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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Chri5 on May 05, 2018, 02:23:03 PM

Title: Snaking brick near top end speed
Post by: Chri5 on May 05, 2018, 02:23:03 PM
Hi,
I had an issue today a week ago i changed my head bearings as i was getting a strong judder in the bars at 95mph the grease was like glue and the races where slightly notched so i relaced them and the judder has gone great  i rode another 50 mile and rechecked the adjustment the bars fall without drag and hit the stop gently i have also check fork alignment by loosening the lower bolts and pumping the forks repeatedly but at high speed 110-120 the bike starts to weave and doesnt stop untill i shed 50mph it wasnt like a full on tank slap but it did feel like it would any second my tyres are what the last owner put on not long before i bought it avon road riders with a date stamp of 2616 and loads of tread


Ive never done a head stock before but im confident that ive done it correctly and the bike tracks true with hands of the bars in a straight or corner


Any ideas about this snaking should my stock be tighter?
Title: Re: Snaking brick near top end speed
Post by: Laitch on May 05, 2018, 03:20:36 PM
Here's some advice from your kindly British uncle—or nephew, as the case may be.

https://www.youtube.com/watch?v=z3OQTU-kE2s (https://www.youtube.com/watch?v=z3OQTU-kE2s)
Title: Re: Snaking brick near top end speed
Post by: johnny on May 05, 2018, 03:30:42 PM
greetings...

1) tiors
2) wheels
3) suspension
4) head bearings
5) swing arm
6) frame
7) more skill
8) more throttle
9) more squeaky curds
10) more knackwurst

in that order...

j o
Title: Re: Snaking brick near top end speed
Post by: Chri5 on May 05, 2018, 03:59:30 PM
Im surpised you didnt say more speed johnny im all most disapointed  :falldown:
Title: Re: Snaking brick near top end speed
Post by: Chri5 on May 05, 2018, 04:17:23 PM
Laitch i think i know what your saying  :yes  i would like to state im no speed demon i ride for the journey not the raw speed but i am a very light rider! Coming in at 54kg ~105 lbs that might be my issue
Title: Re: Snaking brick near top end speed
Post by: Chaos on May 05, 2018, 04:36:46 PM
Cheese and bratwurst may be the answer :lets-eat: :lets-eat: :lets-eat:
Title: Re: Snaking brick near top end speed
Post by: johnny on May 05, 2018, 04:47:46 PM
see 7) n 8)...

see 9) n 10)...
Title: Re: Snaking brick near top end speed
Post by: stokester on May 05, 2018, 07:13:39 PM
Cheese and bratwurst may be the answer :lets-eat: :lets-eat: :lets-eat:
Must be squeaky!


From a transplanted Cheesehead, that means they are fresh curds :lets-eat:
Title: Re: Snaking brick near top end speed
Post by: Chri5 on May 06, 2018, 05:20:21 AM
Thats the johnny i recognise ill apply 7 through 10 with enthusiasm!
Title: Re: Snaking brick near top end speed
Post by: Laitch on May 06, 2018, 09:21:15 AM
Laitch i think i know what your saying  :yes   
Believe the video, is what I was saying. Weight isn't the only factor, although someone with your charm could make wearing weightbelts fashionable.

Of course, j o's recommendations are always on target. :2thumbup:
Title: Re: Snaking brick near top end speed
Post by: oneplustwo on May 06, 2018, 01:22:27 PM
Wow, that video was nuts!  Has anyone fitted a steering damper to their K-bike?
Title: Re: Snaking brick near top end speed
Post by: Filmcamera on May 06, 2018, 02:16:42 PM
My 1991 K100RS came with a steering damper from the factory.  However it was missing on my bike when I brought the bike.  I had fairly bad low/medium speed wobble and so got a second hand damper and fitted which basically made no difference.  Changing my worn front tire totally fixed the issue however. As steering dampers go the OEM one on the bike is pretty flimsy but I am sure BMW added it for a reason so I am glad I got one, if only for the sake of originality.
Title: Re: Snaking brick near top end speed
Post by: The Mighty Gryphon on May 06, 2018, 04:30:09 PM
I brlieve tat your K75S has a damper built into the steering head.
Title: Re: Snaking brick near top end speed
Post by: Martin on May 06, 2018, 04:48:54 PM
K75's came with a built in damper called a Fuidbloc in the steering head. It requires the application of very heavy silicone grease into a rubber cylinder which has indentations in it. The grease may be still available through Dow Corning as High vacuum grease. The actual Fluidbloc is no longer available and if you still have one treat it with care. All the workshop manuals should have a section on the fluidbloc dampers.
Regards Martin.
Title: Re: Snaking brick near top end speed
Post by: Laitch on May 06, 2018, 05:31:58 PM
I brlieve tat your K75S has a damper built into the steering head.
K75's came with a built in damper called a Fuidbloc in the steering head.
Not necessarily. In the models from 1992-on, the Fluidbloc was a stock part.
Title: Re: Snaking brick near top end speed
Post by: Martin on May 06, 2018, 05:54:13 PM
 Sorry did'nt check my facts. According to my Haynes Manual it was standard on all 75 models from 1985 on and can be retrofitted to any earlier K75c models.
Regards Martin.
Title: Re: Snaking brick near top end speed
Post by: Laitch on May 06, 2018, 10:13:57 PM
According to my Haynes Manual it was standard on all 75 models from 1985 on and can be retrofitted to any earlier K75c models.
As they say in Ochopee, that don't make a lick of sense. If it was standard on all K75 models from '85, there aint no earlier K75 to retrofit, nohow. That's writ in the Good Fiche, plain as day for the world to see.
Title: Re: Snaking brick near top end speed
Post by: Martin on May 06, 2018, 10:34:11 PM
See Largiader site early 1985 K75C's were sold as 86 models and did not get the Fluidbloc later in 85 they fitted the Fluidbloc. It's sort of confusing. http://largiader.com/k75/khistory.html
Regards Martin.
Title: Re: Snaking brick near top end speed
Post by: Laitch on May 07, 2018, 03:24:45 AM
It's sort of confusing.
No doubt about that.  :popcorm