# Cyclocross gearing - maximum cassette rear



## rhylkema

Will use bike mostly for single track- relatively steep. What is the easiest gearing I can get? Now the bike has FSA Gossamer cranks 36-46 and10 speed 12-27 in the back? Can I put a 34 ring up front and 11-34 cassette in the back?


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## Dajianshan

I can't imagine a course that would require a 32 tooth cog.


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## kbiker3111

I don't think a road derailleur can handle a cog that big and you'll be approaching the limit of its capacity anyway.

At some point you'll reach the limit of traction on your skinny tires. If its really gnarly singletrack, a rigid MTB might be more your style.


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## dudad

For a few years, I ran a single 42T w/ XT 11-32 9 speed cassette.
Rear derailluer was a short cage Shimano Ultegra.
Worked great- no problems handling the 32 cog.
Really nice having a granny gear for riding off-road.


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## Brentos

I imagine if your run a single ring you would have enought chain take up in the der. cage. But if you still want 2 rings and a big cassette, you may have to get a mountain bike derailleur. If you have shimano shifters, a shimano derailleur should work. If they're sram shifters, you're out of luck unless you ante up for the expensive XX der.


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## pacificaslim

I've run my bianchi axis with a mtb crankset 48-36-26 and an 11-34 cassette with a mtb rear derailleur. But Kbiker is right: the problem is that skinny cross tires just can't hold the traction on really steep uphills, so you can't stand up and "mash" like you can on the road because weight will shift off the rear wheel when you stand up and then it'll just spin out. So it's nice to have easier and easier gears to shift to so you can keep moving while seated.

But eventually you just realize that riding at 3mph or walking at 2mph isn't all that different so I just run a compact double up front and 11-26 rear and if I have to walk up the super steep soft dirt trails, so be it.


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## atpjunkie

*well I'm a Clydesdale*

and I like to run 44 / 46 or 48 / 36 - 34 front with a 11-28 or 11 -30 rear
Stay mostly in the big ring and use
Shimano XT or XTR short or med cage der.
oh and 8 speed cause it has those options

8 is great, just like choc'lit cake


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## velociped jones

seems to me that 36x27 should be plenty low. i presently run a 38x25 and only rarely wish for a lower gear.


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## ZoomBoy

atpjunkie said:


> oh and 8 speed cause it has those options
> 
> 8 is great, just like choc'lit cake


Another 8 is great believer here.....

Yeah I can see wanting those low gears but most of the time you are better off just hoofing it.


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## jmoote

velociped jones said:


> seems to me that 36x27 should be plenty low. i presently run a 38x25 and only rarely wish for a lower gear.


I would think so as well. 27 or 28 (with the SRAM or Ultegra 6700 11-28 is an option). I did a mtb ride today and kept up fine with a single 42t in the front and 11-28 out back. I'd have liked lower a few times, but nothing a 39t up front or even 36t if you have a compact couldn't solve.


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## darkmother

I ride my cross bike on MTB trails as well, and unlike cross racing, I do need some pretty low gearing to handle the steep climbing. I use a 50/34 compact crank with a 11-32 9s MTB cassette, and I frequently use the lowest gear. I use a short cage ultegra 10s rear derailleur, and it handles the MTB cassette just fine. I'm not sure if anyone makes a 10s cassette bigger than 27. With 9s shimano or sram spacing, you can get 11-34 or even 36 which is pretty low with a 34 tooth chainring.


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## davidka

For those that are using 32-34t rear cogs, MTB type derailleurs are available in mid length cages that shift better than long cages. The bigger reason to use them is that the derailleur's angle of travel is appropriate for the larger cogs. These "should" shift better than road derailleurs but it sounds like some of you are having good results with the road peice.


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## PlatyPius

39/26 front chainrings and 11-36 cassette 
(SRAM XX)


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## AJL

darkmother said:


> I use a short cage ultegra 10s rear derailleur, and it handles the MTB cassette just fine. I'm not sure if anyone makes a 10s cassette bigger than 27. With 9s shimano or sram spacing, you can get 11-34 or even 36 which is pretty low with a 34 tooth chainring.


