single speed to 3 speed

[crankbrother]

Obviously, I'm no mechanic, so here's my dumb question: Is there anything that would prevent me from adding a triple crank, front derailer and chain tensioner to a single speed specific bike, specifically a redline monocog (basic, not flight)? I'm looking for a cheap 29er setup, but not that hip on being totally confined to one gear.

[MTJ]

If it makes you feel better, I thought about doing this myself.

2 problems - chainline and chain tension.

The chainline related problems with this are not totally insurmountable, but you will have issues. Your chainline will be off in two of the three rings, thus increasing the odds that you'll throw the chain in one of the rings that doesn't line up just right. So if you line it up on the middle ring, your best compromise, you're effectively increasing your chances of throwing the chain when you're grinding up the hill in your granny aor when you're screaming down the back of the same hill in your big ring. Neither is good, and if you decide to line up on either the granny or the big ring, you greatly increase your chance of throwing the other. So that's one reason why I wouldn't do it.

Your much, much bigger issue here is chain tension. Let's say you're running a typical 22/32/44 combo up front. The difference between your granny gear and your big ring is 22 teeth, and we'll account for the fact that only half of the chain is wrapped on the ring, so that's now 11 teeth worth of chain that your chain tensioner has to compensate for. That's a whole lot of chain (5+ inches). And let's talk about tensioners; the only kind of tensioner that would have a hope of taking up that kind of slack would be an articulating derailleur-style tensioner, which you can't mount because you don't have a derailleur hanger (because if you did we'd be talking about a 1X9 instead of a 3X1, wouldn't we?)

If you want gears on that frame, your only real option is to go with an internally geared hub; the only ones really suitable for off road are ridiculously expensive, and that's not what you're looking for.

Have you bought the bike yet? If not, try to find a used Karate Monkey. That will give you the choice you're looking for, as it has horizontal dropouts and a derailleur hanger. I ran mine as a geared cyclocross bike, then as a 1X9 mountain bike, and now I run it single speed with a drop bar and 29" knobbies. If you have the bike already, you may just learn to love single speeding after all . . . . .

[LWright]

cable stops for the derailure cable

[TonyTheTiger]

yeah it can, and has been done, here is a thread:

Is It Still a Monocog..........

here is a second fellow who did the same:

forums.mtbr.com/showthread.php?t=263477

I was thinking of doing the same to my mc and couldn't find the derailer hanger that was used in the above build but a wizard in a castle in a magical land far far away told me that someone at redline said that you could use the suntour derailer hanger mentioned at the bottom of this thread:

Monocog 29er + gears question

[MTJ]

Never saw those add-on hangers before. Pretty cool. Well, I did say the bigger issue was chain tension, and that sure as hell fixes that problem.

Have I been schooled here?

[singlespeedinca]

I am looking for one of these chain tug/derailleur hanger combos. On-One's is sold out, and I can't find the DMR one in stock anywhere. Any ideas?