ProFail

I realized today that I rarely ever switch gears on my rear cassette. On top of that, the whole cassette has been a hassle. Plus, there's nothing wrong with losing a pound of cassette, RD and shifters, right?

However, I want to know if it's possible and what problems would arise if I tried to convert it to a single rear cog. Is it possible? What parts would I need? If it's impossible, what parts would I need to just turn my whole bike into a SS?

barba

You can just get a single cog and use spacers fill up the rest of the freehub. It makes it easy to adjust the chainline- just swap around the spacers.

rankin116

I believe you buy a SS conversion kit? I've seen them at performance.

ProFail

Sounds good... I can't make up my mind between half-SS or SS, but either way I'm going to my LBS tomorrow for opinions. SS sounds tasty right now, I like the idea of a light, efficient and easy to maintain drivetrain.

Any ideas for gear combinations though? I typically don't **** the DH parts of my local trails.

elemental

Are you planning on leaving your front chainrings?

As far as a full singlespeed conversion, you will need the spacers to turn the cassette into single speed and shorter chainring bolts so that they aren't too long when you remove two of your rings. You can then remove your shifters, FD, shifter cables, and obviously two of your chainrings and all but one of your cogs. If you leave your RD, it can work as a chain tensioner. You could also buy one, which is included in the Performance SS kit. If your frame has horizontal dropouts (unlikey), you'll be able to move the axle to get good chain tension without a tensioner, but otherwise you'll either need one or have to run a magic gear ratio (there are several calculators online).

ProFail

I think I get the gist, but it's still something I need my LBS to help me with.

From what I understand, I need shorter bolts, spacers, a chain tensioner, and thats it. How much will this cost me?

Oleanshoebox

Somewhere in the $50 region, I think. Maybe less. You may also want to get a new chain although it is not absolutely necessary.

-edit-

I misread that last post; if you are trying to do this on the cheap you can make your own spacers from pvc and keep your rd as a tensioner. The bolts will likely be in the 5 to 10 dollar range.

ProFail

Hell no I'm not trying to be cheap! I want it to be a quality conversion, not some half assed job, courtesy of my own crappy handiwork.

$50+Chain sounds lovely. Chain recommendations?

Oleanshoebox

KMC makes some SS chains in fabulous colors!

elemental

Are your dropouts horizontal or vertical? That determines whether or not you need a RD/chain tensioner.

monogodo

I got the Forte SS Conversion Kit from Performance for less than $20. I picked up SS chainring bolts from NYCBike.com for $3 or $5. I ended up not needing the tensioner, as the gearing I picked happened to work perfectly w/o one.

ProFail

Vertical, I need a tensioner.

cryptid01

please explain.

ProFail

I just didn't feel like typing out "Single cog in the back, three rings in the front".

pinkrobe

I use the Spot spacer thingy with a Surly cog on one of my bikes. I got lucky with my ratio and chainstay length, and haven't needed a tensioner. I went to my local road/track LBS and got the shorter chainring bolts as well. Quiet, smooth, no dropped chains to date.

biknbrian

Try 2lb 4oz (net), which is what I lost off my Cannondale went I went SS.

Consider a “half link” type chain that lets you take a single link out without always having to take a wide and narrow one together. Or get a half link for the chain you buy and use it if needed.

Also I bought the Nashbar kit with tensioner and would not recommend it. It has play in it that allows the little gear to lean a bit. If you just want to try it out then the kit is a cheap way to go, but if you are serious, get a better tensioner. I’d like to get one with a push up feature.

Another thing, the kit spacers are smooth and don’t click when you install the lock-ring. I used my 11 tooth cog with teeth ground off and the cassette lock-ring.

I briefly tried a 2 speed crankset, but you need the derailleur since I don’t think a simple tensioner can handle a large chain length change. Certainly not on a triple. You must have good chain wrap.

Also just by having the option to shift, even infrequently, you will have to always think about when it is the right time to shift and therefore negate some of the joy of a SS. When I rode briefly with a 2 speed set up every little hill presented the question of to shift or mash. It is liberating to not think, just mash.

One more thing, the Nashbar kit comes with 14, 15, and 16 tooth gears. The Performance kit includes 16, 18, and 20. I've found 32:20 to work good for a beginner here in the hills and Winter of Western PA, but and 18 would be nice come Spring when I'm stronger and the trails are in better shape. This on a 26" with 175mm cranks.

cryptid01

Mmmmkay. Whatever works for you I guess...but that idea sounds downright silly to me. If you're rarely shifting in the rear, I submit that perhaps it's your technique rather than the cassette that needs modification.

Bike Lover

Has anyone actually done this? If so, what were the results?

0O0O0

I was thinking of doing the same to my Hardrock Sport, is this an easy conv? More posts !!!!

ProFail

Delivered.

biknbrian

As I said before:

Please try it if you want, but you are making something too complicated when you can ride a true SS.

JiveTurkey

I've thought about making a 2-speed conversion. What if the bike had, say, a 32/18T combo (~46") on the inside and a 36/12T combo (~67") on the outside? That way I could use the outer combo on the road en route to the trail and the inner combo once on the mountain.

Seems like, since each combo has 50 total teeth, the chain length would be about the same for both, so it'd just be a matter of moving the tensioner laterally with the chain when manually changing gears.

Sounds cool in theory, but may just be extra, unneeded hassle.

Edit: Sheldon did a similar deal (though it's 3-speed: 2 free, 1 fixed): https://www.sheldonbrown.com/singlespeed.html#framemtb

diff_lock2

I went to my local mtb shop and picked up a few used cassettes for free (he was going to trash them).
I got the spacers from them by grinding the pin heads off.

For the cog, if you are going all single speed (the larger chain) you could get a surly god, those things looks FAT. I got a cheapy 5$ ss cog, works well so far.

On a friends bike we used the original derailer as a tensioner, and aligned it with a short piece of cable, and a nut+bolt.

BrianN

Paul Melvin tensioner, Surly cog and spacer kit, Salsa front rings......it works well. I was spinning myself silly on flat terrain and downhill. The option of a "big" gear has been nice. The weight loss was an added bonus.

-B