Bottom Bracket Selection Guide
BBInfinite T47 Power Meter Friendly Design Explanation and Crank Install
Too many people running T47-internal and even some T47-external bottom brackets are encountering crank rubbing issues due to the way the tool-engagement-flanges are designed on our competitor's T47 bottom brackets. These tool-engagement-flanges feature notches for a driver or wrench, and therefore must be thicker to allow for high torque applications. These larger flanges cause rubbing problems with many power meters, especially those with intrusive backplates such as those found on Quarq and SRM models. We solved this by redesigning the tool flanges to be thinner and smaller so that rubbing is never a problem. And yes, installation of our T47 bottom brackets require a new, special tool, but don't worry, we give it to you with every purchase. Check us out at www.bbinfinite.com YouTube link to video showing how the TruDrive Sleeve works: PressFit 30 Perfection Check out our Before and After spin test here: BBInfinite 1-Piece, Hub-style T47 vs. Sram 47: FIGHT!
Well now we're going to install the crank. In this case it's a DUB crank and first thing we want to do is install these and you guys are going to love this because I get more questions about grease than anything else and I can tell you right now you're allowed to grease stuff. You're going to love this no problem at all right. The reason why I like to use the grease is because in this case it allows these to stay in place just like that. Kind of like a little glue, so once again you're just using a little smear in there now these are the DUB road rings right here. We're going to install them; You can also put a little schmear grease on there if you like follow the directions, but you will see that the skinny one goes in the non-drive side and the one with the offset built into it goes on the drive side. As you can see, this has a true drive sleeve in it so we want to go ahead and now this is actually this lip is going to catch the true drive sleeve so when we push this in, we need to push the true drive sleeve up into position just like that, and then that will push in, boom just like that. So, you see how it captures that true drive sleeve right inside of there. So now let's go ahead and install the crank. Once again, you can use a little bit of grease and we can either put a little bit on the crank itself if you want or you can put it on the inside of the bushings- really doesn't matter. So right on there and we always want to do the splines on this now in our instructions we give you a link to the actual SRAM official instructions for installing the DUB cranks right here by all means we want you to follow those that's all I'm doing right now I am just following the SRAM instructions all you have to do is bolt the crank arm on and torque it down. All right now as I snug this right here, I'm going to do a final torque in just a second, but I always like to do as I'm assembling any crank set, I always like to spin it intermediately as I'm doing these different steps just to make sure everything is still functioning as it should be and as you can see it's functioning pretty well. I'm going to torque this to the spec that is actually laser etched on the crank fixing bolt itself and I have to tell you it's 54 Nm in this case always pay attention to what it's supposed to be and I got to tell you that's actually about 38 ft lbs that's a lot of torque that puppy ain't coming off what some of you will notice is that our flange on our T47 is actually smaller than a lot of the ones that are being used by well by SRAM and some others because we had a problem with um with this ring inside these SRAM DUB power meters they the quarks in general have this back plate that can intrude onto that diameter right there and we can have some rubbing problems we want to make sure that wouldn't happen so we went a little thinner a little smaller here and we ensure that that's never going to be an issue with this so as far as setting the preload you'll notice that I got this little back and forth action right here that's completely normal we want to push everything over to the non-drive side and it's got a nifty little plus with an arrow there shows us which way to turn it to reduce that gap and take that up so we're now applying preload now with most systems you want to balance the preload that's so you don't shut the bearings down that's not necessary with the bb infinite system we have the true drive sleeve in there I'll link a video below that explains how that works so what you want we what you want to do is just tighten it about as tight as you can get it which is plastic so uh don't go crazy and then go ahead and lock this little bad boy down right here the fixing bolt I'll just pinch that right together right there and we're done so we want to do that spin test well what the heck let's do a spin test the best spin test is what I like to call an acceleration test see that let it spin itself that's how you know the bearings are not being impinged okay let's just do that big beautiful spin so we can do that before and after so we saw the before now let's see the after I don't know how long do we want this video to be let's spin this bad boy visit bbinfinite.com for our new t47 internal bottom brackets
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