chagzuki

I've never used a drum brake; would there be any negative consequences of installing one on the rear of a Brompton such as ease of disconnecting the cable for wheel removal, or fitting the brake arm bits neatly inside the rear frame?

badmother

First of all it is a space problem. Drum brake hubs tend to be not as narrow as a B at the back so you`d need to widen or get a new rear triangle.

Disconnecting cable should be no problem, it is about learning how to do it and getting used to doing it before you really need to do it- in the dark and rain.

There are some "quick release" options where you slide the brake arm innside a clip instead of atatching it with a nut. Not sure if it fits and can be used on a B. If not I have some times used a sprung washer and a wingnut to atatch the clip to reduce the amount of tools needed. Brake wire detatches and atatches without tools.

The Smut Pedaller: Sturmey Archer XL-FDD & X-RD3 review

https://greenspeed-trikes.com/support...ke-truing.html
Scroll down for info about drum brake for B front wheel.

Rick Imby

I have not seen drum brakes that were very effective? I know Sturmey made one back in the 90s for the front that was before discs. Are there good drum brakes that work with an internal geared hub?

Schwinnsta

I had a drum brake on front wheel, not a Brompton, but was underwhelmed by its stopping power.

chagzuki

The reports I've read are generally positive but intuitively is strikes me that with the mechanism so close to the axle they ought not to be very effective.

Getting accurate stats for the OLD on older Sturmey hubs is not so easy. Websites often seem to misquote them... for the most part in my experience the ones listed as 130mm can be shortened by changing the nuts on the non-drive side. The brompton rear frame can probably be spread to around 120mm without much trouble.

Winfried

Ben Cooper @ Kinetics may have tried it:
Kinetics ? Recumbents, Folding Bikes, Custom Framebuilding

BassNotBass

badmother

If you read the pages I linked to you get the info you need at least about stopping power and getting rid of pulsing (if any). Like all other brakes it is about setting them up the right way, the right brakelever, the right cable and housing and adjustment. The guy in the blog bent his front fork becouse the drum brake was so strong (after he changed housing)and I think I remember he is the one that said it is no problem setting up a drum brake so you can dive over the bars if that is what you want.

fietsbob

As far as I can guess It will be incompatible with the narrow rear dropout spread , unless you in your shop can modify one of the freewheel rear hubs..
I have had one of the freewheel hubs with a 6 speed freewheel, in an old MTB
now as my pull it out when road ices up, studded tire fitted bike.

> (NB: Stopping is very adequate on dry pavement, I don't want flip me over the bars braking on Black Ice)

Their chainstay clamp uses 2 separate bolts, one clamps the bracket on, for the arm bolt, I substituted a pin I pull out (from under the chainstay)
which has a tiny ball with a spring behind it, that keeps it from coming out, unless I pull it out by the ring thru the outside end.

there are clamp on barrel ends that engage a U shaped hook end of the actuating arm.. Other end of the cable cantilever pull brakes .

looks like at 119, their current 1 speed freewheel hub can be re assembled with other axle spacers ,
and moved to the right, to line up the chainline.


https://www.sturmey-archer.com/files/...AKE%20HUBS.pdf


I'm thinking the smallest freewheel that fits standard thread is 16t , IDK if You may like the 54:16 gear.

I recall seeing Greenspeed in Australia, modified the S-A front drum hubs to fit in the confines of the narrow 74mm fork.

GreenSpeed the recumbent bike company is the Brompton wholesale importer, there.

they used the Drum Hubs and made them work on their Tadpole trike front wheels..


FWIW My Bike Friday Tikit uses a 349 24 hole rim and a 36 , skip some holes, rear hub [ 2 cross ]...


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