Panda 100 is no longer in my possession. I used art# 306249. Not sure if they are still available from Westfalia, but someone might have NOS somewhere.
gr J
gr J
Technical No cut towbar
- Thread starter Dtpmatt1
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Technical No cut towbar
Photo 1 no fuel in the tank and nobody in the back
Photo 2 empty fuel tank, with one light and one heavy person in the back.
At load it’s the bump stops that stop the rear sagging and they becomes part of the suspension
I wouldn’t be changing them for shorter
Photo 2 empty fuel tank, with one light and one heavy person in the back.
At load it’s the bump stops that stop the rear sagging and they becomes part of the suspension
I wouldn’t be changing them for shorter
Really guys? You can't compare the springs from a normal Panda to the shorter, but stiffer ones on a 100HP.
This thread is about a towbar for a 100HP with a cutout as small as possible.
Now it is turning in a pissing contest about springcompression and bumpstops. IMHO there is no need for that.
gr J
This thread is about a towbar for a 100HP with a cutout as small as possible.
Now it is turning in a pissing contest about springcompression and bumpstops. IMHO there is no need for that.
gr J
My response was to the advise to fit shorter bump stops given in good faith
which in my opinion the shorter stops will make it worse for carrying loads
The bump stops on the panda including the 100hp and the 500 and are carefully designed to became part of the suspension and stiffen the suspension keeping the car reasonably level
when the rear is fully loaded the bump stop is the spring which is why they never sag much when fully loaded. I have filled the boot with bags of slate chipping and it still looks okay which far exceeds me and the GF sitting in the back in the photo above and already touching the bump stops
The Panda Nut
Nutty about Pandas Infected by Panda virus and OPD
It seemed to me that they were just put there to make the suspension rock hard and largely for superficial reasons. In standard trim it seemed there was a VERY small amount of allowable suspension movement. While It may utimately help the handling (on a track) it is my opinion that the car was not only hugely more comforatble but safer as it did not move about on the road when the going become unexpectedly bumpy. In standard for you had to restrict speed in my locality in order to precvent it jumping about. On occasion it was scarey. With greater travel, dampers were able to do their job over a greater range of travel which I preferred as stability was improved over bumps.. As for them being part of the suspension, for around the first 10,000 miles you are correct. As they fell off after this sort of milage from being bashed and squashed I am not sure Im convinced . Fiats price for a pair of blocks of compressed foam was £65 each as far as I remember and febi bilstein charged £11 each. When I sold the car they had coverd around 25000 miles and were still sound. I made sure my car was always supplied with the bump stops as required, but I m pretty sure thats a rarity and there are many running around with them missing or worse still one missing, and without any bump stops there would be a severe loss of stability. WIth only one my car was unsafe on bumps at moderate speed. Im generally a supporter of staying standard but due to the pathetic lifespan of the Fiat genuine 100HP bumpstops and the horrendous price I made the swap someone on here had suggested and IMO to good effect. Its good to hear the OP saying he gets on with the standard setup. I always felt the 100 would be a great towcar due to the power and gearing so this doesnt surprise me. On our bumpy Norfolk roads its not something wanted to try with around 3cm of spring travel available. I have towed with various vehicles at the very least 100,000 miles and Ive towed with little cars such as an 854cc renault 5 to bigger engined turbo cars and like Koala my opinion is made in good faith and backed experience of having made the change. and not on supposition. No one has to follow said suggestions if they dont want to/ I can however staethat there was no noticable reduction in the cars excellent handling and behaviour with a full complement of passenges on board on my car.
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Unfortunately it is not what bump stops are for. The bump stops are pretty much last line of defense against metal hitting metal when for any reason you run out of suspension travel.
When car is sitting on bump stops after being loaded - it's bad. It means you don't have enough of spring rate for what you're trying to do so you either overloaded the car or your springs are buggered. Here is why.
