Tips & Tricks / How to's

How hard is it to replace the chain and sprockets on a sv650
From: Mark Magnusson

I posted this up on another board a few months ago, and it may help those contemplating a chain swap.  The change is on a Kawi ZX12, but the steps are the same.

And, for what it's worth,  I always budget getting the correct tools, or borrow a friends correct tools, for a job.  Do it one time, do it right.  Using the wrong tool is OK in the field, but only in an emergency.  There is enough sh!t to worry about on the road, without hoping that your chain doesn't let go and take your case, or your leg, off with it.

The Motion-Pro kit is about $90 new, and it is worth it!  Includes a pin driver to remove the pin, a plate press to press the plate back on, and a pin flare to flare the tips of the new master link.

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Changed out the chain and sprockets this weekend.   I had a gentle 22,000 miles on this set, and although things looked still in serviceable condition,  I felt it was indeed just better to do this in the relative comfort of my garage instead of having to wait on the side of the road somewhere in Hardee county for a tow,  or an ambulance!  I had no obvious signs of eminent failure, however things to look for when servicing your chain are tight spots/small kinks,  smooth points on the sprockets where it should be shaped surfaces.  Of course, your service manual will also give you advice on how to measure chain stretch and sprocket wear.

Tools you will need:

  • Impact wrench (air or electric) & sockets
  • Torque wrench
  • Die Grinder to grind the chain rivet head
          * a Dremel tool may work, but it will take a while
  • Chain Breaker and Chain Press tool – I used Motion Pro here
  • of course, new chain and sprockets. 
  • Some way to get the rear of the bike in the air.  Rear stand is the obvious way, but you could suspend it from the ceiling.

My service manual states that front and rear sprockets should be replaced whenever a new chain is put on the bike.  Failure to do so will result in premature wear of the chain.  I replaced my sprockets with JT Steel sprockets, front and back, and put on a gold RK530 X-Ring chain.

Note:  Again, the 530 chain was for a ZX12.  My SV650 takes a 525.

Cost:
  • Front sprocket : $15
  • Rear Sprocket:  $35
  • Chain: $140
Time required: 
    plan on a minimum of two hours, and could go to three depending on how fast you work.

These are the steps I followed:
1.)  Replace the front sprocket
2).  Remove the old chain from the bike using a chain-break tool
3).  Replace the rear sprocket
4).  Mount the new chain on the bike using a chain-rivet tool.
Note: this is JTCMA ... the order of the steps, the steps I followed, the torque values and other references are just documenting what I did to make this adjustment on my bike.  Your values and steps may be different.  Also, please remember to always wear safety glasses when working on your bike!


Step 1. Replace the front sprocket
 
Small Note:  Notice that I am replacing the front sprocket completely before cutting the chain, because the chain is used to hold the sprocket from spinning when you loosen / tighten the nut on the shaft.  If you cut the chain off first,  the front sprocket will spin when trying to remove/tighten the nut.  That is because you should have the tranny in neutral when taking this nut off/on.

HUGE NOTE:  Please make sure your transmission is in NEUTRAL before whacking the sprocket nut on or off.  If it is in gear it will put un-necessary strain on the transmission gears and could cause gear failure.  That's why I leave the chain on to do the front sprocket.

  • Remove the chain guard.

  • Remove the front sprocket cover. Picture

  • If you have a washer that bends over the flats on the nut, you will need to straighten the washer out before you can remove the nut.

  • Have someone stand on the rear brake pedal.  Use an impact wrench to remove the front sprocket nut.  I suppose you could try and use a ½” breaker bar and about 4-feet of pipe as a cheater, but good luck!  That didn’t work for me.  You can get a cheap electric one from HarborFreight for about $50 , and it’s worth it! 

  • Anyway, once the nut is off,  you will not be able to just pull the sprocket off until you get the chain off of it.    To do that, loosen the rear axle, and then loosen the chain all the way in, by backing off the chain adjusters  as far as you can.  You may even need to remove the chain off the rear sprocket.  Picture

  • Once you have enough slack in the drive chain,  you should be able to loosen it from around the front sprocket enough to pull it off the splined countershaft. 

  • Put the new front sprocket on by reversing those steps.  Slip it into the slack chain, then slide it on the the splined countershaft.

