chain strain

[john swenson]

just curious, is it more stress on the rear chains if you remove the front ones when running tracks. some say it helps eleviate chain windup. how about turning also ? i'm sure some of it depends on the terrain deep mud, snow ... i removed the front ones just to see the difference.... on the max 2 not sure i can tell. johnboy va.

[amphibious drew]

John,
From what I've read and discussed, chain windup is more prevalent in rubber tracks due to the coefficient of friction they have. On Adair tracks, the tires can slip easier in the track and does not really require tuners or front chains removed.

[msafi65]

I was advised by the factory years ago to remove front chains on rubber track vehicles. In testing the vehicles had slightly higher top speed without. Having done so with several vehicles I notice less rolling drag. The vehicle seams to roll to a stop a bit slower. Having measured a lot of tires it isn't uncommon to see 3" difference in circumference in a set of atv tires. Anything you do to help eliminate the chain bind caused unequal tire size means less drag. If you happen to be one of the lucky few that has a really uniform set of tires, the difference may not be noticable.

[john swenson]

thanks guys, also when the chains do windup is that when at some point you hear a popping snap sound ? is that the chain readjusting ? j.b.

[john swenson]

drove around awhile thru the woods, seems to turn as well with the front chains removed, plenty of power, etc. when i pull into a deep mudhole with the whole machine (sticky gooey mud ) and stop... then start to climb out which takes alot of torque and power, thats when i hear the chains pop some. have you experienced that under the same heavy load conditions ? thanks again. johnboy va.

[Buzz]

jb, that popping happens frequently when a chain sees the highest amount of slack that is possible..on one side (a heavy load condition where the other side is ultra-loaded and tight). The slack droops down (hinges) into the upward-rotating face of the sprocket (I'm talking about the front chains in this instance) instead of travelling straight forward and over the the top of the sprocket. This will happen up to a point...then the rotating sprocket forces the "hinged" or "kinked" or "binded" link around to the top of the sprocket, and you get a sudden "pop" as things straighten out again. Problem is-it will continue to happen under heavy-load conditions and gets worse as your chain stretches more and gets more loose. Shorter chains and especially chains w/o tensioners are the worst. It's almost always the front chains because the top side is the slack side and allows this drooping/binding of chain links (because of gravity) to happen.
It happens both when running tracks and with tracks removed. It's heavy load conditions and loose chains that cause the problem. Climbing hills and turning is the worst. It gets your attention for sure

[Buzz]

Your track will drive most reliably if you have both corner axles turning. The centers contribute very little in the way of driving the track. If you drop a corner axle from driving, you are far less capable under heavy load, especially if you encounter a condition where the inside of your track gets wet, muddy, icy, or especially if your track gets loose. The term wind-up doesn't typically describe "popping" experienced with loose chains and the loads seen when driving your machine. That's normal chain stretch and wear and happens eventually even when running w/o tracks and can still happen when running track tuners when a front chain gets loose. I think of wind-up as resistance to tires turning. Some tires act like brakes on the drive system. They all transfer power to one another. The tire treads will never cover the same amount of distance, so some are always going to act like "brakes" because they are connected to the others. The best you can do is position them properly so that you don't over-load the tensioner side of the chain..in the forward direction as that's 90-99% of what you do. You'll always have to give up some horsepower to slipping at least (1) tire (usually the rear) just a little...even if track tuners are used. Some tracks moreso than others. Take care and Merry Christmas!

[john swenson]

thanks buzz, great explaining. seems like i never heard of anyone else mentioning their chains popping from time to time. i realize too that if just the rear and center tire are driving, in slippery situations as you said you may get less grab on the track. adairs compared to ''rubber style '' are smoother. i know when i was at busco in some deep slippery mud and was hardly moving, it was just the tires spinning in the tracks. also because i have the exsposed chains on my '' highboy '' design, things may be alittle more pronounced. those floating tensioners though really work well. with a tensioner block on both top and bottom of the chain, the '' hourglass'' shape gives alittle more bite on each sprocket. as you said when you hear that sound you go ''oh no'', but nothing has broken or bent at all. and it's just once in awhile. thanks again and merry christmas to you and your family. p.s. i can't wait for some snow !! j.b.

[Noel Woods]

John, post some detailed photos of your set up. I saw in the gallery some pics but would love to see detailed photos.

[john swenson]

o.k. noel, i am getting ready to remove the tracks so i will take some pictures soon. johnboy va.

[john swenson]

buzz, i'm still thinking about your great explanation above on chain windup, etc. couple of more questions. even if front chains were removed, you still have 2 wheels that are connected with the chain. so as you said, if windup is more about one tire maybe being a brake due to different rotation speed at some point.. the windup can still occur and will then release and you get the chain noise.... correct ? it does sound on mine more like a bind letting loose than a pop. it never seems to occur when just driving along the road. only under load such as when i was driving thru deep snow this afternoon. also, you said in your explanation that the best you can do is position them so you don't overload the tensioner side of the chain. what does '' position them'' mean. ( all this is when my adairs are on ) never seems to happen with just the tires... thanks again, i enjoy learning more. johnboy va.

