How BikeCheck computes wear
Every number in BikeCheck comes from your rides. Here is exactly how.
Real km: the distance you actually rode on a part since it was installed. BikeCheck always shows this first.
Wear km: the same rides, weighted by how hard they are on that part. A muddy ride wears a chain much faster than a dry one; a direct-drive trainer doesn't touch your tires at all.
Example: a 50 km ride in the rain counts as 50 real km, and 75 km of wear for the chain (×1.5).
When the two differ, they are shown side by side, e.g. 50 km · 75 km of wear. When they are equal, only real km are shown.
A part counts every ride of its bike from its install date onward, including rides on the install day. When you replace a part, rides on the replacement day go to the new part.
Km already on a part before your first imported ride (for example rides deleted from Strava) are added as-is, at ×1.
A ride's bike and trainer are fixed when it is imported. Changing a trainer's linked bike only affects new rides. You can reassign any ride from the Rides page; Strava won't overwrite your choice.
Tag each ride's conditions from the Rides page. The multiplier depends on the part:
| Part | Dry | Wet | Muddy | Dusty | Winter |
|---|---|---|---|---|---|
| Chain | ×1 | ×1.5 | ×2 | ×1.5 | ×2.5 |
| Cassette | ×1 | ×1.3 | ×1.5 | ×1.3 | ×2 |
| Chainrings | ×1 | ×1.3 | ×1.5 | ×1.3 | ×2 |
| Front brake pads | ×1 | ×1.5 | ×1.7 | ×1.3 | ×1.5 |
| Rear brake pads | ×1 | ×1.5 | ×1.7 | ×1.3 | ×1.5 |
| Front tire | ×1 | ×1.1 | ×1.3 | ×1.1 | ×1.3 |
| Rear tire | ×1 | ×1.1 | ×1.3 | ×1.1 | ×1.3 |
| Bottom bracket | ×1 | ×1.5 | ×2 | ×1.5 | ×2 |
| Cables & housing | ×1 | ×1.5 | ×2 | ×1.5 | ×2.5 |
| Front rim (braking surface) | ×1 | ×2 | ×2 | ×1.3 | ×2 |
| Rear rim (braking surface) | ×1 | ×2 | ×2 | ×1.3 | ×2 |
- Rim brake pads: ×3 in rain and ×2.5 in winter, instead of the values above.
- Sintered disc brake pads: ×1.2 in rain.
- Parts not listed wear at ×1 in every condition.
Rides whose conditions are not set count like dry rides (×1). Strava doesn't tell us the weather, so tag your wet or muddy rides for more accurate wear.
An indoor ride wears the parts of the bike mounted on the trainer, depending on the trainer type. ×0 means the part doesn't wear at all.
| Part | Direct drive | Wheel-on | Rollers | Smart bike | No trainer set up |
|---|---|---|---|---|---|
| Chain | ×1 | ×1 | ×1 | ×0 | ×1 |
| Cassette | ×0 | ×1 | ×1 | ×0 | ×1 |
| Chainrings | ×1 | ×1 | ×1 | ×0 | ×1 |
| Bottom bracket | ×1 | ×1 | ×1 | ×0 | ×1 |
| Rear brake pads | ×0 | ×0 | ×0 | ×0 | ×0 |
| Front brake pads | ×0 | ×0 | ×0 | ×0 | ×0 |
| Rear tire | ×0 | ×1.5 | ×1.2 | ×0 | ×0 |
| Front tire | ×0 | ×0 | ×0.5 | ×0 | ×0 |
| Bar tape | ×0.2 | ×0.2 | ×0.2 | ×0 | ×0.2 |
| Grips | ×0.2 | ×0.2 | ×0.2 | ×0 | ×0.2 |
| Cables & housing | ×0.5 | ×0.5 | ×0.5 | ×0 | ×0.5 |
| Derailleur pulleys | ×1 | ×1 | ×1 | ×0 | ×1 |
| Front brake rotor | ×0 | ×0 | ×0 | ×0 | ×0 |
| Rear brake rotor | ×0 | ×0 | ×0 | ×0 | ×0 |
| Fork service — lowers | ×0 | ×0 | ×0 | ×0 | ×0 |
| Fork service — full overhaul | ×0 | ×0 | ×0 | ×0 | ×0 |
| Rear shock service | ×0 | ×0 | ×0 | ×0 | ×0 |
| Rear shock — full overhaul | ×0 | ×0 | ×0 | ×0 | ×0 |
| Dropper post | ×0 | ×0 | ×0 | ×0 | ×0 |
| Front wheel bearings | ×0 | ×0 | ×0.5 | ×0 | ×0 |
| Rear wheel bearings | ×0 | ×0.5 | ×0.5 | ×0 | ×0 |
| Cleats | ×0.3 | ×0.3 | ×0.3 | ×0 | ×0.3 |
| Pedals | ×1 | ×1 | ×1 | ×0 | ×1 |
| Electronic shifting | ×1 | ×1 | ×1 | ×0 | ×1 |
| Other | ×1 | ×1 | ×1 | ×0 | ×1 |
- Indoor rides without a configured trainer only wear the drivetrain and contact points: wheels, brakes and suspension don't wear.
- Parts that belong to the trainer itself (such as a direct-drive trainer's cassette) use their own multiplier, set on each part.
Each part has a replacement threshold in km, hours or days. The % used is the km counted so far divided by that threshold.
| Level | % of threshold |
|---|---|
| Good | under 70% |
| Approaching | 70–85% |
| Warning | 85–95% |
| Critical | 95–100% |
| Overdue | 100% and more |
Email alerts are sent for the levels you pick in Settings.
By default, % used, status and alerts are based on wear km. If you prefer, switch to real km in Settings: every km then counts the same. Both values are always computed, so switching is instant.