Sunday, 7 March 2010

First the good news.
My new brake blocks work well, and so does my new rear-view mirror as does the trailer hitch modification. Even the shiny new chain was perfect and so were the wheel nuts.

The sun was shining, and I fancied a ride on Chopper - not a long one, just a short one hour ride.

Here comes the bad news.
Off I went, whizzing along in the chilly March sunshine and changed into top gear. (3rd on the Sturmey Archer, big ring on the front and small cog at the back) The chain started to jump! This is caused by a worn sprocket. It didn't jump on the big 28 tooth sprocket but it did on the 18 tooth.

This 18t sprocket is a very old one that I used to use nearly 20 years ago, and I wasn't aware of it being worn. When I went over to cassettes, I kept all my old freewheel sprockets for ages and have since given some away. The 18t was perfect as a ratio on Chopper, and now I need a new one.

You may ask why this wasn't a problem before. The thing is, as sprockets wear, the "pitch" between the teeth becomes wider, and as the chain wears, everything is ok - until you fit a new chain! That's just what I've done! The good chain I've fitted with perfect pitch doesn't match the old sprocket.

You may ask why I just don't put the other chain back on, and that's what I may have to do, but continued use will ruin the 28t sprocket. I can't win. The best solution is to get hold of a new 18t sprocket.

So it's off to the bike shop tomorrow morning to see if I can get hold of one. It would be best and cheaper to buy a whole freewheel assembly with an 18t sprocket included and strip it down.

Oh well. I'm off the road until I can sort this. Poor Chopper has his legs in the air in the workshop awaiting some tender loving care.

1 comment:

  1. Excellent effort my man.big well done.
    now come on over to and tell your story to all the raleigh chopper collectors there.
    cheers Iain, qwerty5oo