this is your derailleur this is your cassette this is your chain this is your chainring and this is
your shifter and you'll need to know a little bit about all of those things to make your bike
stop shifting like garbage let's do some more anatomy this little guy up here on your shifter
is your barrel adjuster then back here at the cassette these are individual cogs the big ones
are your low gears and the small ones your high gears then on your derailleur this is the body
of the derailleur this is the cage these are your jockey wheels these are your limit screws and this
little guy at the back that's your B screw this is your derailleur cable it clamps to the body
of the derailleur this little guy here that your derailleur bolts into is the derailleur hanger I
know that sounds like a lot of anatomy but stick with me we're gonna go over all of it again
now every time we hit the thumb switch the derailleur is actually shifting up the cassette
into larger cogs or lower gears it is actually pulling on the cable to make it do that when you
are shifting into smaller gears or higher gears it is actually loosening the cable and causing
the derailleur to spring back towards the bottom of the cassette uh oh now if your shifting isn't
working properly he's making clanging noises it's shifting in between gears that's skipping around
there are a number of different things you can check with a chain wear Checker derailleur hanger
alignment gauge I would imagine if you're watching this tutorial you don't have any of those things
and so let's start with a visual inspection if your chain is completely Haggard might be time
for a new chain if you have broken worn looking teeth all over your cassette might be time for a
new one all of those things can affect shifting and you can just look at the bike to see whether
that might be the symptom and so start with a visual inspection but there's other things that
you can look at here if we pedal the bike we can see that the chain is making clicking noises and
it's skipping around take a look at it which way is it skipping so you can see as I'm pedaling that
chain is trying to move on to that larger Cog but it can't quite make it because the cable is not
tight enough how do we know that well because that's what it is ninety percent of the time
cables don't magically tighten themselves they end up getting looser over time because the cable
stretches or the ends settle into the housing and so let's try tightening the cable and see
what happens you can make little adjustments with your Barrel adjuster you actually loosen
it to tighten the cable a little bit so I would start with half turn so now as we start the pedal
we can see it shifts up into there now it almost stays in gear let's try tightening it a little
bit more so we'll just go another half turn here let's try shifting down back up it's working but
let's shift through all the gears to make sure it really is make sure we didn't go one gear too high
so when your bike is more or less shifting okay but it's still making those clicking noises and
the derailleur appears to be crashing into your cassette you might want to check your
B screw so with an initial visual inspection it appears that this upper jockey wheel is
way too close to the cassette you can see it's just rubbing against it when we adjust this B
screw at the back of the derailleur or your B tension which you're actually adjusting is the
distance of your upper jockey wheel from the cassette and so if we tighten it it's going to
move it away from the cassette and then we can try it again see if it makes disgusting sounds
so that seemed to solve the problem right away why don't we just crank down the B tension all
the time why shouldn't that just be the only setting well if your B tension is too high
when you go down to your smaller gears the jockey wheel is really far from the cassette
and it's going to have trouble keeping the chain in the right space it's going to skip
around and so the correct way to set B tension is to shift through all of your gears get the
upper jockey wheel as close to the cassette as possible without crashing into the cassette or
shifting hard so start further away and then start bringing it in until you start getting
adverse effects and then back it back out not very scientific but that's how you do it
so you learned a thing or two now you're working on your derailleur and you have it shifting more
or less perfectly in like two or three years and then if you go to low on the cassette or
too high on the cassette it just starts to skip all over the place what's going on you
probably have a bent derailleur hanger and you can check that with a visual inspection so the
alignment of your derailleur hanger has to be so precise that actually they make a gauge for
it but you don't have one and so sight down the back of your derailleur and look at the piece
that it's attached to is it kind of bent in One Direction now if you can't see it
visually there is another test you can perform and all you're going to need is a cup of water
first remove your back wheel and then the derailleur hanger it's going to be held
in with some screws or possibly your axle you can figure it out once you have the derailleur
hanger loose off of the bike you're going to drop it into a cup of water I like to use a
clear glass four ounces four to eight ounces is going to work drop it in [Applause] [Music]
and if it sinks to the bottom you should try replacing your derailleur hanger now I must
have done this demonstration three or four times in different videos YouTube shorts somebody always
chimes in with I'm a flotation engineer at the Academy of complicated science and derailleur
hangers are made of aluminum aluminum sinks no the flow test is a joke goes right over people's heads
it's a joke what I mean is replace the derailleur hanger and see if that fixes the problem if it
