Singlespeed & Fixed Gear - Best way to achieve 69 gear inches?

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Chesha Neko
01-10-12, 03:45 PM
My Steamroller came set up 44/19, which makes going uphill easy, going downhill a *****, and is slow everywhere else. According to Sheldon's calculator 61.1 gear inches (For 700 X 25 / 25-622 tire with 165 mm cranks). So I'm aiming to move up to around 69 gear inches and there are quite a few ways to make that happen.

The stock Andel cranks have a 130 BCD and I see rings up to 50t available, so I could go 50t up front and keep the 19t in back for 69.4 gear inches. However it seems that most here are running 46t and 48t rings, is there any reason why going to a 50t would be a bad idea in this case?


Nagrom_
01-10-12, 03:53 PM
keep the front chainring... put a 16t cog in the back... 72.5... a little over, but its not a big deal

or if it is a big deal... throw a 17t on the back for 68.3.....

EDIT: only bad reason for not going up is due to cost... a decent front chainring will run you like 50 bucks minimum... you can get a rear cog for like... 15 bucks?

TejanoTrackie
01-10-12, 04:07 PM
The stock Andel cranks have a 130 BCD

I think you are wrong. I have 4 sets of Andel cranks and they all have a 144mm BCD.


Chesha Neko
01-10-12, 04:44 PM
http://img835.imageshack.us/img835/2692/chainring.jpg

I would prefer 144s, but you can see for yourself they're 130s.

jdgesus
01-10-12, 04:49 PM
the and els on my roller are 130 aswell. FWIW BBQ

TejanoTrackie
01-10-12, 04:51 PM
Well, I'll be. First time I've ever seen Andels in 130bcd, and Steamrollers used to come with 144bcd cranks.

DiabloScott
01-10-12, 05:41 PM
it seems that most here are running 46t and 48t rings,

I think there's some bias in the data, or how you perceive it. People with big rings are more likely to mention how big their rings are, or you're more likely to remember. I've got a 42-16 for 71". A 44-17 will be a fine gear for you at 68.3". There's no reason to change your ring except for looks, or unless you really want something part way between 68.3 and 72.5.

BTW, crank length has nothing to do with your gear... it does affect another parameter that Sheldon discusses, but not gear inches.

Kayce
01-10-12, 05:58 PM
The chain ring and the cog are of about equal quality, so thats not a reason to change one over the other. Cogs are cheaper than rings, advantage cog. Rings are easier to swap out at home, advantage ring. More ability to fine tune things with rings, advantage ring. Rings wear out faster than cogs, advantage cog.

Thats how i see things.

Spoonrobot
01-10-12, 07:07 PM
48t chainrings and smaller are mainly so common because they're stock on a lot of cranksets/bikes from the factory since they usually allow generous clearance with a wide variety of frames. Once you get past 48t you start running into chainstay clearance issues with the short spindles most SS/FG run.

So, nothing inherently wrong with running bigger chainrings, just make sure they fit on your frame.

Chesha Neko
01-10-12, 09:31 PM
Rings wear out faster than cogs, advantage cog.

Part of why I am looking at changing the ring is to go to a steel Surly chainring.


48t chainrings and smaller are mainly so common because they're stock on a lot of cranksets/bikes from the factory since they usually allow generous clearance with a wide variety of frames. Once you get past 48t you start running into chainstay clearance issues with the short spindles most SS/FG run.

So, nothing inherently wrong with running bigger chainrings, just make sure they fit on your frame.

Excellent point, one I had overlooked. I checked and Surly states that the Steamroller has clearance for up to 50t -- and that explains the indentation on the drive-side chainstay. Thanks for the heads up.

TejanoTrackie
01-10-12, 09:35 PM
Part of why I am looking at changing the ring is to go to a steel Surly chainring.

¿ Porqué acero ?

jdgesus
01-10-12, 10:54 PM
Well, I'll be. First time I've ever seen Andels in 130bcd, and Steamrollers used to come with 144bcd cranks.

and rollers used to be better.
i swear to god this 2011 roller is a ****ign piece of ****

TejanoTrackie
01-10-12, 11:12 PM
and rollers used to be better.
i swear to god this 2011 roller is a ****ign piece of ****

And to think they upped the price by $100 as well. Pay more for less.

Too bad you never got the Big Block.

markaitch
01-11-12, 07:34 AM
@Chesha Neko...as someone who uses alu chainrings i will echo the question "why steel?", but fyi surly does offer steel rings in 130mm.

& sorry to hijack your thread, but as a steamroller owner/devotee i feel obligated to bring a few facts into the jdgesus & TejanoTrackie steamroller discussion...

mine is a 07 model, it came with 130mm rd2 crankset. i believe surly switched to 130 andels for completes in 09. so i don't see when 'rollers could've ever come with 144s. i have not even seen a 2011 sr in person so i cannot make a factual statement as to its quality, but are rd2 cranks so much superior to andels, & are differing handlebars so terrible & hard to change-out that they turned such a universally well-regarded bike into "a ****ign piece of ****"? because besides the colors, those are about the main things they changed over the years. and TT, could you please tell me about any bike, including your beloved bikedirect offerings, not going up a few bucks over the course of 3-4-5-years?

AEO
01-11-12, 07:49 AM
hey, if you're going to replace the entire thing, then you might as well go for 42x16.

http://www.gear-calculator.com/#

JohnDThompson
01-11-12, 08:02 AM
¿ Porqué acero ?

Uhh, "steel is real?"

TejanoTrackie
01-11-12, 08:07 AM
Uhh, "steel is real?"

Yeah, and very very heavy....

Chesha Neko
01-11-12, 09:49 AM
Steel wears more slowly. My Steamroller is a daily commuter.


hey, if you're going to replace the entire thing, then you might as well go for 42x16.

http://www.gear-calculator.com/#

So my question is why would 42x16 be a better solution than 50x19?

AEO
01-11-12, 10:01 AM
Steel wears more slowly. My Steamroller is a daily commuter.



So my question is why would 42x16 be a better solution than 50x19?

from a wear stand point? 50x19 would be better in that case. It's just that you never mentioned that you were looking for longevity.

The more teeth a chain engages, the longer it will last.

markaitch
01-11-12, 10:05 AM
So my question is why would 42x16 be a better solution than 50x19?
the main reason to buy just a new cog rather than chainring is simply cost. on the other hand, if you have to buy both a new ring & a new cog to get the g/i you are seeking, there is a school of thought that a bigger ring/cog combo will give better wear & longer life...

Xgecko
01-11-12, 10:15 AM
42x16 gives you 8 skid patches 50x19 gives you 19....primes are good that way. I ran 44x17 on 28c's with good results