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Hi guys, I am looking to build up an old timer bike and I have found this frame. Can I put a rear derailleur in that socket?

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    It has a derailleur hanger, so why not? (And it's not that old.) Jun 16 '19 at 12:18
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    (But note that, unless you have access to a pile of spare parts, it would be cheaper to buy a new bike.) Jun 16 '19 at 12:19
  • I am full of spare parts!!!
    – Agamemnon
    Jun 16 '19 at 12:37
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    For a single speed setup you need adjustable horizontal dropouts (with a long slot). There is no similar requirement for a derailleur setup, since the derailleur takes up the slack. Jun 16 '19 at 12:50
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    (Note that there are multiple chainrings, so it's always had a derailleur setup.) Jun 16 '19 at 12:52

Yes, that is a standard derailleur hanger. Before attaching a derailleur, make sure that the hanger is aligned straight. There are tools to do this, but you can usually tell by eye if it's out of alignment. On a steel frame like that one, you can typically bend the hanger back into alignment with no problems. Also check that the threads are not stripped. If the threads are damaged, you may be able to use a thread tap to clean them up, or in the worst case, insert a helicoil. If you're not familiar with a helicoil, search "rear derailleur hanger helicoil" for examples. They will usually come with instructions for installation.

With regard to the dropouts, horizontal dropouts were standard on bicycles for many decades, whether they were single-speed or multi-geared. Look at pretty much any picture of a bike from before the late 80's. The only difference from a vertical dropout frame is that you have to pay a bit more attention to aligning the wheel properly in the frame when you put it on. Check that the wheel is properly positioned with respect to the brake pads and that the rim is equidistant from the chainstays. From your picture, though, it appears that the dropouts on this frame have stops in them, so that you can simply pull the wheel back against the stops. If they are set up correctly, the wheel should be aligned properly when seated against them.

  • Thanks Andrew for your detailed answer. I was confused because the guy that sells this frame has a title like: Peugeut Rennrad fixie singlespeed rahmen retro. Thanks again.
    – Agamemnon
    Jun 16 '19 at 16:59
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    The seller is just putting all keywords they can think of to maximize search hits. This isn't a racing bike ("rennrad") either but a touring bike.
    – ojs
    Jun 16 '19 at 17:55
  • @ojs - If it were a true touring bike it would have doubled eyelets, to accommodate both fenders and racks. Jun 16 '19 at 19:25
  • Dropouts of this kind need alignment screws for the rear axle. Look at the rear end of the dropouts. There's probably a 3mm thread in each. These screws make sure that the axle sits in the correct position when you put back the wheel to avoid fiddling at wheel changes.
    – Carel
    Jun 17 '19 at 16:18
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    @carel They don’t need alignment screws. Typically only higher end frames had them. My ‘84 Schwinn World Sport, for example, does not have any. You just align the wheel by hand before tightening the axle nuts.
    – Andrew
    Jun 17 '19 at 17:20

Shouldn't be a problem as the frame/bike originally came with a rear derailleur. Since the frame is steel, you can spread the rear dropouts to accommodate just about any width rear hub out there. There are many articles on the web on how to do this. Just make sure that the chain, derailleur and freewheel/freehub match in respect to speeds! You should be fine with any narrow six, seven and eight speed group of components as they are all pretty much the same width. If you run an older five speed chain, then the freewheel and cluster must match as those chains are a little wider, the same for a ten plus speed as they are narrower. I have run nine speed derailleurs with eight speed clusters and nine speed chainrings with eight speed derailleurs with good results without having to shim the jockey wheels or the chainrings. I have a bunch of steel bikes dating back to the late sixties and yours is definitely worth saving.


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Thank you guys for your info and everything. The first bike was a little bit strange with the brakes, rear dropouts and all this stuff so I found another one. Road bike, 57cm, 2×6 speed. I'll start by putting a flat bar, flat bar brake levers and that's it. Later I'll try to put a 9 or 10 cassette.

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