Rim question



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none

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I just converted an old road bike into a single speed commuter and I am thinking about replacing the
rims (they are old and warped). I'm not sure what size the current rims are, but the label on the
treads read 700x38c. Does this mean I can replace the rims with any 700c rim? Are all 700c rims the
same width? Secondly, what about hub length, are all road bike hubs the same length? The bike still
has the six cog casette on the rear rim (yeah it looks goofy on a SS but it works). Does this mean I
must replace it with a rim containing a six speed casette?

Thanks, Curt
 
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S. Anderson

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<[email protected]> wrote in message news:[email protected]...
> I just converted an old road bike into a single speed commuter and I am thinking about replacing
> the rims (they are old and warped). I'm not sure what size the current rims are, but the label on
> the treads read 700x38c. Does this mean I can replace the rims with any 700c rim? Are all 700c
> rims the same width?

Not all 700c rims are the same width, but they are all 700c in diameter. If you want to continue
using 38c tires, you should look at some of the wider, touring or hybrid style rims. You'll see
they're marked in slightly wider widths that the more narrow racing style rims. If you intend to
use the same spokes, you'll want to choose a rim with the same ERD so that the spokes will be
the correct length. (they don't have to be identical, but they do have to be pretty close,
within 2mm or so)

> Secondly, what about hub length, are all road bike hubs the same length? The bike still has the
> six cog casette on the rear rim (yeah it looks goofy on a SS but it works). Does this mean I must
> replace it with a rim containing a six speed casette?

The hub spacing is different depending on how many cogs you have on there. You probably have the
older 6sp 126mm (?? I'm guessing there..) spacing. Newer bikes have 130mm spacing to accomodate 8sp
cassettes. You either have to stick with a 6sp spaced hub or spread the frame. This frame spreading
SHOULD be done by a frame builder because when you spread it, the dropouts are no longer parallel
and should be straightenend. Overall, if you can live with the 6sp, that might be the best thing.

>
> Thanks, Curt

Cheers,

Scott..
 
Q

Qui Si Parla Ca

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none-<< I am thinking about replacing the rims (they are old and warped). I'm not sure what size the
current rims are, but the label on the treads read 700x38c. Does this mean I can replace the rims
with any 700c rim? Are all 700c rims the same width?

yes, any 700 'rim' but becareful about hub choice(the best thing is to re-uese the hubs, if they are
okay) and no, rims are not the same width altho most will accept fat tires w/o problem.

<< Does this mean I must replace it with a rim containing a six speed casette?

No, either re-use the hub or get a freewheel hub to use, for single spped

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"
 
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Sheldon Brown

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A shy person wrote:
> I just converted an old road bike into a single speed commuter and I am thinking about
> replacing the rims (they are old and warped). I'm not sure what size the current rims are,
> but the label on the treads read 700x38c. Does this mean I can replace the rims with any
> 700c rim? Are all 700c rims the same width?

They're all the same diameter, but come in a range of widths. The really wide ones aren't generally
a good choice for a "road" bike.

> Secondly, what about hub length, are all road bike hubs the same length?

No.

> The bike still has the six cog casette on the rear rim (yeah it looks goofy on a SS but it works).
> Does this mean I must replace it with a rim containing a six speed casette?

The rim has nothing to do with the cassette, but you will want to get a hub set up for the same
width as your frame, most likely 126 mm.

See my articles:

http://sheldonbrown.com/frame-spacing.html

and: http://sheldonbrown.com/chainline

and: http://sheldonbrown.com/fixed

Sheldon "Fix It!" Brown +-------------------------------------------------------------+
| I still feel that variable gears are only for people over | forty-five. Isn't it better to
| triumph by the strength | of your muscles than by the artifice of a derailleur? | We are getting
| soft...As for me, give me a fixed gear! | --Henri Desgrange, _L'Equipe_ article of 1902 |
+-------------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
shipped Worldwide http://captainbike.com http://sheldonbrown.com
 
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David L. Johnso

Guest
On Sat, 07 Jun 2003 10:57:52 +0000, non wrote:

> I just converted an old road bike into a single speed commuter and I am thinking about
> replacing the rims (they are old and warped). I'm not sure what size the current rims are,
> but the label on the treads read 700x38c. Does this mean I can replace the rims with any
> 700c rim? Are all 700c rims the same width?

Well, no, they aren't all the same width. A wide rim, such as a touring rim or one meant for
tandems, will work better with those really big tires.

> Secondly, what about hub length, are all road bike hubs the same length?

Again, no. All recent ones will be 130mm, but they have been getting wider, very slowly, over the
years. Bikes from 1990 or earlier will probably have 126mm dropouts, and really old road bikes have
120. Touring bikes now will often come with 135mm, which is standard on mountain bikes. Tandems use
even wider hubs, some as wide as 160mm.

The bike still has the six cog casette on the rear rim
> (yeah it looks goofy on a SS but it works). Does this mean I must replace it with a rim containing
> a six speed casette?

No. that will probably be a 126mm spacing. It's easy to modify a track hub to fit, and you can
convert a freewheel-type hub (many are 126) to single speed easily. There are even conversion kits
for your cassette hub, but it may be hard to find.
--

David L. Johnson

__o | To announce that there must be no criticism of the president, or _`\(,_ | that we are to
stand by the president right or wrong, is not (_)/ (_) | only unpatriotic and servile, but is
morally treasonable to the American public. --Theodore Roosevelt
 
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