It has gotten too routine, so instead of doing something difficult like intervals or tours I've got the urge to change up the bike. I'm thinking "single speed". Last year it became clear that it makes more sense to start out with a FG/SS frame and wheels than to convert something, but I don't want a new bike and I don't want to buy a new wheel ... or buy much of anything really ... so I was thinking what if ...

I have spare wheels and old cassettes, I could salvage a cog out of one and get a bunch of spacers to get the chain line straight. I think I could rip apart an old derailleur and clamp the pulley part to the chain stay for a chain tensioner. Or buy one if that fails. Buy a cheap ring, strip off the DR's cables and integrated shifters from my road bike, and put on a couple of brake levers I have in the parts box. It seems like that would be a cheap, relatively easy conversion that I could reverse without much trouble. What do you think; am I forgetting anything?

Of course I could just tie off the DR's in one gear combination, but part of the point is shedding weight and taking stuff off, so I really prefer an actual conversion.

Great idea and a fun project but not having done this myself I have two questions that I don't have the answers to.

1. Would around 10 or more spacers plus one cog be a solid enough structure?
2. How would you be able to get the tensioner to fit in the chain line?

1. Dunno. Seems like it would be if the spacers are the same diameter as the flange on the cogs.

2. I figured that the chain crosses the chain stay at some point, so somewhere near there would be close enough. Am I wrong?

What do you have to lose?

1. I'm not positive about the sizes of PVC pipe that are available, but I'm betting you could find one that would work. If not, you can actually BUY commercially manufactured spacers to convert a cassette hub to single speed. For that matter, just leave the rest of the cogs in place.
2. That's what the high and low limit screws on your derailleur are for.

Actually, I think that the biggest peril of this plan is that you might like it. If that's the case, at some point you'll probably have to buy yourself a spiffier, new single speed bike.

How about a barter with one of your old wheels or checking in with a bicycle coop near your home? As many of these types of conversions as are being done I'd think some here could have ideas and offer their experience much better than I could. Keep us posted on how this goes for you, best of luck on the conversion.

Bill

That's a real danger, because I'm sure exactly that would happen if I did like it, and the road bike would revert back to form. I wouldn't give up the SS when I want my road bike back.

Even if I buy spacers and a chain tensioner, I don't see it costing more than $20-$30. Plus the chain ring, almost forgot about that.

PVC pipe, that's a different approach ... reckon cutting an aluminum pipe would work, assuming it was the right size? I'm not sure I'd trust pvc not to wear out or crack.

It's a common conversion w/ lots of vendors making kits:

Universal Cycles -- Cassettes & Cogs > Single Speed Conversion Kits

The active cog is keyed onto the freehub body. All the PVC spacers have to do is hold it still laterally. I'd think it would handle that.

You might be right - I'm worried about lateral wobbling if it's not perfect or the chain line isn't precise, putting stress at the end and pvc having a bad reputation about that ... could be nothing though.

Price is right. If it doesn't work you can always spend the money for a commercial spacer set but part of the fun of this kind of project is doing it without spending any money. I'd also use one of my current chainrings and the existing chain. The cheap, dirty solution, of course, is to just leave the unused cogs in place.

I don't think I've ever seen those words written in that order before... I understand them all individually, but together they don't make sense.

I have converted two classic bikes to fixed; it was a fun process but I wasn't happy with either one so I bought a new one and I loved it. Then that one got stolen so I bought another new one and love it.

I did a single speed conversion for my wife and a fixed gear conversion for myself and both are relatively easy to do (or un-do if you decide you don't like single-gear riding of either type).

So I say go for it!

Rick / OCRR

Ah. I think you understand the goal here. I was just thinking that I do have a single ring on my rain bike which is 1x7, and I could swap my double with it and use just one of the rings there, and avoid buying a new chainring. At least right away. With a pvc (or whatever) spacer and rigging up a tensioner I'd be out nothing at all on the project. I could always use the whole cluster if I can't make a spacer work.

Unfortunately I don't think we even have a coop in Alpharetta. There's one in Atlanta but it's a good ways away from here.