[Buzz]

j.b. without being there, you might have a chain that gets slack on one side under high load. It might be the root cause of what's happening around the sprocket. Of course, I'm just sitting here pretending to know your machine

I consider "wind-up" a situation where certain tires are not rotating at the correct speed that their driven chain wants them to rotate. It can become a power-suck(resistance) to overcome or in some cases an "undesired" early rotation. Wind-up if not managed can make even easy driving situations a power suck. And, it's additional load on chains, bearings, axles, and tensioners.

By position the tires correctly I mean index them to ensure that most of the tires will "overdrive" the track (ever so slightly in the case of some tracks, moreso with others, but it holds true for all styles), as opposed to positioning them incorrectly which can cause the track to "overdrive" the desired chain-driven tire speed on many of the tires. A large tire positioned on the front for instance will give a slightly faster track speed, but this faster moving track will now move under the center tire(s) FASTER that the chains on the inside are attempting to drive those tires. These tires will then be forced to rotate from a belt/pulley effect because of contact friction from the track...not from proper power transfer via the chains. The tensioner side of the chain can end up seeing a tremendous load in the forward direction (which is most of what you do)...this is the opposite of what you want. A similar thing happens in reverse even with correct tire-indexing, but we just live with it because the use of reverse is far less frequent.
Fixed-position tensioners are affected more than a floating style tensioner. Anytime a chain sees a very high load, the maximum amount of slack will manifest itself on one side. This can happen with or without tracks, but this high load will be seen whenever your machine is working very hard to turn the tires (steep climbs, plowing snow). Without tracks installed the tires can frequently slip or spin-out on the ground when high loads are encountered (a situation where you are limited by traction). On the other hand, if your tires have excellent bite or you have tracks installed, the tires can see a much higher resistance to turning before they 1)slip or 2) rotate and the machine drives forward (this is especially true of corner-axle tires with tracks installed. When you push the machine harder, you tension up one side of the chain to the max, and the slack manifests (to the max) on the opposite side. Depending on your tensioner's ability to remove slack (sometimes the tensioner is maxed out and chain is still loose), the chain can droop down instead of going straight over/under the top or bottom of a sprocket. A link binds up and sticks momentarily then suddenly releases. Not good. Our machines have plenty of power and the gearing to make things rotate, so this can and will happen, especially as chains get higher time and stretch.

Proper indexing will protect some tensioner styles and will keep the correct side of the chains tensioned in the forward direction.
There are a few other things that can be tweaked to reduce load and reduce side effects, but that starts to get more specific as to individual machine and track needs.
We have to keep some of the axles driving for best performance (corners are best). Tuners help on the centers. Some axles don't have tensioners or have floating tensioners which are more forgiving to some of this.

Hope that helps! I'll try to help more if needed
Are your tires indexed in any way at the moment? I'm also curious about your machine and tensioner type/location if non-stock.

[john swenson]

thanks buzz .. first of all why i keep pursuing this is to find out if the '' chain noise'' from time to time'' is due to what we are talking about or is it a different issue on my max 2. they are the adair tracks with the kenda dominator tires which are not a aggressive tread. i will remove a track and the 3 wheels in the next few days and take some pictures of the chains and tensioners. that will maybe help your ideas. also because of the custom design i did, maybe i created a different problem. running at busco last oct. the machine did great. only a few times did i hear the chains in deep mud. i just have never ridded in anyone elses machine and heard the same, but maybe it is more common than i thought. nothing ever seems to break or snap. also i have'nt indexed the tires which i assume means measure circumfrences and air up as needed ? would like to try that if you don't mind explaining that procedure again. and yes, always thought it would be nice if guys were closer to help each other figure stuff out. j.b.

[Noel Woods]

John are you having issues with the set of chains inside the tub, or is it your chains on the exterior track system?

[john swenson]

you know i'm not sure what it is. little frustrating in trying to zero in on it. i'm not sure it's chain windup, but ...? it may be something to do with my subframe design. that's why i am going to take some detailed pictures and maybe we can approach it as a '' custom design'' and then see some other possibilities if you guys are game. . the only chains in the tub are the t 20 chains going to the jackshaft and the jackshaft chains down to the center axle. outside the tub the center axle has a #60 sprocket that drives the center axle on the subframe and then a # 60 chain running to the front and rear axles. tensioners are on the slack side of the chains. the outside drive chain that drives the center subframe axle is tightened by raising the tub and the inside frame. ( pictures will help ) . i just took a ride in the snow. drove maybe 50 yrds. no noise and then it started. ( off and on ) . once i started down our gravel lane, no snow, drove a good ways then back home and never heard a thing. so it does seem to only occur under load or maybe because the chains are exsposed, snow gets inbetween chain and sprockets and is getting '' crunched ''. i have some other ideas we can address once pictures are posted. i know there is a answer, hope you guys can explore the answer. thanks j.b.