Thanks for the info Paul. The front tyre is a Continental Road attack and is virtually new with maybe 1500 km on it. I have checked it thoroughly and it isnt really marked in anyway atm. Both tyres have 36 psi in them. Let me know if I need more there. When I move the bars from side to side there is no clunkiness or roughness to suggest the bearings may be pitted etc. I only noticed this shake during my last major ride a couple weeks ago. It only does it at 80 km/h. Either side of that it isnt there. The wheel is perfectly balanced so it isnt that either. I'm not overly experienced with this sort of stuff. I will go through your list of possibilities and see how I go before I pull her apart. The head stem bearing swap out doesnt seem that difficult. I think Sprock or someone has a how to on here and I have a Haynes manual to help me. I would usually just take it to the dealer and pay their exorbitant prices but I want to try and sort this one myself and do the work myself if thats possible. If it gets beyond me I will take it in though.....lol. Thanks again. I have a few days off this week and I am going to sort this one way or the other !!!!! Cheers.

 

Thanks Sprock,
I did an alignment check the other day using Classics method he put in the how to section and from what I could see it was millimetre perfect with the front to back alignment. I will try Pauls list of ideas he posted for me and go from there. I am going to put some time into it next week and try and sort it out. Thanks mate. Cheers.

BTW the Acumen DGV is here. Again it will test my soldering abilities but I am keen to have a go at it. Our bikes need the speedo upgrade kit though as we have the old speedo cables. Is an extra $50 US it seems to get that.

http://cgi.ebay.com/ebaymotors/Acume...Q5fAccessories

 

hi Bordo
thanks for your reply
further question
you say you use the conti on the front , the same make on the back?
if not the tyre stiffness difference may contribute to the shimmy
also 36 is just enough for the front
back should be 42 at least a little more will not hurt and will stiffen the tyres sidewall up
tyre pressure at stone cold
add 2 to 3 psi for warm tyres
the steering head bearing should be checked last , the lower one is difficult to drive out as it is the same dia as the inner dia of the head tube
you can buy taper roller replacements that are better and stiffer
more likely for the wheel bearing to be rough and wobbly
look forward to your news
paul

 

Good ya did the alignment Bordo but what I was kinda getting at was the
fork tubes themselves being twisted a bit , a front to rear alignment won't remedy that
loosening the clamps on the tubes and making sure they are dead parallel to each other
will.

Only time I ever got wobbles on mine were on super hard decel' and braking around
15mph and that was due to the above and a cupped front tire

keep us posted on the Acumen DGV ....... they look cool..... but reading the install
instructions online ...... good bit of work putting it on maybe ??

 

gas/ petrol tap failure
to add the the list of cbr miseries i now have a leaking tap
what happens
even of you leave it on no gas can come though if there is no suction( that the theory)
now even if it is turned off gas will dribble through
why?
1 the valve in the main tap is worn
2 the secondary vacuum valve bladder is failing ( neoprene rubber )

symptoms :
smelly carbs
flooded nr 2 cylinder with gas ( had to remove the plug and blow it out !

remedy
pay honda 160 eur + vat for a new one
( you cant buy the bladder parts )
or go to bits for bikes in rochdale uk and buy the repair kit for about 20 gbp
about 5 min job to repair it ( once you have taken off the tank from the bike and inverted it )
have fun
paul

 

Paul,
I've got a BT021 on the back and come to think of it I have only noticed the shake with the Conti on the front. I went on a 1200km ride two weeks ago and noticed it during the ride. I have done shorter rides with it on though and never noticed it. Now before I went on the big ride I added some air pressure to the tyres. Probably running 40 in the back and 38 or so in the front. I also hardened the rear shock up a bit. I dont know why I did these things I just did lol........ I am going to try and put everything back how it was and see if that fixes the problem. I will take the time to muck around with different pressures and the former shock settings to see if I can get the shake out of it. It seems odd that one day the steering bearings were fine and the next they werent. I'm thinking its not them and some other issue. I will also replace the wheel bearings before I do the head stem as they are an easier job. Like you say I will check the head stem last. If none of these other things work I will do them. I have two bikes so while the old girl is not totally right I will ride the Blackbird.

The shake is only at 80 km/h in any case but it does bother me and I am going to sort it out because I'm not one to leave these things especially something as important as steering geometry if in fact thats what it is. Starting 2mrw morning I am going to play around with tyre pressures and the rear shock and go from there. I will post 2mrw night my time on how I went and see if you guys can help me get this sorted. Thanks for your input. Cheers.

 

Thanks for the input Sprock. I am determined to get her right. As far as the DGV goes yes....it looks like a hell of a wiring job. I had a plug and go loom for the one on the BB and it was pi$$ easy to install. They make it sound easy to install on some of their ads but it will take a while I'm sure. I just get a bit antsy about splicing into old wires and soldering etc. Taking it slowly will be the key for sure. Cheers.

 

OK so this work wasn't all done today, but here's an update on the work I've done on the bike since it failed it's MOT.

Stripped the swingarm and re-painted along with all the suspension linkages.

Installed new Hagon rear shockabsorber.

Rebuilt front forks, with new seals, new chrome tubes and new Hagon progressive springs.

Re-painted front fork sliders.

Rebuilt front and rear brakes with new seals and stainless steel pistons.

Bled brakes, replaced rear brake switch.

Was going to repaint the front fender, but lost patience and just refitted it as is. Will give me something to do when the weather gets really sh1tty.

Now it's time to

 

Changed the alternator damper, she's been in hospital, for surgery;->
The doc's not given a virdict yet.
posted a thread if anyone got ideas...

 

Hi Bordo
i think that the mix of makes is a large part of the issue
i did that before with a michelen on the front and a pirelli on the back( back last longer )

horrible ! also the bike would not want to turn
now it drops its self into the corners ( got to watch it doenst go too far )
now i just run bt 21 on front and back and never a probem if the are pumped right 42 on rear and 36 on front min
if i have less then it could shimmy and the cornering becomes heavy
i tried to instigate a wobble yesterday at about 80 kmh by knocking the bar ends
it wobbled twice and then settled down
have fun
paul