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How to fix a creaky frame can be something we ask ourselves quite often as cyclists. Often we look towards changing bearings and adding excess amounts of grease to areas that may not even need it. Sometimes the problem can run even deeper. This is why facing, reaming and tapping frames is essential. This ensures that components interface correctly with the frame.
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00:00Creaky bottom brackets and rubbing disc brakes are two extremely common complaints among cycling
00:11enthusiasts and pros alike. Very often we look at the components instead of the frame when we're
00:17looking for a solution and that might well be an error. Bottom brackets disc brake mounts were
00:22designed to be seated in frames that are up to the job and unfortunately that isn't always the
00:28case straight from the factory and that's where facing comes in. This is the process of removing
00:33excess material to ensure that holes that are meant to be round are in fact round and surfaces
00:38that are meant to be flat are flat. We're here at Velo Atelier up in Warwick to face this frame and
00:44see what a difference that extra step of TLC can make. Co-owner at Velo Atelier, Lee Prescott has been
00:57designing and manufacturing frames for 37 years. He designs and manufactures own Meteor Works metal
01:03frames as well as working with partners creating carbon frames such as Fesca and Open and also
01:09servicing frames from a great many brands using lots of different frame materials. Now he tells
01:15me that he never builds a frame up without first checking the tolerances and then facing, reaming
01:20and tapping if it needs it. Now tell me why that is. We wouldn't even dream of not facing and reaming
01:28and tapping all the interfaces on the frame because it simply makes the build easier and more efficient
01:34and it means that all the parts will last longer and just work more efficiently. Okay so you've got a
01:40brand new frame that's just come in or it's a frame that's come in for a really high level service
01:44and you've stripped it all off and you're going to check each of the elements of the frame to prep it
01:48before building it. Just run me through what exactly you're going to be doing with each area of the
01:52frame. So starting with the disc brake bosses on the frame and the fork what we're doing there is
01:59making sure that they are both parallel to each other and also creating a face that is perpendicular
02:06to the disc rotor so that the pads hit it squarely. Then with the bottom bracket what we're doing is
02:14ensuring if it's threaded that all the threads are free and clear and round so that the threaded
02:21bottom bracket will go in nice and easily without damaging any threads. But most importantly we're
02:27making sure that the faces on each side are both parallel to each other and straight and flat so that
02:34any cup that's biting into it is pushing in level and maintaining a level of parallelism. With the headset
02:41we're facing the surface that the bearing is going to mate to so whether that's an external headset,
02:47a zero stack headset or an internal headset we're braiding those faces so that they are parallel to
02:54each other and ensuring that they're round as well. That way the bearings sit in alignment and prevent
03:01any excess wearing of the bearing.
03:09Facing reaming and tapping are generally associated with metal frames and less so carbon frames which are made in a mould
03:17and in theory should be up to spec and shouldn't really need it. Why might you need to face ream or tap a carbon frame
03:25frame and is it something we should perhaps see more of? So you're right it's it's much more prevalent on
03:31metal frames because on a metal frame you have to overcome any warping or distortion that's happened
03:37during the welding process. On a carbon frame as you say you know they come out of very expensive moulds
03:43that are built to very high tolerances so most of the time providing all has gone well with the build
03:49the layup is in the right place the shrinkage has happened at the appropriate rate the humidity they
03:54were built you know all these factors that need to be controlled and are controlled in good quality
03:59factories should mean that the frame comes out in a in a pretty good state and then any final fine
04:05finishing can be done at the factory just to polish up areas that need a higher tolerance. So it's it's
04:12less required typically on carbon frames but where the issue arises is when you get
04:19certain designs that have separate cups and then if you're fitting for instance at the bottom bracket
04:25end bottom brackets are two separate cups that aren't joined and the faces are not parallel for
04:32instance when you press them in they can then deform slightly and that's when you get bearings that are
04:38not concentric and parallel and that's what leads to excess wear and the dreaded squeaking and creaking.