  • Then put the washer and nut back on.  Since you will be applying a torque force to these items, my manual suggested putting grease between the new sprocket/washer/nut sliding surfaces,  and oiling up the threads on the countershaft with engine oil.  That’s a good idea!  Picture

  • Take the slack out of the chain in the rear by sliding the rear axle back into position and either sliding the adjusters out, or temporarily tightening the axle nut.

  • Grab your helper, have him stand on the rear brake pedal.  You may also want to slip a 2x4 under the swingarm and in front of the spoke to help hold the rear tire from turning.
    Then torque the nut to spec.  Mine was 94 ft/lbs.  Bend one of the flats over on the washer, if so equipped, and take a well-deserved break.
 
You are done with one-quarter of the project.


Step 2. Break the chain

 
  • With a die grinder, grind off the head of one of the rivets on your existing chain.  If you do not have a die grinder, you may be able to do this with a Dremel and a whole bunch of cutting wheels ( the rivets are pretty hard!). Picture

    Note:cover your work area, swingarm, tire, etc,  with newspaper or cardboard, just in case your hand slips while grinding the chain

  • Using your chain breaker, push out the remainder of the pin you just ground the head off of.  Picture

Alright!  Time for another little break … you’re half-way there!


Step3. Replace the Rear Sprocket
Step three isn’t too tough. 
  • Remove the rear wheel.  When it is off, do not lay it down on the disc brake rotor!  That could warp it.  Maybe lay the wheel on the floor where the ‘rim’ is sitting on some 2x4’s, or use a milk crate.  Remove the 5 or 6 bolts holding the old sprocket on the wheel, and pull the sprocket off. Picture

  • I used a little wire brush to clean the threads on the rim.  They had remnants of Loc-Tite on them, and it is always a good idea to clean that stuff out of the threads in order to have a clean surface to thread in to again. 

  • Once clean,  I mounted the new sprocket on the studs, then dabbed a little blue Loc-Tite on the exposed studs, put the nuts back on.  My torque value was 43 ft/lbs.  Always a good idea to tighten things like this in a star-pattern rather than just going around in a circle.  Ensures an even pressure is being applied to all surfaces and prevents warping.

  • O-o-o-o!  Isn’t that pretty! Enjoy looking at it.  You will never see it that clean again!

  • Remount the rear wheel back on to the bike.  Set the chain adjusters to total slack, so the axle will be as far towards the front of the bike as possible.

OK, you are in the home stretch.  Only one more task to tackle.


Step 4. Mount the New Chain
Your new chain will probably be a little too long.  You will need to measure it on the bike to see where to break it.  It also should come with a new master link.
  • Mount the new chain on the bike.  Remember, the rear wheel/axle should be as far forward as possible to permit you to get the chain somewhat tight on the bike.

  • Overlap the chain ends, and mark the link you will be removing. Pull as much of the slack out of the chain as reasonably possible here.  Measure twice, cut once!  You will be removing an ‘outer link’ assembly from the chain, and replacing it with the new master link, which is also an outer link assembly. Picture

  • Remove the chain from the bike.

  • Just for grins, lay the new chain and the old chain side by side to confirm you are cutting the right location.  At $140+  you don’t want to screw this part up.

  • Remove the parts of the new chain you do not need.  It is done just like you did above to cut off the old chain, i.e. grind off the head, push out the pin.

  • Thread the new chain back on to the bike.  Have the two loose ends meet up on the rear sprocket. The rear sprocket will hold things in place for you.  Slide the new master link in from the back side towards you.  Your chain will have new o-rings and (possibly) a grease packet to lube the master link.

  • Use your chain press to press on the master link assembly.  Don’t forget to put your new washers on before you press the new plate on.  You will be pissed if you find them on the garage floor AFTER you get everything put together …. Can you say “$140 mistake?” …

  • Use your chain tool to expand the rivet heads on the master link pins.

  • The last step is to adjust your chain, as normal, and then tighten up the adjusters and axle nut per specs.  Mine was 94 ft/lbs.

Bloody knuckles? Dirty fingernails? Did the kids learn some new naughty words?  Yup, you’re a bona-fide mechanic now.

Now you just need to finish up replacing any parts you removed to start with: chain guard, sprocket cover, shift lever, whatever …

You should check the adjustment at 50 miles, and then after 200 miles.