Correct chain slack on the BMW G 310 R is 40-50 of vertical movement, measured midway between the sprockets. Too tight and you load the countershaft bearing and suspension; too loose and the chain can slap, jump, or wear the sprockets unevenly.
Check slack every 500-1,000 miles, after long rides, and whenever the rear wheel has been removed. Adjust with the bike upright and unloaded, and always recheck after tightening the axle.
BMW G 310 R quick service specs
| Item | Specification |
|---|---|
| Chain slack | 40-50 mm |
| Axle nut torque | 100 Nm |
| Rear axle size | 24 mm |
| Chain type | 520 O-ring |
| Chain links | 112 links |
| Check interval | Every 500-1,000 miles |
How to adjust chain slack on the BMW G 310 R
- Put the bike on a stand, in neutral, and confirm the chain is at its tightest point.
- Measure vertical movement midway between the sprockets.
- Loosen the rear axle nut and turn the adjusters evenly, a quarter-turn at a time.
- Keep the wheel aligned using the swingarm marks and recheck slack.
- Torque the axle nut to 100 Nm, then recheck slack and chain alignment.
Common mistakes to avoid
- Adjusting with the bike on the side stand, which changes slack.
- Tightening one adjuster more than the other.
- Forgetting to recheck slack after torquing the axle.
- Setting slack to the tight end of the range for a loaded touring setup.
FAQ
What happens if the chain is too tight?
A too-tight chain loads the countershaft bearing, stiffens suspension action, and accelerates chain and sprocket wear.
What happens if the chain is too loose?
A loose chain can slap the swingarm, jump under load, and wear unevenly.
Do I need to replace the chain when I adjust slack?
No. Adjustment is routine maintenance, but replace the chain and sprockets if adjustment is at the limit or wear is uneven.
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Dan Heiman
Writer at Helmet Today, covering helmet reviews, fit and riding safety.
