"Bongo's Wobble But They Never Fall Down!"

[spitineye]

Howdy all!

As some of you may know, I've had a bit of bother with my suspension in the past, the rear shocks in particular. Now, technically, everything should be sorted, and i've had my mechanic check over it a few times.
I may just be paranoid now but just how wobbly and bouncy should the Bongo be on your typical pot-hole-infested British 'road' (I use the term lightly)? Of course due to it's size and shape, it shouldn't handle any better than your typical upturned kingsize mattress, but I can't remember how it was when we got him all those years ago....

[Alison01326]

How long's a piece of string? My back seat driver complains frequently that he thinks he is going to be tipped over when I go over bumps, so maybe "quite wobbly and bouncy" is the answer. It's mine, anyway and our local potholes will probably be appearing on the next Ordnance Survey maps if someone doesn't fix them soon

[dunslair]

Ours is quite 'firm' on potholes. Sometimes a little too firm, not sure if our springs have been fiddled with in Jap land! Next time you are down I would be happy to take you for a comparative spin.

All the best

David.

[spitineye]

That's good to know Alison. I assume then that those who have body kits and the like have had theirs stiffened up, otherwise I imagine it would get smashed up a bit with all the jiggling. I quite like the wobbles, I imagine it's similar to being at a rodeo, or riding my bike down a big hill with a large hat made from fibreglass, tent material & some steel mechanisms.

David, I might just take you up on that, maybe in the next few weeks as it seems Laggan is due another snow-storm, having just re-opened after 2 months!

[mikeonb4c]

Ours is quite 'firm' on potholes. Sometimes a little too firm, not sure if our springs have been fiddled with in Jap land! Next time you are down I would be happy to take you for a comparative spin.

All the best

David.

I agree. Although a pretty nice ride on good surfaces, my Bongo does not like potholes (17" wheels may not help but even so) and since the roads round here are full of them, it can get irritating at times. But considering everything else it does so well for us, and that its a reflection also on the bl**dy state of the roads (due to get worse no doubt in the austerity years ahead - assuming we can still afford fuel to ride on them ), I forgive it completely. Its a minor irritation.

[rita]

I would compare it with riding a Camel up Ben Nevis

[mikeonb4c]

I would compare it with riding a Camel up Ben Nevis

Ah but can you sleep inside a camel when you get to the top?

Don't answer that

[mikexgough]

But considering everything else it does so well for us, and that its a reflection also on the bl**dy state of the roads (due to get worse no doubt in the austerity years ahead .

They have already suffered 30 years of neglect...... as have the ditches,gulleys,paths etc. - the public service swinging cuts when a certain lady from Grantham got her hands on the country.....

[dandywarhol]

Ours is quite 'firm' on potholes. Sometimes a little too firm, not sure if our springs have been fiddled with in Jap land! Next time you are down I would be happy to take you for a comparative spin.

All the best

David.

yours looks lowered David

[rapiddescent]

I design suspension systems for mountain bikes - so I'm really really nerdy when it comes to feel of suspension. i have taken a brand new subaru legacy back to the dealer after 5 miles because it had no preload in the springs. that's another story.

anyway.

It's much much more complicated than the discussion above.

bouncy
a coil spring will spring back as hard as it compresses. Unless a shock is properly dampened then the ride will pogo along. If the passengers are complaining about being bounced all over the place then it is likely that you have an oil pressure loss in the dampers. new shocks are required. this is pretty important because under hard braking and cornering the car needs to react the way you expect.

wobbly
usually down to the tyres more than the suspension. A 14" rim with a 75 tyre will reshape over rough surfaces. if you have pimpy 18"'s with 55 tyres and they're pumped up to 40psi then it will 'feel' like a hard ride. i.e. you will loose your fillings on catseyes. Car manufacturers that want a 'sporty' feel do this. The Audi TT is the worst offender where the suspension travel is very short and the wheels are way too big for the weight of the car etc. the ride feels really hard - you can feel it through the steering wheel.

crashing
if the car is crashing through potholes, then you may have a spring problem where the whole travel of the spring is being used up. this is where the car is much heavier than the springs allow for. Sometimes the ride can be 'wallowy' but that's difficult to detect by most drivers. Anyone who has owned an older vauxhall will have experienced this. Bongo's fitted with heavy conversions will get this.

unsprung mass
this is for the physics nerds. The actual weight of the wheel, tyre, brake calipre and some of the strut is called the unspring mass. The heavier this is, the poorer the car will react to bumps in the road. Small bump sensitivity can be improved by lowering the weight of the unspring mass. sometimes adding huge 20" chrome wheels with spinners actually is heavier than a steel rim and will totally cock up the handling. On bongo's this won't make much difference unless you are at 80mph sideways going round Silverstone. but I thought I'd add it for completeness.


So take each of these and each vehicle has a different formula. that's why lowering springs by 'cutting' is one of the daftest ways of making your car look cool. Next time you see a lowered Saxo, watch it crash through its suspension travel on the potholes - ruining the ride.

[dunslair]

Ours is quite 'firm' on potholes. Sometimes a little too firm, not sure if our springs have been fiddled with in Jap land! Next time you are down I would be happy to take you for a comparative spin.

