# 27 inch vs 700 wheels..are they interchangeble?



## oldbikes (Jul 7, 2003)

on some bikes or are they totally never interchangeble, all my bikes have 700c wheels and I am looking at buying a fixie for winter riding but I pause at having to stock two sizes of tires.
I've heard that they are interchangeable except for the reach of the brakes ( longer brakes needed to fit 700 wheels on 27" tire equipped frame..thanks..


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## supercorsa (Apr 23, 2002)

totally dependent on the frame. a good micrometer is your friend here. put one wheelset in, measure from the bolt hole to the center of the rim, do this for both wheels. now do the same for the other wheelset. now you'll know what reach brakes you'll need, and if one set will accomodate both wheel sizes. sometimes you get lucky, sometimes you don't. you just never know until you mic everything out.

good luck.


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## curlybike (Jan 23, 2002)

*Something definite*



oldbikes said:


> on some bikes or are they totally never interchangeble, all my bikes have 700c wheels and I am looking at buying a fixie for winter riding but I pause at having to stock two sizes of tires.
> I've heard that they are interchangeable except for the reach of the brakes ( longer brakes needed to fit 700 wheels on 27" tire equipped frame..thanks..


There is 4 mm difference in brake reach, and many frames do not have the clearance for the bigger tires which usually have a taller section also.


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## dnoyeB (Jul 11, 2008)

I am about to put some 700s on my Spalding Blade. There is at least 1/2" clearance above the tire. I'm sure I can get a brake to work. Question is, 1/4" is going to the 700 rims, how much will the metric tires take?


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## Dave_Stohler (Jan 22, 2004)

I know a lot of people try to fit 700's on a 27" bike, but never the other way around. 27" has been obsolete for almost 20 years now, and selection is becoming limited.


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## JCavilia (Sep 12, 2005)

*Not sure I understand your question*



dnoyeB said:


> I am about to put some 700s on my Spalding Blade. There is at least 1/2" clearance above the tire. I'm sure I can get a brake to work. Question is, 1/4" is going to the 700 rims, how much will the metric tires take?


If you''re saying that there's plenty of clearance now with 27" tires, and asking whether you'll have clearance with 700c, the answer is almost certainly yes, unless you put some giant fat tires on it. If you had room with 27x 1 1/8 tires, you'll have even more with 700cx23, or even 25 or 28.


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## miller_2727 (May 19, 2007)

*27" to 700c*

This may be a very amateur post/question, but I am looking to install an extra set of 700c wheels on an old beater frame (70s Raleigh) that I use for grocery getting. (Reason is the bike is a tad too big and the change in wheel size will/should be perfect and I will trust the newer wheels a lot more..)

The problem I have encountered is fitting the front wheel between the fork....Do I need to remove the entire hub to get the extra space or just the nipple fitting on the outside of the wheel? Or, alter the fork?
As for the rear, I am assuming it will fit fine...just add or subtract spacers that are on the single speed conversation currently.

(The first pic is the 'rubber nipple' I referenced on the 700c wheel and the second pic is the 27" wheel mounted in the fork)

Thanks for any input.


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## rdolson (Sep 2, 2003)

I'm thinking you have a 96mm spaced fork, which was, while not common, sometimes found on bikes of that vintage. Here's a Sheldon Brown linky that will let you know what I'm talkin about. 

Also, with a steel frame, it is sometimes possible to "cold set" the spacing to a modern standard. You'll see a link on the SB page for that as well


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## JCavilia (Sep 12, 2005)

A few points:

- I'm not sure what you mean by needing extra space at the fork. The spacing between the dropouts should be the same for a newer wheel (that 96mm spacing is very rare), so if it's tight your fork has probably been bent. I'd inspect it for damage, but if it looks okay I'd say just spring the fork open enough to fit the axle in. If the alignment is alright it should work.

-are you sure you've got enough brake reach adjustment to reach the rims? That's oftern the problem when making this switch.

-I don't know what you mean about switching to get a better fit. The 700c wheels are smaller, but only by a tiny amount, and fit won't be altered significantly. 

-on the rear wheel, you can move spacers around, but if you do it properly to get good chain alignment you may end up with an off-center rim, and you'll have to re-dish. Not a big deal, but another chore.

-bottom line may be that this is more trouble than it's worth. the fit change is illusory, and if the issue is "trusting" the wheels, there may be nothing wrong with the old ones, especially for a grocery-getter/beater. Unless there is apparent damage to the old wheels, I'd probably just keep using them, personally.


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## miller_2727 (May 19, 2007)

*Thanks*

Thank you both for the input. After reading/reviewing options, I think I will just keep it as is.......no reason to put time and $ into something that only travels 3-6miles/week.

Have a good one


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