fork problem

dunk 1 · Post by **dunk 1** » 29 Jul 2009 09:23

replaced the fork seals at the weekend - i was lazy and didn't drop the fork legs - just took off the sliders -i also just took out the springs and guides leaving the dampers intact. i replaced the seals and simply reversed the dismantling - the forks seemed fine, damping seems good but after no problems for about 10 miles I then started to get a strange sensation under breaking - almost crunchy -also felt on the rough ground at the back of my yard- i could also feel more road through the bars. when the bike was still pushing on the forks again seemed fine.I can't take it apart until it stops raining- ho hum - but can't think what would have gone wrong in reassembly- is it possible the this is the bearings that have gone coincidentally or am I missing something- duncan

danomar · Post by **danomar** » 31 Jul 2009 01:37

The only thing I can think of is that perhaps something did not seat properly upon reassembly. Did you by chance change springs? Sometimes springs can make noise under braking. Maybe the noise was there before and you did not notice until now..?

I know you tried to avoid the bother of removing the stanchions, but your really ought to re-do everything with forks off the bike. I always do one at a time to avoid having to re-align the triple clamps.

Hope you figure this one out!

dunk 1 · Post by **dunk 1** » 16 Aug 2009 13:31

been away so i finally completely stripped both forks down - both seem ok and i can't seem to see the cause - there is a slight notchiness in the head bearing so i will replace those and see if that cures the problem.

i have never touched head bearings before - is this an easy job - do i have to take the whole of the front end apart or is there an easier way- can it be done just removing the top yoke- there is only one bearing in the manual blow up but i would expect one at the top and bottom

anything i should look out for? - thanks duncan

also when adjusting the steering head bearing should the bolts holding the forks on either the top or bottom yoke be loose - this would seem to be necessary but is not mentioned in the manual it just says undo the pinch bolt.

dunk 1 · Post by **dunk 1** » 16 Aug 2009 16:48

ok so i found the hard way that there is a bearing at the top and bottom - could someone confirm the number of balls that should be in each one - 22 I think but i didn't catch them all-

3potjohn · Post by **3potjohn** » 17 Aug 2009 05:46

Ah yes.. balls. They go everywhere don't they. Wouldn't it be annoying if you didn't have the spark plugs in..........
I think you should have 22 per race.One less than full should do it. What are the races like?

dunk 1 · Post by **dunk 1** » 17 Aug 2009 07:32

thanks John the races don't seem too bad so I wont try reversing them or anything yet. although since there was a central notch is this likely to be a race problem as much as a ball one?

it was interesting taking the whole thing apart - i hung most of the switches, lights etc carefully on pieces of string to avoid too much dismantling - i'll be fine next time after doing it once.

I would still like to know whether either of the sets of yoke clamps should be undone when adusting the headstock when fully complete as this would seem to be needed so that it can all draw together.

what time do you get up in a morning John?!

dunk 1 · Post by **dunk 1** » 17 Aug 2009 13:49

problem solved -i think but not in the way i expected - i replaced the head bearings and have spent this afternoon slowly tightening them - going for a ride - swearing and then tightening them some more etc etc all to no avail- noticed that the vibration was coming through at certain revs even when the bike was still - suspected something nasty in the engine but decided to have a good look round. found the the front engine mounting bolts had worked loose - i don't know why as i check them regularly- tightened them and so far - half a mile - the problem seems to have gone - why i felt this more under breaking i don't know- still at least i now know how a head stock is constructed. - thanks - Duncan

3potjohn · Post by **3potjohn** » 18 Aug 2009 05:58

I tend to operate on daylight, but work around the clock.We never close! I am useless in the Winter.I have been stripping my R60/7 transmission for the last hour!

3potjohn · Post by **3potjohn** » 18 Aug 2009 06:01

I also remember when I had my first bike,a C15 I read that if it knocked going uphilll,that was the big end but if it knocked going down hill it was the rear engine mounting bolt. Presumably if you had a worn big end and a loose bolt the engine would be so smoooth......

EVguru · Post by **EVguru** » 18 Aug 2009 08:15

dunk 1 wrote:found the the front engine mounting bolts had worked loose - i don't know why as i check them regularly

They aren't stainless bolts by any chance?

Jem · Post by **Jem** » 21 Aug 2009 17:16

Paul,

tell us more! I have SS engine bolts and twice had problems with them loosening. Two years ago at Cadwell and this year going to Cassington. What difference does SS make?
By the way, loose rear bolts are most noticeable at slow speeds (and knock like a big-end going), getting smoother as the revs rise whereas loose front bolts are not particularly noticeable at slow speeds but become unbearable by middle revs - I lost a tank bolt, broke both horn mounts & had an exhaust nut come out (luckily pipes are colletless)

dunk 1 · Post by **dunk 1** » 21 Aug 2009 17:34

in this case the bolts weren't stainless but the area had become oily - dunk

EVguru · Post by **EVguru** » 21 Aug 2009 18:24

Stainless bolts don't have the same elasticity as high tensile steel, so it's difficult to install them with enough tension.