Hello All,
I have a question about a spring link for the rear chain, what size should it be.
The details, the chain is a good fit on the rear sprocket, but it has 2 spring links because it has a half link fitted.
The original links that came with bike are not the correct ones, the pins are much too long, so I ordered a 420
spring link but, the pins are too small while being the correct size for the chain. I have now ordered a 428, so
while I am waiting I thought that I would ask the question.
It has been over 50 years since I last bought a motorcycle spring link.
George.
Forgot to add it's for a 1955 D3 plunger Bantam.
George
The original chain fitted to your bike would have been BSA part no. 90-9037 (Reynolds part no. 110044-117L). This is a 1/2" x 3/16" chain which also is designated as 415. HTH
The problem is that all chains aren't the same, even those of the same nominal size. They vary by maker, so it's not easy to buy spring links sight unseen and hope they fit.
There are international standards for roller chains (ISO 606 B, BS 228, and DIN 8187). These specify dimensions such as side plate thickness so any chain components produced to these standards should be compatible. I tested this myself by fitting a cranked link from an online bearing supplier to an Elite chain from a classic bike component supplier and it fitted perfectly.
Sadly my experience is very different to yours. Maybe every chain components I've tried weren't to the specs you mention? I've had pins too large and too small in diameter, and pins not long enough to be able to fit the clip.
Are those standards for industrial chain rather than bike chain?
Chains are chains, so the standards should cover "bike" chains as well as industrial ones. Of course everything changes when we're looking at X and O ring types......
Sorry to disagree, but bike chains are made to higher standards than some/many/most industrial chains, which often have split rollers, thinner side plates etc.
Some years back we had an industrial salesman from a bearings etc company, and when he mentioned the price he could supply long lengths of industrial chain for, I made a joke about using some on my Bonnie.
He visibly blanched and replied "please don't ever do that".
You may be right. However I'm not aware of any national or international standards for motorcycle specific chains. So how can you tell the difference?
Well, that has certainly opened a discussion, I did realize that all chains are not the same, I have down loaded lots of charts about chains
of good old Google. And I have purchased a couple which do not fit (they fairly cheap) and I have gained some useful hands on experience.
Which is what it is all about.
My last experience was when I was seventeen and a had BSA Road Rocket, went to the local bike shop (where I worked) and bought a spring
link and guess what a perfect fit. Life has got complicated.
Quote from: Ian C on 22 Apr, 2024, 12:44
The original chain fitted to your bike would have been BSA part no. 90-9037 (Reynolds part no. 110044-117L). This is a 1/2" x 3/16" chain which also is designated as 415. HTH
415 may be nominally 1/2" x 3/16" and can possibly fitted, but the inside width is different and the rollers are not the same size as 110044.
Bantams originally used an unusual size chain (the above mentioned 110044) so if you have original type sprockets you must use the correct chain or rapid wear will occur.
If you have 415 or 420 sprockets (which are occasionally available), then fit the appropriate chain.
Be aware that a lot of retailers are unaware of the differences and will insist that 415 or 420 are direct replacements when they clearly are not.
See here for full information with size comparison charts.
https://www.bsabantamclub.com/forum/bantam-technical-archive-faq/chain-sizes/#p24256 (https://www.bsabantamclub.com/forum/bantam-technical-archive-faq/chain-sizes/#p24256)
Quote from: iansoady on 24 Apr, 2024, 12:47
You may be right. However I'm not aware of any national or international standards for motorcycle specific chains. So how can you tell the difference?
Having some time to spare I got out my tin of chain off-cuts, split links and cranked links to check compatibility. I have bits of Regina, Renold, Izumi and others I've never heard of before, and the compatibility seems almost non-existent.
Maybe those International standards refer to material and specs rather then sizes and compatibility?
No, they do specify dimensions. The attached is an extract. Having said that, I agree that chains of all sorts have been sold over the years and like you I have various mismatched bits and bobs collected over 60 or so years. But provided the chain consorms to standards all components should fit.