How To Get Perfect Gear Shifting On Your E-Bike

How To Get Perfect Gear Shifting On Your E-Bike


– E-bikes may well offer
you electrical assistance on your bike, but you
still need to have full use of your gears in
order to maximize on that. Now, adjusting the gears on
any mountain bike is important, but it’s absolutely vital on an e-bike because with no adjustments,
that motor can wreak havoc to a transmission
and your rear derailleur in particular. Which can be frustrating, and immensely expensive. So, getting your head
around how the mechanism actually works and what
all the adjustments do is the best port of call to get perfectly indexed gears, so let’s start there. (groovy music) – Now, let’s take a look
at the derailleur itself. Also known as the rear
mech, the derailleur takes it’s name from the simple fact that it’s job is to derail the chain. Simple as that, derailleur. Now, the derailleur itself
first made an appearance in the 20th century, and
although it has come on leaps and bounds,
fundamentally, still works in the same way. It’s made of two main
parts: there’s the upper, which is a sprung
parallelogram design, and then there’s the lower which is
a sprung cage containing two guide wheels, also
known as jockey wheels. Now, the job of those
wheels is to basically take the chain across the range of gears. That’s what the parallelogram
does, and the sprung mechanism basically takes
up that chain slack when you’re in a higher gear which
equates to having a slightly looser chain, it’s very simple. Now, most modern derailleurs
have some sort of clutch mechanism on there. You can see on Steve’s bike
here, the clutch is based in this part and is essentially
a friction damper in order to maximize on the
tension given to that chain to help the chain
stay on, especially on these one blade chainring
design bikes you see now. Now, Shimano also has a
clutch but differs slightly from the SRAM design. On the SRAM one is a
non-adjustable clutch, but it does have a lock on the
lower cage and the lock is useful for when removing
a wheel from the bike. On the Shimano design
you can actually turn the clutch on and off to
achieve a similar effect. (groovy music) – Now before we get to
any of the adjustment points of the derailleur,
we just wanna talk you through what sort of checks
you need to do first, because you could be wasting your time if something is damaged. Now, first I’m going to
make sure that the wheel axle is secured in the
bike and everything is aligned correctly with
the wheels, you wanna make sure that that’s actually spinning correctly in the frame. Next up, you wanna make
sure that everything is aligned correctly. What you’re looking
for here is that hanger that the derailleur
attaches to on the frame, you wanna make sure that that hangs down vertically, so it’s not bent to one side. If that happens, then
the whole derailleur will be moved to side and the
movement range will be offset slightly, which
you might not be able to compensate with adjustments,
which I’ll later show you. Next up is a visual inspection
on the derailleur itself. You wanna make sure,
again, that those jockey wheels are in line with
each other and they’re in line with the relevant sprocket that is actually suspended underneath. If it all looks okay, the
next step is to make sure that the five millimeter
bolt that secures the actual derailleur to
the hanger on the frame, make sure that is secured properly. If like on Steve’s
bike, the hanger is part of the frame that’s
actually removable in case you damage it, just
make sure that the bolt that holds that in place is also tight. Any sort of movement that can happen can dramatically affect the
shifting of your gears. Now if that is all good
to go, the last thing you wanna make sure is good
is the chain on your bike. Now generally speaking,
you can get two, sometimes three chains to one
cassette in terms of wear. And the reason for that
is as the chain wears, if you replace your
chain before it gets to a certain point, you
will stop the sprockets, the teeth on the
sprockets, front and rear, wearing out prematurely. Now if you think about
this, the chain itself is made of pins, and has got
inner and outer plates and it’s got rollers. Now those rollers need
to sit into the troughs between each of the sprocket teeth. Now if the chain stretches
a tiny bit, which it does over a duration of
time, it’s gonna start wearing the wrong parts
of the teeth on the cassette and on the
chainring, which are far more expensive parts of components to replace. So this is why we do
recommend some sort of chain checker, there’s
two models really on the market: there’s the basic
one, and there’s the slightly more advanced one
which has more readings on. The way this works is you
would simply put the pins into the chain itself,
you would take up the slack with the actual
device and you would take a reading and it will
tell you exactly how worn your chain is from 1.0 to zero. Now ideally you wanna
be replacing your chain when it’s about .5,
certainly no more that .75 because beyond that is
gonna be too stretched, and you’re gonna be
wearing out your cassette and your sprockets at the
same time, which if you work it out is quite a lot
of money to spend in one hit. So if you replace your
chain before it gets to .75, you’re gonna get
at least two chains to one cassette, saves you
money in the long run. (groovy music) – On every derailleur there
are 4 main adjustments that can be made. There’s the high and
the low limit adjustment screws, they literally follow the range of movement the rear derailleur has. There’s the B-tension,
also know as the B screw, which adjusts the height
of the upper jockey wheel in relation to the
