fixie gear ratio

fixie

hi
i have an old raleigh frame that im converting to a fixie.i have a rear wheel with a bolt on hub.im just wondering what ratio would be good?
the front spockets are 42 and 52.so what cog should i put on the back wheel?

any help appreciated

Lumen

Fixie gear ratio
What gears do you commute in?

etc

fixie

thanks for the links!
Was running 40-15 on my previous fixie but that weighed a tonne and had big fat tyres,found it pretty good all round but i think with skiny wheels and a lite frame it will be a bit different!!
so im looking at running either
42-15
42-16

blorg

They sound like sensible ratios, I have 42-15 on my own commuter.

parko202

42-15 is what I have aswell and I find it is fine for all around dublin, any steep-ish hills I just get out of the saddle which has improved my strength considerably

fixie

thanks for the replies.was fairly set on getting a 15t cog off ebay but now im not sure.
follow the link below and read the desription and theres a note saying somthing about interferance between the cog and hub.i dont undertand it and it doesnt apply to the 16t cog!
a simple desription of the note would be good.

and will i need to do anything to the bottom bracket since im going fixed or any other mods??

http://cgi.ebay.co.uk/BOLT-ON-Disc-Mount-15t-3-32-FIXED-COG-track-sprocket_W0QQitemZ300350714602QQcmdZViewItemQQptZUK_sportsleisure_cycling_bikeparts_SR?hash=item45ee4c32ea&_trksid=p3286.c0.m14

(if the link doesnt work just search for "bolt on cog 15t" on ebay)

thanks again

niceonetom

fixie wrote: »

thanks for the replies.was fairly set on getting a 15t cog off ebay but now im not sure.
follow the link below and read the desription and theres a note saying somthing about interferance between the cog and hub.i dont undertand it and it doesnt apply to the 16t cog!
a simple desription of the note would be good.

and will i need to do anything to the bottom bracket since im going fixed or any other mods??

http://cgi.ebay.co.uk/BOLT-ON-Disc-Mount-15t-3-32-FIXED-COG-track-sprocket_W0QQitemZ300350714602QQcmdZViewItemQQptZUK_sportsleisure_cycling_bikeparts_SR?hash=item45ee4c32ea&_trksid=p3286.c0.m14

(if the link doesnt work just search for "bolt on cog 15t" on ebay)

thanks again

That's bolt-on cog and, unless you're using a mtb front hub as a fixed rear, it is not what you want.

What wheel/hub are you using?

What chainring are you planning on using?

fixie

im using a bolt on hub.and im using the origional 42tooth chain ring

Thomas_S_Hunterson

You might want to consider using the 52 tooth chainring with a suitable sprocket rather than the 42 tooth:
http://sheldonbrown.com/fixed.html#bigsmall

Greenman

Used 42 x 16 when I lived in Dublin. Good luck and tell us how you get on.

fixie

i dont want to use the 52t chain ring because the ratio would end up a bit heavy
can anyone explain the note in the desiption of the cog?????(in the link i posted)

does anyone have any different chain rings that might work for sale

niceonetom

fixie wrote: »

can anyone explain the note in the desiption of the cog?????(in the link i posted)

As I read it : With bolt-on cogs there is a minimum possible diameter below which the chain would interfere with the bolts. 15t might ordinarily be below this minimum but apparently the problem is resolved by using counter-sunk bolts. There still might be a problem with certain chains though, presumably chains with larger links than usual.

16t cogs wouldn't have that problem because they're bigger.

42x15 = 75.6"
52x18 = 78"