Everything else being equal on a 10 mile course:
How much time difference will be to ride a road bike on the hoods with a regular road helmet and tires vs a TT bike with aero kit and wheels?
2mph, which is alot. Take the road bike with all the goodies and it will be very close, as the wheels, helmet and aero postition are king.
Everything else being equal on a 10 mile course:
How much time difference will be to ride a road bike on the hoods with a regular road helmet and tires vs a TT bike with aero kit and wheels?
Depends on how fast you are. If you ride the roadie at 14mph, then the diff will be tiny. If you could ride it at 24mph, then maybe 1-2 mph more?
The position will be much more important than any wheels, aero frame, etc. Like by a factor of at least 10.
I ride the roadie a fracture over 23 mph…
I actually did this expariment in a TT series. The last race of the series I did on my road set-up, on spoked wheels. Time difference was about 90 seconds if I remember right, on a not-too-flat 10 mile course.
I also did a test with 2 setups on a just slightly short 10 mile course (9.91 miles). These were back-to-back runs about 10 minutes apart
First run - Hooker TT frame with 700c front/rear wheels (disk rear, trispoke front), VisionTech bars, aero helmet, no bottle, non-aero fork - time was 23:47 (25 mph)
Second run - Cannondale race bike, 16-spoke 40mm deep rim Campy Zonda wheels, head buried down by the traditional bars to get as aero as possible, hands alternating between hoods and drops, forgot to wear my regular road helmet so the head was naked - time was 25:27 (23.36 mph)
So 90 seconds for 9.91 miles for me, which is a significant difference for a short course.
Last night - 24.5 miles with the race bike, 32 spoke wheels, hands everywhere, sometimes an aerodynamic tuck, but often not - time was 64:36 (22.75 mph)
Position does count, which the TT bike will help you achieve, and the wheels give you that little extra too.