Results 1 to 18 of 18
  1. #1
    mtbr member
    Reputation: ALS650L's Avatar
    Join Date
    Apr 2009
    Posts
    510

    Cross/Road 1X Gearing

    I've got an older Cannondale 29er frame I'd like to build into a "cross" bike of sorts with spare parts and some new stuff. I would like to run it 1X. What sort of gearing is typically used in this scenario? I'll be riding it on the roads in VT, paved and not so paved. I'm thinking I'll run a 36-40 tooth front, but what sort of cassette? I'm more concerned about climbing than top speed.

  2. #2
    mtbr member
    Reputation: A1an's Avatar
    Join Date
    Jun 2007
    Posts
    1,573
    I am running a 1x10 setup with a 42t chainring and 11-32T cassette. Pretty good road and dirt compromise here in mostly flat and sometimes extremely sandy FL. Did two 75 mile rides back to back up in Southern GA mainly on dirt roads with some nice rolling hills (not sure how it compares with your area). There were a few times when I was climbing up in the 32t and wishing for a little relief but overall it was okay.
    Signature

  3. #3
    mtbr member
    Reputation:
    Join Date
    Feb 2008
    Posts
    104
    That's the gearing, 42 tooth front with 11-32 cassette, that I'm wanting for racing CX. I'm just waiting for someone to make an XX1 type profile in the 42 tooth size. Then I'll pair it with an X0 or X9 clutch rear derailleur.

  4. #4
    mtbr member
    Reputation: blackgriffen_1's Avatar
    Join Date
    May 2010
    Posts
    165
    I run 44 up front to 11-28 in back, but that's because I'm using a short-cage road derailleur that won't handle bigger than a 28t, and even that seems iffy at times. If possible, I'd use a mountain mid-cage with an 11-32, as that would be perfect. I would suggest 42t because there are a lot of companies that do straight rings in that size.

    A valid question: what BCD cranks are you using for this semi-monstercross conversion? You'll have an easy time finding 39t or 42t rings for 130mm BCD road cranks, and likewise for road compact 110mm BCD cranks, but finding straight rings in these sizes for 104 BCD cranks can be hit-or-miss.

  5. #5
    mtbr member
    Reputation: ALS650L's Avatar
    Join Date
    Apr 2009
    Posts
    510
    Quote Originally Posted by blackgriffen_1 View Post

    A valid question: what BCD cranks are you using for this semi-monstercross conversion? You'll have an easy time finding 39t or 42t rings for 130mm BCD road cranks, and likewise for road compact 110mm BCD cranks, but finding straight rings in these sizes for 104 BCD cranks can be hit-or-miss.
    I have a set of Truvativ SS cranks that have 104BCD which I may use. Buying a crank may not be out of the question though.

    I was riding my 2X10 full suspension 29er on a short section of pavement the other day with 36 tooth front and 11 on rear, didn't seem like enough. I think closer to 40 will be the ticket, provided I have clearance.

  6. #6
    mtbr member
    Reputation: A1an's Avatar
    Join Date
    Jun 2007
    Posts
    1,573
    For what its worth, I'm having zero issues with my chainring and cassette combo with a short cage X7 10-speed der.
    Signature

  7. #7
    mtbr member
    Reputation:
    Join Date
    Mar 2009
    Posts
    191
    42 front with 11-28 rear is the common CX setup in my area. If you are willing to trade off top end for climbing then a 38 or 40 front with an 11-34 or 11-36 cassette should do it along with a box guide or chain guards.
    2009 Redline Conquest Pro, 2008 Trek Fuel Ex8
    2007 Kona Cinder Cone utility bike
    Yes I spent too much on bikes.

  8. #8
    mtbr member
    Reputation: ALS650L's Avatar
    Join Date
    Apr 2009
    Posts
    510
    Sounds like I may need to experiment with a few different rings sizes at least. As long as we are sort of on the subject... Sram road shifters/brake levers will work with sram mountain rear deraillieurs, correct? And they will also work with brakes such as BB7s? I'm going to be building from a disc brake mountain frame.

  9. #9
    mtbr member
    Reputation: blackgriffen_1's Avatar
    Join Date
    May 2010
    Posts
    165
    Quote Originally Posted by ALS650L View Post
    Sounds like I may need to experiment with a few different rings sizes at least. As long as we are sort of on the subject... Sram road shifters/brake levers will work with sram mountain rear deraillieurs, correct? And they will also work with brakes such as BB7s? I'm going to be building from a disc brake mountain frame.
    As long as you're using 10-speed trigger shifters to a 10-speed rear derailleur, absolutely yes. Front derailleur shouldn't be a problem. As for BB7s, you'll either need the road versions that match the cable pull of integrated/short-pull levers, or you can run MTN BB7s with Travel Agents in-line so that the ratios match up.

  10. #10
    mtbr member
    Reputation: A1an's Avatar
    Join Date
    Jun 2007
    Posts
    1,573
    One thing to consider with running a mountain SRAM rear der is you will have much less rear cable housing to snag on crap. I do a lot of riding on dirt roads that aren't well maintained so this is a big plus for me.



    compared to the Rival that was on it before:


    I think the housing was probably cut too long by whoever assembled the bike, but still there will be quite a bit there. With the SRAM Apex levers the X7 feels like it shifts much quicker. Could just be that the Rival is super low end...not sure.


