MAVIC Open Pro CD

[Tonyf33]

A shop changing what product they sell in no indicator of material performance, it can be purely down to business. Rigida rims are generally far cheaper than Mavic's and thus with more and more riders wanting handbuilt rims a 30 or even £40 difference between say an open pro and something light in the Rigida range like the 'flyer' it makes sense to a business to not only compete with other shops/factory made wheels but also offer their clients a wheelset that is perceived as value for money. If you had the chance to buy a set of Rigida handbuilt wheels for say £140 or a set of Mavic rimmed wheels (same hubs& spokes) for £180 which would you choose if you were new to the market or indeed a returning customer? Unless you had a particular penchant for one rim or the other most would happily go for the Rigida as they are a well known/respected brand with a good product.
Does that make Mavic rims overpriced, maybe so but the open sport is available for around 20 sovs, I've not used them so couldn't comment on the differential to the OPs

As for the CD coating, I've run coated rims for around 12 years now on various bikes, the one with the longest constant use was an open pro CD on tiagra (front) on the commuter bike. I bought it used (circa 2k on it) and I put another 4/5k on it before I sold it on (as I got a free MA40/Sansin sealed ). it was still in very good condition with bags of life left.
I'm not exactly light, the bike was used in all weathers and being a front took most of the braking, though the coating had worn off by the time I got it I've never had an issue with wet weather braking on any of my wheels CD coated or not. Maybe some people just expect to brake in the same distance as to when it's dry?

I've not tried this particular rim model but if it is like previous mavic CDs then it is more likely to crack, and the brakes don't work properly until the black stuff has worn off the braking surfaces

Given you've said you haven't tried the Open pro CD how can you make comment based on direct first hand experience, where's your evidence to suggest it is more likely to crack than any other rim, i'd be genuinely interested with the results? Is it that one or two people (out of tens of thousands no doubt) have noted that they had a problem, does that not happen at some juncture to manufactured products, are all products made perfect every single time without likelihood of failure. Do we know how/why the failure took place, could it in fact have been human error? We don't know though sharing experiences can help on niche products, a few failures amongst a mass produced item isn't cause for concern IMO.

personally I reckon there's not a huge amount of difference in performance at the level the majority are at, yes there are differing rims for different uses but the question should be if X rim does 90-95% of what Y rim does (even if that is quantifiable) is it worth forking out the extra?
So long as people are happy with what they bought and not feel as if they've been let down by the product in terms of your personal requirements where is the problem?

[531colin]

Wow!
But what would chose over them?

You have to tell us your intended use, and maybe your weight?

Open Pros are fairly light rims in the grand scheme of things. There is at least one regular poster on here who uses Mavics on his best/event wheels, and something cheaper, heavier, and hopefully longer lasting on his everyday wheels. I can't fault that logic.

If you want a rim to be both light and long-lasting, be prepared to seek out and pay for a ceramic coated rim.
Whatever rim you buy, be aware they are made to tolerances.

[JohnW]

.......................If you had the chance to buy a set of Rigida handbuilt wheels for say £140 or a set of Mavic rimmed wheels (same hubs & spokes) for £180 which would you choose if you were .................a returning customer? ?

On the basis of my previous experiences with Mavics - up to say 6 or 7 years ago, I'd have always chosen the Mavics on the basis that experience would have shown that you get what you paid for.

However, later experience has shown how many miles I get for the £, and the cheaper rims may very well be the better value on that basis. For a stiffer, more responsive rim, I'd pay the extra, but for the ridiculous reduction in mileage that I've experienced - never again.

It is usually worth paying moor for better, but there are limits.

[garygkn]

It sounds like I need to tread carefully?
I only want some wheel building done.

[pedalsheep]

I might try Spa or Harry Rowland?

I had a wheel rebuilt by Harry Rowland recently. I posted the hub back to him on Wednesday and the rebuilt wheel arrived the following Tuesday. Excellent service. Incidentally he told me that he would only build with Mavic rims at the moment.

[PhilWhitehurst]

I have these rims in 32 hole built onto my existing hubs. One a Son dynamo Hub. I've put 7,000 miles on them since last year, pot holes, the lot. I've also done lightweight tours with them (i.e. B&b / YHA).

I've found them excellent and able tot ake a lot fo abuse.

