Shimano Lark Derailleurs?

[blondiebiker]

The good news is I just purchased a new mixte. Pictures are forthcoming, but the bad news is that first I have to figure out how to get her back together (bought over e-bay and shipped in parts). I'm all done except I'm stuck on the rear derailleur. There is a hole that's not matching up where it should (based on the marks on the paint from before it was taken apart)... Does anyone have a close up picture of a Shimano Lark SS (or any Shimano Lark or Skylark series rd - they are all pretty similar) that they could post? I'm desperate here - one weenie little derailleur is standing between me and my first ride on a mixte!

[DebW]

The only ones by that name I'm familiar with were the Shimano Eagle and Lark that came on department store bikes in the late 60s and early 70s. They had a big honking curved steel shaft attached over the derailleur so it wouldn't bend when the user dropped the bike on its right side.

Pictures might help if you can, so maybe someone here can recognize what you've got. What's the vintage of this bike? Does the frame have a rear derailleur hanger, or does it use a plate on the derailleur to attach to the dropout?

[blondiebiker]

Pictures might help if you can, so maybe someone here can recognize what you've got. What's the vintage of this bike? Does the frame have a rear derailleur hanger, or does it use a plate on the derailleur to attach to the dropout?

Here are more pics.

1. Rear Derailleur
2. Dropouts
3. How I thought it went together
4. Wheel
5. Bolt and nut for assembly

[DebW]

The bolt and nut go through the derailleur, but not through the screw hole in the frame. That shaped piece that the bolt screws into fits into the dropout itself, the same slot that your rear wheel axle fits into. It fills the space in the rear of the dropout slot, and your axle fits up against that. See how the shape of that piece is recessed to fit the dropout on 3 sides, and the axle on the 4th side? This is the way all rear derailleurs were mounted before derailleur hangers were built into the frame.

[DebW]

The hole in the frame above the dropout is for mounting a rack or fenders. The big slot in the derailleur's mounting plate will end up matching the frame's dropout and your rear axle will go through both. Derailleur should end up hanging almost straight downward. When you insert the rear wheel, the right side of the axle will butt up against the derailleur mounting plate, and the left side will be in the middle of the dropout. You just hold the wheel so it's centered (check the rim at the chainstays) and tighten the axle. Sometimes a pain to center the wheel because there is nothing to hold the left side in position.

[blondiebiker]

THANK YOU! I love te. :-)

[blondiebiker]

btw, it only took me about three minutes to put it together with your instructions - as opposed to an hour trying to figure it out last night. Thanks again!

[DebW]

THANK YOU! I love te. :-)

Old fart bike mechanics are sometimes good for something. :D