Walking around on a roof is far different to bolting a roof rack to one and subjecting it to dynamic and shock loads.
can you tell me what model this is?
- Thread starter safir
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Walking around on a roof is far different to bolting a roof rack to one and subjecting it to dynamic and shock loads.
crushers
post ho
there is a difference between bolting a rack on and doing it properly... on any material.
just because an idiot attempts to achieve a task does not make it a fact.
the top is seperate from the tub, even though it is bolted down it moves differently. the twisting of the main body will have limited effect on the cap.
just because an idiot attempts to achieve a task does not make it a fact.
the top is seperate from the tub, even though it is bolted down it moves differently. the twisting of the main body will have limited effect on the cap.
Just because someone attempts a task,does not make them an idiot either.
As I said before about aftermarket FRP top and makers not bolting roof racks to F/G tops.
This come about by talking to the products manager for Flexiglass,Australia's biggest and oldest(est 1950) fibreglass top manufacturer.
He said it was physically impossible to bolt a roof rack to any f/g top without it breaking up or making a top so heavy it was impractical to fit to a vehicle.
Even on steel roofs they are supported by the gutters
The other reason I would never penetrate the FRP top is that it will no longer be water proof.
You still haven't bothered to tell us how you would bolt one on.
crushers
post ho
take offense if you wish.
to first attempt something does make you a layman since you are ignorant of the actual process. even if you have studied the process, the actual doing is unfamilar, hence layman.
idiot:
Etymology: Middle English, from Anglo-French ydiote, from Latin idiota IGNORANT person, from Greek idiōtēs one in a private station, layman, ignorant person.
of course in todays definition it means retarded, but it was said with the idea of ignorant or layman.
simple, you sandwich the fiberglass with a plate top and bottom, rubber gasket (seal), 4 bolts per mount. if it is mounted with 4-6 supports then the mount will mave WITH the fibreglass.
of course then you are back to COG. if the rack is strong enough to hold 500 lbs or more then you have an issue with over balancing the vehicle to the point of being unstable on the road or trail.
common sense is needed when installing and using a roof rack and the resulting characteristics.
to first attempt something does make you a layman since you are ignorant of the actual process. even if you have studied the process, the actual doing is unfamilar, hence layman.
idiot:
Etymology: Middle English, from Anglo-French ydiote, from Latin idiota IGNORANT person, from Greek idiōtēs one in a private station, layman, ignorant person.
of course in todays definition it means retarded, but it was said with the idea of ignorant or layman.
simple, you sandwich the fiberglass with a plate top and bottom, rubber gasket (seal), 4 bolts per mount. if it is mounted with 4-6 supports then the mount will mave WITH the fibreglass.
of course then you are back to COG. if the rack is strong enough to hold 500 lbs or more then you have an issue with over balancing the vehicle to the point of being unstable on the road or trail.
common sense is needed when installing and using a roof rack and the resulting characteristics.
Always fun to pop on the 70 series section and be entertained.
Now Wayne, no pooping in the sand box.....we all need to play in it...
Rob
Now Wayne, no pooping in the sand box.....we all need to play in it...
Rob
crushers
post ho
Rob,
share your insight into this discussion...
<i have been noted as a poop disturber for decades, do you really want me to change now?>
share your insight into this discussion...
<i have been noted as a poop disturber for decades, do you really want me to change now?>
- Joined
- May 16, 2008
- Messages
- 2,735
Hello,
Yes, fiberglass is as tough as steel. Yes, you can walk over it without damaging it. And yes, you can bolt components to fiberglass provided you know what you are doing.
However, an important thing is missing. Composites, from fiberglass to carbon fiber, are tougher than steel, weigh less and do not corrode. However, when subject to enough loading, they just break. Steel deforms but recovers it original shape; only when a certain force has been passed it deforms and eventually breaks.
Steel is elastic, which basically means it bends when a force is applied, recovering its original form when the force is no longer applied. Composites are plastic, deforming and breaking when enough force is applied.
A composite/fiberglass top saves weight and makes a hell of a component in a Cruiser, if it is left alone. As Rosco noted, dinamic loads that deform elastically steel, break (or deform plastically, as engineers say) fiberglass. That is why 73s and 74s keep the soft top's bar, and a good reason to get a trailer. Or travel light.
A trailer also keeps the COG low enough for wheeling.
By the way, that is one nice 74. And that engine rocks.
My two cents.
JuanJ
PS: If I could only get a 73/74 in decent shape...
Yes, fiberglass is as tough as steel. Yes, you can walk over it without damaging it. And yes, you can bolt components to fiberglass provided you know what you are doing.
However, an important thing is missing. Composites, from fiberglass to carbon fiber, are tougher than steel, weigh less and do not corrode. However, when subject to enough loading, they just break. Steel deforms but recovers it original shape; only when a certain force has been passed it deforms and eventually breaks.
