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Old 04-03-14, 11:46 AM
  #83  
overbyte
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Join Date: Jun 2007
Location: Santa Cruz, CA, US
Posts: 250

Bikes: 3 folders, 2 recumbents (1 is electric), 1 recumbent trike, 1 touring, 1 mountain, 1 road bike -- So many bicycles, so little time.

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Originally Posted by tk1971
Overbyte,

My bike shipped, so I guess I'll be getting it in a couple of weeks or so, but in the meantime, I'm going to keep pestering you with questions.

I was given a Forever folder with a rear band brake and was not impressed by it, even after I adjusted them. My fake A-bike also has band brakes and they're not especially effective. How feasible do you suppose it would be to replace the rear wheel with one that has a coaster brake? The only issue I would imagine would be: 1) Rear triangle spacing; 2) The grafting of the belt pulley to the new wheel.

What are your thoughts on this?

Thanks.

tk
I agree that the band brake is not great. It takes a lot of squeeze pressure to get just a modest amount of braking. It stops, but not as quickly as I would prefer. Therefore, I always use both brakes equally. Lubricating the cables and moving parts of the brakes may also help with pressure to the pads and band.

I haven't measured the stopping distance yet. There is a US standard for braking in the CPSC bicycle regulation 16 CFR 1512 which involves riding the bike on a flat road with no significant wind and a rider weighing 150 lbs (as I recall) at a certain speed (I think 12 mph) and then testing how far the bike rolls once the brakes are applied hard. Even the front caliper brake on this bike isn't especially strong. I asked my local bike shop mechanic about getting other pads, but he said the ones he has that fit the caliper (bolt-on type) look the same as the grey ones on the Free Ride now, so he didn't think it would make a difference. I wonder whether the band brake improves a little as it wears in and maybe makes more complete contact with the drum. Also, I notice that the way the band is sitting in the housing is a little off of the ideal position relative to the width of the drum. I think one more washer under the band bolt would shift it into a better contact with more of the drum.

I also wonder if I can fit longer brake pads to these front calipers, such as the ones that are on my full-size touring bike. There are more types of rubber pads available for them, some which are better at stopping but don't last as long.

I considered the feasibility of changing the hub to an internally geared hub with a built-in brake, such as one that Sturmey-Archer makes with a coaster brake or one that Shimano makes with a roller brake. The problem is that those hubs don't come in 20-spoke configuration, which is what these 12" wheels have. The standard is 36-spokes for larger wheels. I haven't measured the "over-locknut dimension" (OLD) of the rear fork. To do it accurately, I'd have to remove the rear wheel, which I haven't done yet but I will so I can see if there are difficulties that would be encountered to fix a flat tire (tyre). That's what you'd need to do to determine if a different brake would fit. Then you'd have to take the existing one apart to determine how the things bolt together, which I'll probably do at some point to see how to replace the band if it wears out. I don't plan to ride this bike enough to wear out the thickness of the brake lining, but it would be good to know how it's done.

I also am thinking that changing from the existing 80mm drum to a different band brake with a 90mm drum might improve the stopping power since more band would be in contact with a larger circumference, if it will fit the bike with the existing hub. The links I posted above show that 90mm are available.
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