doesn't you can put the old one back on or keep it as a spare doesn't hurt to have extra
derailleur hangers and that is the root of many shifting issues so you've made micro adjustments
you've adjusted your B tension you've even replaced your derailleur hanger your derailleur
is Shifting perfectly but then you're riding down the trail you hit a bump and this happens
ah
you're minding your own business trying to enjoy your day and then your change shifts
into your wheel it's probably your limit screws these two screws on the body of the derailleur
that are next to each other those are your limit screws they're going to control your low limit
and your high limit so here you can shift into the smallest gear over here and actually grab
the body of the derailleur start pedaling and you can actually push the derailleur through its gears
if you are able to push it into the wheel you have to adjust your limits those limit screws
should physically stop the derailleur from doing that so that if you hit a bump and it jumps it
doesn't just shift your chain into your spokes and cause all sorts of Carnage see if you look
closely you can see where the screw makes contact with the derailleur body and stops it from moving
anymore just look in there as we tighten this it's actually going to stop it from moving any
further now if we tighten it too much then you're not going to be able to shift into your largest
gear but if you get it just right it can shift into the largest gear and not any further and
that's how you set your limits but now that we got through all that I can show you a few
finer points about drivetrain issues so before I mention a specialty tool a chain wear Checker
these don't cost very much you can pick one of them up on Amazon and you can check to see if
your chain is worn out by inserting it into the chain pulling down tightly over here and seeing
whether you can insert this probe into your chain the deeper you can insert this into your chain
the more worn out it is but there's another way you can check hook your tape measure onto your
chain stretch it out to 12 inches and at the 12 inch mark it should fall exactly on the edge of
a chain link if the chain links a little longer like an eighth of an inch even a sixteenth of an
inch your chain might be worn worn out and it's time for a new one another little tip this little
Barrel adjuster is for micro adjustments if you find yourself just cranking this Barrel adjuster
eventually it's going to max out and that's not good what you really want to do is bring
the barrel back in loosen up the clamp on the body of the derailleur and actually pull it a
little bit tighter try to get it close enough and then do the final adjustments with your
Barrel adjuster and for that matter when you are adjusting the tension of your cable you want to
first shift into the smallest gear to do so or else it's going to be fighting you one other
thing throughout this video I've been using a specialty tool that many of you do not have
a bike stand I did that to make it easier to demonstrate but you don't need one you can just
turn your bike upside down and diagnose just about any drivetrain issue
found knowledge maybe we can figure out what the hell is going on with this bike
this is my father-in-law's e-bike it is all business you can tell by the stack height
not only does it shift like garbage but it actually pedals like garbage listen to this
let's start with a visual inspection it's a little dirty but I don't see anything that's
that worn in fact you can still see the cassettes nice and shiny the bike's not that old and so
that makes sense and so we can rule out that everything here is worn out just by looking at
it so let's pedal it and take a look at what it's actually doing here I can tell by where
the shifter is that it is supposed to be in the lowest gear but it is in the second to lowest
gear and so what does that mean cable tension is probably the culprit now do you reckon it's
too loose or too tight remember what I said before about 90 percent of the time it's too
loose let's try tightening it so let's start with the barrel adjuster actually on this bike
the barrel adjusters on the derailleur itself let's give it half turn and see how it shifts
I think we're gonna have to do a float test
now I don't need to flow test it I have a derailleur hanger alignment gauge but I can
use it to illustrate that the derailleur hanger is definitely bent because we checked all those
other things and it's still shifting horribly so let's try and it's funny how there is a
derailleur guard here yet freaking derailleur hanger still out of alignment [Music] [Music]
oh yeah way out of alignment okay she should be back in alignment so now we can put it back
on adjust the tension and see if it shifts right okay up into the bigger gear down one
down two shifts well this is not exactly the most high performance shifting system there is
but we can see if it shifts through the gears correctly now that we have a line
the derailleur hanger now I understand you don't have a derailleur hanger alignment gauge but if
you would have used the float test you would replace the derailleur hanger with a straight
one and achieve the same result so for the audience members that already know how to
work on drivetrains I realized that I left a lot out I realized not all of this is by
the book that's because it wasn't meant for you you already know how to do this this is the get
somebody who hasn't really worked on a drivetrain before up to speed and able to diagnose certain
shifting issues and I'd say we've covered about 90 percent of them assuming you have a semi-normal
bike I hope you found this video interesting I hope you learned something and if you already
know how to do all this and you didn't learn anything I hope you at least feel like sharing
this video or maybe you were entertained thanks for riding with me today I'll see you next time