04:45And one way to deal with that might be facing it in terms of the bottom bracket there are probably
04:50more cost effective options available right? Yeah absolutely unless it's wildly out in which case
04:58it's a manufacturing defect and should be under warranty anyway you can normally get around a lot of these
05:03problems by the use of a good quality bottom bracket that's connected in some way so you know something
05:08like this that screws together with a very fine thread that maintains the concentricity and parallelism
05:15of the bearings so that reduces any issues you're going to get with misalignment. Whereas at the back
05:21end with the bosses that is something that often you might get just that little bit of paint or something
05:26it can really could be beneficial with a carbon frame it's not quite so expensive? No well the tooling
05:31exists for facing carbon disc brake mounts so actually facing a carbon frame in that area is no more time
05:41consuming or expensive than doing a metal frame and it's something that most frames could benefit from
05:47even if it's just to remove excess paint that's slightly misaligning the caliper and it's the key
05:53thing is just creating a perpendicular surface to the disc so that when you're clamping that brake caliper
05:59to it it's parallel so at least your pads are hitting the rotor squarely.
06:10So if you've had a bike that's come into your workshop it's perhaps not had the best QC it's not
06:15maybe the best frame and the components haven't been running in it very smoothly what are the very
06:19common symptoms that you would see as a result? So I guess starting from the rear moving forwards
06:25obviously disc brake bosses that are not parallel and perpendicular to the disc you get the rubbing
06:32that we all have heard from time to time it's maybe slightly spongy action on the brake regardless of how
06:39well bled it is disc pad wear being very uneven is a real common symptom and then coming forward to bottom
06:48brackets creaks that can't be defined when you remove the crank arm you know in the worst case
06:55scenarios it misaligned bearing will destroy the crank axle so things to look for are when you remove
07:02the crank arm check in the axle to see if there are small scores or uneven wear patterns you know really
07:10your crank arm axle shouldn't be sliding inside the bearing the bearing should be rotating if
07:18then the bearings are misaligned then it prevents free rotation which means you'll start to get more
07:25sliding which as soon as metal slides over metal you're going to start wearing it away so you know if
07:30you've got a very expensive power crank that's an expensive mistake and then for for headsets if
07:38if the bearings in headsets are misaligned you'll either feel kind of tight spots so your steering won't
07:44be free and even that can obviously lead on to the the actual bearings pitting the races and then you get
07:52kind of indexed steering and there's no need for it you know a nice flat parallel bearing surface means that
07:59your headset should last for as long as you want to keep it you know i have a chris king headset
08:04that's over 20 years old and it's swapped from a bike to bike and it's still running as good now as
08:10almost the day i bought it so you mentioned to me earlier while we were preparing the last frame that
08:16it might be a process that people do if they're going to hold on to a bike for much longer is it fair
08:20to say that it would take some time to notice that a bike actually was presenting with these problems
08:26yeah potentially i mean you know most brand new bikes with brand new components
08:30are going to work um and work fairly well and not creek straight off the production line so for a
08:36bottom bracket for instance wearing of the bearings due to misalignment is going to take a little time
08:42i would say you know if you're really unlucky and you've got a slightly non-concentric bottom bracket
08:49with um separate cups that were misaligned in when they were pressed in i mean you'll feel it straight
08:56away because the the crank won't want to move freely it might have tight spots in its rotation
09:04and if that's the case you're going to wear the bearings out really quickly within months most problems
09:09are not that bad um you know that's worst case scenario and if you ever come across that actually
09:16that's a manufacturing issue and a warranty issue so you know you shouldn't be coming to people like
09:22us to pay to get it sorted you should be speaking to the manufacturer and having that problem resolved
09:35we've talked a lot about what we have talked to we will talk a lot about tolerance
09:39um it will be good just to define that and also to understand i mean our videographer earlier
09:44i'm sure you won't mind me mentioning was that was asking what he was looking for when he was
09:48filming the bosses and the kind of numbers that we're talking about are not viewable to the eye
09:54right not really no no i mean we're talking about fractions of a millimeter tolerance essentially
09:59refers to the amount above and below the optimum size something can be and it still work properly
