Bottom Bracket Selection Guide
Reaming a Pressfit BB Frame Shell to Size Part 1: Introduction
Part 1 of 5: Some bottom bracket frame shell openings are too tight. Some by a lot. In order for your bike to be any good you must correct this condition, but the first step is to confirm your suspicions. This is how it's done. Check out these links:
- Part 1: Introduction
- Part 2: Preparing the Ream
- Part 3: Exactly How Does Press-Fitting Work?
- Part 4: Cutting Operation; Let The Ream Do The Work
- Part 5: Post-reaming BB Install
- Part 6: Post-reaming BB Install (Bonus Vid)
when you have a bike that's going through multiple bottom brackets, and they just immediately go bad or when you put them in, they feel bad right away you need to then go and check the frame. You very likely have an issue with the frame over compressing the module for the bottom bracket or the bearings because this hole is way too small everyone assumes these are going to be right from the factory because it came out of a factory right don't assume anything okay the first thing you need to do is measure it all right now this is the typical way people try to measure it you are never going to get a good measurement with a vernier caliber it's just never going to happen okay sorry to tell you um what you need to do first and foremost is clean it because if it's dirty one of the things you're measuring is the dirt and the kind of measuring we're going to do here is sensitive enough that that will make a difference you will be measuring the dirt and you will throw off your measurement now what i'm going to use here is I'm going to use an inside mic okay this measures in three spots okay so it is so it is very accurate of course this is a nice quality tool and i'm just going to chuck it up in here and I am going to send it read it okay now i've already done this that's why i know this bike needs to be reamed okay we're going to be using this okay to open this hole up very shortly but the first thing you need to know is this is about 5 000 of an inch too small okay that is a lot okay that is normally the amount you would leave on if you intended to remit so what very likely happened is this bike missed getting reamed and it ended up in a box now this can happen okay factories are a very confusing place sometimes they're generally orderly but things like that can happen so you have to be on the watch for this sort of thing so now we're going to show you how to correct this in our next video
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