[Closed] What's the difference between Mavic 321s and 521s?

521 is a little lighter and much stiffer than the 321 (IME from building a pair up)

this should help.
the letters before dictate the use the rim is for.
xc -xc
en - enduro
ex - extreme -dh

the first number is the grade of alu that is used on the rim

3 low
5 higher
7 higher again
8 highest

the last two numbers are the width of the rim
also the 3 series rims are usually pinned as opposed to welded

200

the first number is the grade of alu that is used on the rim

3 low
5 higher
7 higher again
8 highest

3 = pinned
5 = welded
7 = f*** knows, it used to be that 7 was disk and 5 was V's
8 = like 7, but with no holes on the rim so it's tubeless.

The above poster is correct in asserting that the letter codes correlate to the intended use.

The first digit numerical codes refer to the joint, eyeletting and tubelss compataibility (if present) followed by the width:-

XC117 - Pinned, non-eyeletted internal 17mm width
XC317 - Pinned, eyeletted 17mm internal width
XM719 - Welded, eyeletted 19mm internal width
XM819 - Welded, tubeless 19mm internal width

And you need to ensure that you order the correct non disc version if you're running rim brakes.

200

and that's the really great thing about mountain biking isn't it................everyone's included 😆

i belive also that the 321's are only pinned together and the 521's are pinned and welded making them much stronger

i had 321's orginally and bent them on the first outting to Afan

have now got the 721's and had no problems in the year and a half i've had them

buy cheap, buy twice - IMO

obviously not quick enough on my post about the pinned and welded 😀

As a qualified engineer I can confirm 16stone pig is correct

TimP CEng

i have the older d521 the trials/jump/dh rim they were all dased around once upon a time waiting to be laced up when i decide on my rear hub.

Big difference is the 521 is a SUP rim which welded and milled smooth where as the 321 is pinned. If you look at the links the extrusion is different.

[b][url= http://www.chainreactioncycles.com/Models.aspx?ModelID=71049 ]crc 321[/url]

The best value for the money on the Enduro "FR" segment. 28 mm wide, eyeleted and solidly pinned join, EN 321 Disc is the perfect rim to withstand the rigor of light freeriding. Perfectly priced to ride with only the next singletrack in mind.

Features:
• 6106 aluminium alloy
• Pinned
• Traditional drilling
• Single eyelet
• Clincher
• Disc

Dimensions:
• ETRTO compatible size: 559 x 21
• Valve hole diameter: 8.5 mm, supplied with valve adapter
• Recommended nipple length: 12mm
• Recommended rim tape: 559 x 23 x 0.6
• Recommended tyre widths: 2.10 to 2.50
• Weight: Ø 650: 570 grams

[url= http://www.chainreactioncycles.com/Models.aspx?ModelID=71050 ]crc 521[/url]

The reference rim in the enduro segment - new

28 mm wide, SUP welded, eyeleted and made from the finest 6106 alloy, EN 521 Disc is a disc specific rim, especially designed for enduro riding.

Technologies:
• SUP: Soudé Usiné Process. After bending, the rim joint is arc welded. The welded seam is then milled for a smooth finish. A welded and milled rim joint is extremely strong, eliminates shuddering when braking, and offers superior wheel balance.

Features:
• 6106 aluminium alloy
• SUP
• Traditional drilling
• Single eyelet
• Tubetype
• Disc
• Weight: 540 grams

Dimensions:
• ETRTO compatible size: 559 x 21
• Valve hole diameter: 8.5 mm, supplied with valve adapter
• Recommended nipple length: 12 mm
• Recommended rim tape: 559 x 20 x 0.6
• Recommended tyre widths: 2.00 to 2.50