largest sprocket out back. Then, of course, there’s
the cable clamp which, of course, adjusts the
tension of the cable which dramatically affects
how to shift and work. So let’s start by looking at the upper and lower limit screws first. (groovy music) Now the limit screws
may differ on different rear derailleurs,
sometimes they’ll require a crosshead screwdriver,
and other times they’ll require an Allen key, in this case it’s a SRAM derailleur which means
the use of an Allen key. Now they can also be
positioned on the side of the derailleur, or on the
back, usually on the back. Now just an important
thing to note with these, they obviously represent
the high and low gear adjustments on there, but
the actual screws themselves don’t necessarily correlate to that. You’ll find that the one
that correlates to the high gear adjustment,
or the smallest sprocket in the rear is actually
the one towards the inside of the bike and vice versa. Can be quite confusing,
but very easy to work out if you actually loosen
off the cable clamp. By doing that, it means
the cable has nothing to do with the movement of
the derailleur, makes it very easy to understand
what is going on. So, first things first,
you wanna make sure you’re shifted into the highest gear out back. Which means the smallest sprocket. And at that point, what you’re looking for is the adjustment of
that upper guide wheel, you want it to be
completely in line with that smallest sprocket. So, taking your Allen
key, simply just make the appropriate adjustment, whether it’s clockwise or counter
clockwise until you see the derailleur move very
slightly and line up. It won’t take a lot of
adjustment, and then literally you just wanna peddle around and make sure that it’s
operating nice and smoothly. Of course, when you’re
doing this on an e-bike, you have the disadvantage
of the fact that you can’t peddle backwards
because the way the motor disengages it from the drive chain. When you’re doing this
on a non e-bike, this process can be a lot
easier ’cause you can just coast it backwards
without having to revolve the wheel around every time. The process for adjusting it at the top isn’t quite so simple. Now, you can either
choose to leave your cable attached, or if it’s
with a new derailleur and you’re setting this up,
leave it unattached. There’s something you must
bear in mind with this adjustment for the bigger
sprocket is, if it’s not adjusted correctly,
A you won’t get to that gear or B, it could be
worse, you could over shift. And depending on the
particular wheel you have on your bike, and a
particular cassette you have, if you have an Eagle
12-speed cassette, there’s not much room behind that cassette for a chain to fit and if that
happens, when you’re pedaling, with the extra
power that you get from the electric motor on
e-bikes, you can actually wreck spokes, you can
snap the chain, you can really, really make
some damage to the back end of the bike. Now, Steve’s got the e-bike
specific 8-speed cassette on him, it’s quite a
bit of room out the back which does mean that that won’t happen. However, you still don’t
want the chain to drop over the top when you’re
pedaling because it’s just not an ideal thing
to happen, and it’s completely unnecessary. So, taking that Allen
key once more, you make the relevant adjustment
when the cage is sat underneath there. Now, you can either
manually move the cage if you’ve not got the cable
attached or with the cable attached, shift
it in that direction, but take care, especially
if your e-motor is switched on when doing
so, because if it’s not adjusted correctly and
it wants to hop over the top, the e-motor’s actually gonna help put it over there even faster. (groovy music) Now the same thing
applies, obviously, using the opposite screw that
you did with the smaller end there, and you wanna
make sure that upper guide wheel is completely in line with the top sprocket there. Now, it can be quite
hard, especially if your e-bike has got a plus sized tire on the back like Steve’s has. Now if I sit back a
little bit here, I can see just about that that is
completely aligned, so in theory, that does mean
that the limits are adjusted. So next up is to move on to the B screw, or the B-tension. (groovy music) – Now B-tension, or the B screw, is found right in the back and at
the top of a derailleur. Just for sighting, there’s
the Allen key right there. Now what this is
responsible for is adjusting the height of the upper
guide wheel in relation to that large sprocket. Now the height this is
set at completely varies depending on whether
you’ve got a nine, ten, eleven or twelve speed rear
derailleur and cassette system, or if you’re got Shimano or SRAM. Now, it also varies on
whether you measure this when it’s sagged, or not sagged. In this case, this is
a SRAM set up and they helpfully do provide these little gauges, which means you can
offer them up, so you’ve a guide wheel and you can
literally see what the gap is. In this case, it’s a twenty two move gap between the largest
sprocket here, and the top of the highest point of the guide wheel. Now I’m just gonna throw
on-screen some measurements for Shimano, the sagged,
and non-sagged options for Shimano and SRAM there. (groovy music) Now it’s really crucial to make sure that the B-tension is adjusted correctly, for a couple of reasons. Firstly, you can foul
on the cassette which means A, it’s gonna wear
out your upper guide wheel really fast and it’s
obviously not gonna be very good for the derailleur
and B, it means your downshift and your up
shift into that biggest sprocket will be hopeless
unless it is adjusted correctly. Now, it’s just a case of
adjusting clockwise or counterclockwise in order
to adjust that height. So you can either use a
