Possible to add easier gearing to old cannondale?

Discussion in 'Cycling Equipment' started by Palisades, Sep 20, 2006.

  1. Palisades

    Palisades New Member

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    I have an old (10-15 years old) cannondale road bike. I am starting to get into cycling and have been trying to ride 3-4 times a week, about 10-15 miles each time for the last 2 months. And actually did a 30 mile ride for the first time last weekend, with good results. But I have a big problem, currently getting a new bike is financially not possible this season, so I am stuck with this old bike. I live in San Francisco, and the hills really kill me. Everything I have read says keep your cadence high 80-100 rpms up the hills and on the flats. The problem is up the hills, the easiest gearing only allows me to do maybe 60 rpm up the hills, and my knees are beginning to protest. The hills have been getting easier throughout these 8 weeks, but I feel they would be much easier with easier gearing. I am also concerned about my knees developing problems with this slow painful cadence.

    The bike has old dia-comp components, with seven gears (cogs?) in the back, and a double crank. My question is can I somehow add a different rear sprocket to get easier gearing on this bike? I am trying to invest as little money as possible in this bike because I am definitely buying a new setup at the beginning of next season. I will update this post with a picture of my bike so you guys can get an idea of what I am dealing with. Any recomendations? Thanks.
     
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  2. dabac

    dabac Well-Known Member

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    Haven't had much to do with dia-compe, so I don't know quite how they compare to the systems I know.
    I suspect your biggest obstacle might be to find a bike mechanic willing to undertake a budget conversion. If your crank has a square taper it might be easier to replace that one instead, or finding a shimano rear wheel, which would give immediate access to a lot of compatible components.

    If you find the "right" LBS or bike mechanic, one who has a decent stockpile of used stuff it should be possible to change the gearing at a low cost.
     
  3. gclark8

    gclark8 New Member

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    I would suggest a new rear wheel.

    If you have friction shifters, a Shimano 8 speed should work ok.

    If the Rear Derailleur will take it, an 8 speed 11-30 Shimano cassette is one way out.

    The existing gearing I suspect is a 14-28 7 speed spin on with a double crankset.
    Can you inspect the crankset?
    Cotterless or square drive?
    Count the teeth on both the chainrings.

    There will be something (Sunrace or similar) available with a smaller inner ring. I have a catalogue of old stuff.
     
  4. dgregory57

    dgregory57 New Member

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    Your gearing can be impacted by changing to a smaller chainwheel (front), a larger cassette cog (rear) or both.

    What are the tooth counts for yours?

    Oh, and the brakes are probably Dia-Compe, but the other components are likely to be Shimnano.
     
  5. alfeng

    alfeng Well-Known Member

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    Consider putting a USED, square-taper MOUNTAIN BIKE crankset on your bike ... you should be able to get a fairly 'nice' one for under $30 on eBay ... just check the picture in the auction to ensure that the chainrings are still good.

    The main problem is that pedaling while going downhill will be a meaningless endeavor since the largest ring will have between 42-to-46 teeth. The middle ring will probably have 32t. The granny will probably be dead weight ... you can keep your bike as a double by simply removing the granny OR by not adjusting the front derailleur's stops to reach the granny.

    You may want a new rear derailleur, but that's more a matter of handling excess chainwrap ... and, a slack chain is really less of a problem in a low-performance (non-hucking) environment than a cosmetic issue ...

    If/when you sell the bike, you can put the original crank back onto it.
     
  6. Palisades

    Palisades New Member

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    Ok I counted my gears to find out the ratios. The rear is a 7 speed 12/28, and the front is 37/52. Here are some pictures of my bike. Can I somehow replace my small ring with a smaller one? If not then what about the rear cog, can i just get a bigger one? Let me know what you guys think. Thanks a lot for all the help.
    [​IMG]

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  7. gclark8

    gclark8 New Member

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    OK, its Suntour gear, leave the cassette at 12-28, its a spin on.

    Change the crankset to a Sunrace 7/8 speed Triple MTB/Touring/Trekking one with a square drive, 28/38/48 tooth. I can get these (FCM31) new in Aus for under $40!

    See how you go with the FD, you can set it to shift 28/38 or 38/48 with the friction shifter. (a cheap Sunrace Triple FD is only $20 max! )
     
  8. PeterF

    PeterF New Member

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    Get a triple on your next bike. Drivetrain upgrades get pretty pricey. If your knees are bothering you, check saddle height and cleat postion. This bike will make you strong and next year you'll be flying up those hills on your new lighter bike. A 28 rear is pretty generous. I ride a 39/23 but I don't have to deal with Lombard street either...
     
  9. garage sale GT

    garage sale GT New Member

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    Clean your chain, dawg!

    Go to Bikepartsusa and look under chainrings.

    There should be some allen bolts under that five-spoked black thing which says "edge" on it, which the pedal arm attaches to. Take those out and you can pop on another set of chainrings. Just make sure the difference between high and low is not too much for the derailleur cage to span.

    If you're still not sure where the chainrings bolt on to the right pedal, go to bikepartsusa and look at some 8/9 speed compatible chainrings. you'll see the bolt holes.

    Before you buy anything, you should measure the bolt circle first, to see if the holes will be in the right place. I can tell you what the measurement is for a shimano compatible chainring.
     
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