Converting Freewheel to singlespeed

deanvw

Is it true that a 7 speed freewheel can be removed and fitted with a bmx freewheel?

house_trained

Yes and No. Yes, you can remove the 7 speed freewheel and replace it with a single speed spacer kit (easily available these days), which will do the same job. I had this set up a few years ago when i was wandering about switching to singlespeed. If you want to put a proper singlespeed freewheel on the back, you'll need to change the rear hub to a singlespeed specific hub, then you can just screw the (bmx) freewheel onto that.

If you're sure about going to singlespeed and your back wheel is getting a bit old, it might be worth getting a new wheel. If not, then just get the spacer kit and see how you like it...maybe go the whole hog later.

nicklouse

house_trained wrote:

Yes and No. Yes, you can remove the 7 speed freewheel and replace it with a single speed spacer kit (easily available these days), which will do the same job. I had this set up a few years ago when i was wandering about switching to singlespeed. If you want to put a proper singlespeed freewheel on the back, you'll need to change the rear hub to a singlespeed specific hub, then you can just screw the (bmx) freewheel onto that.

If you're sure about going to singlespeed and your back wheel is getting a bit old, it might be worth getting a new wheel. If not, then just get the spacer kit and see how you like it...maybe go the whole hog later.

are you confusing freewheels and freehubs?
freewheel


freehub and cassette



and in response to the original question no idea.

If the threads are the same then it will fit but you will have a crap chain line and the chain will be constantly falling off.

deanvw

its a freewheel with the screw on hub. can i slap a bmx freewheel on it????!!!!!!!!!!!!!!!

house_trained

Oops, yeah Nicklouse is right. I was confusing a freehub/freewheel. You could just slap a bmx freewheel on there, but as Nicklouse says the chainline will be rubbish and the first pothole you go over, the chain'll probably come off. Also, have you got horizontal dropouts? If so, you'll be ok without a chain tensioner. If they're vert dropouts, you'll need to get a chain tensioner.

deanvw

it will have a dmr tensioner. because its vert dropouts but i think that bmx freewheels r better than cassettes converted with a spacers to make it single speed

nicklouse

so where would you put these spacers?

deanvw

you no when you convert to single speed you take th cassette off, then put a spacer thn the single cog then the spacer then the end cap

nicklouse

FFS so you dont have a free wheel you have a freehub and cassette!

so back to the original question NO a BMX FREEWHEEL will NOT fit.

get a ss kit that will fit on a 7spd cassette and sorted.

deanvw

god. I have a Freewheel wheel which has a freewheel on (the one which you screw on!)

nicklouse

right now that is cleared up the thread on the hub is normally the same for "old" mtb hubs and BMX hubs. please note that this is 1.37 inch x 24 tpi (same as bb threads) but not all BMX freewheels use this thread, most do just check.

you will have to use some spacers to try and keep the cog "out there" so as to keep a reasonably straight chain line. i sugest BB spacers.

deanvw

ok thanks