    And just for fun...this is what happened to the Rival. Riding down a sandy double track and I guess some vines or a stick or something got caught back there on the cage and it pulled itself into the wheel. No fault of the derailleur. I would still be using it if it weren't for this incident.
    Signature

  11. #11
    mtbr member
    Reputation: ALS650L's Avatar
    Join Date
    Apr 2009
    Posts
    510
    I was sort of considering a clutch type rear deraillieur but wasn't sure if I needed it on a this type of bike. I think it will mostly see smoother terrain.

  12. #12
    mtbr member
    Reputation:
    Join Date
    Aug 2012
    Posts
    198
    I'm using a 1 x 8 set up with 32 up front and 11-32 at the back which is fine as I don't compete and can just get tucked up and relax on the very fast sections...It's still good to 35+mph though.

    My perfect set up would probably be a 1 x 10 with 36 up front and 11-36 at the back.

  13. #13
    mtbr member
    Reputation: A1an's Avatar
    Join Date
    Jun 2007
    Posts
    1,573
    Quote Originally Posted by ALS650L View Post
    I was sort of considering a clutch type rear deraillieur but wasn't sure if I needed it on a this type of bike. I think it will mostly see smoother terrain.
    That X9 clutch rear der isn't that much more than the regular version. Seems like a worthy investment...never know what sort of terrain you may be tempted to ride down the road.

    My setup is a standard short cage X7 with the front CR sandwiched between a bash guard and a cheap plastic chain stop thing. Pretty much flawless and I ride some really bumpy/crappy stuff.
    Signature

  14. #14
    mtbr member
    Reputation: millertm's Avatar
    Join Date
    Jul 2012
    Posts
    461
    Quote Originally Posted by Hogdog View Post
    I'm using a 1 x 8 set up with 32 up front and 11-32 at the back which is fine as I don't compete and can just get tucked up and relax on the very fast sections...It's still good to 35+mph though.
    What RPM's are you spinning to get that speed. I run 42/11 on my MTN bike with 29X2.1 tires which are larger then the 700X32's and I max out at 31.5 mph at > 90 RPMs at the crank. I am running 114.5" gearing and when my gps states I am at 32 or more mph I am spun out and just cost.

    Mark
    2012 XXL Carve Expert

  15. #15
    mtbr member
    Reputation: Eric Malcolm's Avatar
    Join Date
    Dec 2011
    Posts
    463
    Mark 90 RPM is a normal cruise cadence....to a road racer

    Where I live we had 2 days of 50MPH winds at a steady even pressure. On the 1st day, when riding home on pavement, I pedalled away from cars doing 30MPH no problem.

    Next day I rode home with a perfect tail wind and hit 40mph, on gravel, 44 x 12 = 94.5" gearing 26x 2.1 wheels. l did this in less than 1/4 mile. I spun myself out with the rear wheel chopping side to side underneath me. If I had your gearing.....

    Ride in smaller gears and condition your body to spin more, it is more efficient, you will be more agile.

    Eric
    If I don't make an attempt, how will I know if it will work?

  16. #16
    mtbr member
    Reputation:
    Join Date
    Aug 2012
    Posts
    198
    I was a roadie for 20 odd years so as you say Mark 90rpm is normal cruise cadence for me and I use a shorter crank than most people would to allow for that. I've never understood why cross bikes have such massive gearing, 52 x 11 is 55+mph gearing for me.

    I don't compete so I don't need to be pushing big gears on downhill sections...In an ideal world I'd want slightly bigger gears than that which is why I'd prefer 36 up front and 11 x 36 at the back...I reckon I could get somewhere near 40mph with that .

  17. #17
    mtbr member
    Reputation: millertm's Avatar
    Join Date
    Jul 2012
    Posts
    461
    Yea, that is crazy for me. I spin between 80-90 but I am a Clyde and my wattage is in the 300-400 range. I do not think that I could keep up much over 90 rpms. Based on this gear chart Bicycle Bike Gear Ratio Speed and Cadence Calculator this is what I need to spin for speed. This makes sense since I top out near 31.5mph.
    42 x 11 cad speed
    85 27.9
    90 29.5
    95 31.2
    100 32.8
    105 34.5
    110 36.1
    115 37.7
    120 39.4

    But with a 32X11 and skinny tire 700c x 32

    120 28.1 mph
    I must be missing something unless you have bigger tires.

    Mark
    2012 XXL Carve Expert

  18. #18
    mtbr member
    Reputation:
    Join Date
    Aug 2012
    Posts
    198
    You've got me questioning my gearing now, I've Just looked at my front ring and it's 34 teeth...Doh! Sorry.

    That still doesn't explain the speed though...That gives me a speed of 30mph at 120rpm (35c tyres).

    I don't know exactly what cadence I'm spinning but I know that my mates think my cadence is really high. I could be wrong about the speed though, I'm only looking at the speedo after the event so I'm probably picking up some speed once I'm in a tuck, that might explain it. I'm riding tomorrow so I'll look at it a bit more closely and get back to you

Similar Threads

  1. Replies: 37
    Last Post: 05-31-2013, 08:48 AM
  2. Crank Gearing for Cross: Compact or Standard
    By GTscoob in forum Cyclocross
    Replies: 19
    Last Post: 09-09-2012, 05:17 AM
  3. Gearing my Cross for Climbing
    By S.O.B. in forum Cyclocross
    Replies: 4
    Last Post: 08-09-2012, 09:03 AM
  4. Cross check gearing...how to go lower.
    By sprocket47 in forum Surly
    Replies: 11
    Last Post: 01-05-2012, 03:49 PM
  5. Iron Cross 2011 gearing & training
    By kittens&cobras in forum Pennsylvania
    Replies: 6
    Last Post: 06-24-2011, 10:39 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •