My son's buddy asked me this question and since I've never actually removed a chain and reinstalled it on a bike I figured I'd ask for your opinions. He recently removed his chain as his sprocket had come loose and now he's concerned that when he replaced it he just stretched it across the top of the sprockets reinstalled the clip on the master link and away he went. His concern is did he now make the chain too tight on one side while on the slack was on the bottom of the sprockets? What is the proper way for replacing a chain when it's been removed?
Chain removal/reinstallation
- Thread starter Chili
- Start date
Make sure he adjusts the rear axle so the front and rear sprockets are aligned. (very important) It helps to have the same point of reference on both side that way you can measure each side to that point to align things. You can also take off the chain and run a straight edge from the face of the front sprocket to the face of the rear, if possible.
Once things are aligned, put on the chain and tension each side with small equal amounts until there is about 1/2" of total slack on the top of the chain. This 1/2" measurement is when you have the swingarm pulled up in a straight line with the two sprockets. This would be putting the assembly in a position that the chain is in the tightest point it can be in. I like to use a cargo strap to hold it there while on a stand, but you can just keep lifting it to that point but you will have to remove the shock to do this.
Once you have the alignment and the sag correct, tighten the jam nuts on the chain adjusters. ( I like to put a little never-sieze on the bolts before I start this process)
Once you have the chain porperly adjusted, you can put the bike down on the ground in ride mode and see how much the chain lifts up on top, just in front of the top chain guide. (how many fingers fit in there) This will give him an idea of when he needs to tighten things up a bit.
Recheck everything.
Be sure and loc-tite the sprocket bolts before you start. They are notorious for comming loose even when loc-tited.
I can't stress how important it is to have the sprockets aligned, if not it will eat chain and sprockets real quick.
Hope I haven't confused you, it is a simple task once you've done it a time or two.
Once things are aligned, put on the chain and tension each side with small equal amounts until there is about 1/2" of total slack on the top of the chain. This 1/2" measurement is when you have the swingarm pulled up in a straight line with the two sprockets. This would be putting the assembly in a position that the chain is in the tightest point it can be in. I like to use a cargo strap to hold it there while on a stand, but you can just keep lifting it to that point but you will have to remove the shock to do this.
Once you have the alignment and the sag correct, tighten the jam nuts on the chain adjusters. ( I like to put a little never-sieze on the bolts before I start this process)
Once you have the chain porperly adjusted, you can put the bike down on the ground in ride mode and see how much the chain lifts up on top, just in front of the top chain guide. (how many fingers fit in there) This will give him an idea of when he needs to tighten things up a bit.
Recheck everything.
Be sure and loc-tite the sprocket bolts before you start. They are notorious for comming loose even when loc-tited.
I can't stress how important it is to have the sprockets aligned, if not it will eat chain and sprockets real quick.
Hope I haven't confused you, it is a simple task once you've done it a time or two.
- Thread starter
- #4
By aligned Jaybird are we talking about having the marks on both sides of the rear axle lined up like when you've tightened the chain so your rear wheel is straight?
Confusing me unfortunately doesn't take much :)
It's kind of hard to explain but his concern is that he could possibly put the chain too tight across the top of the sprockets leaving all the slack in the chain sagging at the bottom of the chain while he puts it back on. I'm not sure if this is even possible i.e. going one link tighter from front to rear on top vs the bottom of the chain. The only thing I could think of telling him that would alleviate this fear was to tighten the chain to the point of no slack and seeing if that was tight on top and bottom or even so to speak and then back the chain back off to the proper amount of slack. Hope this makes some sense :eek:
The balance between top & bottom tension changes continuously as the wheel turns, etc. Sounds like he did not have the wheel off the ground when he installed the chain. Otherwise, he would have seen the wheel rotate a bit to equalize tension.
Regarding the marks on the swingarm or axle adjuster clevis, its usually a good idea to go through the alignment check that Jaybird outlines. Mine has snail adjusters, but I still check with a 24" scale every now & then to be sure.
Regarding the marks on the swingarm or axle adjuster clevis, its usually a good idea to go through the alignment check that Jaybird outlines. Mine has snail adjusters, but I still check with a 24" scale every now & then to be sure.
The marks can be off. In other words, if you use only the factory marks to adjust it's possible they won't be true and leave the wheel out of alignment. I like to measure from where the adjuster bolts thread into the swingarm back to the adjusting blocks. Do this once and you can confirm whether the marks are correct. If they are, use them.
You can put the bike on a stand and put it in first gear. Then rotate the wheel putting some pressure on the chain so your slack is on the top.
Once your slack is on the top side, you can lay a piece of flat bar or yardstick accross the top of the front sprocket to the top of the rear. Measure from the bottom of the straight edge to the top of the sagging chain. This is your cantenary sag. (proper cantenary sag =1-3% of total shaft-to-shaft distance) I use 1-1.5%
You can put the bike on a stand and put it in first gear. Then rotate the wheel putting some pressure on the chain so your slack is on the top.
Once your slack is on the top side, you can lay a piece of flat bar or yardstick accross the top of the front sprocket to the top of the rear. Measure from the bottom of the straight edge to the top of the sagging chain. This is your cantenary sag. (proper cantenary sag =1-3% of total shaft-to-shaft distance) I use 1-1.5%