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Hood noise at speed TR4


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Hi all, was out last weekend and had cause to run at high speed (70mph honest officer ;) ) along the motorway for a few hours.

I noticed that the mohair hood vibrates against the front and middle roof support bars. Road atlas stuffed between roof and middle bar took the noise down to a level where I could hear my own thoughts again, but clearly a solution needs to be found and I'm sure has been found many times over the years.

 

Reading other threads going back a few years I can see this is a standard design feature and usually only noticed by southern softies (like myself) who don't have all the Biggles gear and want to put the roof up.

 

I can see some type of felt tape or foam inserts (or an inner roof lining, but that just seem overkill) are required around/between the roof bars and the roof to stop the vibration on the bars, if I'm to have my wife in the car with the roof up.

 

So given the level of knowledge and ingenuity out there I though I'd ask if anybody has had any success with this problem before I begin trying various solutions.

 

The roof and bars are all in excellent conditions and the roof is tight as a drum and in all respects looks exactly as it should with no obvious defects or fault that are causing this to be any worse than as Triumph intended.

 

Mark

 

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The vibration always was, and always will be, a problem.

 

The factory fitted (well, glued) a strip of felt-like material

to the middle bar. I'm sure that idea could be copied (and

improved) easily (in case you need your maps!).

 

Also, on the factory hoods, there was an extra flap sewn

into the hood, with press studs. The flap wrapped around

the middle support, almost the full width of the hood, and

held the hood to the frame.

 

A combination of those two solutions should allow you to

hear your passenger screaming.

 

AlanR

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The vibration always was, and always will be, a problem.

 

Also, on the factory hoods, there was an extra flap sewn

into the hood, with press studs. The flap wrapped around

the middle support, almost the full width of the hood, and

held the hood to the frame.

 

AlanR

 

I have a Skinner hood on my TR4A and it has the flap sewn in.

 

Cheers

 

Graeme

Edited by graeme
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Hi Alan, yes mine too has a piece sewn (1/2 roof width only though) in to the hood that clips around the front bar, but could have benefited from one on the middle bar too maybe when the hood was manufactured. I think the felt is the most likely option to work best and not look too out of place, as it's a bit of a problem to read the map when its above your head :D

 

Niall, though if the pipe insulation and if I can find something with a relatively thin wall and softish outer this might work.

 

Graeme, liking the garage a loooooot.

 

Dave, yes I can see how the shot would dampen down the vibration might be something to be added to a new hood in a few years.

 

All in all I think some extensive use of Google and visiting various outlets to see what's about that could be pressed in to service.

Have to have something in place before Harrogate IWE14 in weeks time. Otherwise might be stuffing tea towels under the bars!

 

When it comes time for a new hood (in a few years) will have to see what the options are to have extra features added.

 

Mark

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Mark

What about a length of velcro, the fluffy half, or would that be too thin? if so stick the hook half to the rail. you can get self adhesive velcro on a roll, maybe iron on stuff too.

 

http://www.ebay.co.uk/itm/VELCRO-SELF-ADHESIVE-STICKY-2mtrs-x-20mm-HOOK-LOOP-B-/271374674196?pt=UK_Crafts_Sewing_Supplies_MJ&hash=item3f2f30e914

 

Steve

Edited by Steve R
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HI Steve, just looking at this felt tape on ebay. Thinking it needs to be softer than Velcro as this may chafe and mark/wear the inner hood surface. Also off to a fabric warehouse at lunchtime to see what they have...

Might end-up with a set of curtains for the rear window :D

 

Mark

 

http://www.ebay.co.uk/itm/ANTI-SQUEAK-ANTI-RATTLE-SELF-ADHESIVE-FELT-TAPE-25mm-x-5m-/271460699638#ht_2347wt_986

 

$_57.JPG

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Hi, yes was not sure if that would be pulled off as the tension was put on the roof, but I suppose it would be the same problem either way around. Was hoping not to have to stick anything to the roof lining, but might be the best way.

 

No curtains for the back window either, a very short non standard drop apparently, so would have to have them custom made.

 

Mark

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Pehaps a Roman blind then? or Swags and Tails....and a Pelmet, there's a word not used for a while....

:)

Edited by Steve R
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Pelmet - ah, reminds me of the Honeywell office at Brentford in the 1960s, and in particular a young, very tall & slim lass called Anne, whose skirt (?) stood a few inches above the top of Vic's desk, which excited him, a middle-aged father of 5, mightily!

Not at all PC, of course.

Ian Cornish

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I have some 3mm wool felt sheet that a I cut a length from and wrap around the front pipe of my TR3A hood. It stops that infuriating crackling noise until I go a bit fast then the hood lifts of completely and it falls on my head. This was disconcerting, so I used small cable ties to hold it, which was successful until I folded the hood down with the wife's help. Now the felt is down behind the passenger seat and all the cable ties are at the end somewhere. When she's in the car with the hood up, she can hold it to stop the noise, but she's arguing that it's noisy and comfortable and that she'd prefer we went in something else, so I'm having to rethink. :(

Edited by Ashley James
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Hi Mark

 

Do you drive with the windows right up ( I'm assuming a Southern Softie would do).

 

You could TRy adjusting the window position a little as this can level the air pressure a bit and prevent the flapping of the hood.

 

Other than that it just typical TR, as my own is not exactly quiet s a whole. And if it has the added effect if drowning out 'her inside', then .......what the heck.

 

Regards

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Strips of the furry part of Velcro glued to the top of the rails does help as does the sewn in tubes across the hood that go over the rails with the poppers, these need to be a tight fit or they will contribute to the noise. The heavier weight of material for the hood then the quieter they are, Its only when you get to very expensive cars with a headlining under the hood frame that you start to get a quieter ride Im afraid.

Stuart.

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Hi all, just a quick update.

added the sticky backed felt to the front and middle bars. What a difference, noise reduction is massive from the hood slapping on the bars. But as always remove one thing and you can hear the next. The hood drums naturally as the speed increases, but given the noise reduction is about 70% my ears won't be bleeded after 3 hours on the M1 up to Harrogate on Thursday for the IWE.

 

 

Mark

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HI Paul, yes, next step is sound insulation under carpets and looking in to sticking some sort of inner hood lining to try to modify the flappy properties of the hood between the roof supports. But at least I can now hear the engine.

 

Mark

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