My Brompton 2 to 3 speed conversion improved

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Fastpedaller

Über Member
I changed my 2 speed to a 3-speed derailleur using the well-documented changes others have been doing for years - change to thinner sprockets and 10-speed chain etc.
Although it worked well at first, now the chain has worn-in a bit, getting into the larger sprocket was a bit hit-or-miss. Careful examination suggested the sprocket was a little too far to the left for the jockey wheels, and they (the jockey wheels) couldn't move any more, even if the pusher was given more free movement. A piece of stainless steel tubing with an ID of 4mm and OD of 6mm, along with longer 4mm set screws was used to good effect. With the tubing cut to 23mm (4mm longer than the original jockey wheel spacers), and the longer screws, the change is perfect! The only issue is that the protective caps on the jockey wheels can't be used because of the increase in movement. Regular cleaning/lube will be needed. The next plan I have is to build a stainless steel copy of the Brommieplus pusher, because that appears to be a much more efficient pusher than the original when more gears are used. I have to say the original is perfect for its intended use; it's because of the changes I've made that further changes are desirable. As an attempt to 'improve' the original, meanwhile, I have rounded and polished the edges of the pusher plates so the jockey wheels don't become damaged.
 
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