Handlebar vibration and knocking

[DrDonnyBrago]

Two questions, bike is a 2001 CBR 600F (fuel injected):
1.
My bars vibrate a lot esp at speed, getting dead fingers after longer journeys... any thoughts on what I should be looking for?
I was thinking wheel bearings (checked they seem fine), tire balancing etc. Should I sync my throttle bodies?



2.
I also have a rythmic 'knocking' coming through the bars at lower speeds, the frequency increases with speed up to about once or twice a second then I can't feel it anymore. I worked out a tight spot (or several )in my chain not long ago and I thought it went away, not sure if it has come back or I just stopped noticing it.

Say I am riding at 30mph; with the clutch out and in gear i can feel the very slight bump in the bars; with the clutch pulled in it stops, if I pull the clutch and rev it to the same rpm it doesnt start knocking again... any ideas?

[DrDonnyBrago]

Ah thought I should add, my front brakes seem to drag quite a lot despite my attempts at cleaning them.

Cheers

[Wu_Dan]

I am not a mechanic. I am interested in bike mechanics.
Maybe my post will give you some help.

I found some advise on your problem.

When your bars vibrate it may be caused by:

- Forks bent (maybe even slightly)
- Front wheel bearings worn
- Front wheel not balanced
- Front wheel rim buckled
- Front wheel spindle bent
- Bent frame

As for brakes - it may be the disc warped or bent.
Check the calippers as well if they are alligned with the discs (maybe the mounting is bent or bolts are bent or something like that).

Check theese and good luck.

[neil.]

Knocking like that sounds like your chain. Mine did exactly the same thing and then snapped after a while (I'd adjusted/cleaned/lubed it loads which would suppress the knocking for a short time but it kept coming back).

Failing that, I'd look at the wheel bearings and perhaps the headstock bearings.
____________________
CBT February 2008 | A2 June 2008 | Yamaha YBR125 (written off) | Honda CBF125 (current)

[chris-red]

I'd check for warpped brake discs first.
____________________
Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[DrDonnyBrago]

[neil.]

Grab the wheel and pull it from side to side, diagonally (push the bottom, pull the top, sideways to try and bend it). There should be no play/knocking which would indicate bad bearings. How old are your C&S/how many miles on them?
____________________
CBT February 2008 | A2 June 2008 | Yamaha YBR125 (written off) | Honda CBF125 (current)

[DrDonnyBrago]

[DrDonnyBrago]

OK, my pics are shit and dont add much (anything) to this thread but meh, everyone loves pictures:

[chris-red]

That sprocket looks fine to me.
____________________
Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[DrDonnyBrago]

yeah the rear seems ok, the front is less great but I didnt photo it. The chain is by far the weakest link (see what I did there ) though, recently it had loads of stiff links (could barely move them by hand) so it is due replacing soon.

[cloric_tzr]

[cloric_tzr]

if you want to check headset bearing raise front end off the ground and try pushing the forks fowards and backwards from the bottom of them you'll need som assistance too keep handlebars steady check wheel bearings to as described b4. check you tyres for bulges or kinks tht can play a detrimentle part in weird sensations tru handle bars.
____________________
i dumped my girlfriend the other day! she wouldnt act out one of my fantasy's. all i wanted her to do was come home from work, catch me fucking her sister and join in!!! miserable bitch!
My wifes so ugly, the only thing that goes down on her
Is the internet connection.

[Wu_Dan]

Yes I did, but from service manual.

I thought of quick reference and I found these in service manual.
It is decent information.

I thought that it may help so he rules things out and find the fault quicker.

I did't try to be a smart ass.

[DrDonnyBrago]

I dont care if the advice I get is from your great grandma's cookbook nso long as it is applicable

Cheers all

I was reading up about handlebar virbation and a thread was mentioning that carb balancing can alleviate it. Obv I dont have carbs on an FI bike but you can still balance throttle bodies - worth buying a set of vacuum gauges?

[DrDonnyBrago]

bump

https://www.threadbombing.com/data/media/8/frog_bump.jpg

[The Tot]

Right,

Hondas in particular haven't been known for the quality of their drivetrain. My 929 blade gets knocking from the front sprocket despite the chain being in good condition, tensioned correctly and sufficiently. It's just honda's nature to have rattly clutches in town when its below 3k rpm.

