If you do any miles worth mentioning, and you ride a chain drive, you'll be getting through a fair few drive chains as the years go by. If you've never done it yourself, it's a messy job, but nothing you should shy away from as you can save a bomb by getting your spanners out. Set aside a couple of hours (less if you have a well equipped workshop).
You will need :
Sockets and wrenches
Something to raise the bike on and straps to steady it.
Screwdrivers
Angle grinder or file
A chain breaker/riveter (Or a pin punch, centre punch, club hammer and ball pein hammer).
A set of new sprockets and a chain.
Here's my bike lift, a couple of railway sleepers. I lifted the back end of the bike up and got one of my boys to slide the wood under the frame rails.
I used a carbo strap under the wood and over the seat to hold the bike steady as the rails are a bit narrow and I will be using a fair bit of muscle on some of the bolts. It's always better to take an extra minute to make sure things are safe.
With the bike secured, I Used the angle grinder to grind off the heads of these two rivets. If you go for one of the links on the sprocket, it's a much easier deal as the chain wont move about under the wheel. You can use a file to do this, it jus takes a little longer.
When it's ground flat like in the pic, you can use the chain breaker tool or, like I did, pin punch the rivets until the link drops out and you can strip the manky old chain away.
Once that's done, take the axle out and back off the chain adjusters all the way and slip the wheel out. I rested the disc on some old rags and undid the 5 bolts holding the old sprocket on. (Check out the missing and worn teeth! Well past it's best, this one).
Here's the new sprocket going on. It's 40 teeth where the old one was 48. My sportster has plenty of poke and I do a lot of motorway miles, so I figure it should cope with the jump from 48 to 40 well enough.
Once you've got the cover off the front sprocket (A real pain on my sportster as I had to slack the rear exhaust off take the rear master cylinder, forward control and both tail pipes). You can see the cog. On Harleys, there will be a small allen bolt in one of the three holes in the face of the sprocket, this locks the big nut and stops it coming undone, so when you remove it, keep it safe and remember to stick it back on the new one.
There's the new sprocket (See the little lock bolt tight on one of the faces)?
Back wheel fitted, put the chain on and either follow the instructions on your riveting tool to secure the rivet link or (if you don't have a tool) Place a heavy lump hammer (or sledge) behind the rivet link and centre punch each pin, then flare them out by hitting them with the ball pein hammer until they're secure.
Most chains come with a rivet link and a clip on link with grooves in. I never use the clip on link, I don't think theyre safe with an o ring chain, so I just carry them in my tool roll incase I ever have a chain break and have to do a quick fix to get me home, but it's your bike, your choice.
That's it! Tighten everything up, get a fat mate to sit on the bike and check for about half an inch of play in the chain and you're ready for the road.
Have fun out there.
Spence