# Big vs Small Chainring - Same Power (ERG Mode Gearing)

**URL:** <https://www.trainerroad.com/forum/t/big-vs-small-chainring-same-power-erg-mode-gearing/6119>\
**Category:** Training\
**Tags:** power-meter\
**Created:** [November 20, 2018, 2:28am UTC](https://www.trainerroad.com/forum/t/big-vs-small-chainring-same-power-erg-mode-gearing/6119 "2018-11-20T02:28:23Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![mcneese.chad](https://sea2.discourse-cdn.com/trainerroad/forum/user_avatar/www.trainerroad.com/mcneese.chad/32/15056_2.png) [@mcneese.chad](https://www.trainerroad.com/forum/u/mcneese.chad)\
**Post date:** [November 20, 2018, 2:49am UTC](https://www.trainerroad.com/forum/t/big-vs-small-chainring-same-power-erg-mode-gearing/6119/2 "2018-11-20T02:49:44Z")

</div>

Yes, gearing in ERG matters and affects the feel.

Higher gearing = Higher Flywheel Inertia  
That generally means “easier” and the flywheel works to keep the drivetrain movement easier.

This is covered in several threads. Usually you want to consider applying the gearing in a way to mimic your event needs.

The rule of thumb is to try to match the flywheel inertia to the majority of your events.

- **Flat and Fast Road Riding = Use Higher Gearing and Faster Flywheel Speed**

- **Hilly and Off-Road Riding = Use Lower Gearing and Slower Flywheel Speed**

> [@Went from dumb trainer to smart. Why does it feel harder?](https://www.trainerroad.com/forumt/went-from-dumb-trainer-to-smart-why-does-it-feel-harder/5136/17):
>
> The core issue is related to this: [[Wahoo Kickr ERG Mode - Does Gear Selection Matter?] ](https://www.youtube.com/watch?v=uHUOhmG04M8) The rule of thumb is to try to match the flywheel inertia to the majority of your events. Flat and Fast Road Riding = Use Higher Bearing and Faster Flywheel Inertia Hilly and Off-Road = Use Lower Gearing and Slower Flywheel Inertia Additionally, resistance changes generally happen faster with a Slower Flywheel, because it has less inertia for the resistance unit to overcome and make adj…

---

_[View the full topic](https://www.trainerroad.com/forum/t/big-vs-small-chainring-same-power-erg-mode-gearing/6119)._