Drum brakes

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cycle tramp
Posts: 3479
Joined: 5 Aug 2009, 7:22pm

Re: Drum brakes

Post by cycle tramp »

kwijibo wrote: 18 Sep 2021, 10:20pm I've not tried drum brakes, but I recently fitted some Clarks hydro disc brakes that were about £40 for the set. Work perfectly well. If you have the mountings on your frame it would Surely be cheaper than new drum hubs and wheel builds.
https://www.colyfordcycles.uk/component ... lack__3721
It's always worth looking at alternatives, but as any accountant would ask, at what point is the alternative cheaper? At the point where the product is purchased or three, five or seven years time when things like maintenance time or cost of spares have to be factored into the costs as well?
My drum brakes cost me more than a set of rim brake blocks, when I purchased and fitted them in July 2016. However since then all I had to do was to adjust the cable tension on my brakes. If I had stayed with rim brakes I would have had to replace them (normally front and back every two years which would have been a further cost of £15 x twice (commuting only - if I had gone touring then pad replacement could be as much as three times in a year) plus time spent fitting them, plus time spent cleaning all the black gunk from my wheel rims. My hourly rate of pay works out on average at 15 pounds per hour, it takes me thirty minutes to change front and brake pads (if things go well) so that's a further costs of £15 x twice x 0.5 hour, plus i spend an hour or year cleaning and checking my wheel rims when I had rim brakes so that's £15 x 5 years. So within 5 years, the front hub as paid for itself and the rear hub is on it's way to pay for itself

(If my hub brakes continue to perform without issue then next year the savings will look like; £15 x three times (not needing rim brake pads) £15 x 3 x 0.5 hours (not having to change rim brake pads) £15 x 6 years not needing to check and clean black gunk off wheel rims.
Last edited by cycle tramp on 19 Sep 2021, 8:44am, edited 6 times in total.
It's time to go :-)
cycle tramp
Posts: 3479
Joined: 5 Aug 2009, 7:22pm

Re: Drum brakes

Post by cycle tramp »

kwijibo wrote: 18 Sep 2021, 10:20pm I've not tried drum brakes, but I recently fitted some Clarks hydro disc brakes that were about £40 for the set. Work perfectly well. If you have the mountings on your frame it would Surely be cheaper than new drum hubs and wheel builds.
https://www.colyfordcycles.uk/component ... lack__3721
Carrying on the discussion... although the Clark's hydro disc brakes may be cheaper at the point of sale, it's worth asking

- do these disc brakes need regular cleaning and checking to ensure they function adequately, and if so how long does that take and what are the intervals when this should be carried out?

- what are is the cost of the replacement pads, how long do they last, and what is the availability of spares like?

- what is the cost of the replacement brake rotors, how long do they last, and what are the availability of spares like?

- how long does it take to change the pads/rotor when replacement is required?

- As this is a commuting bicycle - if it has to be off the road for a length of time, what alternative means of transport is available and what is the cost of using it?
It's time to go :-)
Phileas
Posts: 414
Joined: 18 Feb 2009, 6:12pm
Location: Bristol

Re: Drum brakes

Post by Phileas »

fausto99 wrote: 18 Sep 2021, 10:46am I disagree completly about drag. If set up correctly, there is no drag when the brakes are off.
I assumed he was referring to the Dynamo hub. There is constant drag on the SA Dynamo/drum hub.

I will soon be swapping my 70mm SA Dynamo wheel back in for the winter. I’ve been using a 90mm drum for a couple of years.

Plenty of stopping power with the 90mm. I was a bit disappointed last winter with the 70mm.

I’ve got a BB7 disc brake on the back - technically the lever is wrong (both levers are short pull) but I rarely use the rear brake anyway.
rotavator
Posts: 987
Joined: 6 Jun 2016, 9:50pm
Location: North Wales

Re: Drum brakes

Post by rotavator »

How do drum brakes perform on long descents with a load on board e.g. on the long descents on Lon Las Cymru? Are they any better or worse than rim brakes or hydraulic disc brakes or are cable operated disc brakes the best option? I would imagine that drum brakes get very hot and start burning any grease or oil that is near them but do they also fade or squeal?

I ask because on long descents on a rim braked bike I have twice had front tyres explode presumably because of excessively hot rims because there was no sharp object embedded in the tyre.

