Author Topic: Scary forks  (Read 3996 times)

Offline BSA500

  • Resident Legend
  • *****
  • Join Date: Dec 2007
  • Posts: 705
  • Karma: 4
  • Tonbridge,Kent,UK
Scary forks
« on: 29.01. 2014 19:57 »
Hi,
I have been having issues with the handling on the A7. Leaning into corners and the bike felt like it was falling into it and strange wobbles etc. So I checked the wheel alignment and found the rear out by 5 mm, hoorah says I, easy fix,fool.
Tonight double scary ride,wet,windy and a bike that seemed incapable of staying upright let alone cornering. I was starting to believe I had lost my mojo and was too tense to be able to ride again.
Checked it over and thought I would do the wheel between legs to see if there was any head bearing/fork play. It felt like the wheel was moving about because I wasn't holding it well enough. Looked down and to my horror the wheel was perfectly still and the forks were flexing back and forth and side to side. No wonder it wouldn't bloody steer,bloody lucky it didn't spit me off  *eek* *eek* *eek*.
So my question if any replace the fork bushes?. I have done them before and have all the tools.

Offline wilko

  • Resident Legend
  • *****
  • Join Date: Mar 2010
  • Posts: 681
  • Karma: 4
Re: Scary forks
« Reply #1 on: 29.01. 2014 23:02 »
All pommy bike forks flex with your test. Pump your tyres up. I've had worn and knackered forks without horrendous handling problems.

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 5268
  • Karma: 50
Re: Scary forks
« Reply #2 on: 30.01. 2014 00:37 »
Maybe obvious, but:
Stanchions well home in top yoke?
Fork clamps at bottom yoke well nipped up?

Seems unlikely to me for normal bushing wear to suddenly show up as ride instability. Any other signs of failure around the fork legs, like broken casting around the spindle? Error on the safe side.

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Online orabanda

  • Wise & Enlightened
  • *
  • Join Date: Nov 2008
  • Posts: 1036
  • Karma: 22
Re: Scary forks
« Reply #3 on: 30.01. 2014 01:18 »
Triple clamp bearings need checking?

Offline Bsa Nut

  • A's Best Friend
  • ***
  • Join Date: Oct 2013
  • Posts: 55
  • Karma: 0
Re: Scary forks
« Reply #4 on: 30.01. 2014 02:01 »
Go through everything top to bottom...no need to be spit off your mount due to a simple bearing or bushing.
For it to show up quickly is odd. Something let go, somewhere.
Track it down meticulously. Ride safe.

Offline BSA500

  • Resident Legend
  • *****
  • Join Date: Dec 2007
  • Posts: 705
  • Karma: 4
  • Tonbridge,Kent,UK
Re: Scary forks
« Reply #5 on: 30.01. 2014 08:54 »
I have not stripped these forks down in years. I ride her everyday and I have been covering 5,000 miles a year for the last 3. The handling has been 'twitchy' for a while now, unexplained diving wanting to fall into corners etc. I think it has been getting gradually worse but I have been compensating without knowing(or I am a riding God  ;) ). All wheel alignment is spot on, swing arm no play, frame is ok. The only area with play is the front, tyres have plenty tread etc.
All nuts and bolts are tight, no movement in the spindle clamps, wheel bearings are good, steering bearings also fine its just had an mot and no issues(they don't check fork flex). The amount of movement is horrible. I will of course check it all over as I will replace the bushes but this much more than flex we will see soon enough  :!

Offline Duncan R

  • Valued Contributor
  • ****
  • Join Date: Sep 2008
  • Posts: 291
  • Karma: 3
Re: Scary forks
« Reply #6 on: 30.01. 2014 09:54 »
Might be worth checking your tyre for uneven wear across the profile,despite there being tread there ,fronts can wear uneven and cause all sorts  of handling issues such as dropping into corners and giving vague feel to the front end.
Anglo - Indian A7SS (Actually is a 650)
Kawasaki ZZR 1100
BMW R80GS
BMW R1100GS

Online Jules

  • Valued Contributor
  • ****
  • Join Date: Mar 2011
  • Posts: 304
  • Karma: 0
  • 1956 A10 s/arm Golden Flash
Re: Scary forks
« Reply #7 on: 30.01. 2014 10:31 »
I had an issue like this on my A7 years ago that I traced to sticky/worn head bearings - the steering had a tight/loose feel as you rotate it with the wheel off the ground......