With normally working suspension when you hit the bump on the road the spring stores the kinetic energy of unsprung mass of your suspension (wheel, brake, wishbone etc.) in form of elastic potential energy (compressed spring). At the same time damper is dissipating some of that energy if all energy were to be dissipated the wheel wouldn't contact the road in time again using hydraulic friction in form of a heat. When the suspension reaches the end of compression cycle spring releases stored energy slamming the wheel into the ground and the damper dissipates the rest of it to prevent oscillations of the spring - wheel jumping back up.
When your car is sitting on bump stops your springs are storing all of the energy they possibly could. So if you hit the bump on the road the energy is directly transferred to the body of the car in form of an upward motion. And then energy stored in springs that cannot be dissipated by dampers helps to push the body even more.
What this means is when you hit a bump with a car sitting on rear bump stops with enough speed it will lift your rear wheels of the ground. If that happens in the middle of a corner you're looking at at least a spin. You could see that a lot with FF cars in amateur rallies when they went with too much of rear spring rate - the back of the car jumping a fair distance sideways after minor bump on the road.
Summing things up:
1. Shorter bump stops in 100HP should offer better ride quality (less suspension bottoming out) in exchange for greater risk of suspension damage.
2. If your car is sitting on bump stops after loading and everybody says it shouldn't it probably means your springs are shot.
3. If you plan on towing or heavy loading often it might be good idea to switch to progressive rate springs as a compromise - softer when empty giving better ride and harder when loaded which gives less suspension sag. The downside to using them is that the suspension response while driving fast becomes nonlinear.
I can see the use of a small trailer to take grass cuttings to the tip or for a small camping trailer, some cars for example, Ford KA are not even rated for towing, which always seemed strange to me when Citroen 2CVs were, but putting a small trailer behind a nippy little car seems to undo all the pleasure of driving it .
Horses for courses.
Before retiring I had several Iveco Daily's, my favorite being the SWB 35C13 which meant that on the normal "old persons" driving license the van could legally have a gross weight of 3.5 tonnes whilst at the same time tow a trailer weighing the same 3.5 tonnes, which with the good old SOFIM (Fiat Ducato 2.8) engine churning out 130bhp through a six speed gearbox, could run all day at the legal speed limit with no adverse handling effects etc. No cutting bumpers and nowhere near the bump stops
.
Horses for courses.
Before retiring I had several Iveco Daily's, my favorite being the SWB 35C13 which meant that on the normal "old persons" driving license the van could legally have a gross weight of 3.5 tonnes whilst at the same time tow a trailer weighing the same 3.5 tonnes, which with the good old SOFIM (Fiat Ducato 2.8) engine churning out 130bhp through a six speed gearbox, could run all day at the legal speed limit with no adverse handling effects etc. No cutting bumpers and nowhere near the bump stops
.
According to Fiats advertising
More expensive and higher tech than a traditional rubber bump stop, the elastomer bump stop is used as a spring medium and allows the springs to be softer for a better ride when lightly loaded.. They come into play when the car is heavily loaded or hits a large bump, progressively cushioning the impact and again helping the ride.
I was about to reply when you beat me to it!
The "standard" bump stop is just for stopping metal-on-metal contact at extreme articulation, as above.
The elastomeric bump stop is intended to be more like a helper spring for most of it's compression travel, until it is fully compressed, when it acts like a standard bump stop.
It is possible to engineer in variable compression rates using different densities of material, which is cheaper to implement than progressive springs.
At least that's what goes on in the 4x4 world...
The "standard" bump stop is just for stopping metal-on-metal contact at extreme articulation, as above.
The elastomeric bump stop is intended to be more like a helper spring for most of it's compression travel, until it is fully compressed, when it acts like a standard bump stop.
It is possible to engineer in variable compression rates using different densities of material, which is cheaper to implement than progressive springs.
At least that's what goes on in the 4x4 world...
Re missing bump stops, I believe that is an Mot failure.
Some years ago a salesman at a garage I was working at asked me to put a Ford Transit pickup on the ramp and check it over prior to taking it in as a part exchange.
It was quickly apparent this would not be a good idea, as two lengths of sawn off scaffold tubing had been put in place of the missing bumpstops to allow serious overloading without visually being seen by the Police etc. too the extent that looking from the rear the wheels on the solid rear axle appeared to have negative camber, I suspect if the half shafts were pulled out of the axle they would never have gone in again!!!