tape measure or if you do have one, one of those little gauges which do make things a bit easier. (groovy music) Now provided that your rear derailleur, or your rear mech, is on
the bike correctly, it’s all been tightened and
there’s nothing bent, then in theory, once you
have done all of those adjustments, the B-tension
and the upper and lower limits, the only
thing that’s gonna affect your gear performance will
be the actual tension of the cable, and of course,
the routing of that cable. Now, firstly, let’s just talk
about cable routing a bit. It needs to follow the
path of least resistance, if there’s acute angles
in your cabling, as in the outer housing, the
cables gonna strain on the inside and also under compression, you can get things called ghost shifting. Which means, as the
bike cycles through its travel, perhaps you’re doing a tight turn, if any of that housing
is pulled and crimped in a manner, it can actually change your gears for you, which is not what you want. It may sound cool, but
it’s actually really, really frustrating. So make sure that your
outer housing follows the most direct route,
with the least amount of acute angles as possible. Next up, always make sure that your outer housing has proper
cable end caps and cable ferrules on there, because
they stop the internal parts of that cable housing migrating. And when the inner part
of outer housing migrates, you’re gonna suffer from
bad and very inconsistent shifting, which can be
really, really annoying and of course, is never
gonna be quite right. Now, the final thing is
to make sure that the inner cable can slide freely
inside that outer housing. If it doesn’t you can try flushing it with some lubricant but more
than likely, you’re gonna need a fresh inner cable. Because over time, with
the nature of mountain biking, you’re gonna be
riding in wet conditions. Water can travel into
that outer housing, it can corrode the inner
cable and it will never slide correctly on the inside. So, if you start with
a fresh cable, that is the first point of call. Now if you’re doing
this, you’ve still got a nice fresh cable, it’s
worth flushing out the outer housing as well. If you’re gonna do this,
you’re gonna need to use a spray lubricant,
so make sure it can’t go anywhere near your breaking surfaces. Get oil near your breaking
surfaces, A, it’s gonna be tough on your brake
pads, and B, it might have to be time for new disc rotors, an additional cost that
you can avoid by just being careful when you’re doing this. Now, back at the rear derailleur, assuming that everything is
right with your cabling, which we will cover in
another video on EMBN. What you need to do is make sure there’s enough tension on this. Now, when you’re putting the cable through the housing, it only needs to be taut, never tight. When you’re pulling it,
you should never feel the derailleur wanting
to move, you’re just pulling it up securely against it. Now before you clamp
it down with the Allen bolt that’s on the end
here, just make sure that the cable is following
the correct route all the way to there, because
sometimes it can come unseated, and not be in
the correct position. Which means when you
go to index your gears, it’s never gonna shift quite right. Also, if you have
installed a new cable into a system, make sure
that the barrel adjuster on the shifter is wound through, back into the shifter itself. Now something I learned
to do, just as an extra top tip, is just unwind
it one full revolution. And it takes into account
that if you do pull the inner cable through
there a bit too tight, you can just let if off a bit at that end. The least adjustment that you need to make at this end, the better. – Now finally, if you
are putting a fresh cable into yours, make sure you use a clean and sharp set of cable cutters. Now if you do have a set
of cable cutters, don’t use ’em for anything
else on the bike ’cause they can blunt, which
means you end up with frayed cables, frayed cables are a no-no. Also, make sure you put
some sort of cable end cap on, because it stops your
cables becoming frayed. Of course, frayed cables
are a bit of a pain, but also they can poke
into your skin which is quite nasty. (groovy music) – And now finally, the
last stage, once you’ve done all of these adjustments
is indexing the gears. Now, the indexing of
gears just refers to the fact that one click of
the shifter correlates to one gear shifted at the derailleur. It’s a simple principle. Now you start with the
gear in the highest, which is basically with
the least amount of tension on and one click
of the shifter, turn your pedals around gently,
I recommend doing this with the e-motor turned off so you’re just manually turning the drive chain around. It should correlate to one gear shifted. Now, if it doesn’t quite
jump up, then counter turn that barrel adjuster
a quarter turn at a time until it hops up. Then shift it back the other way to make sure it drops back down. If there’s a slight delay
in telling that cord to turn, turn it back off again. A little bit of fine tuning. Now do this for the first three sprockets, since you’ve got perfect shifting and then in theory, it should work perfectly all the way to the top, and back again. A little bit of fine adjustment, lube your chain, and you’re good to go. So there you go, that is the basics of adjusting a rear derailleur on an e-bike. For a couple more useful videos, click up here if you want to go directly to our maintenance playlist,
that’s all the how-to videos on looking after
your bike and click down here if you wanna see the latest Electric Mountain video
with Chris and Jonesy. As always, don’t forget
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