Extended Cruise - Added to Finished Build Thread

tjwilson

Pro Member
Jan 15, 2016
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Bottom bracket & chainline.

Bottom bracket cut from donor, holes filled with sheet metal, drilled and inserted onto frame lower straight bar.

bb01.jpg


Bottom bracket and frame in the fixture and ready for weld up. I suppose this is probably the hard way to try and get the BB square and parallel to the frame!

bb02.jpg


Before and after the use of a hole saw.

bb03.jpg


Crank, chainring, pedals and sprocket are from a Schwinn Varsity. I plan to use only the smaller sprocket so the larger one will be removed.

crank01.jpg


crank02.jpg


The chainline is a little tight to the chain stay. The images below show a derailleur from the same Varsity the cranks came from. The spring seems a little weak and the distance between the chain idler wheels is longer than the derailleur that came with the Traveler. I think the spring and idler wheel distance are contributing to the droop of the return chain. Hate to do it but after forty five plus years I might have to separate the Varsity components! Either that, add an idler to lift the chain past the stay or, live with the use of only four out of five potential gears. Haven't had a chance to check the other derailleur yet.

chainline01.jpg


chainline02.jpg
 
Sep 14, 2013
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Bradley Illinoiz
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Maybe just a dimple in the stay?

Guitarl.

sent from a banana phone...
 

LukeTheJoker

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Nov 17, 2012
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Broken Hill, Australia
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Interesting way to mount a bottom bracket!

Custom builds with derailleurs usually have chainline issues, maybe hang a derailleur sprocket as a jockey wheel off the back of that tube the bottom bracket is on? That would lift the chain up and should give you clearance...
 
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tjwilson

Pro Member
Jan 15, 2016
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Maybe just a dimple in the stay?

Guitarl.

sent from a banana phone...
Thanks, I seriously almost went with your suggestion. The weight of the chain, even with the new derailleur that had the stiffer spring, was just too much. I think the chain would bounce and hit the chain stay at every bump in the road with only a dimple. At least with the size dimple I think I could manage to put in the stay.
 

tjwilson

Pro Member
Jan 15, 2016
567
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Interesting way to mount a bottom bracket!

Custom builds with derailleurs usually have chainline issues, maybe hang a derailleur sprocket as a jockey wheel off the back of that tube the bottom bracket is on? That would lift the chain up and should give you clearance...
YES!

I initially read your suggestion as using the entire derailleur instead of a single sprocket. And I think that might be what I go with!

I did play around with mounting a sprocket to a front derailleur, moved that around, and various positions of a single sprocket removed from the derailleur. I have additional "mid stays" that I'm adding that I needed to work around. Ended up returning to using the entire rear derailleur. I just happened to have a second one that's the same age/model as the first so I have a matched set. Visually I think it has the same kind of quirkiness that's going on with the front fork and fits the overall design. I'm close to a test ride. That should let me know if I've introduced too much additional drag. Thanks for the input!
 
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Mar 26, 2012
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I like the upside down derailleur on this! And mounted on a welded on fork tab....slick! Oh, to have welding equipment....and skills....and...
 
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tjwilson

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Jan 15, 2016
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Derailleur syncing.

This is a bit of a rambling post. Mostly because I'm still trying to convince myself of the best option. As @The Renaissance Man suggests it would definitely up the "coolness factor" if both derailleurs moved together. The idea also kind of fits in with some of the placement options I originally explored. I entertained trying to get the idler to shift the chain between the front two sprockets. Didn't get too far with that. The idler had to be placed so close to the crank that it would be hit by your heal. Just seams like that derailleur should be doing something in addition to acting as an idler though. The real punch line... the rear derailleur runs through the gears without an issue with the idler derailleur stationary!

But, out of curiosity I went ahead and messed with it to see what I could do. Didn't get any images. Would have been hard to see what was going on plus, greasy chains and cameras don't mix well. I did throw together a couple diagrams.

First image shows the set-up I tried. Pretty simple and straightforward. I ran the cable from the shifter, through the idler derailleur, a barrel adjuster, then back to the rear derailleur. The idler derailleur moved through its full range of motion. The rear derailleur moved through about a quarter of its range. Probably because of cable and cable housing stretch and movement? This would actually be perfect if the cable was running through the rear derailleur first. The idler derailleur really doesn't need to move at all.

derailleurSync_Idler2Rear.jpg


This image shows the best arrangement I could come up with to do that. The problem is that barrel adjuster hanging out in space below the rear derailleur. I'd need to have some type of bracket or arm to hold it in place. Not sure I can make something that doesn't look odd hanging back that far.

derailleurSync_Rear2Idler.jpg


Still haven't made a final decision. I've got a couple mounting points at the rear axle and the idler derailleur that I could use for an arm/bracket. The cable run from the shifter to the rear derailleur wouldn't change either way so, guess I don't need to make a final decision just yet!
 
Oct 3, 2015
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Denver, CO
This may be hard to explain, but im going to try...

What about using an old cantilever style cable hanger to make a "splitter"? Attach it to the cable coming from the shifter, and run two housings/one cable to both derailleuers from that?

Pics of cable hanger i am speaking of...





Of course you could always order a cable splitter from problem solvers, but making one is more fun :)
 
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