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  1. #1
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    3 speed AMF Roadmaster Nimble - need help!

    Hi folks,
    Complete newbie here. I was looking for a 3-speed to commute on, and came across a nice-looking AMF Roadmaster Nimble for $40. I live in a bike town (Fort Collins, CO), and it is very difficult to find a bike of any sort in that price range here. When I arrived to look at the bike, I found that it was rigged to be a 3-speed, but that a part was missing, rendering the bike operational as a single speed only. I told the sellers I would pay $20 for the bike in this condition, and they were fine with that. I thought it wouldn't be tough to fix, but now am not sure.

    The bike seems to be in great shape generally. The part that is missing is the piece that connects the shifter cable to the hub. Right now there is just a bolt on there to keep it in second gear. The hub is a Shimano 3S (that's what it says on it anyway). I am not looking to flip this bike, and I know from reading some of the other forum posts on these bikes that they are not worth much. I just want to restore it to a 3-speed and ride it.

    Can anyone tell me if it is going to be possible to find this part, and also what the part is called?! Does it come in multiple sizes? Does it need to be a Shimano brand? I have been looking at anatomy of the internal gear hubs, but most of the labeling stops at the sprocket. It seems like my other option might be to replace the rear wheel with something that is more intact, but I'd rather go the other route if it is feasible. I guess the final option would be to remove the shifter and ride it as a single speed, until I find another 3 or 5 speed in my price range. Thanks for any suggestions you can give!

    pretty bike.jpg

    shimano 3S hub.jpg

    problem area.jpg

  2. #2
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    Hi there. I am not sure how easy it is to find the part that you're looking for. I had one months ago that I scrapped. I do know that the pawls inside of these hubs are prone to failure and replacement parts can be difficult to find. Good luck.

  3. #3
    Get off my lawn! Velognome's Avatar
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    I'd ride is single speed if you can and look for another used wheel with a Sturmey Archer hub. There is probably a reason the gears are not hooked up...read on from the Sheldon site:

    The Shimano "333" 3-speed Internal Gear Hub and its successors

    While Japan was in stage 1, in 1957, Shimano introduced the "333" 3-speed hub. It was in many ways an innovative design, and managed to avoid infringing on Sturmey-Archer's patents, but it had problems.The 333 hub was much more complicated internally than the Sturmey-Archer AW. The diameter of the hub was smaller, and so stresses on the internal parts were higher. The metallurgy of Japanese steel at that time was not up to the standards of British steelmaking, so the parts were weaker. Japanese cyclists were (and still are) lighter, on average, than Americans.The combination of design and metallurgy of the Shimano 333 hub was probably adequate for the needs of the Japanese market, but when sold in the U.S., the hub acquired a reputation for unreliability.The failure mode of the 333 hub is also different from Sturmey-Archers'.When a Sturmey-Archer AW hub gives trouble (which it rarely does) it is usually due to lack of lubrication, and one or two of the gears stop functioning reliably. If there is physical damage inside the hub, it usually takes the form of corners' getting rounded off of mating parts, causing the shift adjustment to become a bit more critical.When a Sturmey-Archer hub gives problems, it can almost always be repaired, usually without needing any parts replacement.When an older Shimano 3-speed hub fails, it is most often because one of the under-engineered pawls has shattered. The hub may still work after a fashion, so the rider continues to use it until the broken fragments of the pawls have gone on to destroy the gears and other parts, making the hub basically irreparable.[Following paragraphs are by John Allen.]
    In 1964, in my freshman year at Middlebury College, I was riding up the steep hill in front of the college chapel on my Columbia 3-speed -- which I had purchased new 5 months earlier. Something went "crack!" inside the 333 hub, and I felt odd, uneven resistance when pedaling. During the Thanksgiving break, I made my first visit to the Bicycle Exchange (hallowed be its memory) in Cambridge, Massachusetts, returning with a Raleigh-pattern rim and 40 spokes to lace to a Sturmey-Archer AW hub which I had salvaged from a trash pile. (The Columbia's original rim had 36 spokes). The AW hub never gave me any trouble,. The failure of a 333 hub launched my wheelbuilding career. I suppose that could be called a blessing in disguise.Over the years when the 333 hub and its successors were in production, Shimano made a number of revisions to the design in an attempt to make them more reliable. Newer, similar models are the F, FA and G type and the cartridge type, which had a pressed-in right-side ball cup instead of a threaded ball cup. Coaster-brake models were the 3SC TC-100, 3SC TC 200 and the cartridge model 3CC. The cartridge design made it easier to replace the entire internal mechanism at once -- the usual repair.
    The best information available on these hubs -- including comparative parts lists -- is inSutherland's Handbook of Coaster Brakes and Internally-Geared Hubs, which is now online on this site. Sutherland's Handbook for Bicycle Mechanics, 4th edition, includes the same information but is now out of print. Better bike shops may have kept a copy. Glenn's New Complete Bicycle Manual also has rebuilding information. This book also is out of print, but copies are available used at a reasonable price. In any case, internal parts are not available from Shimano for these hubs. Even if you could find a source of parts, you might not get the correct generation of parts for the particular hub you have. The cartridge-type mechanism may fit into an older shell, though.

  4. #4
    Senior Member PatTheSlat's Avatar
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  5. #5
    gna
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    IIRC, a Shimano bell crank should be given 7 revolutions onto the shaft, and the "N" should line up when in 2nd gear. Put the shifter in 2nd, attach the cable, and adjust the barrel until the N lines up..

    See http://www.bikewebsite.com/ins3.htm
    Last edited by gna; 07-08-14 at 01:16 PM.
    Quote Originally Posted by shipwreck View Post
    Sure it works in practice, but will it work in theory.

  6. #6
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    Thanks, everyone.
    PatTheSlat -- do you know if the bell cranks like the one you listed are compatible with any old Shimano hub? I know there are lots of older Shimano internal gear hubs out there and I want to be sure I have the right fit.

    And gna -- thanks for that website. It will be super helpful when I've got the right part in hand.

    And points well taken, BFisher and Velognome. Hoping that I don't have issues with the interior components of the rear hub. I'm guessing it might be tough to troubleshoot that until I have the bell crank hooked up though?

  7. #7
    Senior Member PatTheSlat's Avatar
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    Quote Originally Posted by brittmo View Post
    Thanks, everyone.
    PatTheSlat -- do you know if the bell cranks like the one you listed are compatible with any old Shimano hub? I know there are lots of older Shimano internal gear hubs out there and I want to be sure I have the right fit.
    Should work with any non-Nexus hub. Shimano did at one point use a solid core cable to control their 3 speed hubs, which used a different bell crank, cable, and shifter (would be labeled "PPS"), but it doesn't look like yours is that type. Even with those though, the hub was identical, just the shifter, bell crank, and cable were different.

    And actually it should be relatively easy to check out the hub before the bell crank is installed. Pull that bolt contraption off of there and you should see a little rod sticking out of the axle. The bell crank pushes on this rod to control what gear the hub is in. You can just push on it with your finger to make sure the hub shifts into all 3 gears before putting any money into it. 1st gear should be all the way in, 3rd gear all the way out, 2nd somewhere in the middle.

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