Been putting in some training for the upcoming tt season and it was going reasonably well, so now with a couple of months to go have stuck the tt bike on the trainer to try to nail position.

One immediate thing that struck me was the noticeable drop in power (from an already fairly low number). It’s a new tt bike, and my position isn’t particularly extreme, and I never had the same issue on the old tt bike

Any quick wins to get the power back up. I read shorter cranks may help. I’m 5.9 with stumpy legs, and have 172.5 cranks on all my road bikes and the tt bike. Thinking of swapping to 165 for the tt..will that be of any benefit? Or will i gey similar gains by just playing around with position?

Shorter cranks will need a higher saddle which will increase drag?

It’s a new tt bike, and my position isn’t particularly extreme, and I never had the same issue on the old tt bike

sounds like the position is different between bikes. Angles do that – even if length for length the distances and heights are the same.

changing cranks wont compensate for poor position.

Personally I couldn’t draw any conclusions from power in position on the turbo – has to be done outside. Just too different for me.

Shorter cranks definitely something to look at as part of your overall fit though – I’m looking at this myself after having a bike fit. My saddle ideally needs be raised quite a bit but it aggravates one of my hamstrings, so might see about a shorter crank.

Raising the saddle to the upper end of the range would be normal for a ten or a 25, esp if you dish the Watts out – must be stable position though with zero hip rock. Sit forward on the saddle to rage the pedals.

There’s a school of thought that shorter cranks open up your hip angle and make it easier to get the power out. Also know of people who’ve gone to shorter cranks and actually reduced their saddle height – the aero benefit outweighed any loss of power.

Basically, it might work. No point trying to stick to rules with TT fit, trial and error is the way forward. Also echo the point about trying it out on the road rather than turbo.

Raising the saddle to the upper end of the range would be normal for a ten or a 25, esp if you dish the Watts out – must be stable position though with zero hip rock. Sit forward on the saddle to rage the pedals.

Had fascinating conversation with one of the best TT riders in the country who will on certain courses lower his saddle to decrease drag at the expense of overall pedalling efficiency and has done all the stats to work out how much is too much etc.

Noticed no difference from 170 to 165. Same saddle height, which is lower than my road position by 2 cm. That is including the rotation of the saddle forward in a like-for-like hip angle. I’m not a believer and ride 165s fixed a lot!

It’s a new tt bike

Seat angle different, measure drop of saddle nose to BB and height to top of saddle from BB. Then measure reach. A degree can make a lot of difference (1 cm)

Did some measuring and my seat was far too far back. My understanding is that bringing it forward will open up the hip angle a bit which will help with power.

Will see how that works out before splashing out a small fortune on a new crank as I’d need to buy a new stages as all mine are 172.5

Flexibility is the thing that I believe causes the drop off in power in the TT position.
I focus more on that then spending time on the turbo on my TT bike.