I’ve realised that gearing matters for Half Monty and other Ramp type tests. Why? After all the HM is performed in ERG mode for the ramp section, so surely Watts is Watts, right?
Well I did a Half Monty test at the start of the pre-tour training schedule and did really badly. I know everyone always thinks they could have gone harder but this time I knew I did really badly. In fact I was down about 9% from my last test. I went through all the usual emotions before simply resetting my 4DP Profile to what I thought I should be able to do, but I still wanted to know why it was so poor.
It happened that I listened to a recent The Knowledge Podcast where Sir Neal and Sir Mac discussed types of trainers. Not the most exciting topic but it gave me the info I needed.
I have had an oval inner chainring for a long time and was aware that there may be issues with power meter accuracy when using oval chainrings. So I always used my trainer (previously a Tacx wheel-on, now a Wahoo Kickr Core) in the big chainring which is round. However, my local bike shop recently removed the oval and fitted a round ring. It wasn’t what I asked them to do but they struggled to get the shifting to work with the oval. In fact even with two round rings they struggled and I now find on the Kickr Core the bike drops from the big outer chainring to the small inner very easily. So I was forced to train in the small chainring.
So how does this affect the Half Monty test? Well when using the small chainring and a large back cog (to get a straight chain line) the Kickr Core flywheel is going a lot more slowly that it did in the large chain ring and small rear cog. Therefore it is much more likely to end up in the ERG cycle of death that we all hate, as the flywheel has a lot less momentum.
I think this also helps explain why I am such a poor climber. I find it much harder to produce the same watts for 5-8 mins up a climb, than I do to produce that power on a relatively flat section. I think I struggle to get the pedals past the dead spots in my pedal stroke.
So going forward I am going to predominantly use my trainer in lower speed gears to force me to bring the pedals through the dead spots in my stroke and hopefully this will help me with the real goal, which is to climb better.
Sorry for long post. Thanks for reading and hopefully this will help someone else to understand themselves better.
It may also explain for some people the differences in their FTP estimates from Half Monty to Full Frontal.