What's your favourite gear ratio?

...unless you have the strength and technique to do so.

Not even then, I know plenty of people include myself that could do it but, why?

Who's ever going fast enough to justify it, unless either you're running lights or managing to accelerate to 35 odd in between each.

Point being, there isn't a universally "right" gear ratio.

I've been riding fixed for a long while and I got good technique and strength in my legs. I run a brake so I can ride fast and the aim of changing the chain set is to be able to sprint between lights and on straight stretches keeping a higher top speed and average. i got another bike for tricking and another for city use geared higher, plenty of skid patches when I need it!

44/16 works out at around 74.3 gi, capable on the road and 48/16 at around 81gi

Not even then, I know plenty of people include myself that could do it but, why?

Who's ever going fast enough to justify it, unless either you're running lights or managing to accelerate to 35 odd in between each.

...unless you have the strength and technique to do so.

Ok so will be building up a fixed gear bike with front brake as not quite ready to go brakeless.

On my SS I ride a 48/16 which as mentioned is pretty good for me. With the fixie should I be looking to be a little lower (easier) gearing?

Is there any difference between a bigger front/bigger rear and smaller front/smaller rear? If in theory the gears you chose were the same in both configs would

a. one be slightly easier than the other and/or
b. which would be easier on the knees and
c. more suited to a fixie?

Again apologies in advance for any stupid questions.

48/17 brakeless and for hills

How many times?!

Your limitation on a fixed wheel bike will be going downhill. If you're not comfortable spinning on a lower gear (you'll have to be) then just stick with your usual. The easier gear is only easier when you're going up an incline, not when you're going hell-for-leather down one.

A cog with one tooth difference is basically equivalent to a two-tooth difference on your chainring. There's no other difference. It's marginally easier to change a cog than it is to change a chainring if you decide you don't like the gearing after all.

PS: I ride fixed with not one but two brakes. There is nothing wrong with doing this.

Its easier to control a desent with a lower GI though.

Running 48:16 I can maintain 47kph downhill, via a cadence of 125rpm. With a rider + bike weight of roughly 90kg. I'm bloody glad I have a front brake to help stay in control. Thats 1170 Kg.m/s of momentum to resist.

Why people confine themselves to going slow by riding brakeless is beyond me. Each to their own I guess.

Is there any difference between a bigger front/bigger rear and smaller front/smaller rear? If in theory the gears you chose were the same in both configs would

a. one be slightly easier than the other and/or
b. which would be easier on the knees and
c. more suited to a fixie?

None of the above, if the ratio is the same. Big/big is more efficient, smoother and lasts longer than small/small, but all by such small amounts that other drive train service conditions make more difference.

Big/big looks badass from a distance.

little/little looks badass up close.

All depends where your priorities lie. If an obsessive weight weenie then small/small to save weight, if more interested in smoothness and reducing wear then large/large

You'd need to be riding the Catford/Bec hill climbs for the weight saving to be more important than the power you can save by having the more efficient drive train

hm, my 'new' trek-hybrid-ratbike has a 50/16 [freewheel], it was a courier-bike imho

id like to go 48 ... its a Bontrager crankset but the 50t ring is french but unknown make [so far]

any body know what chainrings might fit

also, most freewheels seem to be 16 or 17 cept for Sturmeys .. are they any good

4 bolts or 5? 4x104 or 5x130 are the most likely chsinring bolt PCDs

Have a look on tartybikes.com (may be .co.uk) for good quality single freewheels

The trials ones on tartybikes.co.uk are very good but mostly 18t, the one I have on my polo bike comes in 16t and 17t too I think, if you want bigger then you're probably looking at a white industries one.

All depends where your priorities lie. If an obsessive weight weenie then small/small to save weight, if more interested in smoothness and reducing wear then large/large

Thankfully I am not a heavyweight at only 60kg so weight wise should not be too much of a problem. Will go bib/big...

4 bolts or 5? 4x104 or 5x130 are the most likely chsinring bolt PCDs

Looks like a 130. Just get your tape measure out and measure across an imaginary circle that the chain-set bolts make. The mm will be the BCD

The trials ones on tartybikes.co.uk are very good but mostly 18t, the one I have on my polo bike comes in 16t and 17t too I think, if you want bigger then you're probably looking at a white industries one.

cool, white industries stuff looks ok [+ echo too] ... tbh its prolly easier to drop a few teeth on the chainring

Looks like a 130. Just get your tape measure out and measure across an imaginary circle that the chain-set bolts make. The mm will be the BCD

excellent, cheers .. that rusty knackered chain on there is already gone, replaced by the shop with a shiny KMC Z510
online quick-BCD-calc http://www.bikeman.com/bicycle-repair-tech-info/bikeman-tech-info/1628-chainring-bcd

can i get this to my phone .. no of course not, itsa POS with a crapoleum BT issue

You'd need to be riding the Catford/Bec hill climbs for the weight saving to be more important than the power you can save by having the more efficient drive train

I am talking about obsessive weight weenies, not sure they are worried about hill climbing.

"I am talking about obsessive weight weenies, not sure they even ride."

Ftfy!

Looks like a 130. Just get your tape measure out and measure across an imaginary circle that the chain-set bolts make. The mm will be the BCD

measures out as a 130

so .. 44t 5-pin 130 1/8th ally ring pls, and the spanner too

recommends for suppliers to the fix-ed market pls ..