Mr. BestRest was riding a forest trail when he noticed that the bike seemed… wobbly.  He discovered that his axle nut was missing and the axle was working it’s way off the swing arm.  Using baling wire to hold things in place, he slowly rode back the way he came until he found the chain adjuster bracket and nut.  It was a lucky day.

The problem started after a tire repair some 10 miles earlier.  He thought he’d tightened the nut properly, but… he didn’t.  There’s no cotter pin holding that nut in place, so it relies on torque to keep it where it belongs.

Once he got back home he went to order a spare axle nut, BMW part number 36317704461. The cost was $16.29.  Ouch.

He did some research and found a source for that same style of nut, with the same dimensions and thread pitch, but at a much lower cost.  Only $6.00.  You do the math.

Carry a spare nut, zip-tie it to the frame so you won’t lose it.  It’s cheap insurance that will someday pay dividends along the trail.

Specs:  Zinc plated Class 8 nut, thread pitch M16 x 1.5 mm
Same dimensions as the BMW nut, fits all tools designed for the rear axle nut