Heavy steering ?

[Tummen]

As a rookie team we wonder if our early 80-ish F2 Ireson should be this heavy in the steering.
Is a real handful to corner with, are out of strenght after a cople of laps.
Have a feeling that we are missing something in the setup of it.
Can anyone give us some input in the matter ?

Thanks
Tomas
Team "Old Battlescars"

[Sideslip]

Steering heaviness varies from maker to maker.
Some chassis were built specifically for the TT, where straight line stability is preferred over chuckability
My early Shelbourne 350 was extremely light - if I sneezed on a straight it would be all over the place. Lol.
I had a ride on Derek Plummer's ASCO 600 TT bike at Donington and that was heavy as hell on a short circuit.
Maybe other Ireson owners can give their opinion?
My Molyneux 600 was a good compromise.
Never arm wrestle a TT sidecar driver.

[steve-e]

Check the steering damper first

Does the front end look modified at all?

[Tummen]

Hi!
Thanks for replies.
Steering damper on softest setting.
Our bike is called "Old Battlescar`s" for a reson, a lot of repair and changes on it.
Other sidecar people here in Sweden think it can be an old TT-racer because the platform is higer then other bikes at the end.
The bike was imported from England for about 14 years ago by Philip Dobernowski, sadly he does not remember so much about it.
Front end dont look modified on it and it is not adjustebel like other frontends that we have seen.

[kew]

I have raced several Ireson chassis and never had a problem with heavy steering.
If you need a steering damper there is something wrong with the chassis, Trevor has never fitted a damper.
Check your trail, if it's more than 3mm maybe alterations to the chassis have altered the angle of the steering head.
What size front tyre are you using?

[Haynesy]

Take the steering damper off for sure. It should be fine without one.

And as said above, check the trail. And if you can, move the chair/sidecar wheel backwards (takes weight off the front).

[smithy1]

Trevor says tire pressure should be :-

Front 14 ibs per square inch
Rear 14
Sidecar 18

Hope this helps

[Haynesy]

And is it more noticeable on lefts/rights?

Does the front ever under steer or wash out? If not, then get your passenger to sit further back so less weight on the front - only getting them to move forward if you get under steer.

[Tummen]

Lots of input;thank you
Can take the sterring damper of, no problem.
Not easy to check the trail, dont have so precise instrument but will try to get some angel meters and so.
Tyre pressure are now : front 1.0 kg/cm2 , side 0.8 kg/cm2 and rear 1.2 kg/cm2
Tyres are Avons 6.2/20-13 Front and Sidecar, recommended compound by Avon
Rear is an old Yokohama 210/515-13 soft compound

It is harder to steer in right corners, left side is "easier". (Sidecar is on the left ).
Yes, it likes to understeer when i apply throttle in corners.
Sidecar wheel is not movable as i can see.
The front fork had short Konis on it that seemed misplaced and gave front swing uppointing statue. That is fixed now and helped a bit. The swing is now pointing up just a little when bike is standing by itself.


My thoughts so far are that we need to check all measurment if we can get hold of them. Perhaps is the bike chrashed so that the steering head has moved.
Anyone know steeringhead angel and other angels on the wheels ?

[Tummen]

Does anyone know from where the bike is level if i want to check steering head angel ?
I mean should i put the bike level via the wheelaxels or lower frame tubes or perhahps somewhere else?

[kew]

You don't need special equipment to check the trail.
Sit the bike on a flat floor and pack up under the chassis behind the front forks, without raising the height of the chassis.
Take off the front wheel and make a mark on the floor vertically down from the centre of the wheel spindle.
Take off the front forks and place a straight bar with a point on the end down through the centre of the steering head, you will need to make some bushes to fit in the steering head.
Mark where the point touches the floor.
The distance between the two marks is the trail.
I hope you can understand all that.

[Tummen]

Ok, yes i understand what you are meaning. That was well explained.
I will do this as soon as possible.
Thanks
Tomas

[Tummen]

Some update on this matter.
Have now measured the trail, it is 30 mm and steering angel 28 degrees.
After having a conversation with Lars-Gösta Schwartz, we decided to modifie the trail and let the
steering angel as it is.
To alter the headstock would be too complicaited for us att this time.
Will modifie the forks pivot so the trail are adjustebel .

[kew]

Well done Tomas,
Try to set at 1mm to 1.5mm

[steve-e]

That small Keith? 1.5mm trail?


Tomas...

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