How to Change or Replace a Bike Crankset | Halfords UK

Need help with your bike crank and want to replace the crankset? Watch our handy video on how to replace a crankset and follow our easy step-by-step instructions!

Bikehut Premium Pedal Spanner
https://www.halfords.com/cycling/bike...

Crankset
https://www.halfords.com/webapp/wcs/s...

Halfords Advanced Torque Wrench Model 60
https://www.halfords.com/workshop-too...

Super b 2-in-1 Crank extractor
https://www.halfords.com/cycling/bike...

Crankset
https://www.halfords.com/webapp/wcs/s...

Gears, Drivetrain & Cables
https://www.halfords.com/cycling/bike...

Not sure how to change a crankset on your bike? It can be a tricky job, but fear not, we’re about to show you how.

Before we start make sure you’ve got:
15mm pedal spanner
The correct size allen keys for your bike
New crankset
Torque wrench
A ratchet to undo crank bolts
Crank extractor
Grease
Gloves for safety

First, you want to make sure you’re on the smallest cog on the front gears and the smallest cog on the rear gears to create the most chain slack. Like so.

Let’s get those pedals off. On the right-hand side, you want to go anti-clockwise towards the back. Just take this one off. You’ll find it easier if you run through the chain and hold onto it as you unscrew. Then you want to go to the left hand side pedal, do the same and this time go clockwise, towards the back of the bike.

Now it’s time for your allen bolt. Bear in mind, these come in different shapes and sizes so it needs to be the correct one for your bike. Ensure it is by checking your owner’s manual. Start by taking the first bolt out. You might find it easier to loosen the bolt with the tool and then use your fingers. Do the same again for the other side.

Now you have the bolts off you’ll be able to pull the cranks off the bottom bracket. In order to do this you’ll need tool number three, your crank extractor. Before inserting the extractor, lubricate the inside of it with some grease. Make sure to tighten the tool with a spanner otherwise you can ruin the threads when extracting the crank. Once this is done, and the tool is in all the way, pull the crank out by turning it and slowly releasing it off. Repeat on the other side to get the other crank off. Depending on the chainset, the other side may just need tapping out with a rubber mallet if it’s a pressed bottom bracket or external bottom bracket.

You’re now ready to put your new crankset on.

Make sure to hook the chain back on the chain rings otherwise you’ll need to remove them again. Start by putting the right hand side one on first, then the left, making sure both are in the 12 to 6 position, once that’s sorted then you’re good to pop the bolts back in.

Right, now it’s time for the torque wrench. But before you move on to the next job, make sure the newton meter is set to the correct settings for your bike – you can find these in your bike’s owner’s manual.

Once this is confirmed you’ll want to tighten this up until you hear a click.

Finally you want to grease the pedals up before we pop them in. For this we are going to use copper grease, but most anti seize greases can be used. This ensures that when you want to take your pedals out or change them in the future, they’re easy to get out and they don't seize up. Bear in mind, bike threads are not necessarily standard threads - Left pedals will have a left hand thread opposed to right pedals, which have a standard right hand thread.

Once the pedals are in position make sure you tighten them up fully. You’re now a crankset-changing expert.
However, gears may need adjusting if it is not a like-for-like replacement. If you need to adjust gears, you can check out our video on this here.

To see our full range of cranksets, head online. Or for more information, pop in store and chat to a member of the Halford’s team. We can even help you fit them for a small service charge.