A20F Bottom Bracket / Crank arm issues

[KatRallye]

Hi folks.

Looking for information on replacement parts.
After 40 km I have a knocking bottom bracket and a crank arm that constantly comes loose.

 

[Nealh]

Show us some pics of the items, other wise we can't advise as we don't know what is in use.

 

[KatRallye]

Show us some pics of the items, other wise we can't advise as we don't know what is in use.

 

[Nealh]

To all purposes looks like squared taper bottom bracket.

One of these and a spanner to remove the crank arms.
Silverline Crank Removal Tool Square Taper & ISIS Threads Bicycle Tools 241095 5024763120954 | eBay

One these to remove the Bottom Bracket.
Bike Taper BOTTOM BRACKET REMOVAL TOOL Socket 20T Spanner Crank Extractor Puller | eBay

Or buy them at any good bike outlet who sells tools for maintenance.

The bottom bracket one will need to measure once it is off as they differ in length, there are two measurements you need to now the actual main body which will be 68mm or 73mm and the overall length of the axle/spindles.

 

[Nealh]

Bottom Bracket, if you look at the drop down box you will see the various lengths.
68mm BB are most common but some bikes do use a 73mm.
Shimano UN300 Bottom Bracket Bike Cycle Bicycle BB Square Taper Sealed Cartridge | eBay

The BB looks overly long on your bike but that depends how close the crank arms are too the rear stays and the gearing on the other side.
It might be possible to go down a length size wise ?