Musing on iLean - yes a morbid fascination .......

Feb 7, 2008
Nottinghamshire England
Ok why ?

Well I think it is neat and gives slight suspension and allows tilting so allowing narrower track and higher seat and still be relatively safe ?

so Lego delta trike with iLean rear end, pointer in centre of iLean axle to see range of movement ?

wheel is 4" diameter and so model is roughly 1/5th scale
yellow beams represent crank arms 6.25" on model [ nearest Lego can get to 7" of a 175mm crank ]
you can see wheel is in hole farthest from crank/axle fixing , however there are 4 more holes the nearest the crank axle representing a crank arm length of 1.56"
cranks in this model are @ 180' to each other

so give it maximum tilt :-

Obviously maximum tilt occurs @ crank arm vertical position so axle pointer has moved through 90'
I was hoping to add a damper there , however can't think of one that could operate through those extremes ?
tilt angle @ wheel measures 60' , I assume this is from vertical and so actual tilt is 30' ?

next thing to try is moving wheel to hole closest to crank/axle :-

and tilted over gives a tilt angle of 80' from vertical or 10' of tilt.

unfortunately long cranks cause tyre scrub so it is not practical to go longer than 7" and shorter is preferable.
also 180' 7" cranks gives the longest trike

However there is one more configuration cranks @90' to each other.

bit harder to see here however crank arms are @ 90' to each other.
Now don't tell DannyC sssh this gives automatic stability when stopped as the weight is effectively pulled a V downwards so the wheels can't collapse left or right like 180' cranks or some other tilters !
another plus is shorter trike as the centre of both wheels are close together

downside is reduced tilt angle
cranks 6.25" 70' from vertical or 20' tilt
cranks 1.56" 85' from vertical or 5' of tilt

if cranks were <>9" the tilt would be back to 60' from vertical or 30' of tilt , however centre of crank axle would be approx 2.5" from ground ! so longer cranks lower pivot point
9" cranks are really to low as crank/axle joint can hit the ground when approaching maximum tilt

so question is ' how much tilt is enough ?

head full of questions Paul