Islabike Creig 26 drivechain overhaul help please!

[foggy]

Fairly recently acquired a used Creig 26 and it occasionally drops the chain off the front chainring when upshifting. Looking at it, the chain seems to bounce, particularly when shifting 3rd to 4th.

I’m green when it comes to bike technicianing beyond adjusting saddles, brakes and rear derailleurs and would appreciate pointers towards what might be an interim fix to keep my son riding please.

To me the front chainring looks worn, one tooth having taken quite a hit in particular. They’re Lasco 152mm cranks with what looks like a pressed on 28t chainring. Tried Islabike, they don’t have any spares. Any ideas on replacement options please for a new chainring to press on? Or is it bite the bullet and replace cranks too, pointers appreciated.

Ta!

Ultimately I guess its gears, chain and chainring replacement to completely refresh everything ready for a few more years of life.

[gazza285]

These are not generally repairable, but a new crankset should not be too expensive. An alternative would be a chain guide to keep the chain from leaving the sprocket.

[moonigan]

There are 152mm cranks available on e-bay which maybe a direct swap. Failing that you need to be on the lookout for 165mm cranks but that will also need a new bottom bracket and chainring. The BB on the ISLA bike is cartridge with square taper fittings for the crank so unless you can find a like for like swap for the cranks I'd suggest taking it to a shop and let them sort it all out.