think heat will be an issue.
2) The clamping force is high. So, it should hold us on a runup.
3) Since these are used in competition... there are different compound pads available.
4) LEVERAGE !! My bike has a 180mm disk... but it can hold a 29" (737mm) tire/wheel. We only have to hold a tire that is 12" or so. I'm honestly thinking about 120mm or 140mm disk and the ratio will be VERY low.

OK... I know the thread was originally asking about cable disks... but why not just use hydro bike brakes? They are plentiful, and easy to find. Not to mention... there are GOOD brakes out there that have been pulled off of high-end bikes because these guys just like to upgrade for the sake of upgrading. Yes... the OEM isn't always the best... but on a $7,000 bike... the OEM take-off's are pretty dang good, and go cheap on ebay.

With all the horror stories I hear about the Azusa brakes... I may look into this before mine is ready to go.

[13brv3]

I bought everything I'd need for the mechanical disc brakes, but when I was surveying the situation, it didn't appear to be wheel pants friendly. The Airbike I used them on before didn't have wheel pants, and had more clearance between the wheel and gear leg, so they were perfect for that plane. The Onex gear doesn't give as much space for the caliper, and the wheel pants plate is in the way front and rear. I could probably go with Van's wheel pants ($550) to work around that, but in the end I just ordered the Sonex hydraulics. They aren't perfect, but it's a clever design that is really compact. I'll save the bike brakes for another project.
Rusty

[Tony4aro]

I get it. The factory hydro isn't horribly expensive... and they fit without needing to engineer anything.

But, on the thought of the wheel pant backer... I figured that would need redone so the caliper has somewhere to mount. And, as far as being "Wheel pant Friendly"... I also assume that the caliper would hang out, and the wheel pant would be trimmed to fit. If I'm missing something... let us know what you found.

[13brv3]

The Onex gear is completely different from the other models, so the situation might be different for the round gear. I figured I'd need a decent bulge in the wheel pants to fit over the caliper since the stock wheel pants are so narrow and flat on the sides. The Van's wheel pants are wide and much more round, so they'd give more space to fit over a caliper. For now it's the path of least resistance, but I do have to make some brake pedals now.

[Spinnetti]

Bike brakes are very powerful and very light. If/When I build a Waiex, I'll use those. 140mm rotor probably plenty. You can get them in single piston, dual and 4 piston calipers too. I got some from China for under $50 for a full set (for a e-trike project) and would be perfect for this sort of thing - way better than the little drum brakes commonly used. (I've got discs on my mountain bike but not my road bike and they are very powerful)