Rims with decent braking surface thickness?

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pwa
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Re: Rims with decent braking surface thickness?

Postby pwa » 12 Mar 2019, 1:25pm

I wonder if, with rim brakes, the most practical solution is just to accept the need to re-rim once in a while and source some affordable rims that do the job well enough but need replacing every 18 months. If you have the skill to do it you only have the odd £20 to worry about. And you might have 18 months to save up.

I've had no trouble getting tyres on Chrinas and LX17s.

Freddie
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Re: Rims with decent braking surface thickness?

Postby Freddie » 12 Mar 2019, 2:02pm

bgnukem wrote:Discs would be a lighter answer and I'm currently due to build up a new bike with disc brakes, but I do like the comfy, springy forks of my old Dawes...
Well, yes and no, if you look at the components themselves (discs vs drums), then discs are lighter, but this is not the only difference. The fork on a disc frame will be 200, maybe 250g heavier, the chainstays will be beefier and heavy, the frame will be stiffer than your Dawes.

Discs also rub, squeal, and need pads replacing relatively frequently. You have many of the same problems as rim brakes, just near the hubs rather than at the rim. With drums you fit, forget and then turn the barrel adjuster once in a blue moon as the pads, protected as they are from the weather, wear down very slowly.

Furthermore, how much is your time worth? (cleaning pads, rims) How much do you want to be fettling bikes when it is cold, wet and windy, when you should be indoors with a hot drink?

Brucey
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Re: Rims with decent braking surface thickness?

Postby Brucey » 12 Mar 2019, 2:58pm

I did a lot of weighing of things and came to the conclusion that if you had a straight choice between

a) an older steel frame using 1" steerer, retrospectively fitted with SA drum brakes and
b) a new steel frameset using 1-1/8" steerer and disc brakes

then there was basically very little difference between them; like Freddie says the 1-1/8" forks and frame are liable to be heavier and this is by about the same amount that drums are heavier than discs. If anything a) is liable to be fractionally lighter and will also ride better. All this is detailed in another thread somewhere.

For a disc-equipped bike to be convincingly lighter, you need to be using a much lighter built frameset. Needless to say there is nothing much stopping you from fitting drums to one of those, either.

One thing is certain, and that is that drum brakes are a lot less aggro than discs; having to make an adjustment to the cable on a drum brake is about as frequent an event as having to replace disc pads outright.

cheers
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landsurfer
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Re: Rims with decent braking surface thickness?

Postby landsurfer » 12 Mar 2019, 3:19pm

In 45 years of cycling with an uppercase "C" i have never worn out a set of rims.
My oldest set are 38 years old but only used for only about 100 - 150 miles a year these days, when new they where my TT wheels.
The Road Goes On Forever ...

Samuel D
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Re: Rims with decent braking surface thickness?

Postby Samuel D » 15 Mar 2019, 3:18pm

bgnukem wrote:Well, to complete this thread, my newly-ordered H Plus Son Archetype rims arrived last Friday and were duly measured.

Braking surface thickness turns out to be ~1.5mm on one side and ~1.3mm on the other […]

I received a black 28-hole Archetype today for a disc-brake build. Wall thickness at the brake track varied from about 1.25 mm to 1.50 mm to the nearest 0.05 mm, with one side averaging about 0.1 mm thinner than the other albeit with variations all the way around. This rim weighed 479.3 g on a calibrated balance. ERD as measured to the top of a 12 mm Sapim Polyax brass nipple was exactly 595 mm as specified, which has slightly messed up my spoke lengths because I read that the ERD was more like 592–593 mm. External diameter was 633 mm and perfectly round.

By the way, the rim has a tiny external wear indicator dimple on each side, not far from the valve hole. I’ve not seen that mentioned.

The spoke holes are staggered but not about the exact centre of the rim as shown by the point of the arch. They’re off by about 0.5 mm to one side. The holes and the valve hole are perfectly deburred unlike the Mavic rims I’ve used.

