Front end vibes...

[Mr OCD]

Biker's Nemesis said:

I would check the headstock isn't oval or the frame bent.

ps off!!!

[leighz]

for the price of a couple of gauges and a bit of time I would check the runout on the discs and the thickness all the way round before you start dismantling the front end - just because they're new doesn't mean they were installed correctly or they were spot on out the box

[Prof Prolapse]

Mr OCD said:

Cheers All.

I'm going down the route of replacing the head bearings ... everything else is done so for the sake of £30 and a couple hours work I might as well rule them out.

OEM or HD taper bearings?

Have you actually confirmed they're knackered?

There's no sense in replacing working bearings...They can last for bloody ages.

Christ are you desperate for something to do?

[Mr OCD]

Prof Prolapse said:

Have you actually confirmed they're knackered?

There's no sense in replacing working bearings...They can last for bloody ages.

Christ are you desperate for something to do?

It is difficult to confirm as it only happens when the front end is under pressure at speed. The majority of CBR1000RR owners are replacing their head bearings around 20k miles with inspection every 12k according to the Honda manual and my blade is about to tick past 29,000 miles and is now 7 yrs old ...they have never been inspected or changed. So given I need to strip the front end down to check them... at that mileage I might as well just change them given everything else is new.

Was going to do it myself ... but local suspension specialist have quoted me £95 to fit ... for that they can do it not to mention I have no time to do it myself.

[Biker's Nemesis]

3rd gear balance point wheelie then rock the bars side to side to see if there's any play.

You can thank me later, no one on here knows nothing.

[Prof Prolapse]

Mr OCD said:

It is difficult to confirm as it only happens when the front end is under pressure at speed. The majority of CBR1000RR owners are replacing their head bearings around 20k miles with inspection every 12k according to the Honda manual and my blade is about to tick past 29,000 miles and is now 7 yrs old ...they have never been inspected or changed. So given I need to strip the front end down to check them... at that mileage I might as well just change them given everything else is new.

Was going to do it myself ... but local suspension specialist have quoted me £95 to fit ... for that they can do it not to mention I have no time to do it myself.

The symptoms only appear in those conditions, but if the headstock bearing is knackered it's knackered, as said earlier you can check just by getting the front end off the ground and turning the bars carefully and feeling for a "notch". I changed mine a few years back and it was pretty easy to confirm.

I get what you're saying, but routinely changing bearings just seems overkill to me. They either work properly or they don't, perhaps confirm what the problem is for certain, that way you can use that time sorting out the correct issue rather than changing bearings just to find your discs are felched...

[Shadow R1]

Any update on this ?

[Mr OCD]

Shadow R1 said:

Any update on this ?

It's having the head bearings replaced next week.

[Mr OCD]

Bike is currently having its head bearings done ... KAIS just sent me this:



Obviously way over due for checking / greasing at a minimum. So new bearings going in as we speak.

Hopefully that will resolve the vibration.

[Mr OCD]

New head bearings has fixed it. Happy days

[Shadow R1]

Good stuff.

[Prof Prolapse]

I like easy fixes.

[Birky_41]

Glad to hear you sorted it

Jumping on this thread my front has started pulsating on the lever and grabbing on the front

I've bought some red scotchbrite and brake cleaner, hoping maybe I cooked the pads on it a bit but it's still doing it

I've cleaned again last night after being out but am I just in denial? I reckon they are slightly warped but bikes only done 5000 miles (9 months old)

[Mr2Mike]

Birky_41 said:

Glad to hear you sorted it

Jumping on this thread my front has started pulsating on the lever and grabbing on the front

I've bought some red scotchbrite and brake cleaner, hoping maybe I cooked the pads on it a bit but it's still doing it

I've cleaned again last night after being out but am I just in denial? I reckon they are slightly warped but bikes only done 5000 miles (9 months old)

At the discs nice and smooth all the way around, no pitted areas from standing outside for extended periods? Are the bobbins nice and free?

Slight run out doesn't usually cause major problems on a fully floating disc, but even very small thickness variations will cause horrible pulsing. The front brakes on my blade were horrendous when I bought it, the forks would literally pump up and down as you slowed to a stop. There was no perceptible run out on the discs, but when the thickness was measured with a micrometer one area on one disc was about 3 thou lower than the rest of it.

[Birky_41]

Mr2Mike said:

At the discs nice and smooth all the way around, no pitted areas from standing outside for extended periods? Are the bobbins nice and free?

Slight run out doesn't usually cause major problems on a fully floating disc, but even very small thickness variations will cause horrible pulsing. The front brakes on my blade were horrendous when I bought it, the forks would literally pump up and down as you slowed to a stop. There was no perceptible run out on the discs, but when the thickness was measured with a micrometer one area on one disc was about 3 thou lower than the rest of it.

Hmm there are a couple small pit marks but they feel very smooth

I wonder if I should try fitting the front again? I always when changing tyres fit the spindle, compress forks, nip opposite side of nut locking clamps up, compress again, tighten wheel nut and tighten other side fork

Only had this happen once before, 11 years ago on my old Benelli

[Jazoli]

Birky_41 said:

Hmm there are a couple small pit marks but they feel very smooth

I wonder if I should try fitting the front again? I always when changing tyres fit the spindle, compress forks, nip opposite side of nut locking clamps up, compress again, tighten wheel nut and tighten other side fork

Only had this happen once before, 11 years ago on my old Benelli

Had you checked the bobbins are all free, nut and bolt through them just nipped up then give them a good blast with brake cleaner whilst turning them?

[Biker's Nemesis]

Mr OCD said:

Bike is currently having its head bearings done ... KAIS just sent me this:



Obviously way over due for checking / greasing at a minimum. So new bearings going in as we speak.

Hopefully that will resolve the vibration.

Was that caused by jet washing?

[Mr OCD]

Biker's Nemesis said:

Was that caused by jet washing?

Very unlikely as it would take an idiot to force water past the seals.

20 k is the norm for head bearings on these bikes apparently ... so I did well to get nearly 30 k miles although it's been vibrating for the past 5k!

[Mr OCD]

Birky_41 said:

Glad to hear you sorted it

Jumping on this thread my front has started pulsating on the lever and grabbing on the front

I've bought some red scotchbrite and brake cleaner, hoping maybe I cooked the pads on it a bit but it's still doing it

I've cleaned again last night after being out but am I just in denial? I reckon they are slightly warped but bikes only done 5000 miles (9 months old)

Pulsing is generally caused by DTV ... I.e. Warped discs, seized bobbins or poor pad transfer.

If you've cleaned up the discs and the bobbins are free then it can only be the discs ... discs on modern bikes are so thin now so easily done.

[Biker's Nemesis]

Mr OCD said:

Very unlikely as it would take an idiot to force water past the seals.

Why do you think I asked.



<don't get your knickers in a twist, I'm only pulling your plonker>