Yeah SRAM and Shimano make 10s road cassettes up to 11-28. You can fit a 32 cassette with a *short* cage derailleur?? Those 10s Ultegras are pretty damn adaptable.


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## darkmother

davidka said:


> For those that are using 32-34t rear cogs, MTB type derailleurs are available in mid length cages that shift better than long cages. The bigger reason to use them is that the derailleur's angle of travel is appropriate for the larger cogs. .


Good point. I find that road derailleurs shift wide MTB cassettes well, because the upper pulley is *forced* to track steeper slope of the big cogs. MTB derailleurs don't shift close ratio road cassettes very well as the pulley doesn't track the largest cogs as closely. 

My bike plays double duty as a road bike and CX/offroad bike, so I have two wheelsets, one with an 11-23 for road, the other with a 11-32 for cross or trail use. The road derailleur is the better compromise for me. (I also remove a section of chain when I switch-two quicklinks)


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## atpjunkie

*I tell ya what*



ZoomBoy said:


> Another 8 is great believer here.....
> 
> Yeah I can see wanting those low gears but most of the time you are better off just hoofing it.


put a backpack on before a training ride
now add weights to backpack to get you up to 230 or so
find a good cxloop with a long(ish) climb, maybe on wet grass
have some wet grass that is a false flat
now do 50 minutes on that circuit

then get back to me

but again at 6'4" and change and 230, (and forever hoping I can become an anorexic 200 lber ) it is nice to have something to spin a bit once in awhile instead of just pure mashing the entire race
but even at this weight I still don't need a triple or 32 or 34

another reason why I like 8, better cassette selections


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## grrrah

If the OP has 10 speed shifters, gonna need a 10 speed cassette. and I'm not sure if sram xx works with shimano shifters. (maybe it does?)



darkmother said:


> I ride my cross bike on MTB trails as well, and unlike cross racing, I do need some pretty low gearing to handle the steep climbing. I use a 50/34 compact crank with a 11-32 9s MTB cassette, and I frequently use the lowest gear. I use a short cage ultegra 10s rear derailleur, and it handles the MTB cassette just fine. I'm not sure if anyone makes a 10s cassette bigger than 27. With 9s shimano or sram spacing, you can get 11-34 or even 36 which is pretty low with a 34 tooth chainring.


you use 9 speed shimano shifters right?


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## PlatyPius

grrrah said:


> If the OP has 10 speed shifters, gonna need a 10 speed cassette. and I'm not sure if sram xx works with shimano shifters. (maybe it does?)
> 
> 
> you use 9 speed shimano shifters right?


My suggestion requires a complete new drivetrain, yes. He wanted to know the lowest the he could get, though....


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## pacificaslim

FWIW, you can run a 9-speed cassette with 10 speed shifters pretty easily.


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## Cyclo-phile

The OP left out a lot of important details. I'll assume he's running either Shimano or SRAM shifters based on his crankset choice. If Shimano 10-speed, then his only real choices for a 11-34 rear cassette are SRAM X.X or custom. He would then need to use a Shimano mountain derailleur. If SRAM, the X.X rear derailleur uses the same cable pull as the road shifters. The easiest way to get this kind of gearing though is with Shimano 9-speed. My choice would be Ultegra 9-speed shifters paired with an XT rear derailleur and cassette.


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## atpjunkie

*by your gear choice*



PlatyPius said:


> 39/26 front chainrings and 11-36 cassette
> (SRAM XX)


I'm gonna guess you make me look like a climber

I feel your pain brother, get her done!


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## aabbas

Cyclo-phile said:


> ... My choice would be Ultegra 9-speed shifters paired with an XT rear derailleur and cassette.


That's basically what I use and I like it a lot. I have a 39t single ring and a Dura Ace STI controlling a medium cage XT derailleur on a 11-34 XT 9sp cassette. I think it's really nice to have an almost 1-to-1 gear for riding steep singletrack... it doesn't run out of traction very often.

Alex


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