How Many Teeth!

[Dan81]

... and sorry.

So you should be.

Now back to my questions...

Debating just getting a more moden set up - b/b (maybe isis I dunno whats best?), crank and screw on chainring. Seems like these bolt on ones are becoming/have become outdated?

Are these http://www.selectbikes.com/index.php?act=v...mp;productId=35 Echo cranks any good? then theres the question of what size crank (more confusion).

Edited October 21, 2008 by Dan81

[grant_hundley]

if it makes it easier to find a good gear....

divide the teeth on the front cog by the ones on back

this gives you a rough idea how hard the gear is

the lower the number, the easier it will be

ill do some for you...

most widely used set ups at the moment

18/15 = 1.2

18/16 = 1.125

others that you can use at the moment...

22/18 = 1.222

22/19 = 1.157

22/20 = 1.1

22/21 = 1.047

20/17 = 1.176

20/18 = 1.111

20/19 = 1.052

[Dan81]

cheers....I sussed that already but its useful seeing it typed out. How do you build crank length into that or just sort of guess?

[grant_hundley]

once you have the ratio of you gear (what i posted up before) times that by how many engagements you have.

now divide 360 by that number you just got (gives how many degrees till it engages)

so for me it would be... 22/18 = 1.222 * 72 = 88. 360/88 = 4.090.

so i get an engagement every 4 degrees.

now double your crank length and times it by 3.14

now divide it by 360 and times by the number of degrees

so for me it would be 350*3.14 = 1099/360 = 3.052 * 4.090 = 12.482

this means you have to move the crank 12.482mm to get an engagement (22-18 gearing using a chris king)

was that what you were after?

[Dan81]

For someone like me of the "**** it, I can probably make that." mentality, its probably overkill but yep, at least I can work it out before forking out. Appreciate that - thanks.

Any thoughts on the echo cranks anyone? or just put the £ towards middleburns (is 16T front going to be the new standard?)

[grant_hundley]

'burns are stronger, stiffer and lighter (i think)

but echo's are cheap.....

i'd go with the burns personally, i've owned both and my echo's snapped.

the 16t bash's are alright, chains are more prone to snapping and when the sprocket wears out, you have to pay a lot to get it replaced.

thought about 'burns with the heatsink bash? solid bash's with replacement sprockets.

[Dan81]

remember people using middleburns when i last was into riding so looks like theyre pretty much tried and tested. think im better goin with those if I do anything.

thanks again

Edited October 21, 2008 by Dan81