Corima Viva on Record hubs?

BenderRodriguez

Hi folks,

I am looking to build up some tubular wheels on a pair 32 hole Record hubs that I have. These will be my 'big event' wheels, used primarilly for Alpine sportives, so reliability and the ability to maintain them on the road are important. This means wheels with enough spokes to remain rideable if one goes, with external nipples in case a quick tweak with a spoke key is necessary.

Thing is, the choice of high spoke count tubular rims is limited these days, whilst 'old school' Mavic Reflexes and so forth are neither particularly light, aero, stiff or strong. (And require tensioning beyond their design limits on the drive side when used with Campagnolo hubs if the non-drive side spoke are not to have all the tension of a plate of spaghetti, not that this has ever caused me any problems.) Conversely, performance-orientated tubular wheels tend to be low spoke count deep jobs like Boras and so forth.

One option I have is to order a custom pair of Corima Viva rims. These are 32 x 22.6 mm, weigh 290g, and seem to be better than many when it comes to quality, braking performance and so forth. Corima can also supply these with external nipples and a 32 hole drilling at around £300 per rim, so not cheap but not stupidly expensive either and it would be much cheaper to replace a damaged rim than on something like a Bora. Of course, there are some Chinese suppliers that will provide 32 hole mid-section carbon rims, but their QC often seems to be lacking and for few hundred extra the Corima option seems to make a lot of sense.

I know these wheels will be rather over-spoked but am looking to use Sapim CX-rays, other than on the rear drive side, to compensate for this a little.

So, what is the consensus on the above build? A good compromise between weight, performance and reliability, or is there something I am over-looking?

I guess I could use the hubs for something else and for the same cost just buy a pair of Shamal Ultra's, but I can't help feeling that the above build would be superior for my needs and that if a spoke were to go on the Shamal I would probably be be stuffed, especially given that the lateral clearances on my frame are quite tight.

cycleclinic

1) I build a lot with record hubs a lot and with 1200 newtons drive side the non drive tension is high enough for a stable wheel.
2) rims I would recomend are kinlin tb25, velocity escape and the ambrosio nemesis.
3) there are far eastern suppliers of carbon rims that have excellent qc and do custom drillings but if you do not know which are the one to use like I do then you are best stickinv with corima for carbon if you want to source your self which it seem you do
4) you can have 32 spoke wheels that perform well. Record on velocity escapes would be light for example.
5) if you use the kinlin rims you can have 24h/28h but dfferent hubs will have to be used, I can think of a few.

BenderRodriguez

thecycleclinic wrote:

I build a lot with record hubs a lot and with 1200 newtons drive side the non drive tension is high enough for a stable wheel.

I would concur and I also use around 1200 newtons on the rear drive side. Thing is, aren't the Mavics officially limited to 900 newtons? From the Mavic Technical Manual:

Respect the appropriate spoke tensions. Mavic recommends spoke tensions between 70 and 90 kg (for a front or rear wheel, on the drive side with crossed 3 lacing). Inappropriate spoke tension can generate too much stress and damage the rim

thecycleclinic wrote:

there are far eastern suppliers of carbon rims that have excellent qc and do custom drillings but if you do not know which are the one to use like I do...

Not wedded to Corima, but I would really like to know which other carbon rim suppliers you would recommend who will supply custom drillings!

ugo.santalucia

BenderRodriguez wrote:

thecycleclinic wrote:

I build a lot with record hubs a lot and with 1200 newtons drive side the non drive tension is high enough for a stable wheel.

I would concur and I also use around 1200 newtons on the rear drive side. Thing is, aren't the Mavics officially limited to 900 newtons? From the Mavic Technical Manual:

Respect the appropriate spoke tensions. Mavic recommends spoke tensions between 70 and 90 kg (for a front or rear wheel, on the drive side with crossed 3 lacing). Inappropriate spoke tension can generate too much stress and damage the rim

thecycleclinic wrote:

there are far eastern suppliers of carbon rims that have excellent qc and do custom drillings but if you do not know which are the one to use like I do...

Not wedded to Corima, but I would really like to know which other carbon rim suppliers you would recommend who will supply custom drillings!

