riding on bumpstops

[55EXX]

i replace my shocks last week to find all my bump stops had crumbled into nothing. so i ordered all new oem honda bump stops all round (made of a soft foam like rubber). the first thing i noticed one it was off the jack stand was that it sat about a cm higher. getting in the car the difference in handling was felt straight away! suspension was nice a firm and bodyroll was less and after driving it now for a few 100k's it feels great! now what is the down side to this? i know that i will bounce and get air born over ripple strips just like high rate springs etc but what on the street does this mean? will it only mean a harsher ride or are there other problems/mechanical faults that this might cause? my 215/45/15 tyres do a pretty good job smoothing out the ride so it isn't very rough at all! it just seems too good to be true! $60 bucks in bump stops = better handling from what feels like stiffer springs?

[aznpsuazn]

Thats terrible. The bump stop exists to prevent your shocks from fully compressing, which may cause contact between ur wheels and the guards, coil binding, heaps of bad stuff.

Your wheels shouldn't be doing the "smoothing out".

From what you said, after you installed the bump stops, your car was 1cm higher. That sounds like you are actually sitting on bump stops, which gives your car Zero suspension travel/movement.

This is bad. Firstly, the safety of your car is compromised severely. God help you if you have to swerve and break. I assume that your car is probably as low as it can go if your shocks are fully compressed!
2nd, you're gonna need new shocks in a few week,s and those bump stops would have had it by then also if they're constantly taking the force. your suspension bushings are gonna get chewed up also taking so much jarring, its just bad overall.

Save up and buy some coilovers to lower your car properly, or get a good shock that is designed to be lowered/and or packaged with lowered springs.

[Limbo]

your running OEM bump stops with OEM shocks. I think you've just put your car to it original performance. The old bump stops prob were giving vibrations as they were crumbling. I don't think there is anything bad about it.

[aaronng]

Is your car on lowered or stock springs?

[55EXX]

car is on super low pedders springs with kyb agx adjustable shocks which will cope fine with the shorter stroke.

aznpsuazn sorry to say but there is little truth to what you said. there is still suspension travel. both the bump stop and spring can still compress also but just to a lesser degree... like as if i had higher rate springs. the bump stops aren't made of a hard rubber but a softer foam so they still compress.

i know i'll kill my bump stops quicker but is there anything else bad?

[SHOGUNOVDDRK]

car is on super low pedders springs with kyb agx adjustable shocks which will cope fine with the shorter stroke.

aznpsuazn sorry to say but there is little truth to what you said. there is still suspension travel. both the bump stop and spring can still compress also but just to a lesser degree... like as if i had higher rate springs. the bump stops aren't made of a hard rubber but a softer foam so they still compress.

i know i'll kill my bump stops quicker but is there anything else bad?

I dont see much worse coming from it other then spending 60 bucks every so offen for bumpstops...

But i thought there were aftermarket bump stops available that were more "Stiff" (Read it on Ht so i dont know the amount of truthfullness to it)

[teh_mechanic]

so basically because your so close to the bumpstops,so close that you hit them often (your 1 cm higher,so pretty much sitting on them constantly), you have created the effect of having higher dampening shocks and stiffer springs,as the bumpstops are resisting both of them from moving freely as they want to.

Its not an optimal situation but all that could come of it is that the bumpstops wear out,so hey if it feels better go for it.

ps.saw you out yesterday,so low,so clean.coudlnt hear the dyn's from across the street sadly though lol

[55EXX]

or hear the dyns past all that dynamat. saw you too man near the vale. you got new wheels? only quickly saw you either way you car looked good too! black wheels with red look good as!

[aaronng]

car is on super low pedders springs with kyb agx adjustable shocks which will cope fine with the shorter stroke.

i know i'll kill my bump stops quicker but is there anything else bad?
It's not the shorter stroke that damages the shocks. It's the springs lowering the shock travel until it is all the way at the bottom that will damage the shock valving.

[teh_mechanic]

yeah i swapped a guy on boostcruising with a gtir my gay medusas for his hsr wheels.i won that swap i reckon,he can keep the bling,luckily i dont think he knew how common the medusa's are these days,a win for ozhonda against the nissans

[55EXX]

pics man! like these?http://www.lakeshorewheelandtire.com/wheels/speedy-hsr-black.JPG
would look dope on your car! no wonder its what caught my eye!

and that what i mean i have shorter shocks built for lower cars. do you now what i mean? so instead of the shock being near the bottom it isn't cos it was designed for cars that are lower.

[JohnL]

so basically because your so close to the bumpstops,so close that you hit them often (your 1 cm higher,so pretty much sitting on them constantly), you have created the effect of having higher dampening shocks and stiffer springs,as the bumpstops are resisting both of them from moving freely as they want to.

Its not an optimal situation but all that could come of it is that the bumpstops wear out,so hey if it feels better go for it.


The bump stop has no affect at all on the damping properties of the damper itself, even when the car is resting on it. The "created effect" of riding on the bump stops is that they will act to increase spring rate in bump motion.

The bump stop will act like an auxilliary spring adding it's rate to that of the coil, and since the 'rubber' (probably an expanded foam like substance made from polyurethane or something similar) is likely to be somewhat conical in shape it will become progressily stiffer the more it's compressed, so the overall spring rate becomes somewhat progressive in nature as spring compression increases. The affect only exists in bump, or for a very short distance in rebound motion until the bump stop loading becomes zero as the suspension droops.