Steel is elastic, which basically means it bends when a force is applied, recovering its original form when the force is no longer applied. Composites are plastic, deforming and breaking when enough force is applied.
A composite/fiberglass top saves weight and makes a hell of a component in a Cruiser, if it is left alone. As Rosco noted, dinamic loads that deform elastically steel, break (or deform plastically, as engineers say) fiberglass. That is why 73s and 74s keep the soft top's bar, and a good reason to get a trailer. Or travel light.
A trailer also keeps the COG low enough for wheeling.
By the way, that is one nice 74. And that engine rocks.
My two cents.
JuanJ
PS: If I could only get a 73/74 in decent shape...
Last edited:
Got nothing to offer, just having some fun first thing this morning.
Lots of good opinions and points on one of my favourite cruisers.
Cheers.
Rob
crushers
post ho
steel rips, deforms, dents easier than a good piece of fiberglass.
fibreglass does crack if exposed to continous flexing and this depends on the manufactuing process. if a boat builder designs and creates the piece then it will stand up better than an individual that builds for the trail. boats see continuious pounding from the waves, continous twisting and bending and survive for long durations doing so.
i have seen crap fiberglass products and i have seen excellent ones, same as i have seen tough steel and pop can steel. take a 40 series from before 1974 and compare the steel with a unit after 1979, before 74 you can walk on the hood without any issues, after 79 and you will dent it.
all in all, it comes down to what you want to load on the top, where the weight it and how it is mounted.
i was really hoping that Rob would have pitched in here with his experiences one way or the other.
personally, i am not a fan of roof racks at all but i have one to sleep on. even a spare tire and a tool box on the rack makes me uncomfortable when wheeling.
fibreglass does crack if exposed to continous flexing and this depends on the manufactuing process. if a boat builder designs and creates the piece then it will stand up better than an individual that builds for the trail. boats see continuious pounding from the waves, continous twisting and bending and survive for long durations doing so.
i have seen crap fiberglass products and i have seen excellent ones, same as i have seen tough steel and pop can steel. take a 40 series from before 1974 and compare the steel with a unit after 1979, before 74 you can walk on the hood without any issues, after 79 and you will dent it.
all in all, it comes down to what you want to load on the top, where the weight it and how it is mounted.
i was really hoping that Rob would have pitched in here with his experiences one way or the other.
personally, i am not a fan of roof racks at all but i have one to sleep on. even a spare tire and a tool box on the rack makes me uncomfortable when wheeling.
People cross the Simpson all the time with roof racks clamped to the gutters and with 200kgs up top and the steel roof holds up.
The FRP top would never last the distance with 2000 dunes to cross.
As I said before ,Flexiglass(and ARB) recommend steel frames to support loads above their FRP tops for a good reason.
Toyota never offered a luggage rack for the FRP tops ,but they did offer one for the steel roofs.
All the big accessories companies make a roof rack for steel roofs but NO ONE ever made one for any vehicles with a FRP (unless it had purpose built frame for the rack)
Maybe they know something you dont Wayne
crushers
post ho
yep, Toyota offered a roof rack system for the 60s here with a load rating of 150 lbs mounted to the roof and not the gutter...
go figure.
go figure.
crushers
post ho
and
i am sure there is lots the boys at Toyota know that i don't,,,
i am sure there is lots the boys at Toyota know that i don't,,,
lowenbrau
SILVER Star
True. That's part of the reason I bolted my Roof Top Tent through the FRP to the rollcage below.
Did you know that many US built vehicles use fibreglass leaf springs? I guess when engineered and manufactured properly they can flex pretty reliably.
- Thread starter
- #34
it appears that by posting the picture and asking the question i have sparked an argument, lets call it a discussion.
now that we have reached page 2 on this topic i propose to end the discussion by flipping the 74 to see how the FRP roof holds up, ill then post a picture to settle the argument....sorry discussion.
fyi i bought the truck yesterday and its a peach!
all the best from saudi arabia.
now that we have reached page 2 on this topic i propose to end the discussion by flipping the 74 to see how the FRP roof holds up, ill then post a picture to settle the argument....sorry discussion.
fyi i bought the truck yesterday and its a peach!
all the best from saudi arabia.
crushers
post ho
no discussion = no new knowledge = boring forum = loss of individuals participating in discussions = <repeat>
when you roll it make sure you note the speed and time of day, ambiant temp, load, tire pressure so that you can repeat the exact senerio with a steel hard top...J/K
when you roll it make sure you note the speed and time of day, ambiant temp, load, tire pressure so that you can repeat the exact senerio with a steel hard top...J/K
So your FRP isnt strong enough and you had to bolt it to the rollcage. I agree 100%
Carbon fibre and fibregalss springs are being subjected to a different kind of load and one that they were designed to take
They also build jet fighters out of similar materials but they dont bolt roof racks on top
make sure its video in slow motion