[Brucey]

I've not tried this particular rim model but if it is like previous mavic CDs then it is more likely to crack, and the brakes don't work properly until the black stuff has worn off the braking surfaces

Given you've said you haven't tried the Open pro CD how can you make comment based on direct first hand experience, where's your evidence to suggest it is more likely to crack than any other rim, i'd be genuinely interested with the results?

The comment I made was conditional; if it was like previous Mavic CD rims. However, I see little reason to doubt this; they use coatingsthat look the same, have the same name, that (by all accounts) wear off as quickly on the braking surface, applied to the same alloy grades which are just differently shaped from previous models.

As I think you have said, you have not ridden CD rims with an intact coating. I have. In the dry they are OK when new, in the wet they are blinkin' awful (not quite as scary as chrome steel rims in the wet but not far off) with very many brake block types until the coating is gone. Maybe someone knows of a brake block that works OK on these in the wet from the get-go; I didn't find one by accident.

When any rim is built there are localised loads that can cause plastic deformation around the spoke holes. The (mainly Al2O3) surface oxide layer is hard and brittle, and it cracks. If native oxide (on a polished rim) it reforms immediately. However an anodised coating cracks and it cannot reform; the cracks (which are now stress concentrations with a very high SCF anyway) then can become the site for localised anodic attack which can help cracks along at a fine speed. [In essence this concentrated attack is similar to the difference between a passivated surface and one that is likely to suffer pitting corrosion; with some materials in some service conditions the act of polishing the surface (once, when new) can be enough to prevent pitting corrosion for ever.]

On a freshly built CD rim you can often see that the anodizing is very lightly 'milky' looking round the spoke holes, and catches the light differently; this is the effect of microcracking in the anodized coating.

Since mavic helpfully supply the same rims with and without various coatings it is possible to make observations about how likely they are to crack. All can crack, (and indeed there are occasional extrusions where there is a cold lap in them which will fail anyway) but generally polished rims crack least, silver anodised ones are worse, and the dark anodised ones (CD type) seem to crack worst of all. (I suspect that the dark anodising may be thicker than the silver anodising BTW)

The cracking also seems to occur worst on rear wheels; partly because they see more road salt, partly because the spokes see a little more stress. Spoke holes on the drive side crack more than NDS spokes.

The cracks propagate primarily through a combination of corrosion, fatigue, and SCC (stress corrosion cracking). All weather riders suffer worse with it, and those that don't clean their bikes suffer worst of all; the rims can even crack during storage through SCC.

Note that anodised components are very often verboten in applications that demand the highest fatigue performance for similar reasons; once the coating cracks, you are in trouble. On wheel rims simply regularly cleaning and polishing with a wax polish (from new) will certainly slow things up because it will help to inhibit the corrosion in the crack.

I daresay some people will object to what I have written above; to which I'd comment that;

a) one counter example means little

b) the observation re the cracking is one that I have made over many years and over many different mavic rim models. It is also one that has been independently obtained by many others.

c) the explanation is one that not everyone will agree with, in good part because (despite my efforts to make it intelligible) they won't understand the mechanisms and variables involved sufficiently well. Nor I believe do the rim manufacturers, obviously, or else they wouldn't ship things like this out. (There are lots of good books on these subjects out there BTW but they are heavy going and bicycle rims don't feature heavily....)

cheers

[gxaustin]

I think they look nice on disc braked wheels

[JohnW]

Brucey - now that we know that the new 'Open Pro' will not include a 36 hole option in the range, and given my personal caution with respect to single eyelet rims (due to a friend having a disaster with one several years ago), what rim would you recommend to do the job that the 'Open Pro' did until now? - and perhaps give some extra jmoieage enjoyed from their predecessors (in my case Open CD).

[Brucey]

Brucey - now that we know that the new 'Open Pro' will not include a 36 hole option in the range, and given my personal caution with respect to single eyelet rims (due to a friend having a disaster with one several years ago), what rim would you recommend to do the job that the 'Open Pro' did until now? - and perhaps give some extra jmoieage enjoyed from their predecessors (in my case Open CD).

for the present this is a non-issue; they are (I think) carrying on with the old model for now.

