Hi, I have a A10 Plunger 1953 which when riding it feels like the tyres are flattish and my bike feels as though it drifts a bit from side to side, the correct tyre pressure are used, if anyone has a solution to the problem I would be grateful, thanks Richard
I would check the adjustment of the steering head bearings.
Too tight and the steering wanders.
Also check wheel alignment.
Some bikes used with sidecar in the past, and many A10s were, may have a distorted frame.
Have you got the steering damper tightened down at all?
wheel bearings?
Another problem that causes bikes to wander at low speed are triangular tyres, such as TT100 and Roadriders. As the rear one flattens out, the front seems to follow the slightest imperfections in the road surface.
Of course, if you have normal K70's, Avon SM Speedmaster or Mitas, this is totally irrelevant.
Quote from: Richardson on 20 Sep, 2019, 18:14
Hi, I have a A10 Plunger 1953 which when riding it feels like the tyres are flattish and my bike feels as though it drifts a bit from side to side, the correct tyre pressure are used, if anyone has a solution to the problem I would be grateful, thanks Richard
What tyre pressures are you using? If theyre taken from the original handbook theyll be too low - even for the same type of tyre. Construction methods and materials change and modern tyres need to be inflated to a higher pressure. I run my '52 plunger A10 at F32 and R36 and she behaves well. As suggested check the steering damper and head bearing adjustment - if the bike has a gentle rolling weave it's a classic symptom of stiff steering. I fitted tapered bearings to mine which made a noticeable difference. Also check for wear in the rear plungers as that can lead to a wallowing feel at the rear end.
Start with the cheapest 'solutions' and work your way through. For wheel bearings to have that effect theyd need to be very worn.
Steve
Thanks for the great suggestions everyone I will work through them,
Having checked wheels, tyre pressures etc all ok but there is a slight movement when I move the handle bars left and right (front of bike jacked up) would this indicate new top and bottom steering bearings required, no up, down or forward movement on the wheel bearings, thanks
have you tried nipping the top adjuster up to take up any slack?
dont over tighten just enough to have a bit of feel but move freely. if its still there may be worth dropping and checking cups, cones and balls . if ok re grease othewise you could invest in taper roller bearings.
Thanks Chaz, I nipped up the top adjuster but movement still there, are there any problems fitting the roller bearings as I haven't done this job before?
you just have to find the correct size roller set up, my 1966 Triumph T100 Ive just renewed the roller bearings, a total strip down and powder coat, the outer diameter was smaller than the original outside of the cups and therefore had a ring turned up to take up the difference. the bore of the bearing is normally a standard imperial diameter.
the roller conversion may add a few milimeters in height which can normally be hidden.
did you loosen the pinch bolt before making the head race adjustment and tighten it up afterwards?
also make sure the thread is ok in the adjuster nut.
Quote from: Richardson on 11 Oct, 2019, 11:37
Thanks Chaz, I nipped up the top adjuster but movement still there, are there any problems fitting the roller bearings as I haven't done this job before?
Tapered rollers are easy to fit. All you may have to do is to chamfer the inner edge of the headtube depending on the year of the bike. the upper tapered race roller cage can otherwise bind on the frame tube. A simple enough job with a dremel and I found the difference in the steering very noticeable.
The most difficult part of the operation is removing the old cups. Your eally need a threaded expanding puller to suit the small threads in the lip of the cup. Mine was about 40 quid off ebay.
Steve
Thanks for all of the advice lads, really appreciated regards Rich