What are these two cotters under my bottom bracket for?

Question

They look like cotters at least. What are they?

http://i224.photobucket.com/albums/dd33/Murderdogs/101_0943.jpg?t=1218913297

It looks a bit like the eccentric on the bottom bracket of my tandem, but this surely wouldn't be one of those. That would be redundant on a solo bicycle, surely? The bottom bracket is very odd - both the cups have right hand (English standard) threading and are identical in design. Why is this?

Answer 1

It is an old bike!  I have never seen these bolts on a bottom bracket before but as an old Engineer I think they are for tightining the walls of the botton bracket on to the bearings after they are adjusted.  There would be small slots cut on the bottom bracket wall to allow it to close in when the bolts are tightened.  There also does not seem to be any lock rings on the bearings and both threads are right handed.  Hope that helps.

Answer 2

Surely one would have no need to ask.Being (English Standard)

Answer 3

They are to stop the pedals spinning on the shaft

Answer 4

odd... haven't seen that, its not for a kick stand is it?

Answer 5

It just dawned on me. They are spare cotter pins one for each side.I remember them. I always did my own cycle work.

Answer 6

I found this about them, quite technical though...

http://www.patentstorm.us/patents/600388...

or this..

http://www.sheldonbrown.com/tooltips/cot...

Answer 7

I don't know but I think I can tell you who might...

Contact Mercian Cycles in Derby or Bob Jackson Cycles in Leeds. They have both been around for a long time and someone should be able to tell you.

Liam has stumped me!

EDIT: Happy Man... what a great thought! Bikes of that era had hand fitted cotter pins, so perhaps you are correct!

EDIT 2: Kipper- I thought the same thing, but the bottom bracket is threaded and there is no visible slot.