Microcar design faults.

[Bob Purton]

Well explained Al. I will argue no further but only to ad the niggling fact that you can abuse an Isetta gearbox until the cows come home and it takes it like a man!

Its amusing that we all know the design faults of our favourite cars but still go into denial!
As the Apostle Paul once said "Love covers a multitude of design faults, sorry, sins"

[Bob Purton]

Friskies... I can see how the suck it and see development method would be beneficial but also cause havoc for production. As you say, at least they responded to the faults.

A reworked Isetta using the same trial and error process over a few years would have produced a much much better car.

[Big Al]

I have always said that a fully developed concept would have seen the Trienkel outpace and outspace the opposition. Very efficient use of space, lightweight, engine had potential to be much more reliable and knocks out good power. Suspension rode well but was not adequate for road holding and needed more work. It was also a very simple car. Indeed think of a modified front axle and a modern twist and go engine in the back and you have a very usable car, perhaps only out of its depth on a motorway. Much as I like Messerschmitts it would not live with what the Trienkel could be for the most people. Its tandem seating would be to radical and unsociable and it does not offer the space inside that the similar sized Trienkel manages. The Isetta just does not figure I am afraid. But then Heinkel had the benefit of seeing the errors, did he not?

[super-se7en (Malc Dudley)]

The frisky door hinges were wood screwed into soft wood bonded in to the fibreglass. Thats why you see the doors dropping.
Why they could not use hardwood to solve the problem beats me as the cost was negligible in those days.
The front end lifts over 50mph and the steering goes very light. When i was 19 i kept half a slab in the front.
Solved both problems as it never went over 50 after that.

[Barry]

Isetta fault

When I used to go round a large roundabout (at speed) the fuel would not reach the carb and about 3/4 round it would stall, just restarting in time as I ground to a halt (Right hand drive).

Also, hitting a particulate drain cover at 30mph on a left curve sent the steering into full tank slapper mode.  Do you go faster or slower to stop it!!!!!!  I used to take my foot off and let the steering wheel calm down by itself with just light assistance.  Grabbing it hard just increased the effect.

[Bob Purton]

Yep I have had the fuel starvation thing. I cured it by shortening the fuel line. It also helps to keep the tank topped up. Funny enough I never had that in my RHD, only the LHD.

The shake of death as Jim calls it!
Usually caused by too much wear or free play in the steering. Cured by replacing all the bushes of by fitting a steering damper. I think the German made ones had one fitted. There is certainly a bracket welded to the chassis for it to bolt onto.
I have never experienced that, only read about it. Sign of poor maintenance.

[Barry]

I will have you know that my Isetta cost nearly £100 at that time and as you can see from the picture was perfectly maintained (at some time in its past).


When someone bought my two Isettas (£150 the pair) but never picked them up.  I left them in Westcliff railway station car park near his house and told him so.  I assume they were both scrapped.....

[Barry]

Heinkel gear change - pulling out in front of a juggernaut with plenty of room and then.  'What No Gears'

My Heinkel was a truly awful car to drive. 
Compared to the Isetta it was horrid. 
Bad brakes, gear change and having to rev the engine to get anywhere.

[Big Al]

Yep I have had the fuel starvation thing. I cured it by shortening the fuel line. It also helps to keep the tank topped up. Funny enough I never had that in my RHD, only the LHD.

The shake of death as Jim calls it!
Usually caused by too much wear or free play in the steering. Cured by replacing all the bushes of by fitting a steering damper. I think the German made ones had one fitted. There is certainly a bracket welded to the chassis for it to bolt onto.
I have never experienced that, only read about it. Sign of poor maintenance.

No tank baffling, then, unlike Trienkel and Schmitt. Good driving though, I approve. Good practice for turbo lag on a Saab!

No the steering geometry on the Isetta is bad. It should not be able to do its shake if the swivel and leverage points were in the right place. It would happily camber steer, which it does not. Would you let go of an Isetta steering wheel at 40 mph? Could go anywhere. The best I had was ex Phil Bowler white and blue 250 but even that was in a trance half the time. 

