*%#@;'! brush hog.

[RoyJackson]

(EDITED)
A mechanical toplink will buckle under compression, or the
implement doing the compressing will bend.

As for a rigid toplink on a RC preventing a rear rollover, I guess it
could help a bit if you were pulling something at the same time with
your ROPS But that's a stretch. I suspect 99.999% of rear rollovers
occur using a PHD or pulling something with the rear of the tractor.

A mechanical top link would provide some resistance to a rear roll over. A chain would provide none...
As far as bending...maybe...that would depend on the load. It might break too, again, depending on the load.
But before it bends, a mechanical (I'm going to use the term "rigid" as I think it more accurately describes the component) may provide just enough resistance to prevent a full roll over or lay the tractor over on it's side (which may be survivable).

As far as your second paragraph...yep, the top link would only help if rigged to an implement (which would also aid in preventing a rear rollover). The only two times I could see this happening is going up a steep slope (with inadequate front ballast) or if the implement (blade, plow or box blade) got hung up on an immovable obstruction (I would think the rears would spin or the tractor would stall...but you never know...)

 

[Soundguy]

I see we hve a different definition of non compressible. I like the dictionary definition which states that non compressible means that something cannot be compressed. A rigid toplink meets that criteria under it's mechanical limits. A chain does not.. nor would a cable.. they would both colapse.. thus be compressed as the distance between both eye lets would be shorter.

I think using a chain toplink on a PHD would be jinda dodgy at best...

Pulling from rops? hmm.. not sure I've ever seen someone do that.. seems like a surefre way to get hurt or break something.

Pivot on a toplink connection not react fast enough? Are you kidding.. if it is adjusted right all is has to do is swing.. it should react just as fast as a piece of chain.. until you lift it then it has to swing down to go into tension to lif thte implement.

Soundguy

A chain is a non-compressible top link (can take tension only). So is
a cable. A mechanical toplink will buckle under compression, or the
implement doing the compressing will bend. Seems clear to me.

RCs I have bought come with a pivoting link as the toplink connection.
Although this helps to avoid damage under compression, it can not
react fast enough to a sudden shock.

As for a rigid toplink on a RC preventing a rear rollover, I guess it
could help a bit if you were pulling something at the same time with
your ROPS. But that's a stretch. I suspect 99.999% of rear rollovers
occur using a PHD or pulling something with the rear of the tractor.

 

[Berniep]

Whenever I see this topic come up someone usually mentions this and I havent seen it yet so here goes.
The rigid top link can help keep the rotary cutter from flipping up into the back of the tractor in the event it hits something. On the one I use it looks like the top of the A frame could get into my personal space if it did indeed flip up.

 

[Soundguy]

Good point.. another 'star' for a rigid toplink...

Soundguy

 

[JerryG]

Whenever I see this topic come up someone usually mentions this and I havent seen it yet so here goes.
The rigid top link can help keep the rotary cutter from flipping up into the back of the tractor in the event it hits something. On the one I use it looks like the top of the A frame could get into my personal space if it did indeed flip up.

I have ask on several sites if anyone had first hand knowledge about a mower that flipped up while using a chain. There was one dealer that was hot under the collar over the use of a chain that said that he had a customer that flipped one up. Given the circumstance, I didn't believe a word he said. I have yet to hear from anyone that has ever seen one or had one flip up with a chain even after asking the same question about 6 years.

 

[Soundguy]

I would kind of expectt he pto shaft to handle some of the 'emergency'.. however.. would expect great damage to my tractor in doing that... I've had to rebuild some JD tractors that had their pto pushe din from careless employees not trimming pto shafts down... I'd hate to use a chain toplink in place of a rigid one and think that the rigid one may have protected my tractor in some small way.. IF an accident ever happened... big ..IF.. I know... I can envision the flip up.. IE.. a mower front edge catching on a stump.. etc. Can't say that it has ever happened to me or anyone i know.. then again.. I've never rolle dmy tractor.. but I do value the rops and seatbelt too... same with shooting glasses when I'm on the range, and snake chaps when i hunt... never had any of those devices help me.. but it doesn't hurt me any to utilize them.

Seems like the need to use a chain toplink on a modern mower is kind of going the way of the DO-DO.. most manufacturers i see have built in provisions for a flexible toplink connection that suitable addresses this problem if adjusted right.. or at very least, partially mitigates it anyway... Even the ones with the folding a-frame and chain link to the tail wheel ( which would effectively negate any benefits of a rigid toplink as have been posed here.. )

Jerry does bring up a good point. most of this stuff pro/con are theoretical.. or hypothetical in nature. You can build up or break down any argument if you fill in enough "IF" variables.

