Osa and Kalk share the same drivetrain components and fitments. Both bikes have the Dana TM4 IPM-200 electric motor, but some models have a belt-driven final drive whereas others use a more traditional chain.
This page details which bikes use which components, plus part numbers and possible alternatives, and notes.
Note that Kalk& changed from chain-drive to belt-drive at the start of 2023 (source).
| Bike | Belt size | CAKE SKU | Gates part number |
|---|---|---|---|
| Osa flex Osa+ |
143 teeth | SP0090 | 11M-143T-14 |
| Kalk& (2023+) | 174 teeth | SP00228 | 11M-174T-14 TBC |
| Bike | Chain size | CAKE SKU |
|---|---|---|
| Osa :work | 122 links | SP00337 |
| Kalk :work Kalk INK& Kalk& (pre-2023) |
136 links | SP00227 |
| Kalk INK Kalk INK Race Kalk OR Kalk OR Race Kalk AP |
142 links | SP00226 |
| Bike | Sprocket size | Type | CAKE SKU |
|---|---|---|---|
| Osa flex Osa+, Kalk& (2023+) |
18 teeth | Belt | SP00229 |
| Osa :work | 15 teeth | Chain | SP00336 |
| Kalk :work Kalk AP Kalk INK Kalk INK Race Kalk INK& Kalk OR Kalk OR Race Kalk& (pre-2023) |
12 teeth | Chain | SP00298 |
| Bike | Sprocket size | Type | CAKE SKU | Manufacturer part number |
|---|---|---|---|---|
| Osa flex Osa+ |
87 teeth | Belt | SP0089 | ??? |
| Kalk& (2023+) | 108 teeth | Belt | SP00238 | ??? |
| Osa :work Kalk :work Kalk INK& Kalk& (pre-2023) |
72 teeth | Chain | SP0070 | Parts by Sweden: 204882 |
| Kalk INK Kalk INK Race Kalk OR Kalk OR Race Kalk AP |
80 teeth | Chain | SP0011 | Parts by Sweden: 203646 |
| Bike | Type | Gearing | Gear ratio |
|---|---|---|---|
| Osa :work | Chain | 15/72 | 0.208 |
| Osa flex Osa+ |
Belt | 18/87 | 0.206 |
| Kalk& (2023+) | Belt | 18/108 | 0.166 |
| Kalk :work Kalk INK& Kalk& (pre-2023) |
Chain | 12/72 | 0.166 |
| Kalk INK Kalk INK Race Kalk OR Kalk OR Race Kalk AP |
Chain | 12/80 | 0.15 |