[Miracleboi123]

hey guys,

i really want to change my shimano deore w/ a 9 speed cassette into a single speed.

problem is, the conversion kits out there that i need w/ a 12t are not available.

cant i just use the lower tooth cog (the one that i need) from my original 9 speed cassette, and just add in spacers, and finally place on the lockring?

has anyone done this?

I dont want to buy a product i dont need, if the cog from the cassette i have right now has the cog i need.

please help me thanks!

 

[H8R]

You can, but a dedicated SS cog will:

a) last a bit longer (generally designed to be the one cog taking all the abuse)

b) hang on to the chain better

Any multi gear cog from a cassette is designed to shift, ie release and take up the chain and transfer it from cog to cog. (shifting ramps, pins, etc) If the chain slips off the cog on a cassette, there's other cogs there to catch it. If it slips off on an SS bike, it's your knee, teeth, or balls into the stem.

Run it carefully, then replace with the real thing asap.

 

[H8R]

I just noticed you wrote 12t - I'd go for a bigger cog if I were you. Something in the 16t-20t range will distribute the wear much better over more teeth.

For all around trail riding I'd run 2:1 (ie 16t x 32t), for flatland go bigger, for very hilly terrain go smaller.

 

[henrymiller]

I just noticed you wrote 12t - I'd go for a bigger cog if I were you. Something in the 16t-20t range will distribute the wear much better over more teeth.

For all around trail riding I'd run 2:1 (ie 16t x 32t), for flatland go bigger, for very hilly terrain go smaller.

I second this.

Plus, a smaller cog will have less chain wrap. Less chain wrap = chain falling off.

 

[EBasil]

Good advice, and unless the original poster is running a very low-level Shimano cogset, they'll be mounted on a spider and not useable individually (other than the smallest, like the 12, for example). Frankly, the most frugal move is to buy a BMX cog for 4 bucks and save the cassette for another bike.

 

[Muffler Bearing]

in addition to what has been said above. if you run a single cog from a cassette it will dig into your free hub body and could get stuck as a result making it impossible to ever fit a regular cassette back on there if you wanted to. the thin cassette cogs will just cut a groove in the alloy free hub body where a dedicated single speed cog is wider at the base and will not.

 

[HardtailHack]

I ran 32-13T with no dramas, I was going to do as you said but internet people told me to buy a dedicated SS gear. I bought a 13T SS cog and it had no more contact area on the hub than a sprocket ripped off a cassette, if you have a steel cassete body on your hub go as small as you like. My hub has a nice groove in it from running SS but with a Hadley and a 13T gear you have to expect it, steel beats aluminium.

 

[Muffler Bearing]

I ran 32-13T with no dramas, I was going to do as you said but internet people told me to buy a dedicated SS gear. I bought a 13T SS cog and it had no more contact area on the hub than a sprocket ripped off a cassette, if you have a steel cassete body on your hub go as small as you like. My hub has a nice groove in it from running SS but with a Hadley and a 13T gear you have to expect it, steel beats aluminium.

sorry to hear that you got the wrong cog. there are dedicated single speed cogs that have a wider mating surface with the free hub body, those are the ones your supposed to get. the cheapos are hardly different from what you would pull out of your cassette other than the tooth profile.

check out the surly single speed cog, its nice stuff.