QNelson

Hey guys need some help and or advice rebuilding my 86 world sport which was identified by you lovely people not to long ago. Heres the situation, I needed a bike, nothing fancy, to ride to school/work/grocery store and have it not stolen when left on campus. I found this lovely gym for next to nothing at the Goodwill and decided to try and build it. Heres my situation, I've been piecing together this bike from parts that I picked up at the Goodwill and parts from a donor bike (wally-world Schwinn Varsity) and every things coming together nicely and now I run into a problem.

I grabbed the wheels from the wally world varsity the front 700c wheel fits perfectly, the back not so much. As far as I can gather this is because the varisity is a 14spd bike and the world sport was a 10(I'm guessing) and thats making the rear wheel to wide and will not fit. So I can think of three possible solutions.

1.) Have the rear of the bike stretched to fit the rear wheel.

My concern with this is will the thumb shifters still work since they were designed for a 10spd instead of a 14spd?

2.) Have two cogs taken off the back.

Will this work?

3.) Just make this into a single speed bike

I hear this is taboo.

Thoughts, suggestions, help?

garage sale GT

You can choose any one of those.

sheldonbrown.com has info on respacing the frame.

If you swapped in 6-speed parts, you would still need to move the rim over by tightening the left hand spokes and loosening the right; it's a bit trickier than choice 1 or choice 3.

QNelson

Dumb question but humor me

if I do get the frame stretched will the thumb shifters still work even though there will be 4 more speeds then originally came with the bike?

garage sale GT

I got the shifter and rear derailleur on my '85 World Sport to work with an 8-speed cassette. You will have to reset the limit screws on the derailleur.

I did not use Sheldon's method but simply held the bike up by the rear dropouts and pulled. Each side should be subjected to exactly the same force, provided you don't brace the frame against anything or let it touch anything and try to pull each side parallel to where the axle would be.

It came out even enough because the wheel was centered in the frame. If you spread the frame this way, though, you will have to bend the dropouts back with a large adjustable wrench. I found my hub wouldn't hold until I bent the dropouts back inward until they bore squarely again on my wider hub. You can't just crank up the quick release or you'll ruin your hub bearings. If you have a nutted axle, though, you can just crank the nuts down.

QNelson

I dont know If I trust myself enough to give that a shot but I'm sure the guys at the LBS could probably do it. So as long as I reset the derailleur it should be fine? That doesn't sound too bad.

DiegoFrogs

Is it friction or index shifting? I had the same bike years ago, but nothing on it was original. Mine came with indexed downtube shifters, Shimano SIS derailer and aero brake levers.

If it's friction, additional cogs shouldn't be a problem for the shifter.

Mr. Embrey

I have the same bike. It would probably be easier to scan craigslist for a cheap roadbike from the same era. A lot of times you can find one that is real cheap. As long as the wheels are still good, they should work. It would be a safer bet than bending the frame. I'd at least look first. I got a free Schwinn Traveler from there one day.

Go here if you want to see mine.

https://www.flickr.com/photos/embreya...7624459463984/

USAZorro

If you changed the axle and spacing on an existing wheel from 5 cogs in the back, to 7, you would need to re-dish the wheel as you have noted. However, since the wheel that QNelson has is presumably a properly dished wheel with 7 cogs, this would not be necessary. Depending on the frame, he may find that either the smallest cog, or the chain rubs against the seat stay. If that happens, the rear wheel might need to have spacers re-arranged, and the wheel re-dished.

Beyond this, the rear dropout would still need to be spread, and the rear derailleur set up anew with the proper high and low stop settings, and the shifter tested to ensure it has the proper pull to move through all the gears.

garage sale GT

I think he was talking about not respacing the frame but just slapping on a 5 speed in place of a 7 speed. Incidentally, it was originally a 6 not a 5 speed freewheel.

It might work if you were able to shorten the axle enough on both sides to keep the wheel centered in the frame.

wrk101

I am kind of confused by your question. I would use the shifters off the Varsity.

Drive component moves like you have made work best if you move everything: wheels, cranks, derailleurs, shifters, chain, rear cassette or freewheel, etc. The more compatible parts you move as a group, the easier it is to get things to work together. Don't take cogs off.

World Sport did not come with thumb shifters, so you are losing me on this one.