As jerry mentioned.. has anyone seen any documented flips-ups of a mower.. IE.. a 3pt mower with no toplink.. or a colabsable toplink in use that has caught on something and flipped back? Anything on the osha site.. I've seen lots of bad stuff there..

Soundguy

 

[bx24]

Well, I think my questions about the chain have been answered. I have no doubt that someone somewhere has had some misfortune and from that point forward, it was recommended to not have a completely flexible top link. Again my question centered around the comparison to a pull type cutter.

Thanks for everyone's input to my question

 

[Berniep]

I have ask on several sites if anyone had first hand knowledge about a mower that flipped up while using a chain. There was one dealer that was hot under the collar over the use of a chain that said that he had a customer that flipped one up. Given the circumstance, I didn't believe a word he said. I have yet to hear from anyone that has ever seen one or had one flip up with a chain even after asking the same question about 6 years.

Good point.
Lots of things people are scared of never happened or happened only under very particular circumstances.
(cell phones and exploding gas stations come to mind)

 

[dfkrug]

Pivot on a toplink connection not react fast enough? Are you kidding.. if it is adjusted right all is has to do is swing.. it should react just as fast as a piece of chain.. until you lift it then it has to swing down to go into tension to lif thte implement.

No, not kidding. If you take 2 rigid links attached by a pivot pin, line
them up straight and apply a sudden compressive force to them, that
force will be transmitted thru both links. Until they rotate around the
pivot. On the other hand, 2 rigid links attached by a pivot pin thru a
slot instead of a hole would act like a chain. And 2 rigid links attached
by a pivot pin where they are NOT lined up straight, would act
in a similar way to a chain.

As for a tractor rolling over backwards.... With a RC attached and
nothing else, it is hard to imagine how this could happen. If the front
of the tractor started to rise relative to the rear, a rigid toplink would
bend the toplink frame of the cutter and/or the tail wheel frame after
maybe 10-15 degrees of lift. This is long before a rear rollover. The
cutter frames buckle very easily and provide essentially no protection
in a rear rollover, IMO. I have never seen a used RC that had not
suffered bent up toplink frame or tail wheel frame. I have not seen
rigid toplink damage from RC use like Shantycoke has....that is usually
caused by BB. The OEM toplinks are usually stronger than the RC
frames.

I stated the 2 scenarios where rear rollovers are known and documented
to happen (PHD use and pulling things with chain, cable, rope etc). We
are only talking about a chain toplink for RCs, not for anything else.
I, like JerryG, would like to know of actual cases where a rear rollover
occurs, not just some myth. Especially using a RC, chain or not.

 

[Soundguy]

Ahh.. so you mean -with them not adjusted correctly-. I think I was pretty clear about having the flex link adjusted correctly. If your 2 coupled links are straight in line with each other.. you should be lifting the mower.. otherwise, in use.. the link should be adjusted so they are not in a line.. but rather where ther is play in either direction.. IE have an angle in the link.. as you also agree to at the end of your paragraph.
Good try at trying to make the statement false by changing one of the variables to a condition outside of the ones being discussed.

We can consider this one settled albiet with the caveot that the links should be adjusted correctly ( why would you want them adjusted incorrectly??? )

No, not kidding. If you take 2 rigid links attached by a pivot pin, line
them up straight and apply a sudden compressive force to them, that
force will be transmitted thru both links. Until they rotate around the
pivot. On the other hand, 2 rigid links attached by a pivot pin thru a
slot instead of a hole would act like a chain. And 2 rigid links attached
by a pivot pin where they are NOT lined up straight, would act
in a similar way to a chain..

Sheer wild speculation. Your statement deals in absolutes..""a rigid toplink would bend the toplink frame of "".. As we have all seen here on TBN.. absolutes are very hard to define beacuse soo many scenerios are possible Better to say that -Some- mower A-frames may buckle with no resistance.. -Some- may not. ( same can be said for the tailwheel... some mowers have more than 1 tailwheel too, to absorb that laod..e tc. ) I can tell you that the A-Frame on my howse mower will probably not be the first thing to buckle in a backflip situation where the mower is acting in a manner as trying to prevent the backflip. I'd bet that my tailwheels will also not buckle.. My bet is it will be my cat 2 toplink that goes first.. or the toplink rocker on the tractor.. perhaps the cat 2 toplink pins... VS the frame or tailwheel; on my Howse HD10C mower

As for a tractor rolling over backwards.... With a RC attached and
nothing else, it is hard to imagine how this could happen. If the front
of the tractor started to rise relative to the rear, a rigid toplink would
bend the toplink frame of the cutter and/or the tail wheel frame after
maybe 10-15 degrees of lift. This is long before a rear rollover. The
cutter frames buckle very easily and provide essentially no protection
in a rear rollover, IMO. I have never seen a used RC that had not
suffered bent up toplink frame or tail wheel frame. I have not seen
rigid toplink damage from RC use like Shantycoke has....that is usually
caused by BB. The OEM toplinks are usually stronger than the RC
frames..

