I would be more worried about the pedals.
So my made-up girlfriend is going to be building up a single speed cyclocross bike for racing. She’d like it to be left side drive. She’s small so I’m guessing bmx cranks but I’m would be fine length wise but will the chain line be a problem?
why LSD? just to be different?
southpaw, I’ve tried to force myself to do things right-handed but it’s just awkward, so awkward that i keep walking my bike on the left even though I cut myself sometimes doing it 
Also because she’s left handed and has trouble carrying her bike on her right side.
How were you planning on getting the freewheel to propel the bike forwards?
Bmx rear hub maybe
Really? I’m left-handed and prefer to carry my bike on the right because it leaves my left hand free to do things like open doors and write.[/quote]
+1
as far as the bb and cranks goes, try a tandem crankset/bottom bracket.
Or use LHD BMX cranks, a LHD BMX hub and a compatible freewheel. I think the BMX hub and LHD freewheel are going to be absolutely necessary. The cranks could work, as long as you got the Euro bottom bracket. It will be heavy, but strong and reliable as fuck.
Someone who knows more than me should correct or confirm all of this, as this is all information I’ve gained from talking to friends about their BMX bikes and reading on the internet.
Chainring/Crank clearance might be an issue.
ding ding ding!
be prepared to run a really really small chainring and possibly have a fucked chainline.
think like, 38 teeth.
ding ding ding!
be prepared to run a really really small chainring and possibly have a fucked chainline.
think like, 38 teeth.[/quote]
Well, if it’s really for racing cross single-speed, being limited to small chainrings won’t really be a problem. Most SS cross folk like to use fairly low gears, around 2:1, it seems. If you use cranks, hubs and BB designed for LH drivetrains, then you won’t have chainline issues.
If chainring/chainstay clearance is fucked up, you could use a micro drive train. If crank/chainstay clearance is fucked up, you could take it to a machine shop and have them put an indentation in the left chainstay.
if you’re going to ride fixed LHD, it should work fine with some locktite on everything.
Having the pedal threads in reverse shouldn’t be a problem either, I’ve ran cranks mirrored on a BMX bike and if you’re pedals are sealed, you can remove the cages and flip them between spindles.
Or buy a Profile LHD cassette hub = costly, but you wouldn’t need a LHD freewheel and cassettes are way better.
Don’t run BMX cranks unless it’s a 5-bolt or 4-bolt style because they won’t stay put, I had profile BMX cranks on my fixedbike for a week or two and the shit was all over the place.
I’m running Truvativ BMX racing cranks (110 BCD i think?)
I really don’t see how you’d have any chainline issues or clearance issues, just use spacers on the spindle if necessary and you could do that same thing to the chainring on the cranks.
but you can’t space out the cog, if you space out the chainring, you fuck the chainline…
go with the tandem BB and cranks…that way you can up the chain ring…I run LSD on my steamroller and my chain line is straight.
thats right. But you can’t do that with a freewheel even if it’s RHD.
The Profile cassette hubs come with cogs that are offset acouple mm one way or the other, so you could get alittle alignment out of it, maybe?
On my bike, I had to push the chainline as far as I could inwards on the cranks to make it line up with the wheel/cog.