Looking for personal experience with both. I’m hoping to pick up a used wheel this spring and am considering both wheels (others too). A little background:
racing primarily sprint tri/du
ride a Titanflex Transition with an Easton EC 90 SL fork
wheelcover on the back over a Mavic CXP 33
racing weight approx 175-180 lb
experienced bike handler
previous wheel was a HED CX 60 tubular which I just sold (really liked it but want to run clincher fr and rear)
I’ve ridden both, actually a 90 not a 60. I used the HED3 on the front for many years. This past season I changed to a Jet90 on the front. I think in real world conditions, accounting for everything, the Jet90 is faster. Its far more comfortable, thus allows me to not move around alot, therefore saving time over 2 wheels that are pretty even aerodynamically. I like the 90 much better then the HED3.
I’ll be staying with the Jet90 or BW100, I use both, front and Zipp disc in the rear.
it’s going to be virtually impossible to pick up a used Jet C2 90 for a decent price, at least compared to a Hed 3. I’d say try to find a regular non-C2 Jet 90 or Hed 3, as they would be cheaper than a used Jet C2 90, and then use the cash saved to find yourself a proper aero fork, as you’re probably losing more time there than the difference between a Jet 60 and Hed 3.
I planned on an older non-C2 version for right now for price reasons unless something surprising popped up. Looking to spend less then $350-400. The fork will most likely be the next upgrade although I have the bike set up as my all-arounder with drop bars right now.
The HED 3 is heavier and less comfortable, but more aero. Unless you are doing a very hilly course it’s going to be faster. The Hed 3 has evolved several times (it started out in the early 90’s made by dupont/specialized), so the weight has changed quite a bit over time (just a note since all the 3s you see on eBay will not be created equal). The 3 can also be converted to a rear wheel later in life with a new hub/axle kit.
I, like you, am torn about what to about aerowheels. Partly because the wife said no more money on tri stuff this offseason, and partly because it made sense, I’m renting from Echappe. I have an email into them, since I am doing 3 Olympic tris this year, and they have some pretty great pricing schemes. I am looking to try the following combos: HED Jet 60/90, HED 3/3D, and Zipp 404/1080. If and when I hear back about the HED 3/3D combo, I’ll shoot something over to you. This way you can really try both setups, it doesn’t cost you a whole bunch, and your rental cost goes towards your purchase price.
I seem to recall HED making an axle/bearing kit for the swapout, but that might have been for some of the older models back in the day. Here’s one guy who did it himself (bottom of attached thread): http://209.20.64.92/thread6735-2.html
Here’s another guy who says he used one (just to convince myself that I didn’t dream this): http://www.trifuel.com/forum/14016/convert-race-wheel-rear-hed-3
Since Andy works at HED it’s safe to assume that a kit is not currently offered.