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Phil Square Taper EBB?!
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You don't know the half of it; if the "lil philcentric" is anything like it's big brother it will be is down right whacky cool and complicated. Bike Rumor!umarth said:
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ditto!umarth said:
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Interesting.
I have a prototype design that is almost identical to this. It uses six set screws from the side, but on the non drive side for ease of access. The Phil Wood version has to be using 2.0mm or 2.5mm needle bearings for radial loads and either thrust washers or small ball bearings for side loads. It probably uses some sort of thread locker or thread builder to close the gap between the bottom bracket threads and the EBB cylinder. The attraction of this type of design is that it very easy to adjust if done properly.
There are a lot of parts involved in making such an EBB as it is both an eccentric(complete with locking mechanism) and a bottom bracket in one unit. I suspect that the Phil Wood version will not be inexpensive. Aside from the complexity and cost, there is the issue of spindle overhang from the bearings being so far inboard. It's probably not an issue, as many cartridge bottom brackets have similar overhangs, but it may me a concern for cranksets which require long spindles. The other potential issue is thrust preload adjustment. Early XTR and Dura Ace Octalink bottom brackets had separate radial and thrust bearing systems that were accessible. You could open them up and adjust or service them. The Phil Wood EBB would probably have something similar, but in a miniaturized form.
I have a prototype design that is almost identical to this. It uses six set screws from the side, but on the non drive side for ease of access. The Phil Wood version has to be using 2.0mm or 2.5mm needle bearings for radial loads and either thrust washers or small ball bearings for side loads. It probably uses some sort of thread locker or thread builder to close the gap between the bottom bracket threads and the EBB cylinder. The attraction of this type of design is that it very easy to adjust if done properly.
There are a lot of parts involved in making such an EBB as it is both an eccentric(complete with locking mechanism) and a bottom bracket in one unit. I suspect that the Phil Wood version will not be inexpensive. Aside from the complexity and cost, there is the issue of spindle overhang from the bearings being so far inboard. It's probably not an issue, as many cartridge bottom brackets have similar overhangs, but it may me a concern for cranksets which require long spindles. The other potential issue is thrust preload adjustment. Early XTR and Dura Ace Octalink bottom brackets had separate radial and thrust bearing systems that were accessible. You could open them up and adjust or service them. The Phil Wood EBB would probably have something similar, but in a miniaturized form.
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