Are these the same as x-type/HT2 etc?
Yes, with the exception that the bearings are made out of compressed rust. At least, that's what mine looked like after a couple of wet rides.
Apparently they are pretty much the same. Hope say no to using their BBs with Megaexo cranks though; something about tophats.
I've got to say I've been quite impressed with my Megaexo BB. It's a little over a year old now and still going. Still, I'll be trying a Shimano when mine packs in, purely because of the price difference.
You might want to check diameter of crank axle. If I recall correctly FSA is oversized so you can't use Hope or Shimano - Explains why their Megaexo BB's aren't competitively priced. I had ceramic BB and got rid of the whole crank rather than pay over £100 for a couple of bearings.
There was mention of FSA spindles being slightly tapered, which necessitates the tophats or something, and makes them just a bit too big (or was it small?) for Shimano/etc. Then again there're about a million simialar threads on roadie forums claiming that megaexo works fine with Shimano.
FSA BB is the same crank diameter as Shimano - I'm using MegaExo cranks with a generic HT2 BB and it works fine.
mega-exo spindles are not the same diameter as shimano, not all of them anyway.
hope make adapters to use mega-exo cranks with ht2 bbs
EDIT: just looking into this, it's further cunfused by the whole GXP thing too - thehope GXP converter part number is:
BBSP109 - BB Truvativ GXP Conversion
[url= http://www.chainreactioncycles.com/Models.aspx?ModelID=26899 ]crc linky[/url]
doesn't help clear up the mega-exo thing though. my old FSA cranks deffo needed GXP bearings, though.
Iahve an fsa megaexo crank and have run it with a shimano HT2 BB, and am now use a blackspire HT2 compatable one, with no issues.
So is megaexo same as truvativ howitzer in that it has a separate spindle, or is it permanently attached to one of the crank arms like HT2?
Permanently attached to the driveside arm on mine.
I run my fsa afterburner cranks with ht2 bb without problems, I also have a cyclocross fsa crank with 19mm spindle cranks that requires their own bb