650c VS 700c

Discussion in 'The Bike Cafe' started by TullyMars, Apr 3, 2006.

  1. TullyMars

    TullyMars New Member

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    OK ... I have been riding a Felt B2 with 650c wheels and feel like I am getting smoked by my friends who ride 700c wheels.

    So My question is mathmatical ... If a rider road the exact same route, exerting the exact same amout of energy, how much faster would the rider with the 700c wheel set be?

    Thanks
     
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  2. Jaguar27

    Jaguar27 New Member

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  3. TullyMars

    TullyMars New Member

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    650c is the size of the wheels.

    Does this help?
     
  4. gclark8

    gclark8 New Member

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    It all depends on your leg and crank length. Having said that, 650c accelerates faster than 700c for the same force, cruising should be about the same. You may not be set up right on the bike. Are the bars comparable? Is the riding position too low?

    I ride a Tri bike with 650, and a road bike with 700. I have recently ridden my GFs MTB with my 650c Tri training wheels over my daily commute, it is 2-7 minutes faster (48m) than the road bike (50-55m). I have yet to ride the tri bike over the same course.

    My dream bike is a Felt B2-650c in 52cm. :cool:
     
  5. TullyMars

    TullyMars New Member

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    I am unsure of the crank length ... but I think I am riding your dream bike +2cm. 54cm Felt B2, Dura-Ace/Ultrega, about 18lbs ... Made in the USA! Not the Twain version.

    I am trying to figure out my best riding options ... My B2 or a new road bike with 700c wheels? As mentioned above, I ride flats-mild hills, other than that nothing too bad.

    It it were you and you had the same choice, B2 or New Road, what would you do and why? Thanks for your thoughts!
     
  6. gclark8

    gclark8 New Member

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    Which bike? Both!! My Tri bike is set up for sprints, 10-12k, my road bike I can ride for hours, they have very different geometry and comfort levels. I run off the tri bike, 78 degree seat post, but not off the road bike, 74.5 degree seat post, the wheelbase of the road bike is 20mm longer. My next bike frame will be a B2-650 from R&A. :D
     
  7. Insight Driver

    Insight Driver New Member

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    The scientific answer is this: assuming you have the same cadence and speed (which would mean you are in a different gear on the 650 bike vs the 700 bike, there would be a slight to no difference in a long ride (possibly slightly better simply because there is slightly lower drag from the smaller wheel). There is no rolling resistance difference to speak of on smooth pavement. The kind of tire and inflation you have are the dominant factors in rolling resistance, not the wheel diameter. In fact, it's more because of fashion that you don't see more road bikes with 650cc wheels. The smaller wheels are ideal for frames made for smaller folks; the geometry of the bike is easier to accomplish.

    You may be avoiding the dominant factor in why you are getting smoked by your peers: The motor is dominant in this case. You are the motor. With just some dedicated training you can increase your power output and endurance. Fix the motor and you will be able to keep up.
     
  8. TullyMars

    TullyMars New Member

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    True.

    I would love an opportunity to blame it on the equiptment though.
     
  9. Scotslad

    Scotslad New Member

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    I have a similiar question. When riding with my friend at identical speeds, actually I was drafting him a little bit, it looked like he was (excuse termonlogy new guy here) in a higher gear ratio than me and using less effort to achieve the same speed. He uses 700c and I 650c, he also has a 29 speed while I have a 24 speed if that makes a difference. But he was a least 4 gear changes higher than I. Now I know it probably is the motor as mention before but thought it was interesting to note.
     
  10. gclark8

    gclark8 New Member

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    He would have been in a higher gear than you to have a lower cadence.

    With your 24 gears, you should have a 53 tooth big ring and a cassette with an 11 or 12 tooth small cog. What are the gears on the front and back of your bike?

    My top speeds are almost the same with the following combinations:
    Wheeler 650c: 53-12
    Felt 700c: 52-13
    or
    Wheeler 650c: 53-11
    Felt 700c: 52-12
    Normally I use on the Wheeeler (650c)a 30/42/53 crankset with a 12-23 9 speed cassette,
    and on the Felt (700c) a 30/42/62 crankset with a 13-23 9 speed cassette.

    I hope these examples help you to understand there is no disadvantage in 650c wheels.
     
  11. Scotslad

    Scotslad New Member

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    Wow, yeah that did help a lots thanks for the example and technical detail.
     
  12. cucamelsmd15

    cucamelsmd15 New Member

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    The B2 isnt all its cracked up to be. I bought one through my team, and like most of the other folks who also bought them, we were kinda disappointed. Now, if Felt would hurry up and make one in carbon (as Ive heard is coming), Id be all over that like a fat kid on cake:D
     
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