Just for interest on the retro/modern debate, I raced a short course XC event on the DOGS BOLX last night instead of the my normal full suspension XC race bike (Turner Flux).
While my average and maximum heart rate were about the same for the event (178 & 190bpm), I was about 10 - 15 seconds a lap slower than normal which doesn't sound that bad until you consider than a lap is sub 3 minutes and the event is only 20 - 25 minutes in total.
So why was in slower you may ask??
Well I'd put it down to the following factors:
Brakes: While the course is fairly flowing, Suntours finest from 1993 just don't allow you to brake as late XTR discs and braking sooner makes you slower.
Grip: Not just talking tyres (I don't think they made much difference last night), but more inportantly compared to the rigid DOGS, the full suspension keeps the tyres in contact with the ground so much better under braking and cornering, that I retain more speed in the corners. The course last night as a few rutted and rippled berms and the rigid bike skips around all over the place.
Anyway, it was great fun shashing it up the short climbs and blocking other riders in the bumpy/twisty bits, even if it wasn't the fastest option. My back is saying that it can feel the 20 minutes of hard racing and it may prefer something different at the next one though