Mavic talk a lot of cobblers... bit like when they say that their SLR wheels have no reported issues. Load all the tension you want on a Mavic double eyeletted rim. Single eyeletted rims you have to be careful with (Dt 415, Kinlin 200) or box type rims with no eyelets.
Why do you want carbon rims and 32 spokes? Is this one of those attempts to get the best of both worlds? As one could flip the coin and also say that you are seeking the worst of both worlds... (crap aerodynamics and bad braking)

on-yer-bike

What number on my blue Park tension meter is 1200Nm using 1.5 mm spokes?

ugo.santalucia

on-yer-bike wrote:

What number on my blue Park tension meter is 1200Nm using 1.5 mm spokes?

Don't you have the conversion chart?

BenderRodriguez

ugo.santalucia wrote:

Why do you want carbon rims and 32 spokes?

As I said, I have the hubs and would like to use them. I particularly like the way Record hubs can be set up to take account of the compression force exerted by the QR levers. Also:

BenderRodriguez wrote:

These will be my 'big event' wheels, used primarilly for Alpine sportives, so reliability and the ability to maintain them on the road are important. This means wheels with enough spokes to remain rideable if one goes, with external nipples in case a quick tweak with a spoke key is necessary.

And:

BenderRodriguez wrote:

the choice of high spoke count tubular rims is limited these days, whilst 'old school' Mavic Reflexes and so forth are neither particularly light, aero, stiff or strong.

Also, there are plenty of reports around of Mavic Reflex rims cracking on the rear drive side under relative moderate build tensions.

ugo.santalucia wrote:

one could flip the coin and also say that you are seeking the worst of both worlds... (crap aerodynamics and bad braking)

I just thought that a mid-height carbon rim would produce a wheel that was lighter, stronger, stiffer and more aero that something like a Nemesis. Would a few extra X-ray spokes really result in 'Crap aerodynamics'? I had thought that all this 'minimal spoking' thing was largely a matter of marketing guff and looks.

If the advantage to be had from modern carbon rims is really all just marketing I would be happy to save some cash and use something like Nemesis rims!

Alternatively, just how reliable are the alloy spokes in the Shamal Ultra and would Shamals really offer much of a performance advantage over a pair of Record hubs laced with X-Ray spokes to a Nemesis rim?

Cheshire Cat

I can't comment on the Record hubs with the Sapim spokes and Nemesis rim, but I can say that the Shamals are an excellent pair of wheel, after approx 5k miles on some of the Lake Districts worst roads, they have proven to be a reliable pair of wheels. No issues at all with mine; I picked up a pair of the 2013 model wheels and have just ordered a pair of the 2014 wheels for my new build. You won't be disappointed with a pair.

BenderRodriguez

Cheshire Cat wrote:

I can say that the Shamals are an excellent pair of wheel

I am sure they they are good to ride on, having at least Record quality hubs, and it would be great if aftermarket alloy rims were available that incorporate some of the technology the Shamal uses, such as having a thicker spoke bed around the spokes that is machined elsewhere. Thing is if a spoke did go I am sure the wheel would be unrideable, given the high tension and low number of spokes.

I have also been burnt in the past when using factory wheels (original Campagnolo Neutron and Shamals) by the unavailability of parts after a few years, or at best the uneconomic repair cost.

BenderRodriguez

P.s. Until thecycleclinic passes this way again, does anyone else know which are the best quality Chinese / Taiwanese rims that can be bought in a custom drilling and where to get them?

ugo.santalucia

And we have discussed tubulars only because they are safer coming down the alps?

HED sell their ever popular Belgium C2 rims also as tubulars, if you want to add something posh to the list... while if you want to consider clincher or tubeless, the newer Stan's 340 have pretty much resolved the issues of the pre 2012 series by adding a bit of weight, not a lot, they're still lighter than most rims around.
I have just built a set of non machined ones for myself... I'm pretty sure a 32 H build with CX ray will come under 1500 grams with the machined ones

http://paolocoppo.drupalgardens.com/con ... tmas-build

Now the question is whether tubeless is a safe technology when it comes to long Alpine descents... to which I don't have an answer...

ugo.santalucia

BenderRodriguez wrote:

P.s. Until thecycleclinic passes this way again, does anyone else know which are the best quality Chinese / Taiwanese rims that can be bought in a custom drilling and where to get them?

Unless you have disc brakes, DON'T... Alpine descents and cheap Chinese rims are not a good combination. The overheating issue is only one issue... even if you have tubulars, the rim can overheat and the resin delaminate. If you want carbon rims for the Alps, get some good ones (Reynolds, Enve to name a few)

BenderRodriguez

ugo.santalucia wrote:

And we have discussed tubulars only because they are safer coming down the alps?

