I just received a 2013 Cannondale OPI Stem -5 degree/110mm length. It came with 4 additional spacers and I don't know what they are for. I'm not talking about the 3 spacers that go under the stem that affect the height. It came with those too. The 4 spacers I am talking about are smaller in diameter and are only large enough to fit around the threaded portion of the steerer. 3 are black and 1 is red. The red one is beveled on the inside. I also noticed the that the steerer uses a rubber o-ring at the base (where you tighten it) instead of a nylon washer I believe. The steerer tube also appears to have a different shape just below the threads, when I compare it to older pictures on the internet. I've never posted pictures on here before. Not sure how to do that.

Does anyone know what those additional spacers are for?

It came with no instructions and the Cannondale website only has info on what appear to be older OPI stems.

Here is my guess: the new small spacers go up into the steerer part of the stem. Red is mandatory, and the black ones are used according to how many height spacers are used. the bottom steerer probably can get tightened fully now, instead of crushing the headset bearings.
Old design balances thread support with bearing preload. The thread contacts have space between them, and the two steerer parts can pivot in the middle, with two fulcrums at the crowns. So it feels like stem torsional flex, but it's really the steerer pivoting in the middle. And it's prone to creaks. this new design should help solve it.
The o ring is to take up any extra space, depending on tolerances, since the bottom steerer is bottoming out inside the top steerer.
I will respond with more certainty when I actually see one for myself.

Can you use OPI stem/steerer with the older style bike? I have a 2011 Flash carbon 1 with a 100mm stem and want to drop to a 90mm new style.

_________________
Curt Brown
2012 Cannondale Supersix EVO SRAM Red 10.8#'s
2012 Cannondale Super X 14.1#'s and dropping....
2011 Cannondale Carbon Flash 1 17.2#'s
1999 Cannondale F2000, SRAM XO 18.9#'s
http://cbevo.com/2012_cd_supersix_evo_31.html

Yes, you can.

Pics please

+1

"thisisatest" you nailed it. Brilliant. I took the stem back down to the LBS. We had one of my Lefty forks clamped in a workstand, so we slipped the stem/steerer in place and came to the exact same conclusion that you did.

The new design must be an attempt to eliminate the creaking issues that many have complained about. I compared the new OPI stem/steerer to the old design, side by side. The new steerer has a substantial lip at the base of the threads. The red beveled spacer appears to be mandatory. It ends up between the lip and the base of the stem. This allows the steerer to thread into the stem and actually bottom out nice and firm. If you want to add a spacer under your stem to raise the stem up, then you must add a black spacer around the threaded portion (above the red beveled spacer) of the steerer too. If you want up to three spacers under your stem, then you must add all three of the black spacers around the threaded portion (in addition to the red beveled spacer). The old model was not the best design, because when the steerer was threaded into the stem it never bottomed out and got completely tight. In fact, with the old design, you could hold the stem in your left hand and the steerer in your right hand (when they were screwed together) and feel the slop as the whole assembly slightly wiggled back and forth. No wonder it creaked.

I think this is going to be a big improvement.

I took pictures of the old and new stem/steerers side by side for comparison. The shop even had an older XC3 stem, so I looked it over too. I just need to figure out how to post pics on here so you can see for yourself.

That's great! Ill pat myself on the back...
Posting pics is kind of a pain, the best way is to have an account with one of the free picture hosting companies, Flickr, etc... and then link to it. Otherwise, the pics can be small and pixelated depending on how you shrink them to <160kb.
Oddly, when I log on here with my phone, I use the Tapatalk app and attaching pics through there automatically shrinks them appropriately.

OK, here are the pics. Enjoy.

Edit to add: The complete weight, with all 3 large spacers and all 4 smaller spacers is 293 grams. That is for a 110mm length/-5 degree rise.

Thank you very much for the photos. I was actually envisioning the small spacers INSIDE the upper stem portion of the steerer tube, but the end result is the same.

Thanks for pics
Two much weight for new OPI?

Yes tomturney, it sounds like you have the 2012 (older) style stem. All of the 2013 Scalpels that we've seen at my LBS did too. My stem was ordered separately and did not come on a complete bike.

Remember, when you compare the older stems, to the OPI stems, you must include the weight of the steerer tube into the equation.
As I mentioned above, the total weight of the newest (2013) 110mm/-5 degree OPI stem/steerer/spacers is 293 grams.

I have a 2006ish Cannondale stem that is 120mm long/+or-5 degree rise. It weighs 203 grams with steel steerer bolts and faceplate bolts. You must add in the weight of a steerer tube to go with it to be comparable to a OPI stem/steerer/spacer set-up. Now, the total weight depends on which steerer tube you use. I have an older Lefty steerer that is mostly straight and has no cut outs. It weighs about 134 grams. Add that too the 203 gram stem and you end up with a total weight of 337 grams. I also used to own a Lefty steerer that was a bit lighter. It was tapered down more in it's middle section and had a large hole cut out of it near where the stem attached. I sold it, but if I remember correctly it weighed about 110 grams. Add it to the 203 gram stem and you would have 313 grams.

Keep in mind I'm not exactly comparing apples to apples here, because my newest stem is only 110mm long, as where my older stem was a 120mm.

My best guess is Cannondale changed to the OPI set-up from the type that could house the tools, to save weight. With that said, the 2012 OPI style is probably a bit lighter than my new 2013 model because it does not contain the 4 internal spacers.

Our best guess for the current revision (with the 4 internal spacers) is to eliminate that awful creaking sound that so many have complained about. This latest version should eliminate that, and still be a bit lighter than the older setup where the stem bolted on (and could house tools). I have yet to finish building my bike, so I can not confirm if the creaking issues are resolved. I should have the thing wrapped up soon. I am still waiting on Mavic to cough up a XD Driver freehub body for SRAM XX1 and I'm waiting on my Magura MT8 brakes.

I am not aware of any reason that would prevent you from running your old stem/steerer on your new bike. I think it should work just fine.

I hope I answered your questions.

wow--i have a lefty steerer that comes in at ~80 grams.

in fact, i purchased an MCFK steerer thinking i would replace the cannondale steerer + OPI stem on a lightweight project, but when all was said and done i really wouldn't save much of any weight.

i don't have my spreadsheet in front of me, but roughly...
* cannondale steerer = ~80g
* OPI stem, 110mm = ~180g

vs
* MCFK steerer (~100g...slightly more i think) -- vs quoted at 79g
* syntace stem (so not ultra light, but one that is durable) -- ~120g
* expander & cap

i was amazed at how light the cannondale steerer is. i have 2 or 3 that weigh about the same, so it is not just a case of an unusual sample.

Did this new steerer come standard on the 2013 F29s? I see they didn't for the Scalpels.