Ivor Tingting
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Joined: 10 Mar 2009, 9:57pm

Re: Rims with decent braking surface thickness?

Postby Ivor Tingting » 15 Mar 2019, 4:12pm

Brucey wrote:I did a lot of weighing of things and came to the conclusion that if you had a straight choice between

a) an older steel frame using 1" steerer, retrospectively fitted with SA drum brakes and
b) a new steel frameset using 1-1/8" steerer and disc brakes

then there was basically very little difference between them; like Freddie says the 1-1/8" forks and frame are liable to be heavier and this is by about the same amount that drums are heavier than discs. If anything a) is liable to be fractionally lighter and will also ride better. All this is detailed in another thread somewhere.

For a disc-equipped bike to be convincingly lighter, you need to be using a much lighter built frameset. Needless to say there is nothing much stopping you from fitting drums to one of those, either.

One thing is certain, and that is that drum brakes are a lot less aggro than discs; having to make an adjustment to the cable on a drum brake is about as frequent an event as having to replace disc pads outright.

cheers


Sorry but I dunno what your genuine experience of disc brakes is, but they are without doubt a stratospheric leap in less maintenance, greater reliability, massively increased length of longevity of rims and actual braking performance compared to rim brakes or drum brakes. It's like night and day. To say otherwise is like maintaining the earth is flat.
"Zat is ze reel prowoking qwestion Mr Paxman." - Peer Steinbruck, German Finance Minister 31/03/2009.

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Sweep
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Re: Rims with decent braking surface thickness?

Postby Sweep » 15 Mar 2019, 4:16pm

Ivor Tingting wrote: To say otherwise is like maintaining the earth is flat.

seems like a somewhat extreme statement.

an insult dressed up as supposedly irrefutable physics (of which I know little I stress).

will be interested in how this pans out.
Sweep

Ivor Tingting
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Joined: 10 Mar 2009, 9:57pm

Re: Rims with decent braking surface thickness?

Postby Ivor Tingting » 15 Mar 2019, 4:26pm

Sweep wrote:
Ivor Tingting wrote: To say otherwise is like maintaining the earth is flat.

seems like a somewhat extreme statement.

an insult dressed up as supposedly irrefutable physics (of which I know little I stress).

will be interested in how this pans out.


Oh give over.
"Zat is ze reel prowoking qwestion Mr Paxman." - Peer Steinbruck, German Finance Minister 31/03/2009.

Brucey
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Re: Rims with decent braking surface thickness?

Postby Brucey » 15 Mar 2019, 4:57pm

Ivor Tingting wrote:
Sorry but I dunno what your genuine experience of disc brakes is, but they are without doubt a stratospheric leap in less maintenance, greater reliability, massively increased length of longevity of rims and actual braking performance compared to rim brakes or drum brakes. It's like night and day. To say otherwise is like maintaining the earth is flat.


no, you don't know that. There's basically no comparison between drums and discs.

cheers
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cycle tramp
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Re: Rims with decent braking surface thickness?

Postby cycle tramp » 15 Mar 2019, 9:33pm

Ivor Tingting wrote:Sorry but I dunno what your genuine experience of disc brakes is, but they are without doubt a stratospheric leap in less maintenance, greater reliability, massively increased length of longevity of rims and actual braking performance compared to rim brakes or drum brakes. It's like night and day. To say otherwise is like maintaining the earth is flat.


Perhaps. I guess it depends on which discs are being compared to hub brakes... personally speaking i fitted my drum brakes almost 3 years ago and all i've had to do was to adjust the cable tension...
...equally at the end of a week's tour of Wales, the only rider with disc brakes had almost worn through the front pad and was at the end of the adjustment... it's not all performance - cost and reliability play a part too
...performance wise I don't think I'd want anything larger than a 90mm drum brake at the front, sadly I can only get a 70mm drum brake for the rear, which is a shame because I reckon that a 70mm front drum brake and a rear 90mm drum brake could be the way to go for touring...
The other thing is development... disc brakes have seen alot if development, whereas drum brakes haven't. Things which may improve drum brake performance could include different brake linings, longer brake arms at the hub and a floating drum brake arrangement where the brake shoes are allowed a degree of independent moment, within the hub. To be fair if drum brakes had a tenth of investment that disc brakes receive then things could be very different. We may have a set of reliable, low cost, low maintenance, high performing brakes which are unaffected by the weather and don't destroy rims. What's not to love. Arguing over which is better discs or drums is, to me, just wasting valuable design and test in time :-)

PH
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Re: Rims with decent braking surface thickness?

