Rims with decent braking surface thickness?

[Sweep]

Question for folks on the CXP22 sub topic.

If you come across rims branded just CXP22 rather than CXP22 Elite, does that mean they have the reassuringly old fashioned depth of rim metal?

[Brucey]

no such thing as CXP22 elite, was CXP22, now 'CXP elite' is the current model.

There were several versions of the CXP22; some made in Europe, some in Taiwan, some with eyelets some without, some called CXP22S. They may have varied but IME none had the guts machined out them like the examples of the new CXP elite that I have seen.

FWIW I have recently found an Archetype with rim wall thickness of ~1.2mm when new. Now goes on my 'sometimes crap' list.

cheers

[Samuel D]

The last Mavic Open Elite, 32-hole, silver rim I built up weighed 449.9 g on my calibrated balance. That’s by far the lightest I’ve seen. The walls were down to about 1.3 mm in places. Additionally the valve hole wasn’t drilled all the way through so I couldn’t fit a tube before taking a drill to it. I know it’s a cheap rim but that didn’t impress me.

[Sweep]

no such thing as CXP22 elite, was CXP22, now 'CXP elite' is the current model.

There were several versions of the CXP22; some made in Europe, some in Taiwan, some with eyelets some without, some called CXP22S. They may have varied but IME none had the guts machined out them like the examples of the new CXP elite that I have seen.

FWIW I have recently found an Archetype with rim wall thickness of ~1.2mm when new. Now goes on my 'sometimes crap' list.

cheers

Thanks brucey for the branding clarification.

[Brucey]

The last Mavic Open Elite, 32-hole, silver rim I built up weighed 449.9 g on my calibrated balance. That’s by far the lightest I’ve seen. The walls were down to about 1.3 mm in places. Additionally the valve hole wasn’t drilled all the way through so I couldn’t fit a tube before taking a drill to it. I know it’s a cheap rim but that didn’t impress me.

Open elite is the replacement for the Open Sport which in turn was the replacement for the MA3; all share a similar extrusion design and ERD value. BITD when they didn't machine them so much these rims weighed nearly 500g.

"Interesting" measurements; obviously this is a training rim and you would have to be bonkers barmy not to want another 30-40g of braking surface on the rim.

I have a feeling that Mavic have these rims produced in a different factory now (what does it say on the label?), and that they can't be bothered to make the rims straight before machining the braking surfaces. The result is that they don't 'clean up' without a lot being machined off and what remains is of very variable wall thickness. Honestly, you couldn't do a better job of sabotaging rim production if you tried.

cheers

[Samuel D]

Open elite is the replacement for the Open Sport which in turn was the replacement for the MA3; all share a similar extrusion design and ERD value. BITD when they didn't machine them so much these rims weighed nearly 500g.

Right. And even the machined Open Elite is specified by Mavic to weigh 490 g. Knocking 40 g off that must mostly come from the excessively machined brake tracks.

I have a feeling that Mavic have these rims produced in a different factory now (what does it say on the label?)

Made in Romania. I’ve seen the state of the art Continental factory in Timișoara so I know that label need not mean what some people in the west believe from the communist legacy, but this rim was terribly made. There were burrs everywhere (but so are there are on French made Open Pros at twice the price), the valve hole was about 4 mm wide because the drill bit hadn’t completed its descent, and then there was the overly machined walls. Not cool.

[axel_knutt]

Does anyone know the thickness of a Mavic A719?

Between 1.5-1.75mm.
The rim wear indicators (when they had them) used to appear at between 1.1-1.25mm.

I get about 20,000 miles out of them with very abrasive Shimano M-55/T blocks.

[flemingcool]

Just wondering if any consensus was reached about this. Currently looking to build up a set of wheels for a”vintage” mountain bike. But am struggling to find much information about what would constitute a good set of rims. I was looking at the Kinlin XM-25T and XM-250, but some of the thoughts early in this thread aren’t too positive. Any recommendations?

[roger72]

I have been using Mavic open pro rims on my three bikes for about 12 to 15years and they are nowhere near worn out. Also I am using tyres (23- 700,s) some of which are 8 years old. Admittedly I do not cycle in the bad weather ( to cold).I run, it is warmer.

[NickJP]

Somewhere I have a pair of Mavic Module 3 rims from BITD. These rims weigh about 520g , are 22mm wide and have brake tracks about 2mm thickness. C'mon Mavic, you know you can do it......stop foisting your current crap on us!!!