The juddering from a warped brake will be prevalent at low speeds because you'd feel the thudding whereas braking from high speed, the frequency of the wheel rotation will give the sensation that the lever is hovering despite applying constant force. When was the last time you cleaned the calipers? If the pads are dragging, strip your calipers and give them a thorough clean - there's plenty of useful guides in the workshop section by Korn. How hot does the brake disk get under normal use (NOT after ragging it on your twisties). If it's hot to the touch, then it's very likely that the constant cycling heating cooling has caused it to warp. I recently had to change my discs after they warped over winter! The irony is that changing the pads (I use Honda original NISSIN HH pads), bleeding the brakes and cleaning them made the problem worse. The levers were rock hard as you'd expect, but it only exacerbated the symptoms.

Solution

https://www.calsport.co.uk/HONDA/3253-2000-CBR_600_F_FXFY/32-Brakes__Wheels/Galfer_Wave_DiscsLinesPads/73172

They were cheaper than getting a set of genuine spares from davesilverspares and they're wavy. I didn't buy them for the bling, I bought them to see if their claim of reduced chance of warpage would be true. I'll know after another 10 years of use I suppose. Granted your bike is 9 years old, you can expect the discs to be past their best so this is a good investment - you'd get the pads as well. They don't take a long time to warm up and they're good in the wet. So from me.

Vacuum gauges? I'm not too sure if that's relevant to a non-carbed bike since fuel injectors don't rely on vacuums to pull the fuel air charge through. It's all electrickery when it comes to synchronizing fuel injectors. Have you checked your air filter to see if it hasn't been pierced? Exhaust blowing? The CBR600's came with mild steel headers so they'll inevitably rot!
____________________
The Tot 2019 Z1000SX - 2007 R1
Never argue with autism

[DrDonnyBrago]

[The Tot]

Err,

I forgot to ask, do you have any bar end weights?! The answer could be as simple as this! Get some bar end weights to dampen the vibrations through the bars! Not the cure but one way of eliminating the symptoms. I noticed my left hand had a bit of a pins and needles sensation when i replaced the handlebar due to a crash - the replacement bar had no bar end weight so it was lighter. If you're au fait with resonant frequencies etc, then a heavy bar end weight (i.e. OEM) will dampen the frequency of the vibration or shift it out of the resonance band when you're at speed.

CHECK THIS first because it'll be only a 10 quid fix as apposed to a £350 set of discs etc.

If your bike drives fine through the rev range then your bike is fine. i'd either get Stainless steel headers as a replacement because the problem of puttying won't hold in the long run. Just a heads up for after winter when you get a greater temperature gradient due to the cold.

Brakes are meant to bind a little. I notice it after a ride. It makes a swoosh swoosh swoosh sort of sound. Totally fine after a ride. As long as you've cleaned your calipers and are happy with the action, then you're fine. Brake discs are fully floating i.e they're designed to have a bit of play - if you look at the discs you'll see that the disc itself is mounted onto the carrier with rivets/buttons which are meant to have some play in it. A little rubbing is fine. If you find they get hot even without applying the brakes, then something is wrong.

I guess with any new bike, just get used to its traits and characters. I've ridden my mate's CBR600F-S of similar vintage to yours and I have to say that it's almost similar to my 929 blade. So, really there's nothing to worry about. Bikes will age, some quicker than others, so you'd need to make account of consumables.

But yeah, CHECK YOUR BAR ENDS!
____________________
The Tot 2019 Z1000SX - 2007 R1
Never argue with autism

[DrDonnyBrago]

I have the OEM bar ends in, I spent about 4 hours polishing them 3 weeks ago

I know the pipes are shite, but I'm all for cheap running of the bike where possible - I have been eyeing up some new StSt ones but having trouble finding cheap ones with balance pipes on. Heard about midrange stutters with some non oem ones too. Money would be better spent on new chain and sprockets at the moment I think

I have a list of stuff to check next weekend so I'll report back if any of it makes a fudge of difference. In the meantime if anyone knows anything about TB syncing or has anything else I should check let me know

[cloric_tzr]

[DrDonnyBrago]

Being as tight as a nun's cunt is the way forward

[cloric_tzr]