rustmyrtle

I'm taking an old schwinn continental and making it into a single speed to be my husband's beater commuter bike.

So questions:

1. The two front chainrings are 52 and 39. I was going to use the 52 and do a 52 - 17 front and back. Is this sensible? My husband likes a hard gear, but doesn't want to rip out his knees.

2. Spacers. Because the 52 front chain ring is the outside chainring, with the chain then run too far from teh frame? will I need spacers on the single speed freewheel?

3. I haven't yet gotten off the old freewheel, since it needed a freewheel remover tool I didn't have (Park tool FR 4). Once I remove the freewheel (the tool is coming in the mail), will the diameter of the freewheel threaded mount be standard? for instance, can I get a freewheel such as this https://www.treefortbikes.com/364_333...ompatible.html and just thread it in?

Thanks!

velo-orange

1. 52/17 is a rather tall gear:

https://sheldonbrown.com/gears/

With 27" rims, it's a gear inch of 82.7. Most fixed road riders are in the mid 70's range, for decent acceleration from stops, ease of pedaling on uphills and control and cadence on downhills. With a singlespeed freewheel, you have more flexibility though. It really depends on what his comfort level and experience is. I'd start with an 18t in almost any conversion though. Freewheels are cheap.

2. The rear axle will need to be respaced so the freewheel is further outboard to line up with the 52t. In most cases it's a matter of flipping the spacers/axle around. The wheel will need to be redished too.

3. Thankfully freewheel threads are pretty much one size and are universal, esp for Schwinns and just about any other american, japanese and taiwan made bike made in the last 50 years. The lone exceptions are French thread, and metric thread for 14 and 15t BMX freewheels.

rustmyrtle

Thanks a ton--this is really helpful.

BCRider

The chainline can be helped a lot by shifting the 52 to the inside of the spider. That way you minimize or perhaps even avoid having to mess with the rear wheel. And even if you do re-dish the rear to reduce or minimize the offset I think you'll find that the front and rear line up better this way. A long straight edge laid up to the face of the ring and extending back to the rear will soon tell you how straight the chain line is.

cny-bikeman

1. Be aware that a single speed freewheel generally needs a 1/8" chain (single speed), not the original 3/32 that came on the bike. 1/8 is fine on the chainwheel.

2. Your husband may "like" tall gears, but on a single speed they are potentially less safe (terrible acceleration) and will NEVER get him in shape. Too long a discussion as to why, but he'll get in much better shape with a lower gear. If high gears got you in shape you would not see racers "spinning" even on training rides (yes with the exception of sprints and some uphills.

3. Getting a good chainline is not too difficult, but I'd advise using someone familiar with the process, rather than just shifting the lg chainwheel or "flipping" spacers.

BCRider

And that "someone familiar with the process" would end up doing the same things we have suggested. Moving the components around to achieve a straight chainline is hardly rocket science.

There's a couple of options that haven't been mentioned because it would be more work and cost than is needed. Swapping the BB to alter the axle length to move the cranks in or out slightly is one such. But it's not needed. Swapping the crankset to a track set is another but why do it if the rings can be moved around to achieve the chainline.

Bottom line is that the method used doesn't matter as long as the final chainline is straight. There's no right or wrong way to do it. Some may not look as pretty as others but the rider won't feel anything different.

velo-orange

A schwinn continental has a one piece crank and a chainset that is riveted together. There is no option for putting the 52 on the inside of the spider.

A lower gear is better for sure- a 42-17 would probably be acceptable and within range of a tall enough gear for singlespeed riding.

wrk101

+1 Many spend more money and convert the old Schwinns to a traditional bottom bracket and replace the crankset. Saves quite a bit of weight, and looks pretty good IMHO.

JanMM

Will he perhaps be commuting on this beater Continental with the original steel rims? That would be pretty dicey in wet weather.

BCRider

Heavy one piece cranks AND steel rims? I'm getting the impression from the components so far that the frame isn't much better than cheap water pipe if this is the case. Perhaps a better and higher grade starting point would be nice.

Or if this is intended to be a bike that won't draw a thieve's eye then I'd say it's not worth the effort and just leave it as it is.

bigvegan

Figure out what it will cost you first.

If you can do it by taking off a chainring, threading on a BMX freewheel, adding a new chain, and yanking the shifters / derailleurs, awesome.

If you're going to be spending much more than that (alloy rims will be lighter / better, etc., a 3 piece crank adapter/new cranks / bottom bracket all start to add up), you may find it easier and cheaper to buy a track bike / fixie / singlespeed from a certain retailer that advertises on this site.

52/17 is going to be awfully steep gearing for commuting. I'd say 52/18 at most.

Good luck!

Bikedued

It's not riveted, but bolted... The small ring IS the spider, and can be used as is, with a smaller freewheel. The 52 CAN be bolted on the inside, simply by flipping it to the middle, and installing the bolts from the frame side. I found a 39 to be perfect, which is the existing small ring. No redish was needed either, as the chain line was nearly perfect with a single speed freewheel, and the inner ring.,,,,BD

If it is meant to be a beater bike, why go through all the trouble of installing a bunch of updated parts? Build it as is?