Friday, June 5, 2009

How To Dismantle a Sturmey-Archer Grip Shifter

After another evening of work on Mauricio's 1969 Huffy/Raleigh Sportsman, I took the grip shifter home to try to figure it out. Turns out, it's pretty simple on the inside, but since I couldn't find any how-to guides on the interwebs about it, I thought I'd post one.

The whole works is basically held together by a little spring clip that fits just under the lip of the dial portion of the grip. I used a small screwdriver to pry the clip out of its channel. In the photo below, you see the clip after removal.

With that done, the housing for the shifter (at left above) just comes off (assuming you've already removed the screw that tightens the shifter to the handlebar), exposing the minimal inner workings of the mechanism. There are basically three parts: a small spring, a bearing, and the rotating mechanism to which the cable is attached.  The spring sits in a little hole, and the bearing on top of the spring. When the grip is turned, the bearing slides into one of three holes in the rotating mechanism, either tightening or loosening the shifter cable, and thus shifting the hub.

In the photo above, you can see the rotating mechanism at right with the red indicator arrow on it. Below, you can see the spring in its hole, with the bearing resting on top. 

That's about it. I haven't put the thing back together yet, but I'm guessing that making sure the cable and bearing stay in place while the spring clip is reattached is going to require at least one more hand than I currently have. I'll have to look into getting another one.

There's a fuzzy diagram here of the whole works, and if you combine it with the photos above, you can get a pretty good idea of how it all works. Apparently, though, this was not a very successful design and seems to have only been on 1960s bikes.

10 comments:

  1. I always wanted another arm with hand growing out of the middle of my chest. It would make working on things so much easier in so many ways. Not to mention that dancing would be much more interesting.

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  2. LOL! It would make clothing designs interesting tho :p

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  3. Not sure how long they made the grip shift. I currently only have one bike with it. IIRC there were issues with the detent ball and spring not being able to hold the shifter in the chosen postion once it got some wear on it. Neat concept poor performance. Oldfool...do they do limb transplants?

    Aaron

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  4. Aaron, that makes sense about the wear issue--I'll tell M. to keep an eye out for it. I'm basing my 1960s guess on the fact that I think S-A introduced the grip shifter in '61, and we've got one here from '69. Not sure if they made them beyond '69 or not.

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  5. i have a raleigh--1966?--with a grip shifter that on the whole works fine--except it slips in second, occasionally. out of curiousity i emailed the Sturmey people to ask if their new twist shifters would fit the old--the rep said yeah they will so far as he knows--so maybe that's an option for someone though not period correct or free. both "Maurico" bikes are way cool btw

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  6. p.s. there is a nice old twistshift with cable, 8 bucks, might work, on ebay
    http://cgi.ebay.com/Vintage-Bicycle-3-Speed-Handlebar-shifter-with-cable

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  7. @MLS: Thanks very much. It seems like the action on M's twist-shifter is pretty crisp, but we'll see what happens when we get it back together. Does your slippage happen in the shifter, or in the actual hub? If it's in the actual gears when you're pedaling, it probably doesn't have anything to do with the shifter, but more likely in the hub itself.

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  8. I've got an old Sunbeam that had its hubs replaced to sturmey archers in 57, and it has a gripshift on it, I'm presuming that the grip shift and the hubs were done at the same time. The grip shft looks different to this though, when I find my camera I might be able to send in some photos.

    Russell

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  9. here's a bit i found on this (havent tried it ) from:
    http://www.cyclingforums.com/archive/index.php/t-42070.html

    Adjustment is dead easy. The small rod which screws into the axle and onto the end of the cable
    needs to be taken out cleaned and oiled. Replace it in the axle and tighten as far as it will easily
    go - if it then lies horizontally OK if not loosen it slightly until it does. Put the gear into the
    highest gear at the grip shift end and screw the chain end (adjuster) of the rod into the end of the
    cable for about 6 turns. Put the gear at the grip shift into second and pedal backwards for a few
    revolutions. To adjust screw the adjuster in or out until the shoulder on the rod lies exactly in
    line with the end of the axle - tighten up the tiny lock ring. Try changing gear a few times and
    pedalling backwards at the same time and then pedalling forwards - all should be OK but this will
    check if you have got it OK.

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  10. I've got one on my 1978 Raleigh Shopper that's held together and on the bars by two screws.
    I seem to have dissambled and reassembed it successfully!!

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