How to covert a mountain into a single speed FR bike ?

Question

i have a gt agressor that i would like to convert to a single speed freeride machine lol.

how would i go about converting it to a single speed operation?

how much would it cost?

and is it a lengthy task?

cheers all

Answer 1

It's not hard to convert it, but don't expect it to be a "freeride machine".   GT's triple-triangle frames are strong, but the Aggressor has always been an xc frame and isn't suited to abuse.   I don't know what you mean exactly by freeride and the riding you want to do, but keep this bike to smaller drops with transitions....drops to flat or anything large are going to tear it up.  

I'd strongly recommend that you get a new rear hub or wheel instead of doing the cog-conversion kits.  You can get those for cheap, but they aren't all that strong and it can be a bit rough on the freehub body and hub bearings.   It's your choice, though.

As for the rest of the conversion, you'll probably want a chain guard for the crankset....leaving the front derailleur on won't help keep the chain in place on rough stuff.   A tensioner is optional for normal vertical dropouts like what's on your bike, but it makes it easier.   Depending on your chainstays and gearing selection, you can usually add a "half-link" to the chain (or buy a half-link chain instead) and get proper tension.  You'll also probably need to pick up some single-speed chainring bolts....see if the ones you have on the crankset now will snug up with only a single ring, though.  Some will, some won't.   If not, you can get a pack of them at a bike shop for about $5 (get steel, not aluminum.....and if you ask for "bmx" bolts they're usually cheaper for some reason).  

Chainline is very important, and you don't want to just eyeball it.  You can learn how to measure it properly, or get pretty close by using a machinist's straight edge laid across the chainring....it has to be long enough to reach the rear cog.  You want to be as close as possible to in-line....3mm is too much offset and will cause wear or chain dropping, so get it close.

So depending on what you need or want, and depending on the parts you have already....you can do it for anywhere from $25 to $100 or more.   Just keep in mind the design of the frame and don't go putting yourself in the hospital by using it for bigger things than it's intended for.  

Hope this helps some.   Have fun with it!   :o)

Answer 2

Arni pretty well covered it.  Here are just a few more things.

Harris Cyclery has a great single speed page.  You might want to check out all of their single speed products:

http://www.sheldonbrown.com/harris/singl...

Performance Bike has a single speed kit you might want to check out:

http://www.performancebike.com/shop/Prof...

Hope this helps.

Answer 3

It's not a difficult task at all!!!  It'll take you more time to take off all the shifters and cables and c**p than to set it up.  Perfecting it and fine tuning can take a little while though.  

What you'll need:

I'm assuming your bike has the wrong kind of dropouts.  They have to be horizontal(inserts the back tire from left to right)  instead of a Vertical dropout(the back tire goes up into where you tighten the hub.)  

So #1.  you'll need a Surly Singleator it's $37 at JensonUSA dawt com.  This will guide the single speed chain and keep it tight and tensioned properly so it doesn't fall off.

#2.  You'll need a new chain Duh, which is about $7.  you'll need a chain breaker too btw if you don't have one, get one they're like $9.

#3.  You can get a cheap singlespeed conversion kit that works with Shimano Free Hubs for about $20.  The spacers take a keen eye to figure out but your chain should be straight in line with the front chain ring.

That's about all you need!!  I'm taking on the project with two bikes and have friends that have done it to their bikes already.  Enjoy the bike!  You should post a pic of it somewhere for people to see it!