None of my 3pt mowers .. or any of my 3pt equipment have bent 3pt a-frames....???


Soundguy

 

[dfkrug]

Ahh.. so you mean -with them not adjusted correctly-. I think I was pretty clear about having the flex link adjusted correctly. If your 2 coupled links are straight in line with each other.. you should be lifting the mower.. otherwise, in use.. the link should be adjusted so they are not in a line.. but rather where ther is play in either direction.. IE have an angle in the link.. as you also agree to at the end of your paragraph.
Good try at trying to make the statement false by changing one of the variables to a condition outside of the ones being discussed.

We can consider this one settled albiet with the caveot that the links should be adjusted correctly ( why would you want them adjusted incorrectly??? )

First, there is no "adjustment" on the common medium duty Worksaver
RCs I have bought new. Nice you have one. Also, it is nice you have
a Cat 2 toplink, and maybe even a dual tail wheel machine.

Talk about changing the variables.....

 

[Soundguy]

The adjustment is in the toplink. IE.. screw it in or out to get it set correctly with the flexlink.. or int he elongated groove.. whatever the mower manufacture provided for that function... Most toplinks are adjustable.. either by sliding apart and bolting.. or screw in / screw out.. or lever open, then slide out, then lever closed.. etc.. This is what were were discussing was it not.. a rigid toplink connection to some sort of flexlink correct?

First, there is no "adjustment" on the common medium duty Worksaver
RCs I have bought new. .....

Ahh.. but I didn't.

Talk about changing the variables.....

That sentence was in reply to your comment. You opened up the entire playing field with the unlimited comment stating :

If the front of the tractor started to rise ...a rigid toplink would bend the toplink frame of the cutter and/or the tail wheel frame .....The
cutter frames buckle very easily ......

With no qualifying descriptors.. in essence you are stating that ALL rotary cutter frames WILL buckle, and that ALL tail wheel assembles WILL fold.. see what I mean about dealing in absolutes. That was my point... there are sure to be some implements that are sufficiently stout as to make them -not- the weak link in a rear compression situation.. It's entirely possible then the toplink or connection to the tractor.. or some other intermediary piece, if equipped would then become the failure point. It's also very possible that due to the structure and rigidity of all the parts involved that a rear flip could be stalled due to a lack of traction.. after all.. if your tractor front wheels can only come 2-3" off the ground before your tail wheel hits.. then you have to look at if those rear rubbers spinning will generate enough force to start buckleing metal on the rear of the tractor. If the angle is low enough .( which it probably would be with the tractor in a position with fronts up at say a 45' or less angle... you won't have tractor weight resting on the hitch to deal with (yet).. you are still stuck with a fight between drawbar hp and traction available to start compressing all that metal back there. Lots of variables here.. that's why I'm not dealing in absolutes. In a low traction medium like a grassy sandy pasture.. I see all sorts of outcomes with tires spinning and no metal buckleing.. In a high traction medium.. I can certaintly see damage occouring. Time will be another factor to look at. All that 3pt metal and mower and linkage back there .. while it may eventually fail in a few seconds..it may also hold for a few seconds.. or a second.. etc. in that time frame starting from when the initial problem occours where the tractor starts it's backflip, front comes up and then meets resistance.. then you can figure in operator corrective actions.. like hitting a clutch, dumping the throttle, killing engine.. etc..

That's my point.. too many varialble to state that all mower 3pt a-frames and tailwheel assemblies will buckle. Lots of other parts could buckle.. or some might not buckle immediatly, but rather provide time.. etc.

In the end.. On the point of a mower or other 3pt implement helping out with stalling a backflip.. I guess we can agree to disagree. I personally feel, looking at the vast variables.. that there is good circumstantial evidence that something rigind and structural extending out a distance from the rear of the tractor, "could" help prevent or stall, or delay a rear rollover event, in somce cases.

Soundguy

 

[dfkrug]

So Soundguy, you say it is "sheer wild speculation" on my part
when I describe the conditions likely to cause damge to a RC
with a rigid toplink. Nonsense. There is evidence of many RCs
being damaged this way, both anecdotal & seen by my own eyes.

On the other hand there is NO evidence of a rigid toplink preventing
a rear rollover. THAT's wild speculation.

