Hi
I recently upgraded my traditional cup and cone bottom bracket with the appropriately sized BB-UN300 on my Viking Prelude bike. However, after fitting, I was concerned that the cup on the non-drive side was projecting some 8 mm or 9 mm. I initially assumed that this was due to the lack of available threads inside the frame’s bottom bracket shell and decided to have it chased out, which would resolve the issue. Despite the mechanic at Evans Cycles completing the work today, the projection is still there and I have been advised that the cup was being prevented from going deeper into the Frame Shell not because of the lack of threads, but by the actual bearing on the Shimano BB-UN300 itself. I am clearly at a loss as to why this might be so, having meticulously ensured that I was purchasing the correct component, on the basis of the original bottom bracket spindle and the specific size of the bottom bracket shell on my Prelude.
I would be grateful for any advice or suggestions on resolving this issue, although I would once again confirm that, according to all the details I had, the correct Shimano component has been purchased. I attach some images of the bike and both sides of the Bottom Bracket installation for information.
I recently upgraded my traditional cup and cone bottom bracket with the appropriately sized BB-UN300 on my Viking Prelude bike. However, after fitting, I was concerned that the cup on the non-drive side was projecting some 8 mm or 9 mm. I initially assumed that this was due to the lack of available threads inside the frame’s bottom bracket shell and decided to have it chased out, which would resolve the issue. Despite the mechanic at Evans Cycles completing the work today, the projection is still there and I have been advised that the cup was being prevented from going deeper into the Frame Shell not because of the lack of threads, but by the actual bearing on the Shimano BB-UN300 itself. I am clearly at a loss as to why this might be so, having meticulously ensured that I was purchasing the correct component, on the basis of the original bottom bracket spindle and the specific size of the bottom bracket shell on my Prelude.
I would be grateful for any advice or suggestions on resolving this issue, although I would once again confirm that, according to all the details I had, the correct Shimano component has been purchased. I attach some images of the bike and both sides of the Bottom Bracket installation for information.