Postby PH » 16 Mar 2019, 11:37am

Ivor Tingting wrote:To say otherwise is like maintaining the earth is flat.

In that case, careful you don't fall over the edge.
The arguments have been done to death, there's nothing more to say on the pros and cons, chose what you want based on your own criteria but thinking that someone with different criteria should make the same choices is like thinking the moon is made of cheese just because you like a bit of cheddar.

Ivor Tingting
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Re: Rims with decent braking surface thickness?

Postby Ivor Tingting » 16 Mar 2019, 12:49pm

Brucey wrote:
Ivor Tingting wrote:
Sorry but I dunno what your genuine experience of disc brakes is, but they are without doubt a stratospheric leap in less maintenance, greater reliability, massively increased length of longevity of rims and actual braking performance compared to rim brakes or drum brakes. It's like night and day. To say otherwise is like maintaining the earth is flat.


no, you don't know that. There's basically no comparison between drums and discs.

cheers


Yes I agree with you that there's no comparison between drum and disc brakes. That is why I have chosen hydraulic disc brakes for my bikes and would every time.
"Zat is ze reel prowoking qwestion Mr Paxman." - Peer Steinbruck, German Finance Minister 31/03/2009.

Brucey
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Re: Rims with decent braking surface thickness?

Postby Brucey » 16 Mar 2019, 1:18pm

having had over twenty years experience with both types of brake, I know which is more reliable, has a more consistent action, requires less maintenance and less likely to go wrong for a stupid reason.

FWIW in addition to my personal experience, folk in several LBSs know that I have an interest in why stuff breaks and they usually mention it if there is any kind of unusual occurrence. They no longer bother to mention when they have a shimano hydraulic brake that has sprung a leak; this is about a weekly occurrence. Their scrap bins are also well-populated with worn-out/contaminated pads, bent discs, you name it. By contrast it happens that there are many more bikes fitted with SA hub brakes locally and I genuinely can't remember the last time I saw one with worn-out linings.

YMMV

cheers
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Ivor Tingting
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Re: Rims with decent braking surface thickness?

Postby Ivor Tingting » 16 Mar 2019, 6:45pm

Brucey wrote:having had over twenty years experience with both types of brake, I know which is more reliable, has a more consistent action, requires less maintenance and less likely to go wrong for a stupid reason.

FWIW in addition to my personal experience, folk in several LBSs know that I have an interest in why stuff breaks and they usually mention it if there is any kind of unusual occurrence. They no longer bother to mention when they have a shimano hydraulic brake that has sprung a leak; this is about a weekly occurrence. Their scrap bins are also well-populated with worn-out/contaminated pads, bent discs, you name it. By contrast it happens that there are many more bikes fitted with SA hub brakes locally and I genuinely can't remember the last time I saw one with worn-out linings.

YMMV

cheers


Well I would not go anywhere near those LBS you mention. This is perhaps why I service my own bikes. At least then I know work is done properly and my bike is safe to ride and is not going to let me down.
"Zat is ze reel prowoking qwestion Mr Paxman." - Peer Steinbruck, German Finance Minister 31/03/2009.

Brucey
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Re: Rims with decent braking surface thickness?

Postby Brucey » 16 Mar 2019, 6:53pm

oh I see, its the LBS's fault when a customer brings in a bike with the pads contaminated with oil that has leaked out of the caliper becuase the seals have failed.

Righto.... :roll:
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