TheLemon

I am in the process of converting a 70's- 80's Colnago steel bike to a single speed (freewheeling) bike.

I was wondering whether it would work to just leave my 5-speed (14-18) pignon (I don't know if this is the correct English word for it) on my rear wheel on a to-be single speed bike. I would remove the derailleur and shorten the chain. That way I can still choose from 5 gears (actually 3 or 4 maximum for better chainline), in the garage with the help of some tools to find the optimal gearing for me. And more importantly, it would save me the money to buy a dedicated single speed rear wheel. The bike currently has some very nice vintage Dura Ace hubs, so I would really like to keep them.

xavier853

Why does this always happen to the rides I would gladly rescue.

What kind of colnago? Keep the gears on plzz

JohnDThompson 

Pignon = "freewheel."

Yes, what you propose can be done and is probably the cheapest way to build a single speed conversion. But don't expect to easily move the chain from one cog to another without the derailleur. Depending on the length of the slots in the rear dropouts, you probably can only accommodate a 2-3 tooth cog size difference without adjusting the chain length. Alternatively, you could leave the derailleur in place to function as a chain tensioner, but in that case, why bother with the conversion?

TheLemon

Actually I'm less and less sure this is really a Colnago frame (I only have the frame, even without fork, so there's no saving the gears or anything else). There were Colnago Super stickers on the frame and also a Columbus sticker, but no Colnago clover engravings anywhere. On the rear fork tubes, just at the seat tube junction, there's a logo: a capital C with a small heart within:
I can't find anything about this logo after an evening on Google. On two of the lugs there's logo's that look like 'SCM', no idea what that might be.
The frame has three brake cable guides on top of the top tube and a small drilled plate underneath which seems to be for attaching a number plate for competitions.

If anyone has any idea what brand this frame might be...

TheLemon

Ok thank you. I really don't need to change the gear while underway, but I thought it might be handy to leave all five cogs on the rear wheel. That way I won't need spacers or anything and whenever I feel uncomfortable with my gear ratio, I can put the chain on a cog with one tooth less or more. Leaving the derailleur is no option for me, since I want the bike as clean as possible (except for the rear cogs then...)

Bat56

You can do it. You won't be able to ensure a straight chainline but that's probably a low priority for your purposes.

Post pictures in the Classic Vinatge sub forum to identify the frame.

The_Joe

My SS conversion was ridden like that for a bit. ANd I had to stop doing it because the chain line was off and gave me trouble. It was easier to buy a wheel than respacing things. If it lines up then the only problem is having a bike that looks a bit half assed.

EpicSchwinn

Relevant photo:




This bike was posted for ID-ing on C&V and nobody replied.

TheLemon

@EpicSchwinn: that's the one exactly! Anyway my guess is that it's nothing special since noone knows this logo. Today I finished sanding the frame and I cut the derailleur hanger and other (for me) useless attachments off. Next thing is thorough cleaning, fine-grain sanding and maybe some filler here and there to get it as smooth as possible for the primer coat.

I think I'll just try my 5-speed configuration first. With luck the chain is exactly straight and since it's a multispeed chain, a little skew shouldn't be a problem?

J Pedals

You shouldn't have any issues with a slightly imperfect chainline, being a 3/32 chain. As close to straight as possible is preferable though, as I'm sure you know.

Nagrom_

The frame is a Clemenso.

Bat56

Can a Clemenso do a no-handed track stand?

Nagrom_

Not unless it has pegs.