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Drum braked rear hub for fixed gear

Posted: 15 Jul 2020, 8:36pm
by SimonCelsa
I realise a fixed rear hub can be braked by using leg power, but is anyone aware of any drum braked rear hub which is specifically designed for fixed gear use (not single speed).

There we go, short and sweet one sentence question. I can't see anything available after a quick google search which leads me to believe this may be a bl**dy stupid question but I can't fathom why.

Re: Drum braked rear hub for fixed gear

Posted: 15 Jul 2020, 8:54pm
by Brucey
niche market. Very niche market in fact, since you will (legally speaking) have twice as many 'brakes' on the rear wheel as is required.

If you want this functionality, I suggest that you use a fixed/free rear hub, fitted with a screw-on drum brake, such as a Kuwahara.

FWIW BITD when most hubshells were steel, SA 90mm brakes were made with the correct threading for a fixed sprocket (i.e. with a lockring thread). The logic here was that a steel thread would be strong enough for a freewheel (with a large sprocket fitted) even if it was about half the usual length, whereas this is less certain if the hubshell is aluminium. Fixed sprockets were often used on carrier bikes simply because they were more reliable than freewheels. So a steel hubshell could be made to do both jobs with no loss. Occasionally you will find one of these older hubs; I have only seen them in 40h format, with 'double' spoke holes on a small RH flange (a bit like old dynohubs).

cheers

Re: Drum braked rear hub for fixed gear

Posted: 16 Jul 2020, 4:58pm
by SimonCelsa
OK thanks for that Brucey. I was mulling over fitting a rear brake on my fixed commuter which is getting quite a bit of use at the moment. There are a few short, reasonably steep hills in the area and with gearing of about 67 inches I try and maintain a speed of below 22 mph with the front brake else my legs can't keep up. If the front brake went AWOL I would struggle to retard the speed with legs alone, perhaps I'll fit some decent pedal straps which should assist.

Re: Drum braked rear hub for fixed gear

Posted: 19 Jul 2020, 3:12pm
by alexnharvey
If you cannot brake the rear wheel sufficiently with your legs are you road legal without a second/third brake?

As a fellow fixed commuter it's a question I have been asking myself recently too, although I am clipped in to the pedals and I think I could stop the bike with my legs if I had to, although I prefer not to do all the braking with my legs and use the front brake too.

Re: Drum braked rear hub for fixed gear

Posted: 19 Jul 2020, 3:21pm
by Jdsk
alexnharvey wrote:If you cannot brake the rear wheel sufficiently with your legs are you road legal without a second/third brake?

AFAICT the statutory requirement for each system is "efficient working order".
https://www.legislation.gov.uk/uksi/1983/1176/pdfs/uksi_19831176_en.pdf

Jonathan

Re: Drum braked rear hub for fixed gear

Posted: 19 Jul 2020, 3:30pm
by thirdcrank
Thread to needle, brakes have to be in efficient working order and, incidentally, the ability of the rider to operate them is not mentioned so tiny hands with big hoods are legally ok in this context.

A fixed-wheel is not a brake as such, but rather having one provides an exception from the requirement to have a rear brake. If push came to shove, then perhaps something like a fixed sprocket coming unscrewed through the lack of a lockring might be judged not to be fitted ie the regs might be interpreted as implying properly fitted.

Re: Drum braked rear hub for fixed gear

Posted: 19 Jul 2020, 3:35pm
by Cyril Haearn
I brake with my legs only, fixed and free

Re: Drum braked rear hub for fixed gear

Posted: 19 Jul 2020, 10:01pm
by seph
Interesting idea...
https://www.ebay.co.uk/itm/Sturmey-Arch ... 2f386dc70e
This has the brake, but is for single speed... How about spinning on a fixed cog and using an old bb lock ring to help keep it in place? As described here https://www.sheldonbrown.com/fixed-conversion.html

It’s not perfect, and though it is sometimes called a suicide hub(!) I think that’s only where people rely solely on leg braking, with no front brake, and then the cog unscrews :shock: .

I think it would be fine if you used the brakes to control the speed and kept the top run of chain tight...

Re: Drum braked rear hub for fixed gear

Posted: 19 Jul 2020, 10:16pm
by seph
required.

If you want this functionality, I suggest that you use a fixed/free rear hub, fitted with a screw-on drum brake, such as a Kuwahara.


Karasawa https://www.sjscycles.co.uk/brakes/kara ... aces-arai/ Interesting...

Re: Drum braked rear hub for fixed gear

Posted: 19 Jul 2020, 10:34pm
by Brucey
oops.. :oops: ….. what is in a name, eh...?

:wink:

cheers

Re: Drum braked rear hub for fixed gear

Posted: 19 Jul 2020, 11:21pm
by mig
Cyril Haearn wrote:I brake with my legs only, fixed and free


not sure i follow that. leg braking with a freewheel?

i trim a bit of speed off with by resisting with my legs but actually coming to a stop using leg braking isn't easy. okay if the rider is only at a low speed in a tiny gear then it's possible but coming to a stop from a regular road speed within a decent time and space is hard to do.

Re: Drum braked rear hub for fixed gear

Posted: 20 Jul 2020, 7:17am
by Cyril Haearn
mig wrote:
Cyril Haearn wrote:I brake with my legs only, fixed and free


not sure i follow that. leg braking with a freewheel?

i trim a bit of speed off with by resisting with my legs but actually coming to a stop using leg braking isn't easy. okay if the rider is only at a low speed in a tiny gear then it's possible but coming to a stop from a regular road speed within a decent time and space is hard to do.

Back-pedal brake
I have a front hand brake on fixed and freewheel bikes, hardly ever use it