10:07certain areas don't really require a high tolerance or a very small tolerance should i say
10:13other areas do need to be toleranced much more accurately to work correctly so such as an
10:20interference fit with a with a hard cup or uh properly aligned bearings and i mean tolerance is
10:28something that the the manufacturer would look at as part of their quality control or qc process but
10:33there are actually two sides to that the other being consistency yeah yeah with anything that the higher
10:39tolerance you want something the more laborious that process becomes and hence the more expensive also
10:45checking gear the finer the tolerance accurately measuring that becomes more difficult and hence
10:51costs more as well with most manufacturing processes the two things are to what tolerance and also
10:59a level of consistency because you always want as much as possible to have them all the same at the
11:06defined tolerance so initially actually wrote a feature about this before i came to speak to you
11:11and i spoke to several bike shops in that process it was probably about six um and it was almost a 50 50
11:18split between those that said yes uh frames out of tolerance that need facing is a huge problem we have
11:24to do it all the time and those that said i don't know what you're talking about this isn't a problem at all
11:28i mean the cynic could suggest that it could just be down to their attention to detail um it could also
11:35be down to the brands that they're stocking what other reasons might you give or are those the only
11:40available reasons i think both of those reasons are potentially valid um i also think you know it's
11:47something that these days with mass-produced carbon frames it's not so prevalent so there's a lot of
11:52shops that may not have the experience to be able to offer that or may just may not you know want to
11:58invest in the appropriate tooling to do um metal work in in-house everything that we've accumulated
12:06through the years if you went to buy it all today would probably cost you in the region of
12:11six to eight grand and we've talked an awful lot about um about tolerances uh there's also an element
12:18of consistency in there as well and all of that comes under quality control or qc now explain to
12:26me what happens that you've worked as a consultant for brands what happens in a factory and why is it
12:33that some of them might have more stringent qc than others it's all about having a defined level of
12:39consistency and having bikes built within a certain tolerance so the more consistent and the higher
12:48or tighter the tolerance that you want the more you're going to pay because that requires more
12:54checks more consistent checking um and you know how that is done within each independent factory again
13:03depends on the price so you know how you want it reported how you want the testing done how you want
13:09the calibration of the equipment done the more stringent you want to be the higher that cost is going
13:14to be so you know if you're trying to put out a one thousand pound complete carbon road frame or road
13:22bike even you're not going to be able to physically afford to have the highest levels of quality control
13:29it would make it not a commercially viable option um and it means all those people that have now got
13:35thousand pound road bikes that are exploring the sport and getting into things wouldn't have had that
13:39opportunity so um you know there's there's a place for all levels of quality control you shouldn't
13:45always just be right at the very highest because none of us would afford to buy a bike i mean there
13:51must be a how much is a reasonable amount of quality control actually adding to the cost of a bike is
13:57it possible to put a number on that it could be anything up to 10 to 15 of the price of a bike is going
14:07towards quality control procedures at the higher level but yeah i mean i think you have to look at
14:13it as a proportion which is probably the way you would normally work out how much you can afford to
14:19spend on on your qc process and we can talk about what happens in the factory until the cows come home
14:24but it might not help a rider at home that's got a bike that's creaking or not running smoothly if someone
14:31is watching this video and they think actually i think my bike isn't quite right what should they do
14:37so i think i think the key thing really is um you just need to go if you don't already find yourself
14:43a good experienced local mechanic and and chat to them about the issue and see what they can do for
14:50you there's lots of good experienced mechanics out there so you just find one that's going to help you
14:58so there you have it hopefully you're riding along in blissful silence and if so good for you
15:03if not then know that it might well be worth having your frame tolerances checked and the good news is
15:09that fixing the problem might not be as expensive as you think so i hope you enjoyed this video if
15:15you did then do hit the like button let us know what you thought in the comments and subscribe if
15:20you'd like to see more of our videos
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