1991 ranger brake problem

...Liked the idea of a Rokon two-wheel drive motorcycle but nearly had heart failure when viewing the price. It's even doubled since I last looked😬 Still think it would work great. Could have carried it on rear of the truck using a hitch mount. Though can't fathom leaving it unattended anywhere with that kinda price tag...

---------------------------- Although Rokons are made nearby I've never seen one on the trails. My Suzuki

We practiced the stunts of Trials competitions such as full-lock turns balanced by the throttle, and stopping with feet up. I got as far as climbing over a tree stump.

If the mud was impossible a folding camp saw cut sticks to 'pave' a firmer trail.

The Suzuki was well suited to conditions here, street-legal plus capable of narrow twisting forest trails. It's previous owner had ridden it in California Enduros but I don't think it was powerful enough to be competitive and the trials universal tires limited its sand, mud and snow traction. It was fine for exploring.

Had a Suzuki TS-250 as a teen with a bit worn 4.50 knobby on the back. Tried/did a lot of stupid stuff with it back then...

I could blast through really mushy spots but if you slowed down for any reason you'd be stuck.

With a Rokon you can walk along side and finesse them over unrideable terrain like logs and such which blocked areas I wanted to get to in the UP. I was never talented enough to do stuff like I've seen in Trials Comps with the Suzuki...

Had a Suzuki TS-250 as a teen with a bit worn 4.50 knobby on the back. Tried/did a lot of stupid stuff with it back then...

I could blast through really mushy spots but if you slowed down for any reason you'd be stuck.

With a Rokon you can walk along side and finesse them over unrideable terrain like logs and such which blocked areas I wanted to get to in the UP. I was never talented enough to do stuff like I've seen in Trials Comps with the Suzuki...

Leon Fisk

-------------------------------- I didn't have the balance or coordination for much of what I tried to learn. I put a lot of effort into some, like walking on a railroad rail to improve my balance. I could ride and slide a motorcycle on ice, but not nearly well enough to race.

I think I mentioned it in another thread. Pickup trucks (classic bath tub bed and std cab on a frame) are usually not very good unless they have a load in the bed. A 2wd open diff pickup would not be my choice either that being said from 2001-2017 all my new service trucks were 2WD with auto locking diffs. (Chevy work trucks) With the normal load of tools, wire, and hardware they were "okay." I did not unload them to go hunting for instance. As long as I stuck to the main trails until I bailed out to walk I didn't even think about it.

Of course tires make a big difference. When I ran trap lines back in the 80s I used a Ford F150 2WD with stock diff and 31 x 10.5 tires. With all my traps, coolers, and camp gear it did quite well. If I remembered to air down all four) it was passable on most sand, but it would still sink in bottomless sugar sand. I got it stuck a couple times, but always got it out on my own. Sometimes it took all day, but that is the life of a wannabe professional outdoorsman. Okay, my first year I used a Plymouth Volare station wagon. LOL I think if it had the same tires it would have been better than the pickup.

I think I mentioned it in another thread. Pickup trucks (classic bath tub bed and std cab on a frame) are usually not very good unless they have a load in the bed. A 2wd open diff pickup would not be my choice either that being said from 2001-2017 all my new service trucks were 2WD with auto locking diffs. (Chevy work trucks) With the normal load of tools, wire, and hardware they were "okay." I did not unload them to go hunting for instance. As long as I stuck to the main trails until I bailed out to walk I didn't even think about it.

Of course tires make a big difference. When I ran trap lines back in the 80s I used a Ford F150 2WD with stock diff and 31 x 10.5 tires. With all my traps, coolers, and camp gear it did quite well. If I remembered to air down all four) it was passable on most sand, but it would still sink in bottomless sugar sand. I got it stuck a couple times, but always got it out on my own. Sometimes it took all day, but that is the life of a wannabe professional outdoorsman. Okay, my first year I used a Plymouth Volare station wagon. LOL I think if it had the same tires it would have been better than the pickup.

Bob La Londe

------------------------------ Ramblers did well in the Baja 500.

That definitely applied to my Ranger in 2WD. It was better in 4WD. If I could get in somewhere with the bed empty I was sure to be able to get out with a load of firewood. Only dirt bike skid recovery reflexes let me drive the Ranger in 2WD on partly dry, partly icy pavement. A particularly difficult icy commute home helped convince me to buy the AWD CRV which was vastly better with (and good without) sticky hydrophilic Michelin Arctic Alpine ice tires. A wet finger rubbed on most tires slides, on the Michelins it grabs and squeaks.

Generally the only complaint I hear about Michelin tires is the price. When I picked up my new truck I was actually a little disappointed to see it came with Michelin truck tires. Now I'll have to wait a few years to wear them out so I can upgrade to some ATs. I'm just to cheap to replace otherwise perfectly good tires.

Virtually every Michelin tire I have owned has had the sidewalls checker and crack long before the tread wore out - and that goes back to early 1960s? Michelin X tires and up to my last xlts. I've never wore one out - - - - and they have hardened up to the point they would have made good "burnout tires" even on a 4 or 6 cyl vehicle. Yes, they all lasted over 6 years - but on many that was less than

Virtually all tires have one major weakness. They degrade with exposure to the C02 in the air. Buna (neoprene) rubber o-rings too. Buna-N, Viton, and silicone much less so.