I know that there is at least one locally produced 'performance' car that deliberately uses long bump stops that are in some degree of 'interference' contact (i.e. slightly compressed) with the damper body at static ride height (I suspect it's an HSV Commodore, but I'm not sure because my info comes from an on-line engineering forum from a post written by the bloke who designs the suspension, but he never says who he works for). The idea is to introduce a degree of progressiveness into the spring rate without resorting to using progressive rate coils.

However, the bump stops in question are specifically designed for this application, more common bump stops may or may not not be progressive enough, i.e. their rate may increase greatly over a very short stroke, or be very non linear in the rate increase (i.e. compress to X then very suddenly become a lot stiffer).

My feeling is that if it works with your car then it works. But, it could make on the limit handling very abrupt, i.e. transitions from understeer or neutral to oversteer could be very sudden, and possibly dangerously so. I'd be very careful until I was sure the handling was OK when pushing harder. The bump stops won't last nearly as long I'd think, making regular inspection a good idea.

[55EXX]

thanks mate gold info! rep point for you!

so there is nothing besides wrecking bumpstops quicker that this has a negative mechanical effect on since it is like as if i had higher rate progressive coils due to the bumpstop adding its rate to the coil?

[JohnL]

so there is nothing besides wrecking bumpstops quicker that this has a negative mechanical effect on since it is like as if i had higher rate progressive coils due to the bumpstop adding its rate to the coil?

As far as I know, and as far as I can speculate, not really. There will be increased stresses placed on the chassis and some parts of the suspension, but not I think more so than fitting very stiff springs. However, if something breaks or you crash I take no responsibility!

[EKVTIR-T]

So your bottoming out regularly?
Apart from mechanical effect's how about safety,your's and other's.
Very dangerous scenario bottoming out daily...
Ive seen bad accident's caused by this

[55EXX]

from what i have gathered i am always sitting on the bumpstops and can't bottom out. the bumpstop itself is a soft sponge not a hard rubber like all you guys think. it is soft not hard. the bump stop compresses etc like a little spring. the ride is fine and smooth and i have done over 200km on them now and am liking it. there is not a bang when i hit it or go over bumps etc. its just like riding in a car with harder springs.

i cannot bottom out. i have tried going over bumps and hard cornering at lower speeds and where i used to scrubb out i no longer do. i may now only have only 1 inch of suspension travel up into the guard but because my car is very low that is all i can really afford to have. the advantage i think of this is the bump stop adds a progressive rate to the coil so the transition from bump stop fully loaded to unloaded is progressive making it smoother but drecreasing excessive roll and pitch but i guess would negatively affect warp (for you that don't know these term do a search lots of great info out there) due to the higher spring rate cause by the bump stop rate being added.

i am happy to leave my car like this

i am not going to change my damper settings.

[rahul]

Hi,

if you are using lowerd springs, shouldnt you be cutting part of the bump stop to stop it from hitting the shock too often? otherwise you can get aftermarket ones which are a bit shorter than the OEM ones when using lowered springs

[SeverAMV]

it all depends on how soft the bumpstop is. if it was a very firm bump stop like lets say polyurethane, just your car hitting the bump stop will be the same as your suspension bottoming out, and you'll either understeer or wheel hop + understeer. but its always better to cut the bump stop a little, so your ride isnt maxed out and stressed out all the time.

[55EXX]

the bump stop is oem from honda and is a soft foam like material. i can squish it between my fingers. having had it riding on the bump stop for a few weeks now am very happy with it to be left like that. the front is more heavily sat on the bump stops than the rear so the car has still a slight tendancy towards oversteer like a stock car but not anymore so than stock. big rear sway would fix that up and make my car be tighter in the rear. i love that i never scrubb out at all anymore! not even while hitting a bump on my out side wheel while hard cornering like all my past cars did! i actually love it

[JohnL]

the bump stop is oem from honda and is a soft foam like material. i can squish it between my fingers. having had it riding on the bump stop for a few weeks now am very happy with it to be left like that.
I think the marerial is likely to be a polyurethane based foam (?), which is a very reslient material (why polyurethane makes good suspension bushes). They're also likely to be somewhat conical in shape toward the lower end, which means they'll compress fairly easily at first then get progressively 'stiffer'.

I'm pretty sure the harder style of bump stop (more 'plasticy' or harder rubber) wouldn't behave the same way, and cause all sorts of ride and handling 'issues'.

Still, I suspect if you get six months out of them sitting in semi constant contact with the damper and the upper spring seat (taking a constant pounding) you'll be doing well, but I'm only speculating. I'm not sure what sort of $ they would be to replace when thet wear out, but they could be a bit pricey if you can only source similar items from Honda...?

[55EXX]

Still, I suspect if you get six months out of them sitting in semi constant contact with the damper and the upper spring seat (taking a constant pounding) you'll be doing well, but I'm only speculating. I'm not sure what sort of $ they would be to replace when thet wear out, but they could be a bit pricey if you can only source similar items from Honda...?

what the bump stop when they wear out? they were from honda pretty cheap. $22 each i think.

[JohnL]

what the bump stop when they wear out?

I'll have a guess as to what your question is actually asking; They will probably split and then start to fall apart.


they were from honda pretty cheap. $22 each i think.
Sometimes Honda can surprise you with a reasonable price, sometimes not...