YBR125 Drive Chain Problems

[vocab]

Hello all!

So i recently fitted a new drive chain and sprocket set, insuring to the align the rear wheel, properly lubricate the chain and maintain the correct amount of chain slack.

However, whenever I release the throttle a strange slapping / loud clicking noise comes from what sounds like it could be the chain. The faster I am going when i come off the throttle, the louder the noise is. Whenever I apply any throttle, the noise is none existent.

What would be some other potential causes of this and what would you propose to be a good course of action?

A little note that might be useful, the replacement chain was somewhat smaller than the original. I had plenty of free play in the rear wheel/swingarm adjusters but it did mean that when i moved the rear wheel in, the drum brake was forced to rotate slightly. There's a supporting bar holding the drum brake in place alas rotation was necessary.

Hopefully someone can get a good grip on what i'm describing, first time posting here so sorry it's a bit wayward.

Warm wishes

Gabe

[Robby]

There are a few confusing things in the post, lets get them ironed out first.

1. Drum brake rotating. The brake should have two things attached to it, the torque arm (which is a fixed length) and the operating rod (which moves to work the brake).

The brake is meant to move/rotate a bit against the torque arm when you move the wheel back and forth for chain tensioning, and also when the wheel is moving up and down with the suspension.

You might need to adjust the rear brake to compensate for the wheel being further forward or back when you adjust the chain, but usually it's such a small movement that it won't make a difference.

2. Chain being "somewhat smaller". I'm assuming you mean it is shorter. Chains stretch over time so a new one will always be a little shorter, but you could also have fewer links in it. If it fits, not really a problem.

3. Clicking noise. That's not good.
To find out if it is the chain, put the bike up on the centre stand and spin the wheel in both directions, listen for clicking and find out where its coming from. Most likely problem is a loose bolt(s) on the front or rear sprocket, allowing the sprockets to move around and make noise.

Also possible that you fitted the wrong chain and sprocket kit, or that the rear wheel isn't aligned properly. Make sure the adjuster marks are clean and you've got good light to look at them, its possible to miss a mark when its covered with a layer of shit.

[vocab]

Cheers Robby!

Awesome, so I'll check the rear brake adjustment and the sprockets. Double checking the alignment if that doesn't work.

Will have a look-see tomorrow when it's a bit less dark and damp..

Thanks for the clear and succinct answer

[jaffa90]

""Double checking the alignment if that doesn't work. ""
The chain should drive and leave the rear sprocket with the sprocket in the middle of the chain and not to one side.

[ThatDippyTwat]

Don't trust the marks on the swingarm - Mine were off by a country mile. All the issues I had with chain slap and noise went away when I aligned it using a tape measure instead.
____________________
'98 VFR800 (touring) - '12 VFR800 Crosrunner (Commuting) - '01 KDX220 (Big Green Antisocial Machine)

[vocab]

ahh nice tips

yeah, i've been measuring from the swing arm pivot to the rear axle with a metre rule, with unknown success aha