Moral of the story "Don't drive too close behind a travelers tarmac gang vehicle" , he might not just be driving slow to save fuel!!!
Some years ago a salesman at a garage I was working at asked me to put a Ford Transit pickup on the ramp and check it over prior to taking it in as a part exchange.
It was quickly apparent this would not be a good idea, as two lengths of sawn off scaffold tubing had been put in place of the missing bumpstops to allow serious overloading without visually being seen by the Police etc. too the extent that looking from the rear the wheels on the solid rear axle appeared to have negative camber, I suspect if the half shafts were pulled out of the axle they would never have gone in again!!!
Moral of the story "Don't drive too close behind a travelers tarmac gang vehicle" , he might not just be driving slow to save fuel!!!
The Panda Nut
Nutty about Pandas Infected by Panda virus and OPD
We you have to be aware of the trailer at all times but I had about 400kg on the hook the other day behind Noops 85HP TA motor and at one point I looked in the mirror and couldnt see the trailer. I htought I had lost the it! Thankfully it came back into view. 30 years ago I was towing our caravan over the Pennines with my BXturboD 5 pasengers on a very bumpy road. We were sailing along at really rather high speed when glancing in the mirror I was reawakened by the large white thing that was 3 feet behind. I had actually forgotten it. That was still a smallish and very lightweight car. Poor old van looked as if it was bouncinga foot off the off the road. It was a pretty fair soup of stuff from every cupboard on teh floor when we pulled in but thankfully no damage. I think its abotu getting a great combination and if you manage this you can still enjoy the drive. I used to tow with a 2.2 Reault laguna dt. I was coming home in the dead of night and had the shock of my life when flashed by a speed camera I reckon wI was doing somewhere north of 85 at the time. Had the camera been live, I would still be in jail 25 years later. We changed caravans shortly after this and the new one was a total pig and required a satbiliear at any speed over 40. After a while driving with one fitted I decided it wasnt worth the risk of masking such instability and re moved it. There was no way you could ever enjoy that experience. Thankfully I managed to trade that van on. The Panda 100 has to be the perfect small car for towing from many angles. but endlessly bashing the bump stops is very tiring. In the 70's my Dad had an Autin Maxi and fitted some things called Aeon hollow rubber springs. The effect was horrible and never to be repeated, You need the springs and dampers to be able to work to accomodate the pitch of a towed load or suspension loadings just go off the scale. Boat trailers are long wheel base in general and even with a properly balanced drawbar weight will exert a lot of pitch loading if there is no spring movement it will tend to lift the car causing much greater instability than a sprung axle and the issue then is one minute tou are OK and the next upside down. Big vehicles arnt immune either. In 83 I bought a long wheelbase landrover defender stationwagon at work. It was only a couple of weeks old when sent off to do a large marquee, It was overleoaded by the crew of thankfully only six people and the trailer flipped the car over onto its roof in a somersault. The rear of the roof was smashed down at an angle of 45 degrees and teh car bent like a banana. there were 6" gaps both sides of the B pillars and the base of the o/s headlamp was exactly the same level as the top of the n/s lamp, the only straight panel left was the ventialtor flap under the windscreen. My big concern with no suspension travel would be the excessive strain on the 100HP spring cups and axle in standard trim when it takes the weight of the boat and the engine together. As with all things if moderation is the chosen path and with some thought you can avoid situations that strain the outfit. I usually reckon if it feels OK and looks OK it will actually be OK but I would certainly exercise significant caution especially as hte pwer train and bearing of the 100 doesnt encourage moderation at all in any way! The close ratio gearbox and fabulous torque of the 100.s engine is a five star set up. The TA also out performs all expectations towing, and itts 2015 towcar of the year write up (Panda 4x4 MJ) says it all about the pandas towing ability. Stability in general is exceptional. Bigger cars inevitably do a better towing job, but they are bigger and therefore just WORSE in every other way! You have to remember when you get to your destination you unhook the load you are still driving a Panda and that will immediatley make you smile, and you dont tow all the time.I can see the use of a small trailer to take grass cuttings to the tip or for a small camping trailer, some cars for example, Ford KA are not even rated for towing, which always seemed strange to me when Citroen 2CVs were, but putting a small trailer behind a nippy little car seems to undo all the pleasure of driving it .