Also, with hydraulic disc brakes, I have experienced fading (and plenty of squealing) presumably caused by the brake fluid boiling. Hopefully I have cured this by changing the brake fluid and switching to organic from sintered pads.
robc02
Posts: 1824
Joined: 23 Apr 2009, 7:12pm
Location: Stafford

Re: Drum brakes

Post by robc02 »

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? Are they any better or worse than rim brakes or hydraulic disc brakes or are cable operated disc brakes the best option? I would imagine that drum brakes get very hot and start burning any grease or oil that is near them but do they also fade or squeal?
I have ridden Lon Las Cymru (south to north) on a bike with SA drum brakes without problem. Certainly no overheating or squealing.
I have subsequently ridden on my LHT with cantilevers. Again no problems, either with stopping or overheating. The braking was a bit better with cantis than with drums.

In each case I was carrying camping gear. However I am around 63kg, so even with the weight of my luggage I am not a demanding load on the brakes!
cycle tramp
Posts: 3479
Joined: 5 Aug 2009, 7:22pm

Re: Drum brakes

Post by cycle tramp »

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? Are they any better or worse than rim brakes or hydraulic disc brakes or are cable operated disc brakes the best option? I would imagine that drum brakes get very hot and start burning any grease or oil that is near them but do they also fade or squeal?

I ask because on long descents on a rim braked bike I have twice had front tyres explode presumably because of excessively hot rims because there was no sharp object embedded in the tyre.

Also, with hydraulic disc brakes, I have experienced fading (and plenty of squealing) presumably caused by the brake fluid boiling. Hopefully I have cured this by changing the brake fluid and switching to organic from sintered pads.
Personally i find that any braking problems caused by heat build up during long descents can be avoided by stopping the bike part way through the descent for five minutes. - I did this during my last descent of Contisbury Hill into Lynmouth. I was using rim brakes - my concern over both the heat generated in the rims as well as some cramp in my hands lead me to pull of onto a layby, for a drink and admiration of the view, part way down the hill. Looking out across the sea, became one of the most enduring memories of the journey

Whilst these five minutes may add to your journey time, its quicker than having to deal with any punctures caused by heated rim brakes, or dealing with any aftermath caused by brake failure and it's more time efficient/economic than purchasing a whole new brake system to deal with descent that you may only encounter a couple of times during a year.
It's time to go :-)
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SimonCelsa
Posts: 1230
Joined: 6 Apr 2011, 10:19pm

Re: Drum brakes

Post by SimonCelsa »

rotavator wrote: 19 Sep 2021, 9:37am How do drum brakes perform on long descents.........
Now you mention it, there is a very steep footpath behind my house, only about 200 yards long with a gate at both ends. As my commuter is fixed gear I tend to descend this hill very slowly with the front drum brake lightly on constantly. Right at the bottom, just prior to chicaning through the gate I grab a full handful of brake and there I always get a squeal. On the couple of occasions I have checked, the hub externals have been pretty hot!

I have never had anything similar on longer descents, although on something very steep and twisty then I would imagine there would be plenty of screeching if you only had the one brake and could not alternate between them.
biketips666
Posts: 217
Joined: 19 Jun 2021, 7:17pm

Re: Drum brakes

Post by biketips666 »

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? Are they any better or worse than rim brakes or hydraulic disc brakes or are cable operated disc brakes the best option? I would imagine that drum brakes get very hot and start burning any grease or oil that is near them but do they also fade or squeal?

I ask because on long descents on a rim braked bike I have twice had front tyres explode presumably because of excessively hot rims because there was no sharp object embedded in the tyre.

Also, with hydraulic disc brakes, I have experienced fading (and plenty of squealing) presumably caused by the brake fluid boiling. Hopefully I have cured this by changing the brake fluid and switching to organic from sintered pads.
I looked into this in some depth a few years ago, when I imagined I was going to take up cycle touring, and do it on a IGH bike with drum or roller brakes. Neither happened.

I can't find all the various discussions again now, but here is one:

https://bicycles.stackexchange.com/ques ... or-touring including a link to Sheldon Brown's thoughts.

On the specific issue of drum/roller brakes overheating on descents, my takeways were:

1. Experiences vary, as usual. Though it's worth pointing out that comments along the lines of - "I've been using them for years and never had a problem" are only useful until that one in a thousand situation where somebody's brakes do fail at the end of a long descent.

2. SA drum brakes are better than Shimano roller brakes. Though sadly the 8 speed SA IGH isn't as well regarded as the Shimano, so for the rear there's a choice between gears or brakes.

3. Later Shimano roller brakes are better. Maybe a lot better, though the very latest may not be widely available in the UK. The last time I looked I think the model number is IM-86. Larger cooling fins seem to be the thing, but whether they can be that much more effective moving heat from the enclosed roller to the outside world isn't something I'm qualified to comment on.

