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26 inchers, what gearing?

pnj

Turbo Monkey till the fat lady sings
Aug 14, 2002
4,696
40
seattle
I got my bike rigged up SS with 32/18. It feels like it's going to be good for XC but street/jumps will entail some serious furious pedaling.

what are you running for jumps/park/street stuff?
 

sittingduck

Turbo Monkey
Jun 22, 2007
1,958
2
Oregon
You: 1.77777778:1 (practically trials gearing)

Me: 2.2727272727272727272727272727273:1 (a tad on the steep side, but I think it's perfect)
 

sixgun_sound

Monkey
Sep 24, 2007
215
1
Yakima, WA
I've had close to 2:1 for a while - 32/15 and then 25/12. There is a formula that takes wheel size into account, and you come up with a number that is supposed to be close to 55. Anyone have the formula?
 

cmc

Turbo Monkey
Nov 17, 2006
2,052
6
austin
I've had close to 2:1 for a while - 32/15 and then 25/12. There is a formula that takes wheel size into account, and you come up with a number that is supposed to be close to 55. Anyone have the formula?

FRONT SPROCKET / REAR SPROCKET X WHEEL DIAMETER = GEAR INCHES (54-57 is ideal for a medium gear ratio)

Running a fat tire in the rear wheel make you go slightly faster because fat tires are usually also slightly taller, making the wheel diameter slightly bigger.

The rule of thumb (easy/cheat/inexact-but-still-roughly-works method) is double your rear cog and add 2 to get your desired front sprocket size. It is that easy.

These combinations will all put you in the ballpark with 26" wheels.

19-9 or 20-9
21-10 or 22-10
24-11
26-12
28-13
30-14
32-15
34-16
36-17
38-18 or 39-18
 

pnj

Turbo Monkey till the fat lady sings
Aug 14, 2002
4,696
40
seattle
thanks everyone.

not sure what gearing I'll be using but I have to change what I have now for sure...
 

newrider3

Monkey
Oct 13, 2007
212
0
Colorado
32-15 on one bike, feels perfect. Tried 25-13 for a while on another bike, but that was waay too soft for my liking. It needed to be 25-12.
 

pnj

Turbo Monkey till the fat lady sings
Aug 14, 2002
4,696
40
seattle
WTF? I have 32/16 now and I need to use a half link (which I don't have, of course) in order for me to use my DMR STS tensioner dealy in the 'pull up' mode. I can use it in the 'pull down' mode but then I run a risk of my chain coming off the rear gear.

I guess it's ok... if the chain stays on. I'll drink a quick beer and go for a test ride right now. :)
 

sittingduck

Turbo Monkey
Jun 22, 2007
1,958
2
Oregon
WTF? I have 32/16 now and I need to use a half link (which I don't have, of course) in order for me to use my DMR STS tensioner dealy in the 'pull up' mode. I can use it in the 'pull down' mode but then I run a risk of my chain coming off the rear gear.

I guess it's ok... if the chain stays on. I'll drink a quick beer and go for a test ride right now. :)
You'll still have plenty of cog/chain contact with a 16.
 

sixgun_sound

Monkey
Sep 24, 2007
215
1
Yakima, WA
I used to run the STS on my STP too. With a 15. Make sure you're actually running a single-speed gear and not just a gear out of your cog. I made that mistake. Chain came off pedaling into the green lake jumps... the soccer game stopped to see if I was ok.
 

pnj

Turbo Monkey till the fat lady sings
Aug 14, 2002
4,696
40
seattle
I used to run the STS on my STP too. With a 15. Make sure you're actually running a single-speed gear and not just a gear out of your cog. I made that mistake. Chain came off pedaling into the green lake jumps... the soccer game stopped to see if I was ok.
did you push the chain up or down with the STS?

also, what difference is there with the cogs vs. single speed gears? aren't teeth teeth?
 

sittingduck

Turbo Monkey
Jun 22, 2007
1,958
2
Oregon
did you push the chain up or down with the STS?
also, what difference is there with the cogs vs. single speed gears? aren't teeth teeth?
I think sixgun meant "cassette" when he said cog.
You want an SS cog, not a cog that came from your cassette. They are thinner, and have the little "ramps" on them.
 

sixgun_sound

Monkey
Sep 24, 2007
215
1
Yakima, WA
did you push the chain up or down with the STS?

also, what difference is there with the cogs vs. single speed gears? aren't teeth teeth?
Pushed down with the STS. What I did was take apart a couple old 9 speed 'cogs' and used the spacers out of them. And then I just grabbed one of the old gears and stuck it in the middle. The gears in a 9 speed are designed so that your chain will easily move to the next gear when you shift. This also means that your chain will fall right off if there is no gear there for it to shift to.

So I made this cool little chain guide from more old gears from the cog or cassette.
 

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