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ss gearing

Defenestrated

Turbo Monkey
Mar 28, 2007
1,657
0
Earth
I'm brainstorming some potential ss builds and ive never built an ss before.

I spotted a deity chainring @ 34 teeth for upfront and I wanted to use an atomlab 1-speed GI hub that limits me to a 16, 17, or 18 tooth free wheel.

My question is, is a 34tooth and 16/17/18 a good ratio for dirt jumping and some skate parks?

I have seen what look like chainrings a lot smaller than 34 on some bike pics floating around so I figured I'd ask.

Thanks. :bonk:
 

A Grove

Monkey
Nov 20, 2007
497
0
State College, PA
A few things we need to know firstly...

What size wheels are you running?

Why run an atomlab GI hub? Freewheels are **** man, if nothing else, run a normal 8-9spd hub and get a SS spacer kit...

What is you're frames hub spacing?

EDIT: Yes, you have seen a lot lower than 34 because people are able to run as low as 9tooth drivers in the rear. These are namely on BMX hubs, but there are a few companies making mountain hubs that use an 11t or 9t driver.
 

Castle

Turbo Monkey
Jun 10, 2002
1,447
0
VA
34/16 on 26 wheels feels decent... anything bigger out back will spin too easy..

I'm running a 26/12 right now on 26's slammed in the drops at 15.625 and it feels great....

for gearing you can take sprocket size (divided by) cog (mult. by) wheelsize = gearing

I think anything from 56-57 feels really good

for instance 26/12x26=56.3

there are a number of monkeys on here running easier and harder gearing....
 

Defenestrated

Turbo Monkey
Mar 28, 2007
1,657
0
Earth
planning on running 24 inch wheels

also I thought a ss specific hub would actually be better/less parts to buy; but if its better to get a standard 8/9 speed hub and convert it I have no problem with that.

edit: so that comes out to a gearing of 51 hmm
 

A Grove

Monkey
Nov 20, 2007
497
0
State College, PA
planning on running 24 inch wheels

also I thought a ss specific hub would actually be better/less parts to buy; but if its better to get a standard 8/9 speed hub and convert it I have no problem with that.

edit: so that comes out to a gearing of 51 hmm
No, what I am saying is that a hub that runs off a driver would be prime. A "singlespeed specific" hub that runs off a ****ty freewheel is garbage. You dont want to run a freewheel, trust me on this one.

What is the spacing on your frame? 110 or 135? Either way, spend the money up front and get a nice hub with a nice driver. look at a profile or something along those lines.
 

Axis

Monkey
Jun 9, 2004
471
0
planning on running 24 inch wheels

also I thought a ss specific hub would actually be better/less parts to buy; but if its better to get a standard 8/9 speed hub and convert it I have no problem with that.

edit: so that comes out to a gearing of 51 hmm

With 24's I run 23x10. I'd stick to a 2.3 ratio. So 26x11, 28x12 etc..
 

demo 9

Turbo Monkey
Jan 31, 2007
5,911
45
north jersey
ok the "ideal" ratio is a score of 55. this is what comes stock on most BMX bikes. higher is more top speed and lower is more accel.

front teeth/back teeth X wheel size

i use a 25-9 on a 26 and love it
 

cmc

Turbo Monkey
Nov 17, 2006
2,059
5
austin
34/16 on 26 wheels feels decent... anything bigger out back will spin too easy..

I'm running a 26/12 right now on 26's slammed in the drops at 15.625 and it feels great....

for gearing you can take sprocket size (divided by) cog (mult. by) wheelsize = gearing

I think anything from 56-57 feels really good

for instance 26/12x26=56.3

there are a number of monkeys on here running easier and harder gearing....

listen to this man.

there is a formula. USE IT.
 

BikeSATORI

Monkey
Apr 13, 2007
723
0
one world...
listen to this man.

there is a formula. USE IT.

yeah.... gear inches... 55 being typical "bmx" stat.

But on that note, anyone see how now "they" are saying gear inches is old news and they have some ridiculous new rack with sensors and rollers on it to measure actual distance a rear wheel travels for each pedal stroke? Takes into account tire size/volume, etc... which the formula doesn't.
It looks rather overpriced and overengineered for what it essentially equates, but I thought it was somewhat interesting. And hey, what do you expect with all these SS'er miner 49'ers out there with nothing else to do....

