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Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

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Old 10-02-10, 09:07 AM   #1
j8715
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Replacing 27in wheels with 650C to gain standover clearance.

Ok. Someone left a decent old Fuji bicycle in my yard. It must have belonged to shaq or bigfoot or someone because I am 6'2" and its slightly too big of a frame for me.

Could replacing the old 27in wheels with 650C wheels be done? how much height difference would that give me? I know that would mean the brakes wouldn't reach anymore, will it be a nightmare trying to find calipers with that extra long reach? Will it change how the bike rides much?

Thanks.
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Old 10-02-10, 09:17 AM   #2
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It would be a MAJOR change. It will reduce the standover by about 30 mm or 1-1/8". However:

First the radial difference the brakes would have to adjust is also 30 mm. You would need a brake reach of 77- 87mm assuming your current brakes are 47-57 "long reach" calipers.

Second, it will have a big effect on the fork geometry and will reduce trail signifiantly. This will really quicken the bike's handling and may make it too "responsive" to be comfortable.

Recommendation: Get a bike the right size.
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Old 10-02-10, 09:42 AM   #3
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I agree, get a bike that fits you. Standover height isn't important anyway (to me at least.) The important dimensions are the top tube length and to some extent the seat tube length. Putting smaller wheels on the bike won't fix either of those. Plus it'll be very difficult to fit brakes to the bike. And your bottom bracket will be lower, probably causing frequent pedal strike around corners.
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Old 10-02-10, 10:36 AM   #4
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And your bottom bracket will be lower, probably causing frequent pedal strike around corners.
Good point. I forgot to mention that problem.
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Old 10-02-10, 11:07 AM   #5
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Bad idea. Get a bike that fits. It's not that hard.
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Old 10-02-10, 12:08 PM   #6
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650B has been a popular comversionof 27/700C frames..
But, Yup, sell what you found, and buy what you need.

First, find out if it was stolen.. then if it was, give it back.

Last edited by fietsbob; 10-02-10 at 06:35 PM.
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Old 10-02-10, 12:52 PM   #7
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Define "slightly" too big. A switch to 700c wheels will lower the bike by a little less than 1/4 inch. Not a lot for sure, but it would not have all of the negative factors above either. Kind of expensive change to get 1/4 inch, but if you have some wheels handy, you could try it and see if it makes a difference. With that change, you will need an additional 4mm of brake caliper reach. Many calipers, but not all, can do it.
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Old 10-02-10, 03:40 PM   #8
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Quote:
Originally Posted by j8715 View Post
Ok. Someone left a decent old Fuji bicycle in my yard. It must have belonged to shaq or bigfoot or someone because I am 6'2" and its slightly too big of a frame for me.
Here is a pic of Yao Ming's bike for reference.
http://www.gunnarbikes.com/newslette...29-04_ming.jpg
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Old 10-02-10, 04:37 PM   #9
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Exactly what do you mean by "slightly too big"? I've got a Trek mountain frame (Model 3500) that I used for a commuter conversion. It's a big frame, the top tub just rubs my naughty bits. If I used this bike off road, I'd be flirting with disaster, but as a commuter it works fine. I usually do a cowboy mount/dismount in any case. As for your wheel project, it's not worth your time or effort. If you're really uncomfortable riding the bike, sell what you have and look for something that fits. If bike feels good when you're in the saddle, you can always do the cowboy mount/dismount, same as I do with the Trek.

Last edited by Fissile; 10-02-10 at 06:11 PM.
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Old 10-02-10, 05:59 PM   #10
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It's a big frame, the top tub just rubs my naughty bits.
Well, there is "just rub" and there is OUCH. I wonder which version the OP has.
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Old 10-02-10, 06:31 PM   #11
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Changing wheel size to make a frameset 'smaller' is dumb. Seriously, get a proper size frame.
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Old 10-02-10, 08:14 PM   #12
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I wonder how high the bottom bracket is already. I have a 68cm Fuji Royale and the BB is pretty effin high (55mm drop).
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