GSX1400 Owners .org

Technically Speaking => General Technical discussion => Topic started by: Del on Friday, 21 July 2017, 10:32 PM

Title: Fork Shudder only at speed
Post by: Del on Friday, 21 July 2017, 10:32 PM
Hello All - I am in need of assistance from you good and wise people.

I have a K2 and am getting a shudder from the forks (can see them vibrating) when I get over 80mph and not able to drive through it - it actually gets worse - it starts as a slight vibration and gradually gets quite bad

Now I have so far changed the following
Front wheel bearings
Head stock bearings
checked tyre for buckles and bulges
checked calipers and brake pads
tyre pressures

Yesterday I noticed that the right hand fork seal (the one that I think is vibrating more) popped the seal - so I stripped the forks to change oil (did seals at same time) and check levels and go over the fork internals - the forks are now set exactly the same but today the same issue is still there

the discs are true as no pulsing under braking (at speed and general riding speeds) 

its driving me mental and ruining what is a tremendous bike

Del

Title: Re: Fork Shudder only at speed
Post by: Rufus on Friday, 21 July 2017, 10:36 PM
Mad idea, but could it be the rear wheel balance or bearing?
I have a similar issue and have done the same front end checks, so the only thing left that I can think of, is that it's caused by the back end, investigating this weekend..
Title: Re: Fork Shudder only at speed
Post by: seth on Saturday, 22 July 2017, 03:18 AM
how many miles as your bike done?
could be worn bushes inside the forks if high milage
worth a check if your doing fork seals anyway.
also as already said check both wheel for balancing as that can affect things.

good luck
:cheers:
Title: Re: Fork Shudder only at speed
Post by: gsxbarmy on Saturday, 22 July 2017, 04:10 AM
Del - I'd look at wheel balance, but would also suggest checking your discs are running true (not warped slightly) and that the bobbins are free.

Strangely though it could also be the front tyre. I had a similar issue on another bike I had years ago, and like you it drove me mad, in the end I changed the front tyre and all was well again. Don't know why, the tyre looked ok, the only thing the fitter could think of was that I had gone down a large pothole at some time and it had damaged the tyre wall in one place.
Title: Re: Fork Shudder only at speed
Post by: Del on Saturday, 22 July 2017, 04:32 AM
Cheers for the help so far gents - I forgot to mention I checked the front discs with a dial gauge and they were running true - I am not sure of the state of the bobbins so imagine there not at there best
Im in for MOT tomorrow morning so will see about a new front tyre as I was kind off leaning toward the tyre . . . . . .mainly as it was the only thing Ive not changed so far

Thanks chaps  :hat:
Title: Re: Fork Shudder only at speed
Post by: seth on Saturday, 22 July 2017, 06:20 AM
worn tyre could be part of the problem. hope you get it sorted . :cheers:
Title: Re: Fork Shudder only at speed
Post by: gsxbarmy on Saturday, 22 July 2017, 07:48 AM
Keep us posted Del - good luck with the MOT tomorrow
Title: Re: Fork Shudder only at speed
Post by: Del on Saturday, 22 July 2017, 06:17 PM
sorry @seth forgot about you mate - the mileage on the bike needed converting - it was 31000 last year before I changed the clocks but my bike was weird it showed speed in MPH but odometer recorded in KPH so was 31196 Km which equated to 19384 miles - so add this year and it looking about 20K on the bike
Title: Re: Fork Shudder only at speed
Post by: seth on Saturday, 22 July 2017, 06:42 PM
no worries buddy its not done mega miles so fork bushes should  ok
a strange one hopefully new tyre helps sort it .
:cheers:
Title: Re: Fork Shudder only at speed
Post by: Del on Sunday, 23 July 2017, 12:42 AM
Well MOT done n dusted for another year - mentioned to the fella who mot'd it (happens to be a mate as well  :undecided:)about the wobble and we put it back on the brake tester - he did say that there was a slight but if run out on the tyre - so new tyre ordered and Ill get it Tuesday - fingers crossed
Title: Re: Fork Shudder only at speed
Post by: seth on Sunday, 23 July 2017, 02:35 AM
 :onya:
good luck buddy
Title: Re: Fork Shudder only at speed
Post by: Andre on Sunday, 23 July 2017, 03:05 AM
good to have mates  :grin:
Title: Re: Fork Shudder only at speed
Post by: Nellywelly on Sunday, 23 July 2017, 09:06 PM
I had the same problem. Found the front tyre was the cause it was a maxxis crap. I didn't fit it previous owner did. I wouldn't put maxxis on a wheel barrow!
Pilot road 4 fitted now, perfect!  :boogie2:

Title: Re: Fork Shudder only at speed
Post by: gsxbarmy on Wednesday, 26 July 2017, 08:05 AM
Quote from: Del on Sunday, 23 July  2017, 12:42 AM
Well MOT done n dusted for another year - mentioned to the fella who mot'd it (happens to be a mate as well  :undecided:)about the wobble and we put it back on the brake tester - he did say that there was a slight but if run out on the tyre - so new tyre ordered and Ill get it Tuesday - fingers crossed

So did you get your tyre today Del - problem now solved (hopefully)?