All the best

David.

yours looks lowered David

I wondered if that was the case, but don't have any ' bench mark' to test it against. Is it possible to un-lower them again? I know you have the air assisters fitted, would that be an option to put a bit more bounce back in the ride?

All the best

David.

[missfixit70]

If it is lowered ( i'm not sure if it's just the illusion created by the body kit), then you can swap out the lowered springs for normal, I'm sure someone would be willing for a swap, although it'd be a good opportunity to fit new springs.

[mikeonb4c]

I design suspension systems for mountain bikes - so I'm really really nerdy when it comes to feel of suspension. i have taken a brand new subaru legacy back to the dealer after 5 miles because it had no preload in the springs. that's another story.

anyway.

It's much much more complicated than the discussion above.

bouncy
a coil spring will spring back as hard as it compresses. Unless a shock is properly dampened then the ride will pogo along. If the passengers are complaining about being bounced all over the place then it is likely that you have an oil pressure loss in the dampers. new shocks are required. this is pretty important because under hard braking and cornering the car needs to react the way you expect.

wobbly
usually down to the tyres more than the suspension. A 14" rim with a 75 tyre will reshape over rough surfaces. if you have pimpy 18"'s with 55 tyres and they're pumped up to 40psi then it will 'feel' like a hard ride. i.e. you will loose your fillings on catseyes. Car manufacturers that want a 'sporty' feel do this. The Audi TT is the worst offender where the suspension travel is very short and the wheels are way too big for the weight of the car etc. the ride feels really hard - you can feel it through the steering wheel.

crashing
if the car is crashing through potholes, then you may have a spring problem where the whole travel of the spring is being used up. this is where the car is much heavier than the springs allow for. Sometimes the ride can be 'wallowy' but that's difficult to detect by most drivers. Anyone who has owned an older vauxhall will have experienced this. Bongo's fitted with heavy conversions will get this.

unsprung mass
this is for the physics nerds. The actual weight of the wheel, tyre, brake calipre and some of the strut is called the unspring mass. The heavier this is, the poorer the car will react to bumps in the road. Small bump sensitivity can be improved by lowering the weight of the unspring mass. sometimes adding huge 20" chrome wheels with spinners actually is heavier than a steel rim and will totally cock up the handling. On bongo's this won't make much difference unless you are at 80mph sideways going round Silverstone. but I thought I'd add it for completeness.


So take each of these and each vehicle has a different formula. that's why lowering springs by 'cutting' is one of the daftest ways of making your car look cool. Next time you see a lowered Saxo, watch it crash through its suspension travel on the potholes - ruining the ride.

an excellent post - sums it up beautifully

I wonder how good a brand new Bongo with well functioning suspension units might be

[dandywarhol]

I design suspension systems for mountain bikes - so I'm really really nerdy when it comes to feel of suspension. i have taken a brand new subaru legacy back to the dealer after 5 miles because it had no preload in the springs. that's another story.

anyway.

It's much much more complicated than the discussion above.

bouncy
a coil spring will spring back as hard as it compresses. Unless a shock is properly dampened then the ride will pogo along. If the passengers are complaining about being bounced all over the place then it is likely that you have an oil pressure loss in the dampers. new shocks are required. this is pretty important because under hard braking and cornering the car needs to react the way you expect.

wobbly
usually down to the tyres more than the suspension. A 14" rim with a 75 tyre will reshape over rough surfaces. if you have pimpy 18"'s with 55 tyres and they're pumped up to 40psi then it will 'feel' like a hard ride. i.e. you will loose your fillings on catseyes. Car manufacturers that want a 'sporty' feel do this. The Audi TT is the worst offender where the suspension travel is very short and the wheels are way too big for the weight of the car etc. the ride feels really hard - you can feel it through the steering wheel.

crashing
if the car is crashing through potholes, then you may have a spring problem where the whole travel of the spring is being used up. this is where the car is much heavier than the springs allow for. Sometimes the ride can be 'wallowy' but that's difficult to detect by most drivers. Anyone who has owned an older vauxhall will have experienced this. Bongo's fitted with heavy conversions will get this.

unsprung mass
this is for the physics nerds. The actual weight of the wheel, tyre, brake calipre and some of the strut is called the unspring mass. The heavier this is, the poorer the car will react to bumps in the road. Small bump sensitivity can be improved by lowering the weight of the unspring mass. sometimes adding huge 20" chrome wheels with spinners actually is heavier than a steel rim and will totally cock up the handling. On bongo's this won't make much difference unless you are at 80mph sideways going round Silverstone. but I thought I'd add it for completeness.


So take each of these and each vehicle has a different formula. that's why lowering springs by 'cutting' is one of the daftest ways of making your car look cool. Next time you see a lowered Saxo, watch it crash through its suspension travel on the potholes - ruining the ride.

Good info .............one of the problems of the Bongo is the "axle tramp" due to the unsprung mass of the collosal rear live axle Mounting the diff to the body and using driveshafts out to the wheels would sort that

[dandywarhol]

If it is lowered ( i'm not sure if it's just the illusion created by the body kit), then you can swap out the lowered springs for normal, I'm sure someone would be willing for a swap, although it'd be a good opportunity to fit new springs.

Even with the body kit - looks to me that the arches are pretty close to the round rubber bits