4. Having alternative braking options, as on the Spa Wayfarer, is a good idea for certain cycling situations.
rotavator
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Joined: 6 Jun 2016, 9:50pm
Location: North Wales

Re: Drum brakes

Post by rotavator »

I am not planning to splash the cash on drum brakes but just pondering the possibility and weighing up the pros and cons. With respect to their ability to dissipate heat, I doubt that drum brakes, being enclosed, can be better than rim or disc brakes which are exposed to the environment so can be cooled by convection and radiation, although cooling fins would help. I was also interested in how they perform in practice on loaded touring bikes or tandems but no doubt some will say they are fine whereas others will say they tend to overheat, burn the grease and screech.

My only experience of hub brakes was on a cheap bike with a back-pedal brake that I bought and used while working in Copenhagen. However, it was never really put to the test because there are not many hills there.
cycle tramp
Posts: 3479
Joined: 5 Aug 2009, 7:22pm

Re: Drum brakes

Post by cycle tramp »

rotavator wrote: 19 Sep 2021, 12:54pm I am not planning to splash the cash on drum brakes but just pondering the possibility and weighing up the pros and cons. With respect to their ability to dissipate heat, I doubt that drum brakes, being enclosed, can be better than rim or disc brakes which are exposed to the environment so can be cooled by convection and radiation, although cooling fins would help. I was also interested in how they perform in practice on loaded touring bikes or tandems but no doubt some will say they are fine whereas others will say they tend to overheat, burn the grease and screech.
Any bicycle isn't restricted to just one type of brake. Some years before I built my cyrrent bike up with drum brakes, the frame had a nu-Vinci hub gear, with a cantilever front brake, a shimano rear roller brake, and a rear cantilever brake operated through a friction shifter The idea being if I was coming down any hill and experienced any loss of power to my rear shimano roller brake, I could use the friction shifter to operate the rear rim brake.

I don't tour now. Don't have the time. But if I was then there would be nothing to stop me adding a similar third brake again, if I believed I needed it.
It's time to go :-)
cycle tramp
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Joined: 5 Aug 2009, 7:22pm

Re: Drum brakes

Post by cycle tramp »

rotavator wrote: 19 Sep 2021, 12:54pm
My only experience of hub brakes was on a cheap bike with a back-pedal brake that I bought and used while working in Copenhagen. However, it was never really put to the test because there are not many hills there.
Absolutely - and that is the main difference between a touring bike and a commuter bike. A commuter bike is built to match a set of environmental conditions which the rider will encounter on their way to the shops, or work, or taking children to school. As these environmental conditions are known, the commuter bicycle is then kitted out with equipment suited to meet these conditions with the aspects of ease of maintenance , availability of spares and low running costs also factored.
A touring bicycle is built in consideration to a wide range of factors that the rider may encounter, and often these environmental factors will be wider than those met when the rider simply commutes. As a result this is the touring bike is likely to have a wider range of gears and brakes which may be more powerful- however the flip side of this is that the touring bicycle may have higher running and maintenance costs and it may also take more time to maintain, when compared to a bicycle used for commuting.

If you're building a commuter bicycle, then providing your brakes can match those conditions (and ideally are cheap to run in both costs and time) then there is no issue
It's time to go :-)
mattsccm
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Joined: 28 Nov 2009, 9:44pm

Re: Drum brakes

Post by mattsccm »

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.
iandusud
Posts: 1577
Joined: 26 Mar 2018, 1:35pm

Re: Drum brakes

Post by iandusud »

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.
If you're concerned that drums might not be powerful enough just fit a 90mm SA on the front and a 70mm on the rear and you'll have more than enough. BTW I find that my drum brake on the cargo bike actually works better in the wet!
rogerzilla
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Joined: 9 Jun 2008, 8:06pm

Re: Drum brakes

Post by rogerzilla »

Drums can lose heat just as well as discs, if appropriately sized and finned. The Arai drum brake, no longer made, was the standard drag brake on tandems for years.

A disc used as a drag brake can fail, especially if undersized. I saw a tandem with both (smallish) discs blued by heat, which is bad.

The origjnal advantage of discs over drums (on cars) was the proportional response to pedal pressure. Drums have a self-servo effect that makes them harder to control.
biketips666
Posts: 217
Joined: 19 Jun 2021, 7:17pm

Re: Drum brakes

Post by biketips666 »

It seems that most types of bicycle brake may fail, in some way or other connected with heat, when used as a drag brake on a long downhill. That's from reports here and elsewhere. It's a specific usage, that cyclists should be aware of. Once upon a time it was an issue that drivers of motor vehicles were (or should have been) alert to.

Brake fade:

https://en.wikipedia.org/wiki/Brake_fad ... brake_fade

Even on a relatively short downhill I pulse my brakes. Depending, to some extent, on what happens at the bottom of the hill.

A difference between bicycles and motor vehicles is that motor vehicles have engine braking, hence the "engage low gear now" signs at the top of long steep downhills.
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