@Del
Title: Re: Fork Shudder only at speed
Post by: Del on Tuesday, 01 August 2017, 05:04 PM
@gsxbarmy

No not yet mate this week hopefully -been keeping bike below 70 till I can get to garage . . . . . .wife's car needed a dual mass clutch so that took care of £600.00
Title: Re: Fork Shudder only at speed
Post by: gsxbarmy on Tuesday, 01 August 2017, 05:17 PM
Quote from: Del on Tuesday, 01 August  2017, 05:04 PM
@gsxbarmy

No not yet mate this week hopefully -been keeping bike below 70 till I can get to garage . . . . . .wife's car needed a dual mass clutch so that took care of £600.00

Ye Gods!!!!

Hope you get your tyre soon buddy, I'm pretty sure that that will fix your issue.

Mind you keeping it under 70 saves the license!
Title: Re: Fork Shudder only at speed
Post by: BlackAdder on Saturday, 05 August 2017, 10:09 AM
What profile tyres do you have fitted in there now? A wide and tall rear combined with narrow and short front might make the bike act nervous, especially with lowered front and jacked-up rear, or with the suspencion set way off.
Title: Re: Fork Shudder only at speed
Post by: Kiwifruit on Saturday, 05 August 2017, 02:24 PM
Im with Barmy.....
Get the tyre sorted or walk.!!
Title: Re: Fork Shudder only at speed
Post by: Del on Tuesday, 15 August 2017, 04:15 PM
Looks like a new tyre has sorted the bugger out - its been pi55ing down up here and I hate breaking a new tyre in when its wet

Got the bike up to 80 and no shuddering - over 80 was okay a swell so looks like its sorted . . . . finally

Oh and the wife's car needs an effin battery now 

Del



Title: Re: Fork Shudder only at speed
Post by: gsxbarmy on Tuesday, 15 August 2017, 04:34 PM
Great news the bike is sorted Del - bad news on the wife's car battery front though
Title: Re: Fork Shudder only at speed
Post by: Notty on Tuesday, 15 August 2017, 05:24 PM
Great news  :smile2:
Title: Re: Fork Shudder only at speed
Post by: KiwiCol on Tuesday, 15 August 2017, 05:45 PM

Amazing aye, bloody tyre!  It really surprises me the difference in handling characteristics between new & worn tyres. Oddly worn ones seem to throw up all sorts of 'ghost' issues, when it's just a damn tyre.
Glad it's sorted for you, now for that battery . . .
Title: Re: Fork Shudder only at speed
Post by: Kiwifruit on Tuesday, 15 August 2017, 06:13 PM
Good on ya Del. Great news.
You will enjoy the confidence having good tyres gives you. And the bike always rides much nicer.
:onya:
Title: Re: Fork Shudder only at speed
Post by: grog on Tuesday, 15 August 2017, 07:13 PM
well done mate. front tyres can be alarming, cause all sorts of probs. mine is worn out on rhs, feels a bit wobbly. next on list. sometimes it feels like it wont even go around corner, really bad cold but ok when a bit of temp. rise. yeah,  i know, slack prick but time not been available. will feel wonderful with a newie. have been very careful, amazing fuel consumption, another 30ks from tank.  :grin:
Title: Re: Fork Shudder only at speed
Post by: Del on Tuesday, 15 August 2017, 07:16 PM
to be honest Im kinda pevved at myself for not checking tyre 1st - would have saved a lot of time and a few quid

@Kiwifruit  - I do like new tires but only after about a 100 miles to bed them in and over here its been fairly heavy rain for a few days so not managed to get out - this mornings commute was a tad upright and the occasional arse going like a rabbits nose  :grin: :grin:
Title: Re: Fork Shudder only at speed
Post by: Kiwifruit on Tuesday, 15 August 2017, 10:02 PM
"Arse going like a rabbits nose".......love it !!
:rofl2:
Title: Re: Fork Shudder only at speed
Post by: KiwiCol on Wednesday, 16 August 2017, 03:17 AM
What did you put on Del?
Title: Re: Fork Shudder only at speed
Post by: Del on Wednesday, 16 August 2017, 03:49 AM
Quote from: KiwiCol on Wednesday, 16 August  2017, 03:17 AM
What did you put on Del?

Michelin pilot 3 - was in stock and matched the rear mate - I do quite like them as they do last (I mostly commute these days) and on the occasional fun filled blat they do promote confidence
Title: Re: Fork Shudder only at speed
Post by: KiwiCol on Wednesday, 16 August 2017, 04:05 AM
Nice, I read the 3's stick like s..it to a blanket but didn't last too long. Think it was Rogues who posted it.   Good they're doing the job for you.  :cheers: