Hi all. I have a 2021 Tiger 850 Sport and loving it! (Used to have a 1200 Explorer launch model, but got too heavy and unwieldy for me as I aged!!) Anyway, I have replaced the drive sprocket (JT with the rubber shoulder), rear sprocket and a DID X Ring chain, and I cannot get rid of an awful whining noise from that area. I have tried tightening, loosening and going from max to minimum handbook stated tolerances but still no joy, even using a vernier to ensure the adjustment is equal both sides! It would appear that 30mm play is the best I can achieve. Under the swinging arm, there is a plastic runner, which seems to be in two parts - a flat strip mounted on the swinging arm, and a ‘bowed’ second strip (imagine an archery bow). I thought that this would take up any slack in the chain when going over a large obstruction/hole etc., but when I sit on the bike and feel the play, it is obvious the chain is running on the ‘bow’ permanently. My question is this: Is this the source of the whining? Should the ‘bow’ be closer to the flat part? Should I increase the play in the chain? Is the rear suspension too soft? etc., etc. Any help, ideas, solutions would be very gratefully received… Ian
I assume from your post that the noise wasn't there with the old chain and sprockets and that it's also speed dependent? I wouldn't expect a whining noise from a lubed chain on a plastic rubbing strip. The strip is a consumable item and will wear out and is there just to stop the chain hitting the swingarm under power or on overun when the tension is correctly set. Some chain/sprocket noise is inevitable but I would call it more of a whirring noise. If the chain tension is set as per the handbook and perfectly inline I'd try and ignore it and see how/it develops. Coincidentally I also get a speed related whine from that area, starting at around 28-30mph but in my case I'm pretty sure it's from the dual sport Metzeler Karoo rear tyre.
Thanks for your response. It is present right from the start and gets louder as speed picks up. It is also still there on decel, which leads me to think the chain is running on the plastic 'bow’ constantly. The chain slack is set correctly, and I don’t want to increase the slack out of tolerance. I will try, just for a test, to cable tie the ‘bow’ up to the swinging arm so the chain is clear and see if that proves where it is coming from. As there is already a flat strip on the swing arm, I fail to see what the ‘bow’ is supposed to protect. No other chain driven bike I have owned has this set up. Alignment set with vernier, and tyres unchanged (Continental TrailAttack 3).
As mentioned, I have tried all chain adjustments for the slack from the lowest to highest in the manual. Don’t really want go for any more slack.
Is this the rubbing strip you're talking about, part No.13 on the diagram? https://www.bike-parts-triumph.com/...850-sport/REAR-SWINGARM/136/10012585227/0/136 It looks as though it fits flat against the swingarm so I don't see how you could zip tie it any higher. Is it broken maybe?
Interesting, yes, that is the offending part! On mine, you can push up towards the swing arm fixed runner, hence my idea of tying it up to test. The other part of this arrangement is fixed flat to the underside of the swing arm. Maybe it is broken? I will go out and lie under my steed to investigate!! Many thanks for the tip and drawing. No doubt if it does need replacing, I’ll have to take out a second mortgage...
At 3 years old and 8500miles on the clock, I would be horrified if the wheel bearings were worn! I have checked the rear wheel for any play and it is fine.
Well.. it doesn’t look broken but it does have a strange kink in it. I noticed that when checking the chain tension, the chain was hitting this lower skid part. So, cable tied it up to the swing arm and took the bike out for an afternoon test ride (;<)), and it was a lot quieter than I have ever heard it! Not as quiet as I would like, but close. However, the opposing skid on top of the swing arm is pushing up by design, forcing the chain to permanently run over it. If the whole thing has worn out, maybe replacing it is the answer, but I am unsure, and even though the part is only £41.48 (less than I had imagined!) I don’t know if that will cure the noise. I may remove the part completely, and secure some thick plastic strip top and bottom of the swing arm, just as an inexpensive way of testing the theory.
OK. Having spoken to a very experienced bike builder/mechanic over the weekend, he suggested that I check the bearing in the rear sprocket carrier. Apparently he had a similar issues on his B..W F800 (hope I don’t get banned for that …!) So that will be my next step before modifying/replacing the plastic..
It seems to me that the rubbing strip on your bike is designed to make contact with the chain so this is bound to create some noise. Is it quieter after lubing the chain? The rubbing strip looks ok and should not need replacing at that mileage.
The photos show that's how the strip is designed and zip tying up to the swingarm is just deforming it. The bottom run of the chain will have very light or even no contact with the strip under power so if the whine doesn't change between on/off power it's unlikely to be the cause IMO.
Have you tried putting the bike in gear whilst on a paddock stand and the engine running to try and locate the source of the sound assuming it makes the noise still with no weight on the wheel. Not the ideal way of doing it but could be worth a whirl in first gear. WhenI measured my chain slack on side stand v paddock stand it was pretty much identical.
Yup, tried that. unfortunately the ABS keeps stopping the engine - guess it’s because the rear wheel is going significantly faster than the front!! Have now completely removed the plastics, fitted rubber/neoprene strips top and bottom of swinging arm, and made the chain slack 40mm (as against 25-35mm in the book. Much quieter, although I can still hear it… Checked wheel alignment with laser, and bearings in both the drive sprocket and rear wheel. Guess I’l just have to put up with it now...
I used the paddock stand method to identify the (tyre) noise I'm getting. Being a Scrambler model I had the advantage of being able to disable rear ABS. Trying it in normal road mode the ABS and TC kept throttling the engine back to keep the speed right down and it threw up an error light on the dash which had to be cured by ignition off, then start and ride the bike for a few hudred yards. I even sat on the bike and lightly feathered the rear brake to load the transmission. Needless to say DON'T TRY THIS AT HOME KIDS!!