Offline BSA500

  • Resident Legend
  • *****
  • Join Date: Dec 2007
  • Posts: 705
  • Karma: 4
  • Tonbridge,Kent,UK
Re: Scary forks
« Reply #8 on: 30.01. 2014 10:36 »
Checked tyre for wear etc and its fine had it on for about 6 months. Will of course check head bearings but believe me the amount of movement in those forks is not nice. As a side comment the roadrider tyres are excellent  *smile*

Offline Briz

  • A's Best Friend
  • ***
  • Join Date: Apr 2013
  • Posts: 209
  • Karma: 7
  • West Norfolk UK
    • Custom cycle developments
Re: Scary forks
« Reply #9 on: 30.01. 2014 10:59 »
5mm wheel misalignment? Thats pretty darn good for an old A10!
One thats hauled a sidecar is usually miles further out than that!

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 5268
  • Karma: 50
Re: Scary forks
« Reply #10 on: 30.01. 2014 12:25 »
Andy,

You have tons more riding experience than myself, since I ride for pleasure only with the gap period between '79 and '06 when I did not ride at all (rebuilding from '03 to '06). So, I can't and won't comment on what happens to forks after years of use. That said, considering all the things you've checked, I was wondering about things invisble that could cause a problem -- leading back to the bushes. I wonder if the lip has sheared off of one of the bushes, then, a slow progession to move out of position might explain the gradual change in riding condition. Seems harder to imagine a circlip sheared or out-of-groove, but might have same result.

Good luck. Very anxious to learn the reality after guessing my ass off.

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Offline BSA500

  • Resident Legend
  • *****
  • Join Date: Dec 2007
  • Posts: 705
  • Karma: 4
  • Tonbridge,Kent,UK
Re: Scary forks
« Reply #11 on: 30.01. 2014 12:30 »
In a strange way I love taking the bike apart to solve these 'little' problems. I did think that one or more of the bushes may have failed in some way we shall see. I have a much bigger project on the go as well a car rebuild. Its a 1932 chassis either Standard or SSII,1948 Studebaker 2.8 litre straight six,Wolseley Hornet 12 inch drums and axles all running on 15 inch wire wheels. So plenty to be getting on with  *smile*

Offline raindodger

  • A's Best Friend
  • ***
  • Join Date: Sep 2010
  • Posts: 30
  • Karma: 0
Re: Scary forks
« Reply #12 on: 31.01. 2014 10:20 »
Hello.
          When I finished rebuilding my A10, I ran it with the recommended tyre pressures 18 PSI front & 22 PSI rear.  It wallowed like a hippopotamus on corners, so I re-checked all settings and alignments but made no improvement.  Then I went on the Avon website and although it doesn't mention A10's, there are other comparable bikes.  I re-inflated the tyres to 25 front & 28 rear as per   Enfield 500 Bullet, The bike now handles very well and corners like it's on rails.
Just a thought.
Regards.
Raindodger.

Offline BSA500

  • Resident Legend
  • *****
  • Join Date: Dec 2007
  • Posts: 705
  • Karma: 4
  • Tonbridge,Kent,UK
Re: Scary forks
« Reply #13 on: 31.01. 2014 10:30 »
Yep I do run the higher pressures as well have done for years.

Offline Topdad

  • bob hebdon
  • Wise & Enlightened
  • *
  • Join Date: May 2011
  • Posts: 2266
  • Karma: 32
  • l
Re: Scary forks
« Reply #14 on: 31.01. 2014 12:57 »
For my tuppence worth can I ask if you have managed to lift the front wheel completely clear of the floor ? The reason I ask is that many moons (1967) ago I had an A10 outfit that suddenly started handling like a bag of s*** from being just normal, did the same check has you did , same results, really scary , lifted  the front end and removed the wheel ,turned round and the fork leg slid down the stanction , the circlip had gone the way of the gods and must have destroyed the bushes has the leg fairly rattled on the stanction ,hope this isn't the case  but ,well, check it out regards BobH
" rules are made for the guidance of wise men and the blind obediance of fools"
United Kingdom