Drum brakes

For discussions about bikes and equipment.
cycle tramp
Posts: 3483
Joined: 5 Aug 2009, 7:22pm

Re: Drum brakes

Post by cycle tramp »

mattsccm wrote: 20 Sep 2021, 6:09am Cheers folks. Food for thought. A bit disappointed actually as was hoping for everyone to say how brilliant they are. Not keen on going backwards in terms of stopping power from my cable operated discs although really good cantis can, I know, match these in dry weather so drums as good as those may be worth a try.
Straight out of the box, the 90mm work well, and now bedded in, it is one of the most strongest brakes I have used - in other forums, some posters believed the performance was almost as good as discs (I've not used a bicycle disc brake so it would be wrong of me to comment)
Out of the box the 70mm was abit like a badly set up cantilever brake... a bit.... meh... better than the shimano roller brake I was using but still... meh... however it's now bedded in and is equal to a good cantilever brake, and on gravel I can lock the rear wheel. However whilst I've described the braking to begin with as ...meh... it was equally as ...meh... in the rain as it was in the dry(unlike my cantilever brakes, which went from good to meh to not stopping at all during some downpours). And now that the hub brake is bedded in I've got adequate rear stopping power whatever the weather - If you're using a bike to commute on and expect to ride in the rain, then brakes which work constantly is a good thing.
It's time to go :-)
LuckyLuke
Posts: 374
Joined: 10 Jun 2010, 11:54am

Re: Drum brakes

Post by LuckyLuke »

rotavator wrote: 19 Sep 2021, 9:37am How do drum brakes perform on long descents with a load on board e.g. on the long descents on Lon Las Cymru?
Hi, I had some brake fade with a 70mm SA front drum Dynamo hub, on one 20% descent in the Lake District. Described here:
viewtopic.php?f=5&t=143594&p=1575053#p1575053
It was a busy narrow single lane road, with passing places, on a laden touring bike. I had to drag the brakes more than I would have liked. This was the only example of brake fade in around five years plus of ownership.
However, I’ve since fitted the 90mm drum Dynamo hub. Braking is stronger, though I’ve yet to test it on a long steep descent.
Best wishes,
Luke
LuckyLuke
Posts: 374
Joined: 10 Jun 2010, 11:54am

Re: Drum brakes

Post by LuckyLuke »

Hi, just to add I totally agree with the positive reviews of the SA drum brakes up thread.

I too have also benefited from an near total lack of maintenance. An occasional twiddle with a barrel adjuster, and once a dab of grease. It’s really impressive on a Commuter bike that sees near daily use in all weathers.

As others have described, the brakes are totally consistent in wet weather. I would say overall the 70 mm drum has the stopping power of an average cantilever brake, And the 90 mm drum has a stopping power of a really good canti. The modulation is pretty nice, not like the “all or nothing” or some V brakes.

Best wishes
Luke
Phileas
Posts: 414
Joined: 18 Feb 2009, 6:12pm
Location: Bristol

Re: Drum brakes

Post by Phileas »

I personally wouldn’t say the SA drum brakes are completely unaffected by rain. I think water does get into the drums in sufficiently heavy rain and reduces the braking.
cycle tramp
Posts: 3483
Joined: 5 Aug 2009, 7:22pm

Re: Drum brakes

Post by cycle tramp »

Phileas wrote: 22 Sep 2021, 12:24pm I personally wouldn’t say the SA drum brakes are completely unaffected by rain. I think water does get into the drums in sufficiently heavy rain and reduces the braking.
It's not been my experience so far, and I've ridden in some complete storms
It's time to go :-)
rjb
Posts: 7183
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Drum brakes

Post by rjb »

When drum brakes on motor vehicles was common there was usually a sign after a section of flooded road or a ford to gently apply your brakes to dry the shoes out. And it didn't mean the ones on your feet. :lol:
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
cycle tramp
Posts: 3483
Joined: 5 Aug 2009, 7:22pm

Re: Drum brakes

Post by cycle tramp »

Phileas wrote: 22 Sep 2021, 12:24pm I personally wouldn’t say the SA drum brakes are completely unaffected by rain. I think water does get into the drums in sufficiently heavy rain and reduces the braking.
I've just nipped out to have a quick look - I'm not sure how rain would get into the hub. The brake mechanism itself, is inside the hub, mounted vertically to a plate which is then mounted via the axle to one side of the hub. The hub itself has a fairly pronounced lip which extends around the circumference of this plate, and this plate has a further pronounced lip making the gap between them both very narrow. Of course, when riding in the rain the hub would be spinning so any rain falling on the hub is likely to get thrown of by centrifugal force. The only way I can see rain getting into the hub is if you parked the bike on its side in a middle of a downpour with the brake plate facing upwards and even then you may have to wait a few hours
It's time to go :-)
alexnharvey
Posts: 1922
Joined: 10 Jan 2014, 8:39am

Re: Drum brakes

Post by alexnharvey »

They definitely get a little water in when it rains heavily, or at least it seems to me like something happens internally in the wet that alters the braking. The braking surface is horizontal. Doesn't make a huge difference to be fair.
Phileas
Posts: 414
Joined: 18 Feb 2009, 6:12pm
Location: Bristol

Re: Drum brakes

Post by Phileas »

cycle tramp wrote: 22 Sep 2021, 7:35pm
Phileas wrote: 22 Sep 2021, 12:24pm I personally wouldn’t say the SA drum brakes are completely unaffected by rain. I think water does get into the drums in sufficiently heavy rain and reduces the braking.
I've just nipped out to have a quick look - I'm not sure how rain would get into the hub. The brake mechanism itself, is inside the hub, mounted vertically to a plate which is then mounted via the axle to one side of the hub. The hub itself has a fairly pronounced lip which extends around the circumference of this plate, and this plate has a further pronounced lip making the gap between them both very narrow. Of course, when riding in the rain the hub would be spinning so any rain falling on the hub is likely to get thrown of by centrifugal force. The only way I can see rain getting into the hub is if you parked the bike on its side in a middle of a downpour with the brake plate facing upwards and even then you may have to wait a few hours
I certainly don’t do that. The bike stays vertical at all times and is parked in the dry. However, the effect of water getting in is very clear - an unmistakable reduction in braking effect that is still there the morning after. This is on a commute that lasts less than half an hour.
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