I've been given a basic full suspension mountain bike that I'd like to strip down and convert to single speed. I initially didn't think this would be possible without using a chain tensioner as it has vertical rear dropouts, and the rear suspension means that the bottom bracket to rear cluster dimension varies with the suspension travel. I've had an idea though. If i set it up with a single sprocket and chainring and a chain of approximately the right length could i fine tune the chain tension by removing the rear shock and replacing it with a custom length solid bar? (or possibly an adjustable one, but that might be tricky to make strong enough) I'd lose the rear suspension, which i don't want anyway, but would the rear of the bike be up to coping with undamped bumps through the rear wheel? I intend sticking to roads by the way.

What kind of frame is it? You might be able to sell it and by a hardtail frame of better quality rather than messing up a perfect fine full-susser.

https://www.performancebike.com/shop/...slisearch=true

Az

Ive got the same exact one, interested? shoot my a PM

You can run single speed without locking up the rear suspension simply by running a chain tensioner that will take up the slack of the varying chain stay length.

If you set it up as you suggest, by using a fixed length solid bar in place of the shock, then the moment you get a little chain stretch (or more correctly chain wear) you will have no method of tensioning the chain - of course unless you remove the solid bar and replace it with a fractionally longer one each time.

For the sake of simplicity i'm trying to do without a chain tensioner. I see that the lack of adjustment is going to be a problem though. Hmmm I wonder if I can come up with an adjustable length shock replacement.......

A chain tensioner might not have enough travel for a FS rig. You might be better off using a rear derailer with the limit screws locked .

Im a hardtail guy myself, but do they not make lockouts for rear suspension? I would probably suggest a rear lockout. that way... should you decide to use the suspension, you could just flip a switch and kablammo. Suspension.

So, an existing, tried, true $40 solution is less simple than an 'adjustable length shock replacement' that has yet to exist and you'll come up with on your own? I like your world. Can I have some pie?

If I were in your shoes, I'd sell the squishy ride and get a hardtail. Seems to me like this project is only worth doing if you're a meth head and have a bunch of steam to work off.

I mean simple because it's doesn't add to the number of moving parts, like a chain tensioner would.

You quote 'adjustable length shock replacement' like I said 'nuclear fission propulsion device', it may seem like an insurmountable technical problem to you but, believe me, it's not rocket science.

It's just a project. Selling it and buying something else kind of defeats the object.

That won't work. It doesn't take up the amount of chain growth that a FS setup will have. A Paul Melvin or just a rear derailleur will be the only way to make it work.

Any sort of locked-out rear shock would work, if your chain never gets stretched and you manage to find a magic gearing.

Never mind the fact that eliminating the rear suspension with a lockout or the solid bar (horrible, horrible idea) basically just leaves you with a very expensive, fragile, and flexy hardtail.

don't forget heavy!

I think you are right. I think i'll stiffen up, but keep, the rear suspension and retain a disconnected rear derailleur as a chain tensioner. Thanks.