The reason I want tubs is because I am convinced that they roll faster than pressures, given the right tyre. I know that some tests show something like a GP4000s to roll as fast as a tub, but these tests typically use a test rig with a smooth roller, and so don't show the advantages to be gained from a really flexible tubular such as a Corsa CX fitted with a super-thin latex tube when used on a typically rough road surface. I know that some might say use an 'open' Vittoria CX, but without the thin latex tube of the tubular a lot of the advantage is lost, and I have never found latex tubes to be reliable in pressures.

On my track bike (which is used on a indoor velodrome) I recently upgraded from Continental Sprinters to Vittoria Pista Evos and the difference is like night and day, with better grip, feel, responsiveness a perhaps 1 km/hr extra speed.

BenderRodriguez

ugo.santalucia wrote:

Unless you have disc brakes, DON'T... Alpine descents and cheap Chinese rims are not a good combination.

Yes, that was one concern of mine, and is why I was considering the Corimas.

Perhaps I should stop worrying about what rims to buy and just get some alloy ones, given that the biggest advantage is likely to come from the tyres (and to a lesser degree the hubs) I use.

ugo.santalucia

BenderRodriguez wrote:

ugo.santalucia wrote:

Unless you have disc brakes, DON'T... Alpine descents and cheap Chinese rims are not a good combination.

Yes, that was one concern of mine, and is why I was considering the Corimas.

Perhaps I should stop worrying about what rims to buy and just get some alloy ones, given that the biggest advantage is likely to come from the tyres (and to a lesser degree the hubs) I use.

Yeah, there is not much choice among tubular alloy rims, but they are all pretty good.

BenderRodriguez

ugo.santalucia wrote:

HED sell their ever popular Belgium C2 rims also as tubulars

An interesting suggestion. Would I have to order these directly from the US, or are they available in the UK / Europe?

P.s. Are these officially discontinued? I can't seem to find any mention of them on HED's site?

ugo.santalucia

BenderRodriguez wrote:

ugo.santalucia wrote:

HED sell their ever popular Belgium C2 rims also as tubulars

An interesting suggestion. Would I have to order these directly from the US, or are they available in the UK / Europe?

P.s. Are these officially discontinued? I can't seem to find any mention of them on HED's site?

You have to give a call to HED UK...they are based in Sheffield, you can find the details on the HED website. Don't Email them, call them, as IME they don't answer emails
Otherwise yes, USA import... when you add the import duties it works how roughly the same cost, maybe a few quid less
Best to call HED UK though, they are very helpful and might give you advice if that's any good for you... wide tubulars can be a problem with narrow tyres

BenderRodriguez

ugo.santalucia wrote:

You have to give a call to HED UK...they are based in Sheffield, you can find the details on the HED website... wide tubulars can be a problem with narrow tyres

So, even if they are available, they might be more suited to cross rather than road tyres in any case. Either way, perhaps the choice boils down to the Mavic Reflex or Ambrosio Chrono (both of which have lots of reports of them being fragile, cracking around the spoke holes on the drive side) or the more heavyweight Ambrosio Nemesis. Not a lot of choice really!

The other alternative is a carbon rim, which is sort of where I came in.

ugo.santalucia

BenderRodriguez wrote:

ugo.santalucia wrote:

You have to give a call to HED UK...they are based in Sheffield, you can find the details on the HED website... wide tubulars can be a problem with narrow tyres

So, even if they are available, they might be more suited to cross rather than road tyres in any case. Either way, perhaps the choice boils down to the Mavic Reflex or Ambrosio Chrono (both of which have lots of reports of them being fragile, cracking around the spoke holes on the drive side) or the more heavyweight Ambrosio Nemesis. Not a lot of choice really!

The other alternative is a carbon rim, which is sort of where I came in.

Yeah, what is left of the alloy tubular market is more cross oriented... Crono do crack if you build them with good tension, never had or tried Reflex... Nemesis are great rims and currently discounted from Planet X... I use them when I ride in Italy... they are really good descenders, the braking is powerful... you can build them at 1.6 Kg easily with CX ray spokes... they are in many ways the best road rims and the best looking too... 8)

cycleclinic

Kinlin TB-25 is a good alloy rim. HED UK really do not want to sell rims. I have bought of them before there trade price is crap and the rim availability is not always goos as they say they sell wheels not rims. It is difficult to get a striaght answer about what they have. They could not even tell how much I would be charged for a pair of rims, It just had to wait and see.

