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    How to (affordably) add range to my Deore 2×10 drivetrain?

    Hey all. I’m looking to add a bit more range to my cassette on a Surly Cross Check so it can handle some more challenging climbs for gravel and bikepacking type rides. Can I just swap my top gear for a bigger one, or will that throw everything off? Will I need a different chain length with this change?

    I’m trying to do it affordably, so I’d prefer to not get a whole new cassette/derailleur combo if possible.

    Thanks for any advice yall can offer!

    by chasmfiend_

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    17 Comments

    2. elginhop on

      I’d probably just change out the whole cassette for the 11-46t https://www.universalcycles.com/shopping/product_details.php?id=102794

      Yes, you will also need new chain. 

      There are a few makers of single wider range cogs: wolftooth, ethirteen, and others make extended range replacement cogs, but they cost as much as the whole Shimano cassette. 

    3. Takeshi_Mimi on

      Bigger casette if your deraileur can handle if not ad hanger extender for extra 4/6 teeth

    4. Feisty_Park1424 on

      Shimano specifies a maximum rear sprocket size of 34t for this mech but you can get away with 36t with the axle forward of the mech. If you put the wheel towards the back of the dropout the guide pulley will buzz on the cassette in 1st gear. You could change the rear mech to an Acera RD-M3020 to get 40t maximum rear sprocket

    5. poop_hadouken on

      It looks like you are already riding a subcompact crankset with a long cage RD/cassette that looks to go up to 34t? That is already a pretty low gear ratio as it is. If you are trying to be budget minded, I am stumped as to what else you could do short of getting lighter components or a lighter frame both of which obviously won’t be cheap. Those Surlys are great but they’re heavy. Maybe train more? Curious what others will have to say.

    6. terdward on

      If you’re trying to get better gearing for climbing you either need a smaller chainring and/or cassette with a larger first gear. A Deore 10spd should be able to handle up to a 42T large cog in the rear. These usually have a bit more range than their rating, though. You might be able to get a 44T or *maybe* a 46T without further modification. If you want to be sure it’ll clear, you can get a road link from Wolf Tooth (or one of the similar knock offs on Amazon that are cheaper to stay in budget). Look for an 11-44T or 11-46T cassette. It’ll keep your top end speed the same while giving you a lower range for climbing.

      An alternative option would be to replace the small chainring with an even smaller one. Going down just 2-4 teeth can make a significant difference. This can be tricker than just getting a wide range cassette, though, as you will need to make sure that you don’t go too small. Different front derailleurs have different tolerances for how big a jump front big to small they can handle. It can be a bit of trial and error to find the limits of your particular setup. But, generally speaking a 2 tooth reduction in the small chainring would almost certainly still work with a little adjustment and combined with adding a slightly wider range cassette in the rear would give you a lot of extra climbing range.

      EDIT: Looks like someone might have better identified your rear mech and said it only handles up to 34/36T. Be that as it may, getting the largest your mech supports (or over by a few teeth) is a good start. If you want to support larger, you can go with the road link type modification I mentioned or get a different Deore derailleur. They’re around $50 last I looked (but who knows now with tariffs doing weird things to prices).

    8. garciakevz on

      Grx long cage rear derailleur apparently rated for 36t but people ran 42t on it. Needs new longer chain

    9. Bag-o-bits on

      You could also get a goat link or similar hanger extender. Would increase max rear cog size but not derailleur capacity.

    10. Bag-o-bits on

      Also if you are buying new check out microshift. They have good prices in good stuff.

    11. chasmfiend_ on

      Edit: Thanks all, lots of good advice here to sift through. I’m new to this sub, but what a wealth of insight!

    12. Comfortable-Way5091 on

      Not sure how you intend to increase range without a cassette change. You can get more range out of your derailleur with a derailleur extender.

    13. Jeffy_Weffy on

      I would replace the inner chainring with the smallest one you can find that has the same number of chainring bolts and same BCD.

      For any change, use a bicycle gear calculator to see how it will affect your minimum speed with a 60 rpm cadence. You can find a great YouTube video from CYCLINGABOUT that explains how to find the steepest grade you can find with a particular gearing.

    14. stupid-computer on

      Cassette isn’t the problem, you really want a 46/30 double up front to handle loads and climbs. The 30t in the front is gonna get you alot farther than an extra 2 teeth in the back.

    16. boosted_01 on

      Amazon has one! Made by a brand that started with an F like Fenix or something, goes on the old style free wheel

    17. Desperate_Jaguar_602 on

      Realistically you’re up for a new rear mech (m5120) and a 11-42 cassette. And a chain. Worth it.

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