I ordered a WCS C-260 over a month ago through my local shop. It finally arrived this past Friday. It is a BB Black 110mm stem.

I really like the graphics as they are more subtle than on the WCS 4 Axis that the C-260 replaced.

The C-260 does seem stiffer using the subjective test of standing in front of the bike, grabbing the handle bars and pushing down a few times. On the road I cannot feel a difference but the stiffness of a stem probably only comes into play during sprinting or hard efforts out of the saddle... neither of which were part of my two rides with the new stem.

The 110mm stem weights 109 grams, which is two grams more than my 110mm 4 Axis stem after I replaced the 4 Axis stem's bolts with Ti bolts.

My one complaint about the C-260 has to do with the bolts. They are soft! The bolts have a small diameter and require a 3mm hex. There are three bolts at the steerer end and four at the bar end of the stem. I used my torque wrench for the finall tightening of the bolts and on several occasions, even through the wrench was properly seated, the soft metal of the bolt head was deformed before I reached 5 Nm.

I wouldn't be suprised at the softness if the bolts were aluminum, or even low quality Ti, but they are made of steel (a magnet sticks to them) so I expected them to be hard(er). I guess the take away is that if you purchase this stem, pay close attention when tightening the bolts, make sure your wrench is properly seated and apply even constant pressure when tightening. Also, it goes without saying, use a torque wrench.

Here are some quick pics of the installed stem (I know, I know, now that the stem has been installed, I need to trim the steerer tube above the stem).

Thanks for your write up - can you confirm the stack height of your stem please ?

Many thanks

Andy

I have been using a white WCS C-260 for about a week and a half now.

I found the same about the bolts - though they just 'felt' soft to me, I was able to tighten with no deforming. Mine has a 41 mm stack height. Claimed 100 mm, I measure it to be more like 104 mm though. 108 grams for mine.

Here is my main problem with the stem so far:



after the second time adjusting it the paint around the bolts has started to flake off.

I thought the stack was 42mm but I am not at home to measure right now. rgkicksbutt may be correct at 41mm. In any event, the stack was identical to the stack on my WCS 4 Axis stem.

It's a shame to hear that about the bolts. Anyone, like me, that takes a good while to get their contact points sorted and re-adjusts a lot to get there, will kill those bolts by the sound of things. I had a similar issue with a Fizik Cyrano post I tried. The bolt felt very soft and after two or three adjustments, the bolt head was nearing being rounded out despite me using a new and non-rounded hex key.

Also, currently all of the contact point components I run now use 4mm hex head bolts so that all I have to ever carry is a 4mm hex key if I want to make any adjustments (cleat bolts included). Having to carry another hex key with me would put me off this stem straight off the bat.

Yikes, I suspect you are over torquing...seems that with the new handlebar clamp/cradle design and the three bolt steertube clamp,
5Nm is simply overkill. The 5Nm designation is MAX torque spec NOT the recommended torque spec. With carbon paste and slow even torquing you shouldn't need but only about 3 Nm on the steer tube clamp and I would venture 4 Nm on the handlebar clamp (especially with the carbon bars that already have the pre-applied grit to them).
EM3

PS - Nice R5...show us the whole bike, please

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My 2011 Cervelo R5

I just eyeballed 41 mm with a ruler - so it very well could be 42 mm if that is what they claim

em3,

The bolts are not over torqued. I do use Tacx past so I don't get near the max torque of 5Nm. I guess my post was not sufficiently clear. I was trying to make the point that even at a torque below max torque, the bolt deformed slightly. I need not intend to represent that I torqued the bolts all the way to 5Nm.

I don't know about posting my bike. I know you have an R5 and it's beautiful. However, there are members on this forum whom are so aesthetically priggish that they nit pick every little aspect of each bike. It's not that my skin is insufficiently thick to handle criticism, I just hate to instigate the negativity. I know, I should just mind Rule #5 and post anyway.

Do you have to remove the bar tape to change the stem?

Yes, a little. I unwound about 1.5 linear inches worth of bar tape. Just enough to allow the clamp to fit over the skinnier part of a 31.8 bar. Then I simply re-wrappred the bar tape. Didn't even have to use new finishing tape.

So this is probably not the stem to use with bars that have a wing or egg shaped top sections, like the 3T Ergonovas.

On my ErgoNovas (tight fit!) I had to unwrap a good bit. Haven't noticed the problem with the bolts though.

Isn't the torque specs 4nm?

viewtopic.php?f=3&t=90859&start=15

The pictures part way down from the top seem to indicate that.

Butcher, the max torque values that are stamped on both the bar end of my stem and the steerer end of my stem read 5Nm. I don't know why the stem in your photograph reads 4Nm. Also, the written instructions found in the user manual that accompanied the stem provide that one should tighten the steerer end bolts to a minimum of 4Nm and that "if the stem is not well secured, increase to 5Nm." The instructions seem consistent with a max torque of 5Nm.

I have now measured the stem's stack height with calipers and the stack height is in fact 42mm.