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1x9 for rough trails?

896 views 9 replies 5 participants last post by  Speedub.Nate 
#1 ·
On my 04 Trek 6700 i have a 44-32-22 fr and 11-34 rear, which i would like to switch to a single 34t ring in the front because i like it simple, i deal with a lot of mud and crap, my bike is too heavy, and i don't use the 22 or the 44 anyways. i have been hearing a lot about chain tension issues with this kind of setup... iwill be using a non-ramped chainring, but i'm going to be riding some pretty rough trails, and racing mostly too, so i want a no-fuss setup that will not derail. how to do?
 
#2 ·
2 Options....

I have been running this setup for over 2 years.

First Option: Run a Rohloff chain guide. Setup is extremely critical. You need to drop the chainguide as low as possible without it hitting the crankset. You also need to run the minimum spacers in front and back of the guide, and not hit the chain. The front will have less space and the back more to accomodate the full range of the cassette.

Second Option: Run a bash ring outside and a guide up against the chain so that it does not come off.

Both options MAY require a chain tensioner like the MRP/LRP or the Heim guide if you are dropping the chain. Personally, unless you do a lot of rock gardens, you should be ok.

Later Mon.
 
#3 ·
YaMon said:
I have been running this setup for over 2 years.

First Option: Run a Rohloff chain guide. Setup is extremely critical. You need to drop the chainguide as low as possible without it hitting the crankset. You also need to run the minimum spacers in front and back of the guide, and not hit the chain. The front will have less space and the back more to accomodate the full range of the cassette.

Second Option: Run a bash ring outside and a guide up against the chain so that it does not come off.

Both options MAY require a chain tensioner like the MRP/LRP or the Heim guide if you are dropping the chain. Personally, unless you do a lot of rock gardens, you should be ok.

Later Mon.
does anyone else make a guide like the rohloff? i can't get any info on their canadian distributor...
 
#6 ·
While you're at it, switch to a medium cage (GS) derailleur or even a **gasp** short cage road derailleur.

You don't need all that extra chain capacity and as a result you'll maintain higher chain tension and a quieter drivetrain.

I built up a poor man's 1x9 that I rode for a season using a GS XTR RD, Spot chainring and no guides. I did drop my chain twice, but not where you would expect -- both times were while mounting up and just getting rolling.

However, a Rohloff chain guide or the bashring / Jump Stop setups are both good advice.

 
#7 ·
Speedub.Nate said:
While you're at it, switch to a medium cage (GS) derailleur or even a **gasp** short cage road derailleur.

You don't need all that extra chain capacity and as a result you'll maintain higher chain tension and a quieter drivetrain.
what are the cons then of a short-cage rd?
 
#9 ·
Speedub.Nate said:
Limited chain capacity for 27 speed drivetrains.

Read >> This Post <<
you're probably tired of answering questins about this, but from what i understand of your charts i wouldn't be able to go from 34:34 to 34:11 with a short-cage, right? that's my planned gear range, and its about what i need (ie i don't want to shrink it...)
 
#10 ·
fish man said:
you're probably tired of answering questins about this, but from what i understand of your charts i wouldn't be able to go from 34:34 to 34:11 with a short-cage, right? that's my planned gear range, and its about what i need (ie i don't want to shrink it...)
Capacity wouldn't be the issue. Capacity requirements of your proposed drivetrain would mirror what's under the 44T column shown in the post I linked to:
_______34T___
1 - - 34 | 0
2 - - 30 | 4
3 - - 26 | 8
4 - - 23 | 11
5 - - 20 | 14
6 - - 17 | 17
7 - - 15 | 19
8 - - 13 | 21
9 - - 11 | 23 <-max capacity req'd

The stated capcity of an Ultrega SS (short cage) is 27T, well within the 23T needed by your 34 x 11-34T setup. (Remember: 34T is is both your largest and your smallest ring, so you only have to concern yourself with calculating differences across the cassette range).

A problem may arise clearing the 34T cassette cog. Shimano states their road derailleurs will clear a 27T cog (jockey pulley to cog clearance), but that, too, is a conservative number.

Search around the web and you'll find lots of examples of guys who clear 32T and some 34T cassettes using SS road derailleurs. I'm not sure what does and doesn't clear, but it seems that most of those who have tried it say it works and those who say it doesn't work haven't tried it. It may boil down to derailleur hanger length. Try it!
 
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