My daughter (junior elite tri racer) owns 2015 Felt AR3 and current model Trek Speed Concept. Both bikes are comparability equipped (see table below) and professionally fitted by the same person. Yet, on SC she averages about 1mph less than on AR3 – under 21mph on SC vs about 22mph on AR3. Since SC is her first TT bike, I would not expect her to go much faster on it right away, but slower?! Just in case – she is 15yo, 5’9", 122lb, average cadence ~95. 14-28 cassette is there to meet the junior gearing (she also occasionally does road TT and crits).
What could be the problem with SC? Wheels? Gearing? Thanks!!
Could it be a poor fit on the SC that’s causing a lack in ability to comfortably push?
She feels very comfortable on SC and basically never comes off the aerobars during the race. That being said, since this is her first year on TT/Tri bike the fitter mostly copied her road fit from AR (she also has mini clip-ons on AR).
There’s no way the SC isn’t more aero. It’s possible the gearing difference is nicking a little off the average speed potential of the Speed Concept in certain circumstances, but it can’t entirely account for a 22 vs <21 mph difference. Some possible explanations:
-AR3 average speed is in a draft pack?
-Course/weather comps aren’t relevant
-She’s just not putting out as much power on the SC
Also, at 5’9", I’d definitely be looking at shorter cranks for the SC. Shimano now has R7000 105’s in 160mm length. While you’re at it, change from 50/34 to a 52/36.
Road bike with clip ons vs. TT bike isn’t that huge an aerodynamic delta. The TT bike should have the potential to be faster, but a lot of other factors can mask that delta. Are you being careful to really compare apples to apples (21mph vs. 22 mph on the exact same course in the same condition, while putting out the same watts). As another poster mentioned, this is where some Chung method aero testing can be important. That all said, you don’t really need to aero test to know the TT bike has the potential to be faster. It is almost certainly some combo of:
-) Her position is worse on the TT bike
-) Her power is worse on the TT bike
I would just focus on improving those two things and the rest should take care of itself.
ETA: I would double check that there isn’t something dumb like a dragging brake.
that’s what I call a “bike shop fit” or a “kitchen table fit”. As in, you just sat down in a chair at the kitchen table and just leaned forward on your elbows to grab a knife and fork.
That said, this has no relevance as to why she’s supposedly faster on her obviously slower road bike. It could be less power, weather, road conditions, etc. It’s NOT because the Felt is faster than the SC.
you did not see a real bike fitter
That being said, since this is her first year on TT/Tri bike the fitter mostly copied her road fit from AR (she also has mini clip-ons on AR).
Also, that fit does look quite terrible. Also, Alistair Brownlee once said in an interview he gets more power out of his regular bike than his TT bike. Slightly different muscle use or a different ratio of muscles used can make all the difference in the world.
The fit is an issue but I imagine she is having a difference in power also and has not really learned “how” to ride the bike yet.
To those asking about the gearing and questioning her being elite - he notes that she is on JR gears and its his daughter, most likely she is under 18 years of age still. It wouldn’t be legal for her to change the gears around and I would venture to say a female under 18 that is able to maintain that speed (although distance/elevation isn’t mentioned) would be fairly “elite”.