Frisky had those BMC van door hinges with a brass ball with a hole in as the pivot. A bit overboard for a small bit of GRP but whatever. I did not remember the bit of soft wood till you said. I never got to understand the sometimes surface indicators, sometimes countersunk indicators.

[Big Al]

When someone bought my two Isettas (£150 the pair) but never picked them up.  I left them in Westcliff railway station car park near his house and told him so.  I assume they were both scrapped.....

Is Westcliffe along the Thames Estuary coast of Essex? I ask, as my good bud Martin collected several (thought it was three) Isetta from near some station and towed them home in one go behind his car like a row of ducks. We were young and indestructible in those flared days. Be funny if it were these cars.

[Big Al]

Heinkel gear change - pulling out in front of a juggernaut with plenty of room and then.  'What No Gears'

My Heinkel was a truly awful car to drive. 
Compared to the Isetta it was horrid. 
Bad brakes, gear change and having to rev the engine to get anywhere.

Oh dear. So many were like that. They do not need to be. Brakes bad? Better than most in class but given that this car was not working well elsewhere, it probably used to do the which side is going to stop first, trick, with accomponying run over Jack Russell sound effects.

[richard]

i found my Trojan brakes if anything a bit fierce but they certainly worked , noisy i would say but what the heck - better when lagged back seat a bit , awful fumes that i do remember - i always preferred when the roof or at least the windows were open . never any gear change problems really nicely set up probably by my old mate mike simmonds - he of 20 odd years experience with them .

the one design fault they all had was the service intervals , they have it right nowadays about 20,000 miles and even then not much to do .if they had been 20,000 i don't suppose many would have ever had a service yet !

[Bob Purton]

Heinkel gear change - pulling out in front of a juggernaut with plenty of room and then.  'What No Gears'

My Heinkel was a truly awful car to drive. 
Compared to the Isetta it was horrid. 
Bad brakes, gear change and having to rev the engine to get anywhere.

Well Barry, I have only had a brief drive of two Heinkels, one of which had a truly terrible engine that vibrated through the whole car and the other I couldn't find the gears and when I did find one I wasn't sure which one I was in. It put me off of those cars totally. Poor build quality as well. The front door always feels like it going to drop off when you open them. Isetta's are so so superior in every way!!   Are we getting tribal?
For Als benefit I WOULD let go of the steering wheel at 40mph on the motorway, I prefer to drive Thumper on the motorway to around town , the steering firms up nicely at that speed. Maybe its a toe in thing?
The rhd is a corruption of the original BMW version of the design and yes , the counter weight is a botch up but because of the aforementioned point doesn't count. But strangely enough I believe the RHD set up actually improves the steering due to the extra long link shaft from worm to drop arm. Wear in the bushes of this longer shaft translates into less play.

[steven mandell]

Is it true that some of the Isettas came with a lead silver painted brick offset under the seat, or was this someone's home brewed compensatory addition?

[Barry]

Heinkel gear change - pulling out in front of a juggernaut with plenty of room and then.  'What No Gears'

My Heinkel was a truly awful car to drive. 
Compared to the Isetta it was horrid. 
Bad brakes, gear change and having to rev the engine to get anywhere.

Well Barry, I have only had a brief drive of two Heinkels, one of which had a truly terrible engine that vibrated through the whole car and the other I couldn't find the gears and when I did find one I wasn't sure which one I was in. It put me off of those cars totally. Poor build quality as well. The front door always feels like it going to drop off when you open them. Isetta's are so so superior in every way!!   Are we getting tribal?
For Als benefit I WOULD let go of the steering wheel at 40mph on the motorway, I prefer to drive Thumper on the motorway to around town , the steering firms up nicely at that speed. Maybe its a toe in thing?
The rhd is a corruption of the original BMW version of the design and yes , the counter weight is a botch up but because of the aforementioned point doesn't count. But strangely enough I believe the RHD set up actually improves the steering due to the extra long link shaft from worm to drop arm. Wear in the bushes of this longer shaft translates into less play.

From my experience of both Heinkel and Isetta I do not see them both in the same league.
The Isetta has a chassis, brakes on all wheels, a 300cc BMW engine and build quality is superior.  More torque, easier to get in and out, windows that slide back, better driving position, better gear change. etc.
Positives for Heinkel.......?