convert Cross bike to Road bike?

Discussion in 'Road Cycling' started by danrche, Mar 8, 2012.

  1. danrche

    danrche New Member

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    Hello All,

    I've got a Fuji Comp Cross that i use to get me to and from work, and to play on the weekends as well, and well just about everywhere I go. I've been thinking though about putting a bigger Big Ring chain ring on it. My intention is to get more speed from it. has anyone done this or something similar to this before? I assume that I can just buy a ring that matchs my bolt holes and slide my front derailer to fit the larger size. I checked the spec's on my 105 derailer and it says it can support the additional size of the ring.

    Anything I should know, or any experiences you'd like to share that may help me from screwing up my bike are welcome
     
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  2. alfeng

    alfeng Well-Known Member

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    When you move the front derailleur higher on your seat tube, you will probably find that you will need to replace the front derailleur cable ...

    You could get an 11t cog for your (12-25?) Cassette as a less expensive & (IMO) slighlty easier-to-implement option OR simply replace the cassette with an 11-2N/(whatever range might work for you) Cassette.
     
  3. rawhite1969

    rawhite1969 New Member

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    would be helpful to also know what the tooth counts are on the front and rear. Are you spinning out when in your best gear? if not, then changing the gearing isn't really going to change anything. Too much difference in the front chainrings can lead to rough shifting (I am told). you may have to move your front der. up too in order to accommodate the larger ring. Rear cassettes are an easy change. Lots of combinations available. I recently explored going to a larger chainring myself, and opted to make adjustments on the rear instead.
     
  4. swampy1970

    swampy1970 Well-Known Member

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    It's probably something like a 48/36 combo up front and a 12 up block on the back. Even if it was a 46 big ring, 46x12 is a fair sized gear and good for smashing around at not too many revs at 25+mph on the flat if you have the aerobic fitness to achieve that.

    FSA do a matched ramped/pinned 52 ring (matched for a 36 inner). It'll be an easy swap and if you have enough gear cable left over as most factory assembled bike do, you should be able to get away with removing the crimp on the end of the cable to give you a enough cable when you move the front mech higher up - but you may, as Alf said, need a longer cable.

    That said, 48x12 or 46x12 should be enough to have a lot of fun on.

    Pro's at the Giro fairly regularly use 52/34 combo - most use that with a regular front mech too.
     
  5. AlanG

    AlanG Member

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    As others pointed out, changing the gear ring is pretty simple. FWIW I have a Fuji Cross Pro and there is plenty of extra length at the end of the cable on mine to move the derailleur higher. I have the same maximum gear setup as you - 46/12 on my cross bike and also have a road bike with 52/12. I can't say there has been a single time I wanted or needed higher gearing on my cross bike. But I'm not you.

    Have you considered that switching to 700C 23mm road tires might make a greater difference in your overall speed if you are on paved roads all of the time?
     
  6. maydog

    maydog Well-Known Member

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    Fuji's page indicates a 46 tooth ring for recent comp cross bikes. Last summer a pretty strong rider used a cross bike with similar gearing on the group rides. He did say that he had trouble with the gearing during some >25mph runs. A 46x12 should allow the rider to go 27mph at 90rpm cadence; a 26x11 would get that up to 29.4 mph at 90 rpm.

    I would try the easy changes first:

    +1 to swap to road tires
    +1 to using an 11 tooth small ring on the cassette,
     
  7. danrche

    danrche New Member

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    wow, thanks for all the advice. Currently I can't keep up with the guys on the group rides when they sprint out at 27 mph. I can run 20 mph for a good while though. I think what I'll do (b/c it's easiest) is start with the tires. I'm currently ridding on 700x32

    I looked up my chain ring = 36/46t
    my cassette = 12-25t

    my exact bike = http://2010.fujibikes.com/Specialty/Cyclo-Cross/CrossComp.aspx if you're interested

    I may swap out the cassette as well after researching the advice you gave.

    I originally bought the bike b/c I was commuting to work on a mtb and wanted to upgrade to a road bike but retain the ability to roll through some trails on the way to work (where the car traffic is most sketchy). I've shortened my time by almost 30 min for the ride in but after ridding with a group ride, I was a little disappointed that I couldn't keep up. I may sell my mtb, and just buy a road bike for those group rides. I do find myself on the off-the beaten path on my cross bike though when I'm just tooling around on the weekends.

    I still enjoy the heck out of my bike, so I don't regret the purchase, but it would be nice to juice a little more speed from her. I'm running all factory components so maybe an upgrade on the cassette is my next step.
     
  8. ambal

    ambal Active Member

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    I've commuted on a cross bike for years. The only changes I made was to use more road orientated tires and use closer gear ratios.
     
  9. danrche

    danrche New Member

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    I swapped out my tires for a set of 700x23c and what a difference. I would have gone with the 22's as once member suggested but the closest I could come was 23 at my LBS (it's what they had).

    I think though after this summer is over I may invest in a closer raito of gearing by switching out my cassette. On the flip side, when I was reviewing my check book last night I noticed that I've gove just over a full month without going to the gas pump. HE HE HE That alone is worth it!
     
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