I'm replacing a SRAM GXP bottom bracket BSA (English BC 1.37x24T) 68mm wide with a aftermarket brand that is supposed to fit both 68mm and 73mm. However, there are a few issues with the width that I can't figure out.
(1) The new sleeve between the two bearing cups is 60mm when the old one was 55mm
(2) The length of the threads on the new cups is about 5mm deeper (longer) than the old cups
(3) The new sleeve has a ridge on both ends that mates with the cups and fixes the width
(4) The old sleeve only has a ridge that mates with the drive side cup and slides into the other side but the new non-drive cup has an internal ridge that won't let the old sleeve slide in far enough
Bottom line is that I don't see a way to make this new bottom bracket work using either sleeve. I have it together and it works great without any sleeve but that's not really not going to work because it will let moisture and dirt into the shell. The new BB came with three 2.5mm spacers but adding them to the non-drive side would increase the Q-factor and I don't really want to do that.. Not sure that would work anyway if given: 2 x 5mm (longer threads) + 5 mm wider sleeve = 15mm wider than old and I can only add 3 x 2.5mm = 7.5mm spacers.
Is this normal, am I missing something, suggestions?
(1) The new sleeve between the two bearing cups is 60mm when the old one was 55mm
(2) The length of the threads on the new cups is about 5mm deeper (longer) than the old cups
(3) The new sleeve has a ridge on both ends that mates with the cups and fixes the width
(4) The old sleeve only has a ridge that mates with the drive side cup and slides into the other side but the new non-drive cup has an internal ridge that won't let the old sleeve slide in far enough
Bottom line is that I don't see a way to make this new bottom bracket work using either sleeve. I have it together and it works great without any sleeve but that's not really not going to work because it will let moisture and dirt into the shell. The new BB came with three 2.5mm spacers but adding them to the non-drive side would increase the Q-factor and I don't really want to do that.. Not sure that would work anyway if given: 2 x 5mm (longer threads) + 5 mm wider sleeve = 15mm wider than old and I can only add 3 x 2.5mm = 7.5mm spacers.
Is this normal, am I missing something, suggestions?
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