I'm pretty new to cycling, and last summer I bought my first road bike, a 2010 Cannondale SuperSix 3. I love the bike and have ridden it very hard. My LBS told me that I should replace my bottom bracket every year, and suggested I might want to do the same with my headset. Is this necessary? Thanks

Welcome to the forum.

Not that I've heard nor read about for either.

Brad

Find another bike shop ASAP.

Did you buy the bike from the same LBS? Well... profits in bike sales aren't as great as in parts, so they're just trying to drum up business.

If in the first year you have BB trouble, it should be covered by warranty. Cannondale created the BB30 standard, so their bikes should be some of the most reliable in that area (you'd think). Threadless headset? One of the most troublefree bike components going. Tell your LBS- No thanks!~

+1 on the LBS's bad advice. Unless you ride on the beach every day, a decent bottom bracket should last for tens of thousands of miles and a cartridge bearing headset for decades.

The rule with cartridge bearings is to use them until they wear out, then replace. No way you can say "replace every year" anyway, because one person might have 500 miles in a year, and another person might have 5000 miles in the same time. Add to that all the other variables (riding style, environmental conditions, etc, etc) and it becomes even more meaningless to try and put a set time frame, or even a mileage interval, on replacement.

With that said, the mechanics at my LBS have told me that they have seen external bearing BB's wear out far more rapidly than more traditional designs do.

I'd have to agree with that. A good quality Shimano square taper bb, or an Octalink bb, will usually last a LONG time. We haven't seen this kind of durability on many external cup bb's. Some are better than others, of course. Based on the ones I've worked with, I'd say Campy's external cups are awfully good in terms of durability, Shimano's are okay but not great, same with SRAM, and FSA's are inconsistent in that some wear out in just a few hundred miles while others do quite well. Subjective info just based on my own observations, don't take this to mean much.

Do keep in mind that a BB30 is not an external bb, the bearings are enclosed in the bb shell. We've not replaced many of the bearings, and have sold quite a lot of bikes with this system, but have had to grease between the cartridges and the shell a lot to keep them from creaking. We actually like the PressFit 30 system so far, with the nylon cups these seem to stay quiet (from what we've seen so far) and the bearings are sealed better by the nylon cups so it may help with durability. PressFit 30 uses the same, very large, bearing size as BB30.

Summer , fair weather, and foul weather & Cyclocross, and such, make a big difference.

Wheelspray, of grit gets directed at the BB.. and External is , out there.. by definition.
If you can look outside the bike replacement parts for bearings, when the time comes,

A submersible pump bearing in the same size as your bike uses , can be sought.
or to Phil Wood spec bearing , that is essentially part of their seal quality specification.

Ceramic BB30 on my bike was shot by 3000 miles. Replaced with steel bearings, which you can get for ~$25.

With the chain off the rings, turn the crank very slowly with a finger tip. It should be smooth, not lumpy. If lumpy, plan on replacing the bearings in the near future.

LBS is full of BS to say something like that. Those parts get replaced when they're worn out. Find a new shop.

Not familiar with the BB30 stuff so cant tell but headsets can overlast the frame sometimes. Is really hard to mess up a headset in specific and if the frame has a semi or an integrated headsets, probably the headtube will fail before than the headset. Second thing, what could fail are the the bearings and bearings are available everywhere. But as usual u have to take care of the stuff too.

Yes, get a new LBS or learn to do the stuff yourself.