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Converting to 650b!!!

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Converting to 650b!!!

Old 05-11-20, 05:36 AM
Tandem Tom
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Converting to 650b!!!

Some time ago I posted that we are considering the above change on our Co- Motion Speedster. Finally getting back to this potential change over!
Currently running 700c x32mm with Velocity rims. Yesterday I swapped out the front wheel with my 650b x 42mm just to see how the clearance looked especially with the fender. Plenty of room and I suspect I could go 48mm.
The BB will only drop 3/8".
This will be great for trail riding!!!
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Old 05-24-20, 09:54 PM
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we run a cannondale RT2, and moving to 650b has been a huge boon to our riding experience. will not ever look back!
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Old 05-25-20, 04:43 AM
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We run a set of 650B wheels when we do serious gravel riding. Love them. It's incredible the difference all that volume makes.
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Old 05-25-20, 04:52 AM
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We have a Cannondale T2 for which I built 650b wheels. It's been great. The clearances on the bike are ideal for this. I am able to fit 47mm tires with fenders. I like how the bike sits slightly lower too. Might be lower than I prefer for a single bike due to pedal strike potential but is fine on tandem. Makes putting a foot down while in the saddle easier.

You will want to check the clearances at the chainstays of your Commotion. We have a 2005 Speedster and the stays wrap around the tire, so that smaller diameter wheel would not give additional clearance for wider tires.
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Old 06-05-20, 11:14 AM
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We’re ordering our new Calfee Tetra with one set of 700c wheels, for the road and one set of 650b for gravel
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
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Old 07-04-20, 04:03 PM
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Another vote for the conversion. Went from maximum 30mm with fenders to 43mm with fenders on Co-Motion Primera.
WOW, what a difference! Along the way, also swapped out fork for one with more offset. Improved handling markedly.
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Old 07-07-20, 05:07 AM
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I'm in the process of converting a 70's Dutch tandem from 650A (590mm) to 650B (584mm) and widening the tyres from 37mm to 42mm. While I just built the rear wheel yesterday, I still have to deal with spreading the rear fork from 120mm to 135mm which is not easy on a stiff tandem fork with a mixte frame.

Should be a fun ride though.
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Old 07-08-20, 03:00 AM
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I made a set of 650B for our quite new Cannondale Road Tandem. On that frame tire clearance was not fantastic, but we do fit 47mm tires which is great as the BB is kept about the same height over the ground as 25mm on 700c which the frame was designed for. However to have at least some space left I dished the rear wheel 1mm to the right as the tightest spot was on the left chainstay. Probably some risk of rubbing still if there is a couple of spoke failures so not something I would recommend for self-supported tours in the wilderness, but for the riding we do it's fine, and the extra volume is great for gravel riding. We still have a 700c wheelset which we use if we want to go really fast on paved roads, but if you're not into that wide tires is fine on paved roads too, they're not *that* slow.
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