who to convert rim width from metric to imperial

[kalex]

i'm after a 26 x 2.125 rim but the wheels i fancy are only in metric

so how would 2.125" read in metric conversion as i'm sure it's not as simple as 1" = 25.4mm

i've been on sheldonbrown and i'm more fooked than before i looked on there

[MartyC]

What sizes are they in metric?

If they are listed as 700c then dividing the 700 by 25.4 will give you them it in inches = 27.55

[kalex]

What sizes are they in metric?

If they are listed as 700c then dividing the 700 by 25.4 will give you them it in inches = 27.55

It's the rim width I'm after

there 26" rims and I Want as close to 26 x 2.125 as possible but they just say 599/21, which is 26 x ? I presume 21mm but what is 2.125" in rim width as I'm dame sure it's not 2.125" x 25.4 = 54mm wide.

There must be a way to calculate it or a conversion table

[Tel-boy75]

I thought they were two different sizes all together. So a 20 x 1 3/8 rim is actually taller than a 20 x 1.5. Something to do with the measuring techniques, so although they are listed as 20s they are actually different heights.

[Dark Diggler]

26 x 2.125 is a tyre size, not a rim size.
You can run that tyre size on any 26" rim pretty much

As a guide to rim width

21mm rim-cross country, typically 1.75-2.125 tyre
33mm rim-freeride, all mountain, typically 2.125-2.5 tyre
33mm+ rim is downhill and typically 2.5 + tyre.

[kalex]

I'm after doing something different and I'm starting to think that it maybe 2.125" wide

see this link as it is the rim width

http://m.ebay.com/itm/Heavy-Duty-Araya-Wide-Rear-Wheel-26-in-26-x-2-125-Chrome-Rim-for-Freewheel-Bike-/281749633723?nav=SEARCH

[Dark Diggler]

I can see what you mean. These days they don't stamp rims with those dimensions.
If you measure an Araya 20x1.75, it's not 1.75"wide, it's the minimum Tyre width recommended for use. 2.125 is the minimum tyre width recommended for use with that rim (although you could use a 1.75 tyre on that rim, just like you can run a 1.75 tyre on a 1.5 rim.)

[kalex]

I can see what you mean. These days they don't stamp rims with those dimensions.
If you measure an Araya 20x1.75, it's not 1.75"wide, it's the minimum Tyre width recommended for use. 2.125 is the minimum tyre width recommended for use with that rim (although you could use a 1.75 tyre on that rim, just like you can run a 1.75 tyre on a 1.5 rim.)

so what is the actual rim width of say that wheel in the link in mm or even inches as that's what I'm after.

doesn't matter what I type in Google it gives me everything but what I would like to know

[griff]

Si knows all about rimming 

[Dark Diggler]

http://mombat.org/MOMBAT/BikeHistoryPages/Araya.html



It looks like they were all 32.2 wide, apart from the ones stamped 1.5 ( 7XN ) and obviously 1 3/8.

[Dark Diggler]

To add a size comparison, Greg Minnaar won last weeks World Cup series downhill race on 34mm width rims.

[kalex]

http://mombat.org/MOMBAT/BikeHistoryPages/Araya.html



It looks like they were all 32.2 wide, apart from the ones stamped 1.5 ( 7XN ) and obviously 1 3/8.

just to through a spanner in the works, I wonder if the cruiser wheel us different then. It could be because they are USA rims and measured differently. i'm not really sure but look at the description in this ebay link I found late last night. It states the rim is 26 x 2.125 but he gives the actual cross section width as 1.5" which is 38mm


http://m.ebay.com/itm/281749633723

[Dark Diggler]

Really not sure on that one, I'm just going off what found, 38mm seems a bit wide though, especially for an 80's mountain bike wheel which what that ebay add is for (it won't fit a bmx without modifying the spacing and shortening the axle)
The downhill bike pictured is using 2.5 tyres with 34mm rims and you can see how big they look.

[kalex]

Do you ever get that feeling you'd wished you never started and done something simple instead. as I'm starting to think that.

All I can guess is from what Sheldon brown says about simply converting tyre size from inches to mm doesn't actually work as it's because of the way it's measured or something, must also work on old USA stuff against more modern stuff.

think I'll stick to 20" bikes