Retrofitting an old Sachs IGH

dequinox

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Not everyone is following my build thread on a Giant simple, so I had to break this question out:

How do I retrofit this Sachs IGH I bought for my build with a shifter and click box that are compatible? From what I can tell by reading articles online, it is supposed to be compatible with a Shimano shifter, and definitely will work with a SA shifter. The trouble is identifying the # of speeds on this thing, and then identifying a shifter to buy for it. I thought about going classic with a shifter like this one, but it's too pricey for what I'm trying to do (the thread is titled "budget build" after all...) and I'm not even sure it's compatible.

Any ideas? I figured someone in the non-hub area would probably know since IGHs are somewhat popular with these builds.
 
The pics you show don't show the shifter end, but if it's like the 3speed Torqueedo I have (and teh similar Shimano333 and Sturmey Archer AW), then you can hand-move the shifter rod, with the wheel mounted in dropouts, and turn the input sprocket, counting the number of turns you get from the hub itself vs teh number of turns of the input sprocket.

If you think it's 3speed, then move the rod in thirds of it's total distance, and get the three ratios. Compare with the Sachs' normal ratios for their 3speeds (probably on Sheldon Brown's site if nowhere else), and if they match it's a 3speed.

If they aren't all different or if they don't match then it might be some other number of speeds, so youc an move teh shifter rod ins maller increments and see if you get any other ratios.

You may be able to feel it change gears while turning at the different points while moving the shifter rod, too.


BTW, if you don't mind building a clickbox/shifter, I can open up my Sachs shifter (looks like the one in that ad) as far as it will go, and take pics for you to copy from.
 
Thanks AW. Not sure that will be necessary though... I'm discovering my dropouts are 113 mm, and the hub is at least 130mm.

This is an aluminum frame, so I'm guessing stretching it is out.

Bugger.
 
It absolutely is not compatible with a Shimano or Sturmey Archer shifter or clickbox. The shift increments are not even close to the same. If your shift positions aren't right, you will break the hub sooner or later when you apply torque to drive dogs that are barely engaged.

You have to get a Sachs or SRAM shifter with the correct number of speeds. The Sachs hubs were Torpedo 3, Pentasport 5, Super 7, and Spectro 7. SRAM renamed them Spectro T3, P5, P5 Cargo, and S7. As far as I know, you can use any shifter and clickbox unit on any hub with the same number of speeds, within this series.

SRAM no longer supports internal gear hubs in the North American market, so you might have to source a shifter from England or elsewhere in Europe.

By the way, don't put motor power through one of these hubs. They're only designed for human power, and not even excesses of that. I've broken two Sachs 7 hubs with pedal power alone, at approved primary gear ratios of about 2:1.
 
Noted.

There is a bike shop in Seattle that specializes in these hubs and parts for them, they quoted $60 for an appropriate shifter set. I really don't want to spend that much.

I am not putting power through it, it was supposed to give me a geared hub + drum brake in the back because the coaster brake is malfunctioning, I don't trust them, and I liked the idea of a drum brake.

This hub doesn't appear compatible with my frame anyways. It's 130mm and my frame is 113 or 114...

I'll probably just offer this up for sale.
 
If 130mm, it's probably 7-speed. If you need to fit 114mm ish spacing, you want a 3 speed. Shimano Nexus 3 is the obvious choice-- for low cost, reliability, and ubiquitous parts and support.

For whatever reason, coaster brake Nexus 3 hubs cost less than freewheel versions. As little as $60 full retail, including trim kit, shifter, and clickbox.
 
Thanks, I'll probably end up picking one up.
 
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