Gear ratio help singlespeed

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Gear ratio help singlespeed
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flag tacoedwheelmtb
Posted: Jan 3, 2013 at 15:25 Quote
i have a halo combat rear wheel on my bike and it has a 9t driver on it. what size sprocket should i use so i have the correct gear ratio
flag That1GuyYO
Posted: Jan 3, 2013 at 17:44 Quote
You would be good with 25 tooth that would give you about 2.8 gear ratio and 72.2 gear inches. With a development of 5.76 meters.
flag cmc4130
Posted: Jan 3, 2013 at 20:41 Quote
That1GuyYO wrote:
You would be good with 25 tooth that would give you about 2.8 gear ratio and 72.2 gear inches. With a development of 5.76 meters.

25 / 9 is a normal ratio with 20" wheels.

But, with 26" wheels, I would not agree! 72 gear inches is verrrrrry stout. That's only normal in the track bike / fixie scene.

The range for single speed mtb is low 50's for xc riders who like to spin-to-climb. 55 for all around riding. higher 50's and lower 60's for stouter ratio, plenty fast for streets and trails which are flat or down...

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flag cmc4130
Posted: Jan 3, 2013 at 20:42 Quote
tacoedwheelmtb wrote:
i have a halo combat rear wheel on my bike and it has a 9t driver on it. what size sprocket should i use so i have the correct gear ratio

20 / 9 X 26 = 57.7 gear inches would be a reasonable choice for mtb/DJ/4x/bmx style riding.
flag That1GuyYO
Posted: Jan 3, 2013 at 21:34 Quote
cmc4130 wrote:
That1GuyYO wrote:
You would be good with 25 tooth that would give you about 2.8 gear ratio and 72.2 gear inches. With a development of 5.76 meters.

25 / 9 is a normal ratio with 20" wheels.

But, with 26" wheels, I would not agree! 72 gear inches is verrrrrry stout. That's only normal in the track bike / fixie scene.

The range for single speed mtb is low 50's for xc riders who like to spin-to-climb. 55 for all around riding. higher 50's and lower 60's for stouter ratio, plenty fast for streets and trails which are flat or down...

Unsecure image, only https images allowed: http://i255.photobucket.com/albums/hh138/upsetbmx/WhatGearRatio.jpg
I didn't think it would be that much more difficult. But makes since I'm running about 55 gear inches but want a bit more. Don't feel like I get the speed I want from that and it's pretty easy. So I guess I will shot for about 60. I was considering going a lot higher.
flag cmc4130
Posted: Jan 4, 2013 at 12:53 Quote
I had 73 gear inches for a while on my bmx bike. I liked riding it on street rides and hauling ass, keeping up with road bikers, a lot of times. But for hills, you really had to charge them and keep momentum. Another fun aspect was fakie rollbacks -you can do them fast and your cranks don't turn fast. So it's definitely rideable, but I just want to be clear that it's not a medium ratio.
flag stranix
Posted: Jan 4, 2013 at 13:15 Quote
I use a 25t front 10t rear on my dj bike, and find its a pretty good ratio, 2.5
flag tacoedwheelmtb
Posted: Jan 5, 2013 at 7:31 Quote
ok none of you said what to use for a 9t driver in the rear. i was thinking somewhere around 23 tooth?
flag That1GuyYO
Posted: Jan 5, 2013 at 14:06 Quote
CMC gave the formula plug in the numbers 23 and 9 I think it is around 65 gear inches. 55 seems to be the average that's what I currently ride but I want a bit more. So 65 may be ok too. I don't know with out having actually tried it myself, and then it's personal preference anyway.
flag cmc4130
Posted: Jan 6, 2013 at 6:07 Quote
tacoedwheelmtb wrote:
ok none of you said what to use for a 9t driver in the rear. i was thinking somewhere around 23 tooth?

yeah I did!
post # 4
flag tacoedwheelmtb
Posted: Jan 6, 2013 at 6:48 Quote
where can i find a 20t sprocket
flag erikthefatty
Posted: Jan 6, 2013 at 10:57 Quote
Flatland bmx sprockets should come that small.
flag cmc4130
Posted: Jan 6, 2013 at 21:40 Quote
erikthefatty wrote:
Flatland bmx sprockets should come that small.


Yep.
http://flatlandfuel.com/sprockets.aspx
flag cmc4130
Posted: Jan 6, 2013 at 21:43 Quote
erikthefatty wrote:
Flatland bmx sprockets should come that small.


Yep.
http://flatlandfuel.com/sprockets.aspx

You may wanna check though, if you can switch the rear cog to 11t, then run 25/11.
flag cmc4130
Posted: Jan 21, 2013 at 21:06 Quote
a helpful chart. remember 55 is medium. below 55 is spinnier. above 55 is stouter/harder.



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