Horses for courses.
Before retiring I had several Iveco Daily's, my favorite being the SWB 35C13 which meant that on the normal "old persons" driving license the van could legally have a gross weight of 3.5 tonnes whilst at the same time tow a trailer weighing the same 3.5 tonnes, which with the good old SOFIM (Fiat Ducato 2.8) engine churning out 130bhp through a six speed gearbox, could run all day at the legal speed limit with no adverse handling effects etc. No cutting bumpers and nowhere near the bump stops
Pands on the top!
The Panda Nut
Nutty about Pandas Infected by Panda virus and OPD
Panda 100 was set up to feel VERY sporty. The bump stops fitted as they are were there to counter the lack of an anti roll bar at the rear and maintain a neutral stance in corners. It does this really well and the characteristic cocking of the rear inside wheel is testimony to it working magic. In reality with the 45 series low profile 195 section tyres and the light weight of the car grip alone does quite enough on this score and allowing springs and dampers to work pays dividends. Unless you are really going for it on a track - not that I have ever done so I would defy anyone to tell there was detectable a change in handling. When you dont have to keep putting your eyeballs back into your head on bumpy roads you dont care anyway!
I think I found source from where this quote comes from (http://www.fiat500usa.com/2010/09/examining-fiat-500-suspension.html). A bit of a gold mine if you ask me.
"Notable on the front suspension is the way the anti roll bar end link is attached to the strut with ball jointed sockets. This type of end link is usually reserved for higher priced cars and boasts a greater ability to filter out vibrations when driving over rough roads."
"In the rear, the compact, torsion beam axle functions both as wheel locating arm and as an anti-roll bar to resist lateral motion of the wheels as the body leans in turns."
"From December 2009, all Fiat 500s have a rear antiroll bar installed. With this addition, Fiat has been able to soften the spring rates and improve the ride of the 500. This addresses the one criticism that had been leveled on previous versions of the 500 (keep this in mind when you read older European road tests on the 500. When a review mentions the ride, they are talking about the older car)."
In that context i would read the paragraph provided by you as: elastomer bump stop is a cheapest "good enough" solution used so owners don't complain about trashy ride when empty or suspension sagging too much when loaded. It's a solution that is a tiny bit better than stuffing your spring coil full of tennis balls when in a pinch.
The more reasonable solutions to the problem would be:
- longer springs with same rate so you have more suspension travel left when compressed with the drawback being car sitting high when unloaded and packaging issues.
- progressive springs which should give you less jarring spring rate transitions than bump stops with the drawback being higher cost and mentioned earlier non-linearity with spirited driving.
And this pretty much makes my point - sitting on bump stops (even progressive ones) means you have too little spring rate for what you're trying to carry.
Ok, let me get this right. Fiat fitted Pandas 100HP with progressive bump stop to counter lack of an anti roll (torsion) bar in a torsion beam rear suspension? And the one thing that proves that this solution works is the car lifting inside wheel - a feat which would require some form of anti roll bar to be present?
Not in this design
My car sit at the right ride height. Springs aren’t shot. Look at the photos above what happens when you add a normal load. unless two people are classed as overloaded
Any Panda fully load but not overload is sitting on the bump stops or very close. Go check it for yourself
In stand form it just does not happen.
The suspension is designed for both light and heavy loads of everything is okay the only reason to fit short would be if it’s been lowered
Not correct
Correct
There quote Fiat directly from Elearn
The car very light. The difference between one drive and 4 people is huge. Fiat has come up with a solution that work well
The solution that Fiat came up with works. Yes there are other ways
Go look at your own car. Most people don’t even notice it’s riding on the bump stops instead of the springs
All panda and 500 are designed to run on the bump stops when loaded. Some have an anti roll bar some don’t
