More rim babble

[johnbryanpeters]

I was thinking about some Mavic 321s, LBS says 3.1s are replacing 321s.

Question - can I run tubes and tube-type tires on these rims designed for tubeless without any ugly failures?

J

[Rev.Chuck]

Yes.

[ohio]

Yes you can run tubes on the D3.1, but you should know in advance that the 321 is both significantly wider and significantly stronger than the D3.1 (and about 70g heavier)

I run the D3.1s and have been perfectly happy with them... but they will not Quite hold up to the abuse that the 321 will, and they'll give you a rounder tire profile.

[johnbryanpeters]

Weight's not an issue; my OEM pinned but not welded rims are getting to end of life.

Not sure how much to listen to LBS; they reduced my faith by claiming that anodizing contributed to strength of rims...

J

[Rustmouse]

hard to believe they'd even try that one...

[Repack]

Originally posted by johnbryanpeters

Not sure how much to listen to LBS; they reduced my faith by claiming that anodizing contributed to strength of rims...

J
It does

[oldfart]

How. I've heard that before but never believed it. Kind of irrelevant as any rim worth having is anodized anyway. But its just a micro thin layer of oxidized aluminum. Colour can be added to the process to make it black or any other colour. There used to be something called hard anodized, at least I heard people refer to that but they weren't able to tell us at the shop what that meant or how it was different.

[johnbryanpeters]

Hard anodizing just reduces the grain size of the Al2O3.

Anodizing has zip for tensile strength compared to the base metal and it's a few mils thick. It provides some degree of protection from corrosion and might resist rim brake wear a tad longer than bare aluminum, but to the strength of the rim it is going to add zip, zero, nada.

J

[SwisSlesS]

Go for the D321s. If you're not running tubeless, and you want the strongest, those seem like the obvious choice to me.

[Repack]

Mavic told me that it does make the rim stronger, but not by much. It hardens the outer portion slightly, making it less suseptable(sp?) to scratches which can leed to cracks. Or something like that.

[ohio]

Originally posted by Repack
Mavic told me that it does make the rim stronger, but not by much. It hardens the outer portion slightly, making it less suseptable(sp?) to scratches which can leed to cracks. Or something like that.

Actually, having the stiff outer layer can cause cracks to propogate, especially around the spoke holes. Most DH rims won't last long enough for that to happen anyway, but anodizing reduces the fatigue life of a part.

For rim brake options, anodizing reduces the friction between pads and rims, so you'll see most modern brake-able rims have the anodizing machined away.

So anodizing rims is basically purely for cosmetics.

[shootr]

it is for cosmetics and to prevent corrosion.
it does not increase the strength,
your LBS personel are probably not trying to deceive you, they are simply misinformed.

[johnbryanpeters]

I didn't think there was any deception, just ignorance, esp. when he started in on how anodizing is baked on - guess he had it confused with powder coat... :rolleyes: