3x9 to 2x9 Conversion

Hey guy's I'm currenty running 44Ax32Ax22S, 4 bolt 104/64mm w/ Shimano HG-50 LX, 9-speed, 11x34t and Shimano M-952 XTR, long cage.

My plan is to convert to 2x9. I have ordered a BBG 32t Bashgaurd to replace my 44t and a Blackspire chain guide to keep the chain on the rings. As I uderstand it all I need to do is install both adjust the limit screw, shorten up my chain and it will be good to go.

Has anyone used this or a similar setup and is it nessacary to change over to a medium/short cage Derrailleur?

Also it was sugested to me to change my outer ring, is it really going to be nessacary to replace the 32t with a 34 or 36? Already having the 11x34t should help the bottom end.

Thanks agian for you help/advice!

 

no need to change to a medium/short cage Derrailleur or switch out to the 34 or 36

 

If your chain works for 3x9 it will work for 2x9.

 

Great, thanks

So I won't need to shorten it up? I figured since the circumference of the 44 is larger is would leave some slack...

 

The 32 and 22 will run fine just as they do now. When you replace the chain it's your option to put on a shorter (by 3" = 6 teeth = 1/2(44-32)) chain.

 

Couldn't I just remove one chain link for every 3 teeth less than the 44 from my current instead of replacing, or use Largest Cog to largest chainring method?

 

I don't think you need a chainguide unless you have a problem dropping the chain with your current setup. I run my 29er's with a 32-22-BG. I shortened the chain by 3 or 4 links (i cant remember exactly how many). i do run 1mm spacers when using the BBG Bash. The chain would rub slightly at the tallest gear (11-32) and the spacers move the bash guard out a little. I am using SLX cranks. You might want to consider not shortening your chain. If you leave it long, it makes it easier to switch back and forth from 3x9 to 2x9.

 

I converted to 2x9 with chain tensioner and bash guard a few years ago. I just took the tensioner off this week. Haven't ridden yet.

Edit - I just took it down Rock-It twice - fast. Chainslap was minimal. It stayed in the big chainring (36t) just fine. Pedaling up was MUUUUCCCH better without the chain tensioner.

22x36 front is much more versatile than just 22x32. I also run 11-34 rear. I dropped to a mid-cage derailleur and shortened the chain to minimize chainslap and improve shifting. Silent, solid running down the bumpiest descents. I believe the Blackspire will push your former middle ring to the big ring location and create a less desirable chainline (and possibly affect Q-factor). That's why I finally took mine off. Also, the bearings on my tensioner froze up a few times, creating serious drag on the chain.

Go 2x9 (34 or 36 big ring) with bashguard first. If your crankset and bottom bracket alignment allow the Blackspire without pushing the rings and crank outboard, go for it. Then shorten your chain accordingly.

 

Ive been running 2x9 since 1999, i will be going to 2x10 on a SC Blur carbon soon. I run a 44/ 29 in front and a 11-34 cassette with a medium cage SRAM rear der. and a Campy road front der. I have never had any shifting problems.

 

Some recommend not using a chain tensioner. Is this with a shorter chain that makes it not jump off the small ring? Sometimes i go from climbing, downhill, to climbing and would rather keep it on the small ring. Would hate for the chain to jump into my carbon BB.

 

As was said before you don't have to shorten the chain. If 32 chainring runs fine now it will run trouble-free no matter what you do to the 44 chainring.
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But if you want a shorter chain (to save weight?) .. The chain wraps approximately half-way around each chainring. The chain engages 22 of the 44 teeth of the big chainring and 16 of the 32 teeth of the middle ring. For purposes of chain calculation the big ring has 22 teeth and the middle ring has 16 teeth, so shorten the chain by 6 teeth.

 

...unless you add a Blackspire. Then you will need to keep a link or two more due to the push of the chain tensioner and the route of the chain.

 

Exactly what I was looking for. I am going to run the 32 with the bash and guide for now and see how that works out, I will add the Medium cage Later just to smooth things out a bit, this is also why I am going to shorten the chain up. I don't plan on going back to a 44 ring and would like to eliminate as much sloppiness and chain slap as possible. I'm not to sure I'll need 1mm spacers or not but will add if I get some rub.

 

A bash guard is recommended IMO. It helps in keeping the chain on big ring when shifting the FD while (dare I say it) being cross chained on the cassette.

 

Should I just be able to get the spacers through a LBS or order online? It seems like online I can only order 20pcs at a time.

 

I run the BG as well but with no spacers. Not in the 32-11 gear all that often, but it does rub sometimes.

 

I bought these off of McMaster Carr, item 98089A381 Metric 18-8 Stainless Steel Shim, 1.0mm Thick, 8mm ID, 14mm OD, Packs of 25. You can also find them on Ebay...here is the link. You have to have short chainring bolts to use the McMaster shims. The others will work with standard bolts.

 

^Thanks man^

 

If you get the right size bash guard, there is no need for shims.

 

I just bought an SLX crankset w/ BG and I'm piecing my bike together. Very interested to see how the chainslap is with the long cage RD. Thinking about buying the blackspire stinger, but if I don't need it...