As for making "absolute" statements..... I have tried to keep my
responses oriented to the original thread, which involves a B7800
and therefore a CAT 1 RC of probably 5' width. Certainly NOT a
CAT 2 10-footer as you refer to.

 

[Soundguy]

So Soundguy, you say it is "sheer wild speculation" on my part
when I describe the conditions likely to cause damge to a RC
with a rigid toplink. Nonsense. There is evidence of many RCs
being damaged this way, both anecdotal & seen by my own eyes..

However there is nothing to indicate that that damage -HAS- to occur. Your statement directly says that WHEN the tractor comes up, the frame WILL be damaged.. That's an IF/THEN logical statement. There are plenty of situational variables to be plugged in there.. It's not unreasonable to expect some outcomes with damage, and some without damage. Thus the IF/THEN statement is fasle since it's only possible outcome is 'damage'.

On the other hand there is NO evidence of a rigid toplink preventing
a rear rollover. THAT's wild speculation..

Theoretical speculation.. I'll give you that much. There is good circumstantial evidence in my arguments to make the case that a sufficiently strong toplink and mower frame -could- help stall, delay or prevent a backflip in certain circumstances. Id label that is 'possibility'... or at minimum.. 'limited possibility'.. however.. not 'wild speculation'..

As for making "absolute" statements..... I have tried to keep my
responses oriented to the original thread, which involves a B7800
and therefore a CAT 1 RC of probably 5' width. Certainly NOT a
CAT 2 10-footer as you refer to.

Respectfully.. you have not kept your statments confined to those parameters. You statements were indeed broad. When you stated that when a tractor comes up, the mower frame or tail wheel will bend. If you only meant to consider the single tractor an mower at hand you should have made that a conditional statement. The way your statement literally reads is that all tractors when they go back will damage all mower and tailwheels all of the time. That's why i have issue with the statement. It is broad.. and not qualified or conditional in any way that i can see, looking at it as a logical statement... it would be easy to chart that on a truth table and see how it turns out with the if/then concept....

have a nice one.

Soundguy

 

[dfkrug]

Respectfully.. you have not kept your statments confined to those parameters. You statements were indeed broad. When you stated that when a tractor comes up, the mower frame or tail wheel will bend. If you only meant to consider the single tractor an mower at hand you should have made that a conditional statement. The way your statement literally reads is that all tractors when they go back will damage all mower and tailwheels all of the time. That's why i have issue with the statement. It is broad.. and not qualified or conditional in any way that i can see, looking at it as a logical statement... it would be easy to chart that on a truth table and see how it turns out with the if/then concept....

Soundguy, I have kept my responses within the context of this particular
discussion. Sorry you feel I was talking about ALL situations.

Often, in dialog, people will state opinions without saying "in my
opinion", and make predictions about things without added qualifiers.
We all do it. Usually the context guides the listener to know what the
speaker means.

 

[Snatchface]

I would like to take this opportunity to remind everyone that while there may be strong arguments to the contrary, kicking kittens is rarely of any long lasting benefit and may result in a painful scratch. Furthermore this action is not sanctioned by PETA or any other morally responsible agencies.

 

[JRobyn]

Amen!

 

[Erik Graham]

Interesting thread on top links. I will be picking up my Kubota 7100 soon and will have to consider a few well made points here. Currently, I have a '53 ford Jubilee that I use with 5 foot bush hog. Interestingly, the Ford has an extremely robust spring that sits between the top anchor point of the top link and the top of the differential housing. I think the theory is that if the top link is subjected to a sudden shock the spring absorbs that force and disapates it into the spring, leaving the top link intact. I think the modern tractor engineers could learn something from the old duffers instead of counting their coins made on selling replacement top links. My top link is about 35 years old and works as well as the day it was made.

Cheers, Erik

 

[Soundguy]

The spring on the old fords had more to do with draft sensing.. however it did cushion shock loads.. but that was more to protect the delicate hyd linkages under the top cover connected to the control / unloading valves..... not to protect the toplink.

Soundugy

 

[Shantycoke]

I would like to take this opportunity to remind everyone that while there may be strong arguments to the contrary, kicking kittens is rarely of any long lasting benefit and may result in a painful scratch. Furthermore this action is not sanctioned by PETA or any other morally responsible agencies.

Soooo.... I can't kick a kitten, or is that just your opinion. As far as the painful scratch, that's speculation, and it sounds like you're talking from experience. Maybe I should have my barn cats declawed if there ever would be an event that a good kicking would be in order. Or, I could just throw a pillow at the cat from a distance, thereby reducing the chance of getting scratched, avoiding the vet bill for the declawing, and hopefully the folks at PETA wouldn't have anything to complain about. (as if I care).
Anyhow, I'm gonna go bend my top link again to see what works best.