I personally would take my chinese carbon rims down an alp as the problems people report are mostly due I am sure to poor braking technique and over inflated tyres (as you brake the pressure will go up may double). Or maybe the road is too busy or the rider is 100kg meaning alot more braking effort is required. A lightish rider who brakes well should minimise the risk of problems considerably if the tyres are inflated to 80 psi to begin with. Also few people report issues with tubular rim as the issue mainly is clincher tyres lowing off.

The whole point of carbon rims is to use lower spoke counts and a deeper rim for the aero benefits. You get none of that with a shloow 32H carbon rim so what is the benefit exactly, saving 100g hardly worth it in my opinion.
For a 32 spoke wheel use an alloy rim like the Ambrosio Nemesis, Kinlin TB25 (~430g 25m deep) or Velocity Escape (the Escape is under 400g).

All are alot cheaper than carbon rim and alot cheaper than HED products. HED rim are nice but I am not convinced they worth the extra premium you pay as you still end up with a round even tensioned wheel with the other three rims I have mentioned.

ugo.santalucia

thecycleclinic wrote:

I personally would take my chinese carbon rims down an alp as the problems people report are mostly due I am sure to poor braking technique and over inflated tyres (as you brake the pressure will go up may double). Or maybe the road is too busy or the rider is 100kg meaning alot more braking effort is required. A lightish rider who brakes well should minimise the risk of problems considerably if the tyres are inflated to 80 psi to begin with. Also few people report issues with tubular rim as the issue mainly is clincher tyres lowing off.

Go aheadm I will not, I'll take my Nemesis instead... 8)

thecycleclinic wrote:

All are alot cheaper than carbon rim and alot cheaper than HED products. HED rim are nice but I am not convinced they worth the extra premium you pay

Of course they are, like the vast majority of bike related stuff on the market... they have the best stickers around, you have to give them that... look at the Pacenti instead, you pay premium for some crap stickers!

BenderRodriguez

OK folks, following your advice I have ordered a pair of Nemesis rims. One advantage is that I will happy about using these in the wet, not just because of braking performance but also because I don't think I could bear to see an expensive pair of carbon rims being slowly ground away by a slurry of road grit.

One final question. X-Rays all round, or should I use normal butted on the rear drive side? I weight 75 kg and at OBLA put out around 300 watts.

Thanks!

ugo.santalucia

BenderRodriguez wrote:

OK folks, following your advice I have ordered a pair of Nemesis rims. One advantage is that I will happy about using these in the wet, not just because of braking performance but also because I don't think I could bear to see an expensive pair of carbon rims being slowly ground away by a slurry of road grit.

One final question. X-Rays all round, or should I use normal butted on the rear drive side? I weight 75 kg and at OBLA put out around 300 watts.

Thanks!

You can use CX Ray all around... it might prove tricky to measure the tensions on the left side as the deflection is too large for most gauges... can you get them in the size required 298-300?
You won't regret the Nemesis, they're the dogs! Don't use tape in the alps, use glue... don't listen to those who say tape is fine... I had a near miss with tape on a steep descent... use glue

cycleclinic

Cx rays are aero spokes which you are going to build with a 32 spoke wheel with a shallow rim. You have lost all ypur areoness if that is even a word with that combo. Laser spokes with alloy nipples are the same wieght a cx rays and there alloy nips. Laser spokes are a bit stiffer as well however for a very shallow rim like the nemesis a thicker spome will most likey benefit you on the rear wheel . Cx ray spokes are areo spokes for race wheels I like using them for that.
The other spoke and I know ugo likes these is the alpina db spoke thicker than a laser and a bit thinner than than a race spoke. You will like the nemesisvrims. And while I would not hestitate to usecarbin rims in the alps they are again race day wheels and for general riding around. For riding ariund not in race I have a variety of alloy rimmed wheels. I am unlikely to be picked by a team for an alpine stage.

ugo.santalucia

thecycleclinic wrote:

Laser spokes are a bit stiffer as well

???? :shock:

BenderRodriguez

As there will be a total of 64 spokes in these wheels, it seems to me that using 'aero' ones will give more of an advantage over standard spokes than in a wheel that uses fewer spokes. No?

I have also read that X-rays build a stiffer wheel than lasers, which are thin full stop, not just in one plain.