There was a brief article about it titled something like "death of the gear inch" in the latest MBA mag, I know lame mago, but a guy can get bored sitting in Border's waiting around for his girlfriend to get "real books", hahaha.... :imstupid:
 

sittingduck

Turbo Monkey
Jun 22, 2007
1,962
0
Oregon
Sheldon Brown's (RIP) gear calculator takes many factors into consideration. Including tire size and crank length.
25/9 on 26 X 2.35 MTB tire with 175 mm cranks works out to a WHOPPING 73.4 gear inches. Practically un-rideable, IMO. Unless all you do is bomb down hills..... :D
I run 27/12 on 26 (59.4 gear inches) and it's a tad steep, but very nice once you get used to it.
36/16 on my 24" (54 gear inches) Not much choice on the calculator for 24s, so it may or may not be as accurate, but it is a bit light. I wouldn't mind 15T on the rear, but it's a freewheel.
 

t1maglio

Monkey
Oct 29, 2001
855
0
southern wisconsin
ACS does make a 15t freewheel, not sure if it has to be used on the smaller side of a flipflop (but maybe you have one). They actually have down to 12t freewheels now, crazy!
 

sittingduck

Turbo Monkey
Jun 22, 2007
1,962
0
Oregon
When did the price go up? I bought one of those for $35 back when you (I think it was you) first posted up the info about them on mtbr.
Great hubs for the price. Didn't you also swap a 10t driver onto yours?
They were $35 for a long time... I noticed about a month ago that they'd gone up, I don't know exactly when it happened. And yes, I did put a driver in one for a while. Ran 25/11.
 

sittingduck

Turbo Monkey
Jun 22, 2007
1,962
0
Oregon
When did the price go up? I bought one of those for $35 back when you (I think it was you) first posted up the info about them on mtbr.
Great hubs for the price. Didn't you also swap a 10t driver onto yours?
They were $35 for a long time... I noticed about a month ago that they'd gone up, I don't know exactly when it happened. And yes, I did put a driver in one for a while. Ran 25/11.
 

A Grove

Monkey
Nov 20, 2007
497
0
State College, PA
Yes.. profile makes one. But will brought up a good point to me a few months ago that the hub-flange spacing is going to be so narry its going to make for a really weak wheelbuild.
 

Defenestrated

Turbo Monkey
Mar 28, 2007
1,657
0
Earth
Basically ive been looking at different frames to build a 24" bike for dirt jumping and decided is probably best to get one with 135mm spacing (ie. no mollys) because I want to run a disc brake out back.

Torn between bmw park bike/Evil DOC atm

This would be my first non DH/FR bike hence all the noob questions hehe.
 

A Grove

Monkey
Nov 20, 2007
497
0
State College, PA
I see I see.. I personally like the looks of the DOC myself... But thats just my opinion. If I was getting a deucequad, I'd go for a v-brake fallguy... They're so sickk.
 

BikeSATORI

Monkey
Apr 13, 2007
723
0
one world...
Yes.. profile makes one. But will brought up a good point to me a few months ago that the hub-flange spacing is going to be so narry its going to make for a really weak wheelbuild.
not necessarily any more so than a 9spd hub.

or a 100mm front hub for disc brakes...






Defenestrated, if I were in the market right now for a frame with 135 rear spacing for a disc brake, I'd probably be steering towards a Dobermann, or a Tonic Fabrications Howie, or possibly wait and see what one of those Eastern26 Black Betty's are all about since it may be a hair cheaper than the previous two... just some more stuff to look at.
 

Defenestrated

Turbo Monkey
Mar 28, 2007
1,657
0
Earth
yeah I was also checking out superco

Edit: hmm never heard about eastern26 before, any thoughts on them/info on the bike your referring to?
 

t1maglio

Monkey
Oct 29, 2001
855
0
southern wisconsin
I've been doing some thinking on this topic.

First of all, on my 26" I was running a 25x12 (54.17 GI), and I will be the first to admit it is way to light. On my 20" I have 36x13 (55.38) which is pretty well perfect. So if I went to a 26t on the 26" I would be sitting at a 56.3. Somewhere along the line I was told to go to a 27t (58.5) which seems a little steep. Thoughts?

Also, on my 24", I'm up in the air. A 27t would put me at 58.9 (way to big, right?), a 26t would put me at 56.73 (ok, I think), or 25t which would put me at 54.55 (maybe a little light, but not bad).

I ride trails, parks, and street, what would my ideals be.
20" - 36x13 (and someday soon 25x9)
24" - ? x11
26" - ? x12