Difference between running a 38/19 or 32/16 (if any?)

[sometime]

Hi all,

 

I'm in the process of converting my 1998 Trek 7000 26" HT into a SS. I've been using this bike primarily as a training bike running 1x9 gearing. Front chainring is a 38t. Going with the rule of thumb of a 2:1 gear ratio I was thinking of fitting a 19t cog at the back.

 

It seems that a 38t chainring is uncommon on SS with a 32t or 34t being more popular. Now I know my gear ratio is the same running a 38/19 or a 32/16 but I was wondering if there is any reason why the one may be preferable to the other - i.e issues with the chain tensioner etc?

 

I'd obviously prefer to keep the 38 but will change if there're compelling reasons to do so.

 

Thanks

[BLACKvoodoo]

Yes on the one bike you'll be running 38/19 and on the other 32/16...

[sometime]

Yes on the one bike you'll be running 38/19 and on the other 32/16...

 

The more time I spend on forums like this, the more I question my belief in Darwinian evolution.

[Iron]

Hi all,

 

I'm in the process of converting my 1998 Trek 7000 26" HT into a SS. I've been using this bike primarily as a training bike running 1x9 gearing. Front chainring is a 38t. Going with the rule of thumb of a 2:1 gear ratio I was thinking of fitting a 19t cog at the back.

 

It seems that a 38t chainring is uncommon on SS with a 32t or 34t being more popular. Now I know my gear ratio is the same running a 38/19 or a 32/16 but I was wondering if there is any reason why the one may be preferable to the other - i.e issues with the chain tensioner etc?

 

I'd obviously prefer to keep the 38 but will change if there're compelling reasons to do so.

 

Thanks

 

with the 38/19 you will have more chain contact on the rings , thus less chance of slippage ( i have had this experiance ) . but other than that its the same ratio so you wont feel any different .

 

use what you happy with . dont worry about what the norm is or what others say . your bike your rules .

[udxcob]

The end result is the same

 

http://www.badasstoys.com/chandler/chandler_gear_calculator.htm

[sometime]

with the 38/19 you will have more chain contact on the rings , thus less chance of slippage ( i have had this experiance ) . but other than that its the same ratio so you wont feel any different .

 

use what you happy with . dont worry about what the norm is or what others say . your bike your rules .

 

Thanks - I'd like to think I'm going with my own rules:

 

Rigid CroMo On-One fork

V brakes

Elf orange respray

Tubed tyres

 

It's not pretty but it's been a great bike for the past 13 odd years.

 

You make a good point about the contact area. I guess my main concern was to what extent the tensioner can operate effectively. Lets take my front chainring to an extreme to try illustrate my point. I could run a 54 front chainring with a 27 and have the same gearing but would the tensioner arm be long enough to effectively tension the chain? i.e. the pulley wheel on the tensioner may be so close to where the chain leaves the rear cog that it doesn't have sufficient leverage on the chain to tension it sufficiently. I just wasn't sure if that would be an issue on a 38 - but probably not.

 

Thanks

[covie]

The more time I spend on forums like this, the more I question my belief in Darwinian evolution.

 

Why becuase you didnt get the humor in that sentance?

[BLACKvoodoo]

Why becuase you didnt get the humor in that sentance?

 

No, because he didn't get the difference in the two ratios.

 

The more time I spend on forums like this, the more I question my belief in Darwinian evolution.

Cool it youngster we are a peace loving nation.

[sometime]

Why becuase you didnt get the humor in that sentance?

 

Exectley

No, because he didn't get the difference in the two ratios.

Cool it youngster we are a peace loving nation.

 

Read my post again and see if you can find the sentence where I say I know the gear ratio is the same and that my question was why the one chainring and cog combo might be preferable to the other.

 

Juvenile sarcasm is something we all eventually outgrow hence my concern over the evolutionary progress of Homo Sapiens.

[BLACKvoodoo]

Exectley

 

 

Read my post again and see if you can find the sentence where I say I know the gear ratio is the same and that my question was why the one chainring and cog combo might be preferable to the other.

 

Juvenile sarcasm is something we all eventually outgrow hence my concern over the evolutionary progress of Homo Sapiens.

 

Sorry Dad, now will you please go find your own forum to terrorise you're embarrassing me.

 

Ps: Mom said to get milk on the way home.

 

When you get home , maybe you can explain what Exectley means

Edited June 13, 2012 by BLACKvoodoo

[divernick]

I use a 38T chainring with a 16, 18 or 20T cog - no problems with anything.

[sometime]

 

When you get home , maybe you can explain what Exectley means

 

The prosecution rests your Honour

[sometime]

I use a 38T chainring with a 16, 18 or 20T cog - no problems with anything.

 

Thanks - that's the kind of first hand feedback I was looking for.

 

Did you get your cogs locally? If so where? I've emailed singlespeed.co.za with no success

[Iron]

Thanks - that's the kind of first hand feedback I was looking for.

 

Did you get your cogs locally? If so where? I've emailed singlespeed.co.za with no success

 

CRC , shimano DX rings with Blackspear front blade and sram SS track chain i have found to be the bomb.

[sometime]

CRC , shimano DX rings with Blackspear front blade and sram SS track chain i have found to be the bomb.

 

Thanks - my chainring is a Blackspear

[divernick]

Thanks - that's the kind of first hand feedback I was looking for.

 

Did you get your cogs locally? If so where? I've emailed singlespeed.co.za with no success

 

Chainreactioncycles.com

 

I bought the normal cheap R45 steel cogs. They work with 1/8 or 3/32" chains.

I use the Gusset 1-ER conversion kit and Gusset Bachelor tensioner. I have a blackspire chainring that is 1/8" specific, so I use 1/8 inch chains. I have tried SRAM PC-1, cheap Giant BMX and now Shimano Nexus chain. I replace the chain once it has worn to 1% stretch, which is about 6 months. The steel cog doesn't show any signs of wear and the alloy chainring has just worn bits of the black anodising off in some small areas after about 2000km.