Clonking/knocking SV650S-Y. F/Sprocket? Rear Wheel?

[ryanh1418]

Apparently I'm cursed and destined not to ride this year. I've recently had to replace the clutch rod oil seal that had started to leak very slightly after the chain snapped and took out the clutch rod. This meant removing the front sprocket and much fart-arsing around for a relatively simple job.

Once it was all put back together I took her for a test spin and all seemed fine until the end of the ride when I noticed a knocking sound and feeling at slow speeds. It's [very] audible from the right hand side and can be felt through the right footpeg. I have to say this issue was probably present throughout the ride, I just didn't notice it until travelling at creeping pace.

The chain and sprockets are new obviously having been replaced when the chain snapped. This knocking/clonking definitely wasn't present until now so something I've done during the recent oil seal replacement has caused this.

I've searched the forums and the suggestions tend to be chain tension/wheel alignment so I checked that to no avail. Today I've checked this for at least the third time and removed the rear wheel to check things closer and start from scratch with the chain tension but no joy. Just a few yards, literally, up the road and this clonking is there.

I'm nothing more than a tinkerer and even then only armed with a Haynes so am no good with diagnosing problems. My initial thoughts were obviously around the front sprocket but in taking off the rear wheel today I noticed what I think is part #13 in this link: http://www.cmsnl.com/suzuki-sv650s-1999-2002-usa_model16251/partslist/97343.html was moving around inside its housing but I assume this would be held in place once the rear axle is put back in place. I also notice that the rear wheel doesn't spin particularly freely when the axle is done up to the correct torque (have just read the latest article in 'news' on the .org home page).

I know it's difficult to diagnose stuff online so I'm just after any general thoughts/opinions really. I think my next step will be to re-do the front sprocket and double check that, unless someone here can think of another possible, particularly with the rear wheel, but bearing in mind this probelm wasn't there before and the old girl's barely been out this year.

I just want to ride!!

[Berlin]

Collapsed rear wheel bearing? Or sprocket carrier bearing?

Is the knocking engine or drive train? In other words, does it follow the revs? If you rev the engine does it increase in speed or is it drive train where you pull the clutch in whist riding and it is constant?

C

[ryanh1418]

Not engine as far as I can tell. It only does it while in motion but at slow speed (<20mph) and either stops or can't be noticed at higher speeds. I'm fairly sure it still does it while coasting with the clutch in at those speeds. I can't see/hear any issues just spinning the rear wheel on the paddock stand or while pushing it.

Cheers,
Ryan

[Berlin]

Hmmmm, Well suspect #1 is stil rear wheel bearing or Sprocket carrier bearing.

Next option could be tight spots in the new chain hitting the swinging arm as they pass it.

Or even front wheel bearings.

What you don't want it to be is the final drive bearings inside the engine. That's not an easy fix.

C

[ryanh1418]

What I can't get is how any of these things could happen when the bike's barely been used. It definitely wasn't a problem before I had the front sprocket off which is why can only think I've cocked something up along the way. You know how it is though once your mind gets working overtime and you start reading things!!

[Red Herring]

Are you sure part number 9 in the diagram is still there? It's basically a spacer between the sprocket carrier bearing and the rear wheel bearing. I've known it to fall out whilst people are messing around with their rear wheel and they haven't noticed, that would also explain why the wheel goes tight when you torque the axle up.

[andrewsmith]

it does sound like a collasped bearing, but elimintate other possibilites like a fork knock if its the front end

[ryanh1418]

Right, night shift number one out of the way, now back to this little gem! Thanks for the time taken to read and reply so far guys. With the rear wheel side of things, I only removed it yesterday, not during the original repair (replacing the oil seal) which only required the chain being slackened and lifted off the sprockets, so I don't see how any of the innards of it could have fallen out/been misplaced at that time - the knocking was there on the first test ride. I suppose it's feasible that the bearing could have imploded DURING the test ride but surely that's unlikely on a short gentle plod.

Anyone have any thoughts on what I could have cocked up/forgotten as far as removing and replacing the front sprocket? I've considered all the obvious stuff like too tight, too loose, backwards, inside out etc!