Yes, I still have unused MA2 and Module 3 rims to build into wheels when needed. When Mavic replaced those models with whatever model replaced them (can't remember what it was), I didn't think much of the replacements, and went round the better local bike shops and bought several pairs of the older model rims.

Velocity still offer some of their rim-brake rims with unmachined sidewalls, and Grand Bois sell nice unmachined rims as well.

[Pebble]

I don't think rims last long at all, esp the rear, couple of winters, and for me with my vintage bike '126 OLD' I have to rebuild the rear wheel as they are not available off the shelf.
I use the Mavic 119 rim, I keep buying the same one as I know it will fit my hub and spokes, but could there be a better rim to use ?

long decents on potentialy icy roads where I don't want to go above 10 mph or use the front brake are disastrous on rear rims, you can hear them grinding away the whole way down

Have recently just replaced this one, started to crack in the usual place, they always go here, any thoughts why ?
I always end up replacing them because of cracking rather than becoming too thin and exploding

[Brucey]

if you say what hub and spokes you have, maybe someone can suggest a rim of suitable ERD.

FWIW the wear indicators on your failed rim appear to have worn away, so maybe you had your money's worth. I have seen a rim crack just there before, but the extrusion was different, so this part of the rim saw the full spoke tension rather than just part of it. The fact that your crack appears to have opened up may signify that the rim is rather warm during your normal braking.

You can very greatly reduce rim wear in planned braking by using an improved strategy. If you first apply the brakes lightly, then release them, several times,until the noise goes away, this cleans most if the crap off the rims. Also, you can fit 'wipers' to brake blocks to make sure the rim is kept free of debris during sustained braking.

IME brake block grooves make a big difference to rim cleaning. to the point that I have added/modified grooves in brake blocks in order to improve cleaning. If you want the ultimate groove, you should cut them at a compound angle, such that debris in the grooves is then ejected forwards and outwards. If the angle is compounded such that an acute angle is presented to the rim by the brake block, this will also help with water clearance. A further refinement is to make the grooves tapered,so that they appear to be widening to any debris being ejected from the groove. This, I think, makes them much less prone to clogging. You won't find such grooves in commercial brake blocks, mainly because it makes it slightly more difficult to remove the brake block from the mould.

[NickJP]

I don't think rims last long at all, esp the rear, couple of winters, and for me with my vintage bike '126 OLD' I have to rebuild the rear wheel as they are not available off the shelf.
I use the Mavic 119 rim, I keep buying the same one as I know it will fit my hub and spokes, but could there be a better rim to use ?

According to Damon Rinard's Spocalc spreadsheet, the ERD of the 119 rim is 604mm. Look for something with the same ERD within a millimetre or so.

[Brucey]

......
According to Damon Rinard's Spocalc spreadsheet, the ERD of the 119 rim is 604mm........

and according to another online spoke calculator, the ERD for Mavic A119 is either 604mm or 607mm,depending on who measured it. And therein lies the problem; we don't know for sure what the average ERD of any rim is, and we don't know exactly how long the spokes are either. So if the rim is really 607mm and the spokes are a touch long then any rim 607mm to 613mm might be OK. On the other hand if the ERD is really 604mm and the spokes are a touch short then any rim ERD between 598 and 604mm could work. This means the total possible range goes from 598 to 613mm ERD, which is most shallowish 700C rims in fact.
Which is why I think we need to know how long the spokes really are. Like the WHO said, 'we won't be fooled again'.

[Pebble]

if you say what hub and spokes you have, maybe someone can suggest a rim of suitable ERD.

FWIW the wear indicators on your failed rim appear to have worn away, so maybe you had your money's worth. I have seen a rim crack just there before, but the extrusion was different, so this part of the rim saw the full spoke tension rather than just part of it. The fact that your crack appears to have opened up may signify that the rim is rather warm during your normal braking.

Could my spoke tension of been too tight ?


But on a bit of digging,
viewtopic.php?p=1492682#p1492682
may be this rim has done a lot better than i thought, can't belivev this was nearly 4 Years ago ! (where does the time go) This rim has done 3½ winters! and a whopping 24,600 mile. WOW, and I built it.

As for the open crack in the image above, I did make this worse by nipping it with a pair of pliers to see if the crack went all the way through (and it does)

I have used a A119 on the wheel I have replaced it with, and I think I will just buy another A119 for the wheel in the picture, and this can be my spare wheel.


So these two rims should see me out, don't think theres is another 25 K in me, let alone 50k (thats twice round the planet)