Speed bump scrape??

[TheScientist]

Any of you guys find that even as standard, your car scrapes on speed bumps?

I have a 1.9TDI on 15" wheels, not low profile tyres. I was thinking about putting some different wheels on and getting it a bit lower, but seeing as it scrapes already I'm going off the idea...

 

[Muttley]

Different wheels should not make any real difference to the ride height, as the tyre profile changes to keep the rolling radius the same.

If you put lower profile tyres on you will upset the speed and mileage readings. The Kouki visual calculator will give you an idea of the effects.

I've got Sports suspension as standard (15mm lower) and find that where the road has sunk on one side after a speed bump has been hacked into it (done by the lowest bidder) I scrape the undertray, and have to put a wheel up on the bump to avoid damage.

 

[andycupra]

depends how its scrapping..
is it scrapping when you initially hit the speed bump or come down the other side? then this is due to the suspension 'give', and many people report that when they lower and have slightly stiffer suspension they can be better than OEM for this.

however, if you are scrapping simply due to ride height only, - eg for those silly speed bumps that dont cross the entire road (allowing larger vehicles to completely ignore them) then you can lower it in reality.

 

[alien1974]

the tdi has a lower sump making the under tray lower too hence the scrape, only thing to do is get a shallow sump and remove the under tray

 

[Brettyboy]

The undertray hangs down quite low,have you had a look to see it any of the screws are missing,i didnt have any scraping when i was std

 

[spoons86]

i plan route before i go out to avoid bumps etc mine catches everywhere really do have to be carefull, worth it tho cos it looks mega

 

[Yatesey8527]

My LCR's totally OEM suspension wise-half the time the front splitter just rubs the speed humps as does the under tray.Havnt got any screws missing from mine.I think Gloucester county council just have extra high speed humps & extra deep pot holes

 

[dazjstuart]

Have a look under your car, my sump guard has had a bit broken off it at some point and a bit of it hangs down. I keep meaning to cut it off or fasten it up with something but havent got access to a ramp at the moment. Anyway it makes a rather alarming scraping noise when I go over a bump. Might want to check that out incase its something as simple as that!

As others have said bigger wheels and lower profile tyres shouldn't make a difference as the overall diameter of the wheel should stay roughly the same.