650c vs 700c Wheels
#1
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Joined: Dec 2002
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From: Nashville, TN
Bikes: 2002 Giant OCR 3, 2003 Giant OCR Elite, 2004 Giant TCR, 2004 Giant OCR Touring, 2003 Giant Iguana, 2004 Cannondale Ironman 800, 2005 Giant Trance 3
650c vs 700c Wheels
I know this has been covered before in the forum, but here is an excerpt from an article that I was just reading.
Using a smaller diameter wheel affects the output of your bicycle’s gearing ratio. For the most part, this actually puts the gear ratio within the reach of most of us. For the strong, however, changing the big front chain-ring to a 55 tooth puts things back to normal.
Is this true? I have ordered the Cannondale Ironman 800 with 650c wheels. Will it take a 55-42 tooth chain ring to be equal to my TCR's 53?
Using a smaller diameter wheel affects the output of your bicycle’s gearing ratio. For the most part, this actually puts the gear ratio within the reach of most of us. For the strong, however, changing the big front chain-ring to a 55 tooth puts things back to normal.
Is this true? I have ordered the Cannondale Ironman 800 with 650c wheels. Will it take a 55-42 tooth chain ring to be equal to my TCR's 53?
#2
cycles per second

Joined: Oct 2003
Posts: 1,975
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From: Minnesota
Bikes: Early 1980's Ishiwata 022 steel sport/touring, 1986 Vitus 979, 1988 DiamondBack Apex, 1997 Softride PowerWing 700, 2001 Trek OCLV 110
Yes, final gear ratio depends on rear wheel size. If you change to a smaller wheeled-bike, you will need to increase the big chainring size or decrease the smallest cog size to offset the change in wheel size if you require the same top gear.
Last edited by Gonzo Bob; 06-18-04 at 07:56 PM.




