Does such a part exist?

[Pothole]

My son keeps having the chain come off the smallest (innermost) chain ring and jamming between crank and bottom bracket. I've spoken to him about his technique (it's probably through changing to the smallest ring while going over bumps, down kerb etc.) but was wondering if there's a part similar to the chainring guard that's used on the outer ring to keep it off clothes/calf etc. This might stop the chain slipping off so easily. I've had the shop check and adjust the mech and seen it tested on a stand and the changes are fine with no recreation of the problem under stable shop conditions.

Anyone?

Bike is 3 month old Specialised Hard Rock MTB

[Pothole]

Excellent, thanks!

[Pothole]

gazza285 said:

Deda dog fang.

Looks good, and uncomplicated!

[Pothole]

gazza285 said:

Pothole said:

gazza285 said:

Deda dog fang.

Looks good, and uncomplicated!

Just make sure there's room for it under the front derailleur...

Working late today, gonna check it when I get home...and measure tube size