Old Sachs drum brake hub?



dabac

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Sep 16, 2003
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Hi guys,

I came across a set of old Sachs drum brake hubs that I've been thinking about using for a (hopefully low-maintenance) commuter bike. Does anyone have any experience with these? Would it be worth the effort, or should I look elsewhere? Given their age I assume they were originally used with caliper/canti-compatible brake levers, so is that a must, or simply a recommendation? (haven't got any easy way of rigging up a test)

Cheers,
 
Jun 6, 2006
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The word on drum brakes is their reaction arm will twist a light fork to the side upon heavy braking, producing a noticeable steering effect.

I have a set of new Sturmey-Archer drums and they are simply great, but I have a suspension fork with a very rigid cast lower assembly.

If the brakes are in good repair they are sure to be a fine addition to a commuter but it might handle funny if it has a light steel frame or fork.

Have you thought about how you're going to attach the reaction arms? If they don't line up with the frame or fork, they will induce even more twisting.
 

dabac

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Sep 16, 2003
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garage sale GT said:
If the brakes are in good repair they are sure to be a fine addition to a commuter

Nice to hear. I've never ridden them assembled on a bike, and some colleagues claims that they are grabby.
garage sale GT said:
...it might handle funny if it has a light steel frame or fork.
I'm planning to use an old steel MTB, so I think the frame will be rigid enough. I can always braze in a strut between chain- and seatstay if it seems needed.

garage sale GT said:
...it might handle funny if it has a light...fork.
I haven't decided on fork yet. Either I'll reuse the old sus fork that originally came with the bike, or I'll track down a fitting (non tapered) rigid fork instead. I'm not too keen on reusing the sus fork, it wasn't that good to begin with and despite rebuilds it's basically turned into a heavy and cluttered rigid.


garage sale GT said:
Have you thought about how you're going to attach the reaction arms?
Not that much. Odds are good that the rear will line up and the old clamp will still fit w/o any tinkering. Front might need a new clamp, but pretty much any strip of steel should do for that.

garage sale GT said:
... If they don't line up with the frame or fork, they will induce even more twisting.
Haven't really thought that far. I guess I'll either have to bend the reaction arms, or braze tabs on frame/fork, or maybe put some effort into turning offset clamps from solid stock instead of using basic steel collars.
 

Retro Grouch

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Dec 29, 2005
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dabac said:
Hi guys,

I came across a set of old Sachs drum brake hubs that I've been thinking about using for a (hopefully low-maintenance) commuter bike. Does anyone have any experience with these? Would it be worth the effort, or should I look elsewhere? Given their age I assume they were originally used with caliper/canti-compatible brake levers, so is that a must, or simply a recommendation? (haven't got any easy way of rigging up a test)

Cheers,
I have no experience with those. I had an Atom hub brake on my first "Frankentandem". I had to modify the brake lever to get enough cable pull to make it work. It sure was a heavy sucker. I think that the rear wheel with the tire weighed around 4 or 5 pounds.
 
Jun 6, 2006
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See if you can inspect the cones. We might have a motivated seller. You can't feel pitting until it's bad.
 

dabac

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Sep 16, 2003
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Retro Grouch said:
.. I had an Atom hub brake on my first "Frankentandem". ..It sure was a heavy sucker.

I haven't weighed mine, but the hubs looks fairly sleek despite it high flanges. Been thinking about saving these for a tandem application as well, but at 36H they're borderline useful, so commuter it is.

Retro Grouch said:
... I had to modify the brake lever to get enough cable pull to make it work.

I've been thinking about that, but short of mocking everything up I can't figure out a reliable way of determining what amount of pull I'll actually need. I guess it should be possible to squeeze in a travel agent somewhere if needed.
 

dabac

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Sep 16, 2003
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garage sale GT said:
See if you can inspect the cones. We might have a motivated seller. You can't feel pitting until it's bad.

Good point, I'll do that. Front is manageable regardless, If need be I should be able to convert it to sealed bearings. Rear is more critical - but let's not worry before its due.
 

Retro Grouch

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dabac said:
I've been thinking about that, but short of mocking everything up I can't figure out a reliable way of determining what amount of pull I'll actually need. I guess it should be possible to squeeze in a travel agent somewhere if needed.
When I installed the cable operated disc brake on the back of my tandem a "Side Track" cable-pull gizmo was recommended. It doesn't need to be attached to the bike frame so it can just hang off of the cable housing that comes from the brake lever. I'd think that would simplify installation on a hub brake vs. a Travel Agent. You need a mountain-style brake cable to go from the Side Track to the brake.
 
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My Cadillac's Promax drum levers look like virtual duplicates of the mechanical disc brake levers which came with my Nashbar mechanical disc system for my Raleigh. The shape of the housing is cosmetically different but the leverage (hence the pull) is exactly the same, and both have two positions to put the cable end in.

The drums wear very slowly after initial break-in and you can adjust them very close because you don't have to account for a wobbly rim. They would work like a charm with very high leverage, low pull levers BUT...you have to account for the flex of the brake cables and housings. Also, they'd be grabby as hell if you used as much leverage as the system is capable of.

So...you can probabaly get the drums to work with standard disc levers. However, I have never seen Sachs drums. It is possible the actuating arm on the brake itself is longer or shorter, requiring different cable pull. My drums have a 2-inch long arm, approximately tangential to the cable.
 

hjulcompaniet

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Oct 3, 2004
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I see them every day. 70mm drum.
Sachs made a few versions front and rear. Some had machine/cartridge bearings.
They quite often squeal like pigs. When they lock up expect a bent fork or chainstay, minimum.
The flange size can give a nice strong wheel. and they look quite nice and neat.
A normal caliper brake lever should work fine.
 

dabac

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Sep 16, 2003
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garage sale GT said:
See if you can inspect the cones.
Got a bit sidetracked by other projects and kept using the "good" bike for the commutes, but finally got around to building up my drum brake wheels.

Front hub looks good on disassembly. After adjustment it runs reasonably smoothly, and lots of brake pads left.
On the downside the seals are bordering on ridiculous, and I really wonder how these will stand up to messy winter commutes. But I suppose if it comes to that I should be able to replace the cup & cone assembly with some sealed bearings, it actually looks like there is a standard size that would fit w/o having to stick the hub in a lathe first.
The "plan" (for want of a better word) is to finish of the front wheel, and then run the bike on a borrowed rear for awhile, while finding out if the drum brakes are worth the effort.
 
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I think people used to seal up their bikes with felt washers back in the day. Not waterproof but keeps the grit out.