Change An E-Mountain Bike Chainring On A Bosch Motor | EMBN How To

– Swapping out the front sprocket in your Bosch Performance Line
or Performance Line CX motor is a quick, easy, and
relatively inexpensive way of tuning your bike, or optimizing it, for the type of terrain that you ride in. In today's video, we're gonna
show you just how to do this. (electronic beeping) Right, first step, let's have a look at two typical scenarios of front
sprocket and cassette setup on your own different e-bikes. This is a Haibike Nduro 8, it's got a 16-tooth front sprocket, and
11-42 cassette on the rear. Now you need to bear
in mind that some bikes actually come with an anti-suck
device on the front sprocket which means it limits
the size of chainring you can fit to the front. So this bike is a Haibike Nduro 10 and it's got quite a different setup in terms of gearing to the previous bike. It, too, has a 16-tooth front sprocket but on the rear is a 11 to 48 cassette which means it can get
up a lot steeper hills than the previous Haibike 8.

Now we've got a range
of front sprockets here from 14 to 22 which compatible
with a Bosch system. Let's get into it straight away. Now the first thing that you must do, this is really essential, is
you must take out your battery before attempting any
work on the motor area. Now removing the front sprocket on your e-bike is super simple. You just need three tools to do this. You need an 8-mil to remove the crank, half-inch drive which you add
on the lockring removing tool. Now the first job to do, after of course removing your battery, I can't emphasize how important that is, is
to take the cranks off. Now some bikes come with a
self-extracting crank nut and you know the difference
because the ones that are self-extracting have a 10-mil
outside and 8-mil inside.

So, very simply, just
undo that anti-clockwise. Now I've got a specialist
Bosch lockring tool here. If you haven't got one,
just simply take your bike into a Bosch dealer and
it's a 10-minute job. So, very simply, you
take the lockring off. It's very simple but remember, it's a left-hand thread on this lockring so you need to turn it
clockwise to loosen it and anti-clockwise to tighten it. At this point, you need to
take up the slack in your chain by moving your derailleur forward. Now remember that some
derailleurs have a clutch in them which means that it will lock out like so and what you do is pop that off that.

So you have your front sprocket out, now at this point, it's
worth explaining that there are different types of front sprocket on e-bike motors. Now this is a Haibike
brand-specific front sprocket and it comes with a
double bash guard on it both on the inside and the outside. You can get other versions which are bash guard on the outside only or some aftermarket sprockets
which come by themselves, in which case, you need to buy
a bash guard to go with that. Now as I mentioned earlier,
there are a range of sprockets available for your Bosch
motor from 14-teeth up to 22. Now the type you choose depends on the type of terrain that you're riding. So a small sprocket from about 14 to 16, that's gonna be way more suitable for mountain biking and hilly terrain. However, a 22-tooth front sprocket is gonna be far more
suitable for flat terrain but bear in mind that you're e-bike has got a 25-kilometer
an hour restrict on it so you're gonna be hitting
that pretty quickly with a 22-tooth front sprocket so a 14-26 is a far
more practical sprocket to use in a mountain bike.


Now before fitting your
front sprocket, bear in mind there's a right way and a wrong way to fit it to your bottom bracket. So some of these
sprockets might be stepped in which case that affects the train line whereas others are quite flat so they go on one way or the other. Now I'm just about to put the
front sprocket onto the motor. On this particular sprocket,
the writing is on the outside and just about as I'm putting it on, bear in mind that there's a rubber o-ringo on the bottom bracket. You need to be careful
you don't damage that when you're mounting the sprocket. Next up, the chain guard gets mounted. Remember it's anti-clockwise on this. Okay, so now I'm
tightening the Bosch guard and I'm tightening it anti-clockwise.

Simple as that. As you find on the guard, you're done. Pop the chain on, loosen off derailleur, and stick the crank back on and remember to get them opposite. So this is clockwise. So there you go. Swapping out a front
sprocket on your Bosch motor, a very quick and easy job, indeed. Don't forget to put your battery back in, as otherwise you'd be going nowhere and there you go.
You'd be away! Now, it's worthing
noting why I actually put a 14- or 15-tooth sprocket on this bike and that's because the small sprocket will increase my range, especially when I'm in the mountains. It enabled me to go up fast steeper hills than, say, a 16, 18, or 20. But there's another side
to that story, as well because if you've got a
smaller sprocket up front, it's gonna mean that you're gonna be able to spin lower gears
which is gonna mean that you can ride the bike in Eco mode rather than Turbo or Trail mode which is gonna save your
battery considerably.

So there you go.
Hope you like this video. If you wanna see motor-related features, there's a motor feature down here. Give us a thumbs up if
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