In the long term an alternative (different) rim may match some but not all of various attributes;

- weight
- width
- ERD
- braking surface thickness
- braking surface treatment
- eyelet construction
- wear indicator
- tyre fitment quality
- cost
- colour options
- corrosion resistance

and so forth. It may be a question of priorities....

cheers

[JohnW]

Brucey - now that we know that the new 'Open Pro' will not include a 36 hole option in the range, and given my personal caution with respect to single eyelet rims (due to a friend having a disaster with one several years ago), what rim would you recommend to do the job that the 'Open Pro' did until now? - and perhaps give some extra jmoieage enjoyed from their predecessors (in my case Open CD).

for the present this is a non-issue; they are (I think) carrying on with the old model for now.

In the long term an alternative (different) rim may match some but not all of various attributes;

- weight
- width
- ERD
- braking surface thickness
- braking surface treatment
- eyelet construction
- wear indicator
- tyre fitment quality
- cost
- colour options
- corrosion resistance

and so forth. It may be a question of priorities....

cheers

Thanks for taking time and trouble to respond Brucey.........................you "think" that the current model will be available "for now" - ok, but will that end when their current stocks are sold out?

My question remains though - what would your favourite replacement be?

[Brucey]

it depends on what the bike is, and what it is used for. So to give you an idea of my choices

- on my 'sunny day' road bike I use (recent model) open pros. The bike doesn't do that many miles and rarely sees any kind of weather. If I prang one or wear it out I shall fit the same (I think I have a pair stashed away somewhere)

- on my most used bike I have a version of the CXP22 rim fitted. These are heavier, don't match the Open Pro for ERD, and the version I'm using (which has a decent thickness brake track) is..... obsolete . The replacement model rim (CXP Elite) has a thinner brake track so (I expect) won't last any longer than an Open Pro does. They are cheaper than Open Pro though, and they are available in 28, 32, 36 drilling. They weigh about 500g, i.e. the weight of the brake track lighter than the older CXP22 rim, for some reason.....

- On a chum's bike I recently kitted it out with H plus Son Archetypes; these accept wider tyres than an Open Pro, are heavier (actual weight about 495g), have a different ERD and also have a decent thickness brake track. I think they are very strong indeed; in view of the fact that he mostly uses that bike for winter training but occasionally uses it for summer touring too (with a rear load), I built them 32F, 36R. Overall I think it is a good combination for 'bombproof but lightweight' compromise. If they were half the price they would be a clear winner; I think there may be a Kinlin rim that is similar but is pin-jointed and much cheaper.

- On a 'beater' bike I'm using twinwall no-eyelet pin-jointed 36h rims that are ~23mm wide or something. These rims weigh ~520g and seem to be strong enough for everything up to lightly-loaded touring. I'd say they are 'no-name' but some of them are branded 'accedo' or something. Think 'cheap but disposable'.

You might well wonder what the attraction is of the 'accedo' rims; the answer is simple- they cost me nothing!! These rims appear in all kinds of cheap wheels that are so badly made that they invariably fall apart with multiple spoke breakages before the rims are likely to wear or get broken. I have salvaged at least half a dozen of these rims. Although they have no eyelets, and a relatively thin wall where the drillings are, so might perhaps crack (which I have not yet seen BTW), I have figured out a way of reinforcing them internally so that (say) the DS rear spokes can be made proof against cracking.

These rims also have the attraction of being ~600mm ERD which means that they are easily substituted for lots of other (stronger) rims should the need ever arise. They accept tyres from ~25mm up to ~35mm without difficulty. They usually wear through to an internal channel when the brake track thins out. I wondered how safe the rim is when it is worn like this so I built a hub brake wheel up with a worn rim and have used it for a couple of years on a carrier bike, (at the loaded end). No problems so far.

However AFAICT (maybe someone knows different?) there isn't a rim that is an exact match for weight and ERD vs an Open Pro; there are rims that are close in ERD (and might work if the spoke length was not quite right to start with), but not exact. Exal do a rim that is close (but has a larger ERD IIRC) and the Rigida/Ryde Chrina is also not far away. Both these rims are inexpensive but also have a few problems; the Chrina won't always take a high spoke tension (and has been variable in size at times) and the Exal rims (also having misleading published ERD values) can be right sods to get tyres on and off of.

I don't know if this helps or hinders BTW....

cheers

[mig]

an ambrosio excellight isnt too far off an open pro or weight and ERD.

not cheap though!