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Collection, Preservation and Display of Old Lawn Mowers

Atco standard chain replacement

Afternoon all,

i recently purchased a replacement chain for my standard and 'cut' to the required length. Unfortunately the chain wont quite reach and would be very tight if i did manage to stretch. When adding a link back in the chain would seen to be too loose as its from the clutch to the cutting cylinder

With my beginners knowledge would this mean that i have ordered the incorrect chain size or (hopefully) that things have moved slightly?

The chain size ordered was a wipperman 385 1/2 * 1/4 inch pitch

Has anyone else replaced one recently that could compare sizes to see if i bought the correct one ?



olcadmin Wed, 21/02/2018

The original spec for chain (from the Standard Parts List) was 1/2" x 3/16" for the smaller models (up to 22" with disc clutch) and 1/2" x 5/16" for the larger models (22" with cone clutch and larger). The nearest I could find to this last year when rechaining a 22" oval frame was this:

This might be slightly narrower than your chain but that won't affect the length as you have the right pitch. It can be quite tricky (re)adjusting the various levers to get the chain right so, like I did last year, you might find a half-link is a good option. It certainly saved me a lot of messing about:

dunnes2002 Wed, 21/02/2018

Excellent, who would of thought such a simple solution that I never knew existed.


I have bought 3 more for future chain changes. Thanks very much for your help. Now to get my blades back from the sharpeners. 

merryman Fri, 23/02/2018

What a weird way of describing chain sizes beltingonline are using. It is 1/4" wide by 1/2" pitch, not t'other way round, and the roller diameter doesn't get a mention, though it is there in the picture. I also find the use of metric measurements when describing imperial chain annoying, though most manufacturers and suppliers do it these days.

gtc Sat, 24/02/2018

I also find the use of metric measurements when describing imperial chain annoying

Ditto, and here in Oz we've been metric since 1974. Goods that were made to imperial dimensions should always have that information in the description. Can't rely on sellers doing the metric conversion correctly.


wristpin Sat, 24/02/2018

I agree , imperial chain should be pitch, width and roller size in imperial units.  However equally annoying is the variation in pin diameter which varies with the country of origin and manufacturer and appears not to conform to any standard. 

I’m not sure whether any chain is still made in the UK but over the years we received chain made in India and Poland  each with fractional differences in pin size which made holding a small stock for immediate  use a bit hit and miss.

The other variation is in chain terminology. Connecting link is self explanatory  but some suppliers use the term “ spring link” which is not.  We had one supplier who used to get quite upset with the use of “ half link” . No such thing, he would say, “now do you want a single or double crank link “?

gtc Sat, 24/02/2018

No such thing, he would say, “now do you want a single or double crank link “?

Sounds like you were linked to a crank already :-)

wristpin Sat, 24/02/2018

Sounds like you were linked to a crank already :-)

Well, yes and no; he knew what he meant, I knew what he meant, just a question of terminology!

dunnes2002 Mon, 26/03/2018

finally decided to get a new set all round instead of using new and old chains. Used the link from earlier to purchase the wychbearings chain and im glad i did. Amazing how much it changes the look of the machine and hopefully will mean i will have a successful first run this weekend. Thanks for your help.