Flapping Top Straps

Discuss all things Model T related.
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules

Topic author
TXGOAT2
Posts: 6411
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
MTFCA Number: 51486
Board Member Since: 2021

Flapping Top Straps

Post by TXGOAT2 » Fri May 07, 2021 9:01 pm

I have a '26-7 roadster. The top is in good shape and looks smooth and tight. There is little or no noise from the top going down the highway 35-50 mph UNLESS there is a crosswind. If there is much crosswind, the flat straps that run inside the top flap furiously and make a nasty racket. Is there any good way to prevent this short of lowering the top? I've been running the car with the windshield closed, no wind wings, and no side curtains. There is no problem driving on a day with low wind. Today the wind is gusting 15-25 mph, and driving crosswind makes the straps go nuts. When the car is sitting still, the straps lay flat against the inside of the top. They are not hanging loose.


Allan
Posts: 5201
Joined: Sun Jan 06, 2019 7:21 pm
First Name: Allan
Last Name: Bennett
* REQUIRED* Type and Year of Model Ts owned: 1912 van, 1917 shooting brake, 1929 roadster buckboard, 1924 tourer, 1925 barn find buckboard, 1925 D &F wide body roadster, 1927LHD Tudor sedan.
Location: Gawler, Australia

Re: Flapping Top Straps

Post by Allan » Sat May 08, 2021 5:29 am

Ratchet tiedown straps will do the same thing at high speeds. The trick with them is to put a twist in them when threading them through the ratchet. Perhaps you could try a bulldog paper clip to squeeze a third dimension in the strap. Easy to fit and take off again, if it works.

Allan from down under.


Topic author
TXGOAT2
Posts: 6411
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
MTFCA Number: 51486
Board Member Since: 2021

Re: Flapping Top Straps

Post by TXGOAT2 » Sat May 08, 2021 9:26 am

It does seem to be related to the shape of the straps. I'll try deforming them with clips or maybe stiffen them with wire ties and foam-wrapped strips of wood or stiff plastic or aluminum. They'd have to come off to lay the top down, but wire ties are fairly cheap. I've seen flat tie down straps on OTR truck trailers whipped to a blur by the wind. The trailer straps are a lot tighter than I could ever get the top straps and yet they still oscillate in the wind. It's the straps that run vertically up the rear curtain that cause the problem with my car.


Erik Johnson
Posts: 850
Joined: Mon Feb 04, 2019 10:25 pm
First Name: Erik
Last Name: Johnson
Location: Minneapolis, MN

Re: Flapping Top Straps

Post by Erik Johnson » Sat May 08, 2021 10:10 am

I question if those straps are factory correct and, if they are not, they are unnecessary.

The tension of the top is in the material inside of the top pads. That keeps the top material itself from taking the stress and tearing.

I'm helping my dad re-do the two-man top on his 1917 touring. The original material inside the top pads is a cotton duck or canvas from the second bow back to the fourth bow. Between the first and second bow, it is a strip of leatherette top fabric.

I have also seen the above on original two-man roadster top pads both without and without the leatherette between the first and second bows.

One of the top vendors uses jute furniture webbing inside the top pads but that is not how they came from the factory. They also use two additional exposed straps from front to back on 1914 through 1922 two-man tops which is NOT how they came from the factory.

I'm not an expert on one-man tops. But, once again, I question if the two extra exposed webbing straps that run from front to back on top of the bows and under the top fabric is correct.

User avatar

Humblej
Posts: 1690
Joined: Sun Jan 06, 2019 12:23 pm
First Name: Jeff
Last Name: Humble
* REQUIRED* Type and Year of Model Ts owned: 1926 Canadian built coupe, 1924 TT C-cab, survivor 1924 roadster
Location: Charlevoix, Mi
MTFCA Number: 28034
Board Member Since: 2006

Re: Flapping Top Straps

Post by Humblej » Sat May 08, 2021 10:59 am

Yes open car tops will flap and make a racket under the right conditions. Putting anything hard or sharp there could rub a hole in your top in short order. I would suggest stuffing some foam between the straps and top and experiment with the upper windshield position for any given days conditions.


Scott_Conger
Posts: 6430
Joined: Sun Jan 06, 2019 11:18 am
First Name: Scott
Last Name: Conger
* REQUIRED* Type and Year of Model Ts owned: '13, '15, '19, '23
Location: Clark, WY
Board Member Since: 2005

Re: Flapping Top Straps

Post by Scott_Conger » Sat May 08, 2021 11:09 am

While Model T's can be pushed to 50 and beyond (MT500 drivers do it all the time with cars built to sustain those rigors for some period of time), it is well beyond anything the T was designed to do from the factory for anything more than very short bursts, and continuing to do so will shorten it's lifespan dramatically and often, spectacularly.

