How To Adjust + Index Your Gears – Mountain Bike Maintenance Tips

How To Adjust + Index Your Gears – Mountain Bike Maintenance Tips


Getting your gears shifting quickly and
smoothly should be quite an easy job to do, but it takes a little bit of knowledge
about how that system works first. A clean, well-lubed chain will make a big
difference to how easily that chain shifts up and down that block, so do that
first. Both front and rear mech work on the system of having the correct
cable tension so both your upshifts and downshifts are quick. So
let’s break that down to three parts. First your cables,
then we’ll look at the limit adjusters. Then we’ll actually
look at the cable tension. So, first thing to look at is the actual condition
of your cables. If they’re worn with loads of friction in them, you’ll never get
those gears to work very well. So, what I do, is I’ll feel for it on the shifter.
If there’s a lot of friction when you’re pushing through that shifter, that’s
a sign that you’ve got a lot of friction in there, or if it’s a bit slow going down
the block, that means the cable’s not returning nicely with the spring
on your mech. If there is any friction in there, now is the time to stick a
new inner cable in, if not the whole system. If the outers are kinked, you’ll
never get them working nice and smoothly either, so that’s when I just replace
the whole gear, cable in it and outer. So, going down to the rear mech, let’s
just have a quick look to make sure that that mech is nice and straight, also
that your rear hanger isn’t bent. So if you look down that cage, it should
be absolutely parallel to your cassette, you know, and nice and square to that back
wheel. If that’s still twisted or pulled out, that pretty means that you’ve bent
that hanger. That’s going to affect your shifting as well, so make sure that’s
straight first. I’ve undone that pinch bolt that holds the cable into that rear
mech, so now, pedaling the bike forward, just push that mech up and towards
the rear wheel and then let it go, and that mech should return nice and
quickly. If there’s a bit of friction in that mech as it drops back down, that’s a
sign that that mech might be a little bit damaged or bent, so that’s not
going to help your shifting either. So now let’s look at the limit screws.
Bear in mind that these don’t affect the actual shifting of the rear mech, they
just limit how far it moves up and down. So if you have that limit screw not set
tight enough, that’s when your mech can go too far and go into that rear wheel, so
that’s something to pay attention to. And the high and low works just like
a car, so a high gear is fast speeds, low is slow speeds. So that’s your
low gear and that’s your high gear, and you’ll have a high and a low
limiting screw on that rear mech. So if we start with the high adjuster,
remember to leave that cable unattached. And as I’m pedaling the bike forward, you
can see the chain is actually trying to jump off the bottom tooth on my cassette,
which means that this is mech is too far outboard. If I give that mech a little
push, now you can see it runs nice and sweetly. So, I need to wind that high
adjuster in clockwise slightly until I get that chain running nicely on there. It’s
not trying to pull it off the bottom of the cassette. On SRAM, the high adjuster,
confusingly enough, is the other side. So I’ll stick half a turn on there, and
see how that runs. Still wants a little bit more, so another half turn. There
we go. Give that mech a push, let it drop back down. If you wind it too
far on, you’ll notice your chain won’t come nicely down into the easiest gear,
so you want to take a little bit back off, just so your chain comes
into that gear, but no further. Okay, so now we’re going to look at the
low speed up at the top of the cassette. Like I said before, that’s going to stop
me from over-shifting and pushing that mech into that rear wheel. You can also
get that if it’s not adjusted correctly, maybe on a big landing or a big hit
on the bike, the mech can jump. If you’ve not got that adjuster set
properly, that mech can jump into that rear wheel, snap your mech, snap your
hanger, and do some damage to that rear wheel. So make sure this one’s set nice
and tight so the mech can’t go too far. So, pedaling the bike, I’m just going to
push that mech up towards that top, and as you can see, mine is going too far.
That chain’s jumped over the back of the cassette and going into that back wheel,
so I need to stick some adjustment, wind that low adjuster clockwise in to
limit that mech a little bit more. Okay, so I’ve put a couple of turns on
that low adjuster, pushed the mech up. By now you can see it’s not quite moving
far enough, so I’ve put too much on that low adjuster. So I need to back it off
half a turn to make sure that chain goes all the way up, but no further. There
we go. Okay, so now the mech is set up so you’re getting the
full range of gears, and it’s going no further. Now I’m
going to put the cable back on, and I’ll double check those again
once the cable’s back on. Okay, so, finally, we’re going to look at the cable
tension to get those gears working nicely. So, with your cables still unattached from
the rear mech, let’s go up to the shifter and just set this adjuster so it’s
clockwise all the way into the shifter, and then go back out one turn. So, you’ve
got a bit of adjustment both out and in, to just give those final adjustments
of tension on that cable. So, make sure your shifter is down into
the highest gear, so I’m all the way to the bottom of the block. Now, I’m just
going to pull ever so gently on that cable to give it a little bit of tension,
before I then tighten this bolt. So now, we’ve mounted the cable through the
rear mech, all the final adjustments come from this barrel adjuster up on the
shifter. So, let’s have a run through the gears. I’m pushing to go up to my
lowest gears, and I’ve given it a push, and it’s not actually moved the chain up.
That means I need to wind this adjuster anti-clockwise, to put some more tension
on that cable. Okay, so I’m going to give that barrel adjuster half a turn
anti-clockwise to put more tension on that cable. Still not quite doing it,
so let’s give it a little bit more. Try again, there we go. It’s
going up and into that lower gear. It’s still a little bit slow, so I’m going
to put a little bit more tension on, maybe a quarter of a turn. Try
again. There we go, nice and quick on those shifts
towards the lower gears. So, let’s now check the shifts back down
the block. If you put too much tension on that cable, yes, your shift’s going
to the lower gears might be quick, but that’s going to maybe slow down the
ones coming down the block. So let’s double check that. See how it’s a little
bit slow coming back down? That means I’ve got a bit too much tension on that
cable, so I’m going to give that barrel adjuster half a turn back clockwise,
take some tension off, and that’s better. So now, we can see we’re getting quick
shifts both ways, which means that that tension’s set nicely. I will double check
those stop adjusters by shifting it up right to the top, nice and quick, and make
sure it doesn’t go over the back of the cassette, and then fire it down to the
high gears, and then make sure that that chain, again, doesn’t jump off the bottom.
Just remember that you do need a nice, clean, gear cable in there. If
there’s any friction in that cable, you might get the gears working one way
nicely, but probably not the other way. So there you go, there’s setting up
your gears. It’s quite a simple process, really. Big one is just definitely make
sure you get those stop adjusters right, so you don’t risk any damage to your back
wheel, or an expensive one where you rip out the mech and do loads of damage, so
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