As to nipples, I was going to get some brass ones to replace the alloy ones that are supplied with X-Rays, or is this not really an issue given the stainless eyelet in the rim? Also, I can't help thinking that brass nipples would be less likely to deform or strip if the wheels are reasonably highly tensioned, which is pretty much a necessity on the rear drive side, particularly when the time comes to true them up. Perhaps alloy nipples are perfectly up to the job these days?

ugo.santalucia

BenderRodriguez wrote:

I have also read that X-rays build a stiffer wheel than lasers, which are thin full stop, not just in one plain.

Nope, alloy nipples are just as crap as they were ten years ago... nothing new there

cycleclinic

The aero benefit of cx rays is not great and not enough to notice which is why they are best used on race wheels were every last Advantage is wanted.

I suggested alloy nipples because then you will have a spoke and nipple that is the same weight as the cx ray and alloy nipple not because they are better. Bras is more sensible and if you were going to use them anyway then brass would be the comparison I did not know this when I posted.

Cx rays are not stiffer than laser spokes rthe myrh is out there but it is not true and phyiscs stops it being true.

Some race spokes on the back if we are foing to be sensible is not a bad idea.

cycleclinic

If you use you spoke tension gauge on a Cx-ray and laser you get different readings for the same tension (I have a sapim gauge which is calibrated for both). If the spokes had the same siffness they would would give the same reading they don't. Given the way the gauge works it is easy to conclude that there the Cx-ray spoke is not as stiff as the laser although I do not think the difference is very significant but it is there.

Please if I am wrong explain how and why rather than use shocked emmocon or however you spell them.

My reasoning a Race spoke show a higher deflection than a Laser and a Laser shopws a higher deflection than a CX-ray on any spoke tension gauge Given we know the Race spoke is the stiffest (given the way the tension gauge works it make sense) the the CX-ray must be the least stiff.

I have tried working out the bending stiffness of Cx-ray from fiorst principle but I have faile so far.

ugo.santalucia

thecycleclinic wrote:

If you use you spoke tension gauge on a Cx-ray and laser you get different readings for the same tension (I have a sapim gauge which is calibrated for both). If the spokes had the same siffness they would would give the same reading they don't. Given the way the gauge works it is easy to conclude that there the Cx-ray spoke is not as stiff as the laser although I do not think the difference is very significant but it is there.

Please if I am wrong explain how and why rather than use shocked emmocon or however you spell them.

Of course you are wrong, you use the deflection of the 0.9 mm side to measure... if you were to use the deflection of the 2.1 mm side, you would get a completely different number.
Stiffness is how the wheel responds when you load it with torque and a bladed spoke responds better with less deflection, possibly because the wide section is in the same axis as the applied torque.
Any wheel with bladed spokes is significantly stiffer than the same wheel made with the corresponding round spoke (which means spoke of the same weight)

cycleclinic

You place the spoke tension gauge sticking out of the wheel so that would be on the flat of the spoke not the edge because when a CX-ray spoke bends is is bending on the flat not bending the way the wheel rotates on the edge. So unfortunatley I am not sure what you are getting at here. When bending a CX-ray is not as stiff as a Laser when bending towards or away from the elbow in the same plane as the elbow. You do not bend the spoke at 90 degrees to the elbow along is sharp edge.

As the lacing pattern is crossed it may turn out that the bending is along the flat and part along the edge rasing the effective bending stiff of the CX-ray spoke,

If you treat a CX-ray as a rectangular beam 2.2x0.9mm the you can work out the stiffness if you treat it as a cantilever.

k = 3EI/L^3 E is 193GPA youngs modulus (193GPa), I is area of moment of inertia and L is the length 300mm.
I for a rectangular beam bend along it length = bh^3/12 for a circle I= pi*r^4/4

For a CX-ray k = 2.87 N.m although as a CX-ray is not rectangluar this result is a bit off but it can't be by much.
For a Laser spoke k = 5.3 N/m
This is again for a spoke bend along its length on the flat section.
Along it edge the CX-ray will have a stiffness of about 17 N/m so about 8 times as stiff.

It is almost impossible to model a whole wheel and this is as far as I can get. Measuements of lateral wheel stiffness are needed. I will try this at some point.

so by these sums the bending stiffness of a Laser is twice that of a rectangular spoke 2.2x0.9mm which I am using to approximate a CX-ray.

Feel free anyone to comment as this statement CX-ray are stiffer than Laser I am having real trouble with as I cannot see any evidence for it. Ugo's comments seem to be a about personal experience of how a wheel behave under torque but that involves tortional stiffness too.

That is my logic anyway.