If what you consider a problem manifests itself at speeds over 35 MPH, then you don't actually have a problem. If I am wrong, then the problem is not that the straps vibrate at 50 MPH, but that you bought a "T", when you meant to buy an "A".
Scott Conger

Tyranny under the guise of law is still Tyranny

NH Full Flow Float Valves
Obsolete carburetor parts manufactured


R.V.Anderson
Posts: 680
Joined: Tue Jan 08, 2019 6:01 pm
First Name: R.V.
Last Name: Anderson
* REQUIRED* Type and Year of Model Ts owned: 1914, 1920, 1923, 1923
Location: Kennedy, NY

Re: Flapping Top Straps

Post by R.V.Anderson » Sat May 08, 2021 11:51 am

The simplest solution would be to install some stick-on black Velcro strips between the straps and the curtains. Not correct of course :D but they would be pretty well hidden and wouldn't cause interference when folding the top, if you're ever inclined to do that.


Topic author
TXGOAT2
Posts: 6411
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
MTFCA Number: 51486
Board Member Since: 2021

Re: Flapping Top Straps

Post by TXGOAT2 » Sat May 08, 2021 1:35 pm

I thought of velcro, but I have some concern about the glue or adhesive causing issues with the top material. As for speed, the problem can occur at lower speeds under the right conditions, speeds as low at 10-15 mph. (crosswinds, especially gusting crosswinds) I don't know how the pads are constructed, but it looks like tension in the top covering material is what is positioning the bows, not the pads or the straps. I'll consider the velcro solution. For now, I'll try wire ties and very thin wood slats wrapped in terrycloth. I don't think they'll be any more abrasive than the straps flapping furiously. If they cause any issues, I can snip the ties and be back to square 1. The straps make a sound like playing cards in bicycle spokes, only louder. The top is certainly not an original, but it is in very good condition and performs very well except for the strap flapping issue. It has survived several Montana 500s with no evident wear of any kind, and it fits better than most tops I see pictured. //UPDATE: I found that it was 22" from the top of the seat cushion to the top bow above the rear curtain. I cut 2 lengths of thin wooden trim, about 1/8 X 1-1/2", and taped the ends with electrical tape. I placed these against the straps, wedged very lightly between the top of the seat and the top bow. I then tied the straps to the slats with 4 plastic ties each pulled as tight as possible. They don't look too bad, and they don't show at all from outside. The wind is gusting 25-30 today, so I decided to try them out. I headed for the highway and took off west bound with the south wind gusting. The straps did not flap at all, and the rear curtain moves around a lot less. Up to 50 mph with a 30 mph crosswind , everything is fine. If the slats will stay in place, I'm done. If not, a small square of velcro at each end will secure them. They can be removed easily by clipping the plastic ties. As far as that goes, the slats could be velcro'd to the straps, eliminating the plastic ties. Then they could be detached and stowed under the seat in less than a minute, and nothing would be attached to the top covering. The wooden slats I'm using are very flexible and weigh next to nothing. They are interior trim pieces from a cheap trailerhouse. I'd think a cabinet shop or lumber yard would have similar stuff. I cut the pieces to length with a pair of scissors.


Topic author
TXGOAT2
Posts: 6411
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
MTFCA Number: 51486
Board Member Since: 2021

Re: Flapping Top Straps

Post by TXGOAT2 » Sat May 08, 2021 4:31 pm

Re: "I'm not an expert on one-man tops. But, once again, I question if the two extra exposed webbing straps that run from front to back on top of the bows and under the top fabric is correct." /// ////// I can't see that the two front to back straps running from the windshield header back to the body behind the seat do anything to support the top material or position the bows when the top is up. They might give some support to the top material when the top is folded down. I'm guessing that's what they're for. Beyond that, they're a nuisance, as far as I can see.


Jerry VanOoteghem
Posts: 2952
Joined: Sun Jan 06, 2019 4:06 pm
First Name: Jerry
Last Name: Van
Location: S.E. Michigan
MTFCA Number: 24868

Re: Flapping Top Straps

Post by Jerry VanOoteghem » Sat May 08, 2021 6:32 pm

It's just part of the charm and experience of driving a T. Embrace it! ;)


Topic author
TXGOAT2
Posts: 6411
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
MTFCA Number: 51486
Board Member Since: 2021

Re: Flapping Top Straps

Post by TXGOAT2 » Sat May 08, 2021 8:50 pm

It's fun to drive, regardless of the popping and flapping, but it's SO much nicer without it. There's a lot less motion in the rear curtain, too. The car started by itself after I put the slats in. I think it's happy with them.

Post Reply Previous topicNext topic