BMX Chain v. MTB Chain

[keithyboy]

I'm in the process of renovating an old bike for my son. It got banished to the shed and raided for parts because the chainring got bent and I could never get it straight again.

The bike in question is a kid's mountain bike built on a BMX-type frame with a BMX-type one piece crank. However, because it has gears, it has a 3/32" chain not the usual BMX-type 1/8" chain. At the moment it has a GT BMX chain ring that I modified with a grinder so that the chain didn't get stuck on it but what I really need is a BMX-type chainring with about 40 teeth to take a 3/32" chain.

Any ideas where I can get one? Ebay has failed me completely and my knowledge of bike parts suppliers is limited to say the least.

Thanks.

 

[Steve Austin]

Not sure you can get one of them.... and if you can, it will be expensive. You could try looking on Billys Bmx, winstanleys both of which sell a large range of parts, but i don't think you'll get a chain ring that size (40) for a singlespeed (bmx) crank for a 3/32 chain

 

[keithyboy]

Not sure you can get one of them.... and if you can, it will be expensive. You could try looking on Billys Bmx, winstanleys both of which sell a large range of parts, but i don't think you'll get a chain ring that size (40) for a singlespeed (bmx) crank for a 3/32 chain

I have come to much the same conclusion. I've e-mailed the makers to see if they can help.

Either way, the modified BMX chain ring seems to be working fine and it's only really to tide him over until Christmas.

 

[Ivan Ardon]

My lad's GT Power Series Pro has a 3/32 chain with an alloy chainring around 40 (maybe 42), so a GT dealer may be able to get something.

 

[Landslide]

You could get a separate spider like this, then fit your choice of chainring to it.

 

[keithyboy]

You could get a separate spider like this, then fit your choice of chainring to it.

Technically, I'm a lot more comfortable with cars than bikes so I might struggle a bit with the vocab.

I take it BCD is to do with the bolt spacing that holds the chainring to it (bolt circle diameter?)? If this is the case, will any 110mm BCD chainring that takes a 3/32" chain work?

This project is going to end up costing me more than a new bike but I've got the bit between my teeth now.

 

[Landslide]

I take it BCD is to do with the bolt spacing that holds the chainring to it (bolt circle diameter?)? If this is the case, will any 110mm BCD chainring that takes a 3/32" chain work?

Got it in one!

 

[keithyboy]

Change of plan time. My lad isn't making use of his gears at all so I'm thinking of stripping them off altogether. The question now is can I get the guy in my local bike shop to whip the cassette of the existing wheel and bung the spare one I have on or is the 20" back wheel with a 6 speed cassette different to a BMX one?

 

[Ivan Ardon]

They should both be the same thread. I've removed the old five speed block on my singlespeed and I'm running an 18T BMX freewheel in it's place.

 

[Landslide]

Or you could just pick one of the 6 existing sprockets and wrap the chain round that one.

 

[keithyboy]

Once again you come up trumps, cheers chaps.

Final question. I'm a fairly hands-on person by my experience of taking stuff apart relates mainly to the automotive arena. What type of tool do I need to remove the cassette myself?