mike425 Posted July 10, 2019 Report Share Posted July 10, 2019 Hi all, I have recently acquired a Leeson 609 which I have refurbed and just in the process of building. I am trying to source a bottom bracket for it, but I have square taper cranks so choice seems limited. Does anyone know the official size of it? I am guessing I will have to turn the lip down on the bb? I have lost the original one so cant measure it. Thanks Quote Link to comment Share on other sites More sharing options...
Danny Posted July 11, 2019 Report Share Posted July 11, 2019 As you say from memory they had the lip machined off and were held in with a circlip. I can't help on size but i'd suggest you get the longest one available. You should be able to measure the shell size. Quote Link to comment Share on other sites More sharing options...
Mark W Posted July 11, 2019 Report Share Posted July 11, 2019 Does anyone know the reason for them doing that setup? I only found out about it after someone I knew had to send their frame off to Leeson to have a new BB fitted, but didn't know what the thinking was behind it. Quote Link to comment Share on other sites More sharing options...
aener Posted July 11, 2019 Report Share Posted July 11, 2019 (edited) I have a vague memory of Ed Potts telling me it was simply because Leeson didn't have a tube bender, and having the super-wide extended BB shell meant he could get away with using straight chainstays. (Hence also having brazed straight tubing for the seatstays.) I kind of want that to be true and not at the same time Edit: Which could be marketed as "for rigidity" if desired. Funny how that whole thing came back around but more purposefully with the Crewkerz frames. Edited July 11, 2019 by aener 1 Quote Link to comment Share on other sites More sharing options...
Ross McArthur Posted July 11, 2019 Report Share Posted July 11, 2019 Quote Link to comment Share on other sites More sharing options...
Mark W Posted July 11, 2019 Report Share Posted July 11, 2019 4 hours ago, aener said: Edit: Which could be marketed as "for rigidity" if desired. Funny how that whole thing came back around but more purposefully with the Crewkerz frames. They do say history is cyclical, I guess. Punz. Much like Leeson's hands were tied in one way, I suppose Crewkerz's'zs's are in another with those weird offset AS30 BB shells and cranksets they have to use nowadays. Cheers for the clarification Ross Good to know what the deal is finally! Quote Link to comment Share on other sites More sharing options...
mike425 Posted July 11, 2019 Author Report Share Posted July 11, 2019 Thanks for the help everyone. It looks like it needs an 83 x 128mm bb. These look like they are only available these days in ISIS, which is a bit annoying as my middleburns are square taper! Photo for anyone interested: 2 Quote Link to comment Share on other sites More sharing options...
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