If I go back to square one and re-remove and replace the f/s and nothing changes, how much of a job is it to renew the rear wheel bearing/s? It may well be in the Haynes but that's locked up in the garage and I need sleep!

Thanks again so far - Ryan

[Berlin]

A bearing can go at any time. Its still top suspect. Whip the rear wheel out and try each bearing with your finger to see if there's any roughness or notchiness. Also do the spriocket carrier

If it is a Wheel bearing its not a big job to repolace. Just drift it out from the other side and knock a new one in with a suitable size socket.

If thats not it, Check spacers (again) and check sprocket bolts aren't touching the swinging arm.

This could also be a sign of a very tight chain but I'm sure that that would have been evident. You didn't put a one tooth bigger front sprocket on without noticing or one link shorter chain?

If its not those it looks like it'll be the final drive shaft bearings. :(

There's nothing loose inside the front sprocket cover is there?

C

[ryanh1418]

This could also be a sign of a very tight chain but I'm sure that that would have been evident. You didn't put a one tooth bigger front sprocket on without noticing or one link shorter chain?

There's nothing loose inside the front sprocket cover is there?

C

No, the chain and sprocket set was a straight change. That must have been done almost a year ago because it wasn't long after we did a euro trip that the chain went. No problems whatsoever after that. I'm certain this clonking has only been there since the f/s has been off on this latest occasion.

Nothing loose inside the sprocket cover, no.

The final drive bearings [here comes my lack of knowledge #-o] I'm guessing they are burried away 'behind' the front sprocket shaft/spindle (please advise if this is a stoopid guess!). Would it be possible to damage these during the repair/replace job given what a bitch it can be to get the sprocket nut off or is it only ever likely to go through wear and tear?

[Berlin]

There are three bearings in the rear wheel assembly. One is in the Sprocket carrier and two are in the wheel itself. As soon as the wheel is out they'll be visible. Stick your finger into them and rotate them and if they feel a little "Crunchy" or Notchy then they're on the way out. If they are very crunchy and notchy and there is side to side play in them, they're dead.

Bearings can go because water has ingressed passed the seal and rusted the balls or runing surfaces and some just break down the case hardening on the balls due to use. Once the hard surface is off them, its all over. (thats the notchiness. The ball bearings are no longer round and hard).


I heard a collapsed rear wheel bearing on an R1 at Mallory from 30 meters away as he came in from the pits and its not a nice sound! I've also seen a rear wheel bearing go on an SRAD 600 that welded the wheel spacer to the bearing and junked the rear sprocket carrier.

Keep you fingers crossed that this is what it is because if its not the next option (final drive shaft bearings) is a whole lot more expensive.

If its the final drive bearings you have to split the engine to get at them. I'm not sure how many there are in the Sv engine and I don't have a manual at hand. Its usually the outer one by the sprocked that goes as this is the one that is exposed to the elements and has the highest twisting moment on it.
You may be able to check if its this bearing by wiggling and turning the front sprocket or the shaft with the front sprocket off. If there's any play, noise or notchiness then its a stripdown to replace I'm afraid.

And if it is the bearings, don't buy "Suzuki" ones. Go to your local bearing factors and buy them by the number on them. It'll save you a small fortune. Bike wheel bearings are commonly used in all sorts of things including generators and electric motors.

As an aside, how tight/slack is your chain? Is there any hooking on the sprocket teeth?
C

[ryanh1418]

Hats off to you lot, you were all right... I conceded defeat and had this looked at professionally and tied it in with the MoT. It was the rear wheel bearing AND the spacers. I'm ashamed and embarassed because one of them was missing and I dread to think how long it's been missing for (still haven't found it despite clearing out the garage). Thankfully I've barely covered any miles this year. But anyway, all good now and the bike's like new after a couple of other tweaks and was rewarded with a nice weekend camping trip around the Norfolk Broads. Just wanted to tip my hat to ya!

[warrenhewitt10]

glad its sorted! Reading this thread is making me want to go check my rear wheel bearings as i have a slight clunk coming from down there also when i take up slack on the chain when accelerating. should check it before it worsens i suppose