Guy adds unusual rear brake to cruiser frame.

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Dec 21, 2007
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Ft Riley, NE Kansas
Many cruisers have a kick-back brake in the rear hub. they are intended for slow rides at the beach, so a back-pedal brake is often enough. More and more, many customers like the style, and are buying multi-speed cruisers. The old way was to "upgrade" to a simple 3-speed IGH, or a 5,7,8,11-speed IGH, if you wanted to get fancy.

Because of this, you can buy a Sturmey-Archer or Nexus 3-speed IGH that has a band brake, or a drum brake on the rear wheel, since these frames often don't have the mounts for a V-brake, or...especially a disc brake.

This guy is customizing a truly rare vintage frame, so I understand why he wouldn't want to drill, cut, or weld onto it...so it can be completely restored later if anyone wants. So...how to add a brake to the rear wheel?

Solid fixed cog on the rear wheel, so it runs a live chain (if rear wheel is spinning, the chain is spinning). Then he adds a freewheeling crankset (like all the mid drives around here), and then finally, he adds a disc brake caliper to a large diameter chainring. Using a sprocket as a brake rotor is sometimes called a "Sprotor" in custom motorcycle circles.

BrakeDiscChainring.png
 
Also brake torq will be reduced by gear ratio - looks like about 4:1 in the picture. Be more effective to put his feet down...
Won't be a problem with all that oil contamination :)
 
Was going to say Gates Carbon Drive but you'd have to mod the frame.

After all this time I'm still surprised there hasn't been an oiless chain produced..
 
Motorcycles have an O-ring chain option, but no bicycles as far as I know. The individual links are sealed with grease inside, and the exterior can look very dry and rusty, even though it's fine.
 
Yeh I'm a motorcycle tech, they do still benifit from chain lube though.

I've found o-ring chains using dry lube don't tend to last as long as ones using coventional lube (TL45).
 
Years ago, Sycip made a one-off fixed gear bike that used a crank with the chainring on the right and a disc rotor on the left. The same general limitation applied inasmuch as it needed to make almost three times as much braking force at the crank as was desired at the wheel. That's probably OK for a rear brake as long as the disc brake is strong and stays clean. And separating the brake pads from the chain certainly helps keep them cleaner than they would be together.

sycip%20disc%20crank.jpg
 
Interesting,, maybe even totally cool for NY.

I recently watched a movie about fixie races,, mostly in Manhattan. You know, those messenger guys. The thing I noticed right away about the riding in NYC, the congestion was so bad, they were blowing by cars right and left, but still barely moving really. They'd run those lights, but the cars were crawling, so they could dodge and dart in front or behind them. Just doing the fixe rear wheel slide was plenty of braking power for them.

I just couldn't help thinking,,, Try that in Phoenix, Dallas, El Paso,, yer dead meat buddy. Cars are able to run red lights at 45 mph out here. You better have great brakes out here.

But in NYC,, with cars barely able to reach 10 mph,, no brakes needed.
 
spinningmagnets said:
This guy is customizing a truly rare vintage frame, so I understand why he wouldn't want to drill, cut, or weld onto it...so it can be completely restored later if anyone wants. So...how to add a brake to the rear wheel?

Well , its a neat solution, but i dont see the difference between mounting a caliper on the downtube (clamped ?), giving him a dubious brake set up...
...when he could have mounted a caliper (clamped) onto one of the rear chainstays, and used a normal hub disc mount ?..and have a real working brake .!
But i guess he was more interested in the clean "fixie" wheel look ?
Form over function again.....but that is typical "fixie" attitude.
 
he could have mounted a caliper (clamped) onto one of the rear chainstays, and used a normal hub disc mount

I agree. I would put a plate to bridge across the chain-stays and seat-stays, like some of the Currie-drives have for their left-side drive motor. Through judicious shimming, it could be made close enough to parallel to be useful.
 
A single iteration of deathbike used a sproter to meet the requirement of having a rear brake for a race. That was the only time I had a rear brake, and it's function was mostly aesthetic.
 
spinningmagnets said:
he could have mounted a caliper (clamped) onto one of the rear chainstays, and used a normal hub disc mount

I agree. I would put a plate to bridge across the chain-stays and seat-stays, like some of the Currie-drives have for their left-side drive motor. Through judicious shimming, it could be made close enough to parallel to be useful.
You can buy a premade caliper bracket that bolts on via the axle nut. <$5 on Ebay !
 
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