1940 Schwinn DX Klunker Build

Discussion in 'KLUNKERS & MOUNTAIN BIKES' started by GTV, Mar 2, 2017.

  1. deorman

    deorman

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    Seems to be a common complaint with morrow hubs, gearing low definitely exacerbates the effect. I have a wheel with one and it has the same behavior, could be they are just that way, like New Departure having a tendency to drag when coasting. I remember as a kid that a lot of old coaster bikes had really tall gearing and even big kids had to really stand on the pedals to stop or get moving. My best solution, get a Bendix.:grin:
     
  2. GTV

    GTV

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    I have an extra Morrow ready to be rebuilt and laced. I rode my '40 and the newly finished '51 with the same wheel set that just happened to have a Morrow hub as well. So my impressions are from riding the '40 (18x10 gearing) and now the '51 (26x10 gearing). It's not too bad on the '51 with the tall gears, but on the '40 with the little chain ring it was absolutely MISERABLE. The '51 is now for sale, if I can make it better before I sell it that would be great, but at a minimum I want to avoid this issue on the '40 as it is a keeper and will be ridden in anger.

    With the bike on the stand the engagement gap does feel slightly variable, between 45 and 90 degrees at the pedal (this is with the big 26t chain ring). I wasn't aware that over-lubing was possible :) So that definitely could be a factor. There was very little sign of wear, it looks like a low mileage hub.

    You make it sound like being a slave is a bad thing :)
    I don't care if they were run on Repack or not, I'm just a fan of the original coaster brake style Klunker. Simplicity at its finest. As for the 650b's, a few years ago I swapped a 650b wheel set from a Haro single speed on to my '82 Diamondback Ridge Runner, and it made a pretty huge difference in the way that bike handled obstacles. All I had to do to make it fit was to grind a little bit out of the fork (less than 1/8") and it was good to go. The rear fit like it was built for it. I also recently put together a '51 Spitfire for a friend with 650b's and it needed no modifications at all to the frame or fork. So if it makes a big improvement to performance and it easily fits, why wouldn't I? My '40 needs some repair/welding around the seat/chain stay braces, so I'm actually considering reworking the rear triangle a little bit and shortening the chain stays to get the tire under the rider- better maneuverability with a short wheel base and easier to wheelie over stuff.

    From what I gather, the original Klunker's were one trick ponies. Go as fast as possible down a fire road. The modifications I'm making to my build (B17 Flyer, riser bars, 650b's, shorter gearing) will turn it into a more versatile machine for single track and anything else I can throw at it. I'm doing my best to hide the fact that the wheels are bigger, so at a glance it will look like 1975.
     
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  3. GTV

    GTV

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  4. GTV

    GTV

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  5. GTV

    GTV

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    Thanks to rrtbike for the pedals, and I also found the fork I wanted :)

    I'll have to cut and re-thread the tube but I got it for a lot less than what was asked :)
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    I'm keeping my eye out for a reasonably priced black Brooks Flyer or Conquest and possibly a early high flange hub. Then I'll have no excuses left to get some hoops and build some wheels.

    In other news, I'm headed to Copenhagen and Amsterdam next week, the bike capitols of the world! I can hardly contain myself! :)
     
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  6. SILVERKINGPC

    SILVERKINGPC

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    Many of the old 26er frames can run "27.5" (650B-rama) wheels. All you need to do is select an appropriate tire that clears the stays. Don't mess with that nice old frame and possibly damage it.:shake: Looking forward to it getting done!
     
  7. GTV

    GTV

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    If the frame was in much better condition I wouldn't consider modifying it, but since it needs work and I'm building a non stock bike anyway I don't feel bad about it.

    I think I'll mock up the 27.5x2.25" front wheel from my Diamondback and gauge how big of a tire fits in the fork, and then make the rear work with that. Maybe I'll shorten up the chain stays, maybe not. I'll cross that bridge when I get there.
     
