Bottom Bracket Selection Guide
DUB Crank Spacing Explained
DUB burst onto the scene with the full weight of SRAM cramming it into our cycling lives whether we liked it or not. Such is life in the age of mega-corporations telling us what we want and why. The good news is that DUB is not a bad thing---not at all---it is just more of the same basic thing. It's everything a 30mm spindle is, except 1mm smaller in diameter at 29mm, and that about sums it up. There is one aspect of the DUB system that is vastly different than most 30mm spindles, and that is DUB's lack of flexibility when being fitted to narrower frame sets such as BB30 for road and MTB, PF30 for road and MTB, BB30A, PF30A, and some others. In this video we tell you how this works. Regardless, we've got a solution to fit a DUB crank to ANY bottom bracket standard you've got.
I want to explain to you guys how DUB works as far as the bearing spacing, because it's absolutely critical. People are asking about adaptations and things like that. Let me show you the street facts. Now you guys have seen this before come on in here this is a threaded bottom bracket insert that would be inside of a bike. You would then put BSA cups in it. So, this is 68mm wide now everything I'm talking about here also applies as far as the spacing goes also applies to mountain bikes just basically add 5mm to it because we go from 68mm to 73mm for most mountain bikes. Yes, there's 70mm there's 83mm out there but for the sake of argument, I'm going to show you how this works with DUB and you see I've got a DUB crank right here this is a 68mm wide shell. If this was BB30 the bearings would be pressed into the 68mm wide shell, and you can see here there would be no way for the bearings to journal on the crank because let me show you this right now. I'm going to go ahead and put this DUB insert on here that makes this BB30 bearing 29mm and if I press it in, if I push it on here you can see once I get in the middle there I can't journal in there there's nothing okay, so whatever happens the bearings have to exist outside of the frame or they have to act they have to be really far out this spacing just happens to be what a BB86 or a BB386 EVO would be it's a 68mm shell with cups threaded into it if you measure that hey it happens to work out so that's where we get that's where we get this from okay we get this DUB spacing from Shimano all right that's how that works and the reason why this is important is because when it comes to a regular 30mm spindle frame you can see right there okay if this was a 68mm wide shell and there were bearings inside of here it would easily be able to journal onto this crank. I'll go ahead and pop this insert out real quick right here push it on there and you can see not until I get in here is there nothing for me to journal to right out here, I can just find, and you see if this was BB30. I could easily add spacers to that and still be able to journal safely on the crank whereas it would be impossible to do with this so what this means is you need specific bottom brackets for dub for this reason you cannot adapt most 30mm spindle bottom brackets like a BB30, PressFit30, PressFit30A if you're running a 30mm spindle in those you're not going to adapt them to DUB, you will need a new bottom bracket because of the needs of the DUB system to journal the bearings so far out at the extremes of the spindle
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