Narrowed beam

vwo60 · 2013-02-25T01:17:55+00:00

I thought i might post my findings on the removal of a narrowed beam and the installation of a standard width beam in my ghia, since i bought the car fitted with the narrowed beam i have been collecting and planning the change out, the ghia was fitted with a set of 16' x 6" fuch's on the front with a ET of 36MM, this put the car way over the allowable track if used with a standard width beam and disc brake conversion that was fitted The beam was narrowed 50MM to fit the wheels and tyres under the guard, when you narrow the beam to fit a wheel with the incorrect offset you still have the remaining issue of the loading placed on the suspension, simply narrowing the beam may give you the track you need but it is still has the same loading as if it is 50MM over track, it is the relationship between the center line of the wheel and a line drawn through the center of the ball joint's/king pin thet interects on the ground. That is the concern and should be concidered in any wheel purchase, the term scrub radius relates directly to this, i tried to maintain as close to standard as possible when building the new beam and ordering the new wheels, one of the problems on the narrowed beam was the increase in bump steer and the tram linning under brakes as well as the wandering on the road, when i pulled the narrowed beam apart the inner trailing arm bushes were worn very badly, i will atribute this to the excessive loading caused by the incorrect offset of the wheels that were fitted to the car. The new standard width beam was built exactly the same as the narrowed beam, same shocks, same size sway bar, same size torsion bars, set up the castor the same along with the same ride height, the exception is the wheels that i fitted, these are 17' x 6" composite wheels fitted with 195/45/17 tyres, these replaced the 16" x 6" fitted with 205/50/16. What a revelation when you drive the car, no more tram linning at speed or under brakes, turns in conciderably better without nosing into the corner, it rides a lot better aleviating my fears about fitting the 17" rims to a link pin front end , effectivly both sets of wheels had/have the same track dimention but the difference is in the offset of the wheels, a total change of 25MM in the scrub radius has totally changed how the car drives. Before you concider narrowing a beam think the engineering time that was invested in it's disign, alot of people change the very things that make it what it is and simple changes alter the fundimentals, look at ways of altering the wheel offsets or purchasing wheels what do not alter the geometry outside the standard configeration and you will be rewarded with a vehicle that handles well and is safe to drive with the added bonus that it is legal.

matberry wrote:Good post hrastoica. I did exactly that and IMO my bug drives beautifully and doesn't look too bad either 😉

Ya wouldn't believe it but i've finally decided to go for a 4.5" beam with shock towers and sway bar, new everything up front, discs and drop spindles. Will try it out, if i dont like it, there will be a narrowed beam for sale soon hehe.

Long story short, i drive a very comfortable and boring Passat on weekdays and said "What the hell! I may as well throw caution to the wind, and go for the 4.5" narrowed beam". After this topic, i am really interested to see the difference between the original ride (stock) and the new one with the 4.5" beam.

Fingers crossed its not as bad as it sounds in this thread.