Reaming a Pressfit BB Frame Shell to Size Part 4: Cutting Operation; Let The Ream Do The Work

Reaming a Pressfit BB Frame Shell to Size Part 4: Cutting Operation; Let The Ream Do The Work

December 28, 2022

 

Part 4 of 5: In this video we show you how to properly ream a frame bottom bracket shell to correct width. Yes, this should be done by the factory, but often this step is skipped, and the bike goes into a box with an out-of-spec shell. Look how easy it is to fix... Check out:

 

All right, if you haven't watched the previous videos go watch them before you can't pick up here okay but we're using a little bit of tap magic right here i'm just gonna put it down inside the hole because we're about to ring this bad boy out. Alright now we're going to take off about 5 000 worth of material and once again i kind of think that maybe this spike should have been reamed at the factory was prepared to be reamed and maybe they didn't remember it and it ended up in a box. Regardless, we want to set a little bit of spring tension right here now. I use this tool pretty frequently but by all means look at the park tool manual to learn how to do it, don't learn it from me necessarily right now. We're going to start reaming at this time. It's going to really want to bite in because 5 thousandths is a lot of material the important thing to do is to be very fluid with your movements okay because as you see the spring pressure is dragging it right in right it's almost home right now so we already measured this we measured this ream we know it's going to do 40.98 so we're going to be good to go and that is actually done look at that no must no fuss now when you're when you're taking it apart i want you to go ahead and turn it backward okay we want to turn it backward because it doesn't cut in that direction we don't want to accidentally cut material as we're removing it because you can so what I'm going to do move my arm so you can see what's going on here this is the tricky part you're getting it out and normally this is the way park tool sets up this room unfortunately normally what you would want look at all this material look at all that material how could that bottom bracket ever be any good all right now let's look in the hole see what we got well hold on a sec i'm going to blow that out a little bit don't go reaching your fingers in there pull chips out it could be bad could end up cutting yourself all right and uh let's see so we're gonna go ahead and look in there and say we'll look at the surface it's not the most it's not the most perfect surface but it is the correct size and we're going to go ahead and we're going to uh confirm that we are at our target measurement and we are we're right about 40. 40.98 it's going to give us excellent fit when we go to put this bb infinite module in in just a second



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Also in BBInfinite exists to elevate the bottom bracket to the high-performance, low-maintenance, reliable component it is meant to be. Rid yourself of press fit bottom bracket creaks and pops. BBInfinite is silent performance.

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