  8. repedaler

    repedaler

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  9. GTV

    GTV

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    I had a minute to fit up the 2.25x27.5" wheel from my other bike. As I expected, plenty of room :) There is 2.6" of space between the fork blades and the tire measures right on at 2.25" with my calipers.
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  10. GTV

    GTV

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    Tried out the rear as well. I marked where the Morrow hub is going to live in the drop outs and offered up the big wheel. Seat stays have loads of space.
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    Chain stays... not so much. I think I'll shorten the tubing in front of the brace about 15mm and lengthen it the same amount behind the brace.
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    It would be pretty easy to shorten the overall length of the chain stays while I'm in there. Half of me wants to do it, the other half wants me to leave it alone. We'll see.
     
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  11. RustyGold

    RustyGold

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    Maybe you can re-contour the chainstay without cutting? Or, cut out the chainstay brace, contour, and then weld it...or a new one...back in?

    Jason
     
  12. GTV

    GTV

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    I'm thinking about making a pattern of sorts out of the seat stay "loop" and getting the chain stay "loop" to match it, at least in tire clearance. I don't want the tubing to look like it has been modified.
     
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  13. SILVERKINGPC

    SILVERKINGPC

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    If you run a 1/2" pitch chain instead of the skippy, you will have TONS more adjustment room back and forth for your axle in the dropouts, possibly giving you room to run different width tires on the 27.5 hoops without having to modify the stays. The skip-tooth chain gives you only one axle position to get the chain tension correct.
     
  14. GTV

    GTV

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    I definitely want to keep it skip tooth. Funny you mention this though, I'm fairly new to skip tooth and suspected the same regarding length and axle position so I tested it out yesterday.

    There is no difference because the distance from one male (or female) link to the next male (or female) link is still 1". So the result is the same (unless you are using a 1/2" pitch chain with a half link).

    Where I had my hub positioned before was fairly far back in the drop outs, far enough that the tension screws were too short and ineffective, allowing the hub to slip forward. So I took 2 links out (1m/1f) and it moved the hub forward 1/2", just as it would with a 1/2" pitch chain. And now the tension screws work as they should. I'll try taking a couple more links to get the tire under me as far as possible for the best handling.
     
  15. SILVERKINGPC

    SILVERKINGPC

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    On some frames, depending on the chain-stay length, some skip tooth drivetrains, when the chain is properly tightened, force the axle into either an "all the way out" or "all the way in" position in the dropouts, depending on sprocket combination. So if you want to run a taller tire, you may have to experiment with different sprocket tooth combos to hit it right on...
    It sounds like yours was "all the way out". A 1/2" pitch chain would have moved in a 1/4" after taking a link out.
     
    Last edited: Sep 3, 2017
  16. GTV

    GTV

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    Either way, I'm happy to have shortened it up a bit. I can't wait to really get on this build but I have two other bikes in line ahead of it. I just sold the '51 Schwinn today, so that will get things moving along once I get back from vacation.
    I also learned that the Brooks Conquest was superseded by the B17 Flyer. So now I'm on the lookout for a Conquest instead.
     
  17. GTV

    GTV

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    I’ve got a better game plan and things are moving forward again :) My locking truss fork had a little bend in it, I was able to use a friends shop press this morning and push it back into shape. Went back home and mocked it all up with a couple stacks of spacers to see how much I need to loose from the steer tube. 2” exactly. I’ll try to get that threaded and cut this week, and hopefully find time to modify the truss rods next weekend. I just received a front hub on Friday and I’ve got some hoops on the way from Belgium soon :)
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  18. GTV

    GTV

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    Soooooo....

    I called a local bike shop that has the die to cut fork threads (obviously not many of them do these days). They want $25 PER INCH. So I'm looking at about $50 :headbang:

    Any other lower cost options? Or just suck it up and pay? If I knew it was going to be this expensive I would have just held out for the correct length fork...
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    Last edited: May 8, 2018
  19. rrtbike

    rrtbike

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    Sounds like robbery to me!!! :bandit:
     
  20. hammer mechanic

    hammer mechanic

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