Different bike different ftp?

Equipment
1

Hello All.

TL;DR on road bike i had ftp 213, on MTB i have ftp 179. Is it normal ?

Since last year i was training regularly, i used plan builder, so my workouts were 3-4 times per week.
I was using all the time road bike. My ftp was increasing but i was using AI FTP detection. My FTP changed from 163 ( measured by AI, 3.June.2024) to 213 (measured by AI 18.July.2025)

After that i decided to sell my road bike which was sava vegur 2.0 and bought grand canyon 6.0 2025, so i would say there is a big difference in geometry and how rider is sitting etc.

But suddenly i wasn’t able to finish any workout, everything was hard and i had to drop the powers. So i decided to perform ramp test and result was 172 FTP. Which is drop around 20%.

Is this normal or did anyone here encountered such different ftp between two bikes ?

Thanks a lot for any feedback, i will continue no Mather what to reach my goal 4w/kg.

2

Three questions:

  • How much experience do you have with structured training?
  • How have you been measuring power? Did you e. g. use a power meter on your road bike in addition to a trainer?
  • Do you have a fan?
3

HI OreoCookie,
I am member of TR since 2022 on and off with some breaks, before i was using zwift for training. So i would say i have some experience with that.
I am measuring power with my trainer which is Elite Suito, nothing else.
Yes i am using fan all the time.

4

Typically, a more upright position is more conducive to producing more power. So maybe it is lack of experience with the ramp test? How many ramp tests have you taken so far?

6

HI Thanks for Answer.

what you are saying makes 100% sense. I didnt lose any fitness because i feel amazing on the bike when i am in the real world, also i can see that i have a lot of PR on strava segments lately.

My current ftp is 179 thats correct, interval workouts feel good, as you mention they are hard but doable.
I will continue working out, it just scared me that my FTP changed so drastically only by swapping bike.