Hello, its me again! I have been riding my bike to work now and again lately, and I am well aware how anxious and sensitive I am about noises etc, especially since my Astra seized and nearly killed me after three mechanics said 'its fine, all Vauxhalls make that noise' Anyway, I noticed that when I cruise on the motorway at say, 70mph, in 5th or 6th gear, with a tickle of throttle, I am getting vibration. The engine sounds fine, revs fine and although its hard to hear behind the exhaust, it makes that characteristic whine that is smooth as anything like it should. Today, I was out and about, and because of the other road users that should bugger off, I spent a lot of time tickling it in 3rd and its doing this vibration again. When I pull out to pass, it launches off just as it should, so no loss of power or anything like that. I was wondering if its misfiring, but it doesn't sound like my cars when they misfire but I don't know lots about bike engines, then I thought it could be the Scorpion exhaust I fitted last year. Anyway, can anyone point me in the right direction? I might ride to work tomorrow and see what it does, I wonder if its due a full service, its on 24k now gotta say, it spoilt the ride today, its just distracting
Could it be something like wheel bearings? Chain is properly tensioned and sprockets not worn? Swingarm bushes ok? Head bearings ok? I think the bike needs lifting and thoroughly checked out by someone who knows what they're doing.
its had new wheel bearings, although the rear ones were totally fine, the front ones were knackered because the wheel was fitted incorrectly by the guy who changed the tyre. chain and sprockets are good, I had the forks refurbished not long ago too thinking more, I can stop the vibration by changing down a gear, dont have to change speed, which makes me think its not wheel bearing type things
I had a vibration caused by a tight spot on the chain even though the chain looked in good condition.
Where do you feel the vibration? Handlebars, footpegs, seat? If it is predominantly on the right side I'd point the finger of blame at the cam chain. I don't believe the cam chain tensioning system is up to the job. Over time either the tensioner wears or the lifter (commonly called the CCT) starts to fail, and some play creeps into the system from either a wearing cam chain or a lack of proper tension, and the play causes the vibration. It is just a theory, however.
When you say you can stop the vibration by dropping a gear does that bring your rpm up to over 5k ? Maybe possible you might have a primary injector that’s not functioning correctly and by dropping a gear, and bringing in the second bank of injectors, you are smoothing out the issue. I wouldn’t rule out electrical either. When your next out, try and make mental notes of exactly what’s happening and then get it to replicate the issue mirroring your inputs. Fine tune to just prior and during. Then post back test rider style. Best of luck mate.
the vibration is just everywhere, its definitely on the handlebars, but its not like the handlebars are vibrating and nothing else is. I didnt realise there were two sets of injectors either. Ill try and watch the revs when its doing it, I just cant remember, I think it vibrates at 4-5k, but not above or below.
ill let you know when i take it to work, oh, one thing, it doesnt change speed with the revs or speed im going, so it must be something resonating
Lots of bikes get vibrations at certain revs, everything generates harmonics and you can damp them out, heavier bar end weights or fill the clipons with silicone or both, I fit heavier bar weights on all my bikes where possible, it can happen more if you’ve fitted lighter parts to your bike as well as you alter the pitch of the harmonics.
I did pinpoint the vibration, 3500-4500, it fades in and out, im sure its the exhaust. Also, parked at work, as heterosexual men do, comparing exhausts and who has the most chrome, wondering why the office ladies are walking away briskly, I noticed the chain was pretty slack, could lift it to hit the swing arm, so I bribed the significant other to help me clean and adjust it Took it for a ride today, and loved it, every minute. The vibration is still there but like i said, im sure its just the new exhaust, the jerkyness has gone, not that I could pinpoint that, but i was either imagining it, or it was the chain. As always, some days, I just find it hard to get into it and enjoy riding, but today was, well, tickle my toes and call me shirley, just great and really reminded me why I took my test in the first place.
Is the vibration more noticeable in a certain gear, you mentioned 3rd gear was noticeable with vibration. Ive had a damaged 3rd gear which had to be replaced. Next oil change check for metal filings. I know when changing gear into 3rd you would notice some difficult, but it could be the start of minor damage. The exhaust would sound differently rather than give vibration. run the bike up on the stand , and listen to the exhaust system. Just saying, is the suspension ok.
Chain tension does affect how smooth a bike will be as all the slack has to be taken up when you open and close the throttle, bikes, cars and pretty much everything have harmonics that will increase and decrease at certain revs, the trick is finding and dampening them out and it’s usually at an extremity as in bar end or foot pegs or the exhaust exit.
Did you resolve this issue? I am experiencing something very similar. I believe it's an issue with the cam chain tensioner