I thought it was exposure to sunlight/UV that caused most of the sidewall degradation ... or are those aftermarket tire covers (in particular for RV's and campers) just another scam ?

Yeah I don't know for sure. UV is certainly capable of damaging a lot of things. I do know CO2 is an issue with some rubbers. I was told by... well somebody... that tires were among them.

Yeah I don't know for sure. UV is certainly capable of damaging a lot of things. I do know CO2 is an issue with some rubbers. I was told by... well somebody... that tires were among them.

I don't have the problem on my Nokians, didn't have on my Dunlops, or my Coopers. My BFGs and Uniroyals were not as bad as the Michelins but darn close. The Uniroyals were the only ones I wore out -less than

It's not Co2 - it's OZONE - which is produced by sunlight acting on oxygen. This brakes down polymers with dual bonds. Some rubbers are a LOT more succeptible to Ozone damage than others.

Nobody likes to be wrong, so I did some look ups.

CO2 is said to contribute to the breakdown of rubber on several sites. Some say "distressed" CO2 and others just generically say CO2. O3 also contributes to the break down of rubbers and is more reactive. Then I looked at concentrations per a few other references. They say CO2 is present at ground level from 300 to 900 PPM (million) where as O3 is typically present at 20-30 PPB (billion).

As to whether the difference in available molecules makes a real difference in which has more net affect I do not know, but the numbers do make you think.

I recall now where I first ran across the reference to CO2 and its reactivity with rubbers. I don't recall exactly who it was (could have been Bob Sterne), but it was in regards to tuning, building, and repairing airguns. Admittedly air can be quite distressed in a spring piston gun generating enough sudden compression to detonate oils or in a PCP gun where air can be stored at pressures as high as 4500PSI. Over

I'm not saying I was right and you were wrong. Not at all. I could very well be wrong still. My "expertise" with material science is limited to rote memory and blue collar experience. I'm just stating it might not be as cut and dried as as it seems. I would argue in full on flat Earther fashion... "Nothing is ever totally settled science." LOL.

Nobody likes to be wrong, so I did some look ups.

CO2 is said to contribute to the breakdown of rubber on several sites. Some say "distressed" CO2 and others just generically say CO2. O3 also contributes to the break down of rubbers and is more reactive. Then I looked at concentrations per a few other references. They say CO2 is present at ground level from 300 to 900 PPM (million) where as O3 is typically present at 20-30 PPB (billion).

As to whether the difference in available molecules makes a real difference in which has more net affect I do not know, but the numbers do make you think.

I recall now where I first ran across the reference to CO2 and its reactivity with rubbers. I don't recall exactly who it was (could have been Bob Sterne), but it was in regards to tuning, building, and repairing airguns. Admittedly air can be quite distressed in a spring piston gun generating enough sudden compression to detonate oils or in a PCP gun where air can be stored at pressures as high as 4500PSI. Over

I'm not saying I was right and you were wrong. Not at all. I could very well be wrong still. My "expertise" with material science is limited to rote memory and blue collar experience. I'm just stating it might not be as cut and dried as as it seems. I would argue in full on flat Earther fashion... "Nothing is ever totally settled science." LOL. Bob La Londe

--------------------------------

While researching I saw some mentions of CO2 damage too, mainly with high pressure gaseous and liquid CO2. It may have been physical rather than chemical damage from absorbed gas and rapid pressure changes, in oil well instruments. I didn't see any for atmospheric pressure on tires. I'm burning through my monthly 10GB data allotment too fast to do more research on it.

From Wiki

iny traces of ozone in the air will attack double bonds in rubber chains, with natural rubber, polybutadiene, styrene-butadiene rubber and nitrile rubber being most sensitive to degradation.[1] Every repeat unit in the first three materials has a double bond, so every unit can be degraded by ozone. Nitrile rubber is a copolymer of butadiene and acrylonitrile units, but the proportion of acrylonitrile is usually lower than butadiene, so attack occurs. Butyl rubber is more resistant but still has a small number of double bonds in its chains, so attack is possible. Exposed surfaces are attacked first, the density of cracks varying with ozone gas concentration. The higher the concentration, the greater the number of cracks formed.

Ozone-resistant elastomers include EPDM, fluoroelastomers like Viton and polychloroprene rubbers like Neoprene. Attack is less likely because double bonds form a very small proportion of the chains, and with the latter, the chlorination reduces the electron density in the double bonds, therefore lowering their propensity to react with ozone. Silicone rubber, Hypalon and polyurethanes are also ozone-resistant. Form of cracking Macrophotograph of ozone cracking in NBR (Nitrile Butadiene Rubber) diaphragm seal

Ozone cracks form in products under tension, but the critical strain is very small. The cracks are always oriented at right angles to the strain axis, so will form around the circumference in a rubber tube bent over. Such cracks are very dangerous when they occur in fuel pipes because the cracks will grow from the outside exposed surfaces into the bore of the pipe, so fuel leakage and fire may follow. Seals are also susceptible to attack, such as diaphragm seals in air lines. Such seals are often critical for the operation of pneumatic controls, and if a crack penetrates the seal, all functions of the system can be lost. Nitrile rubber seals are commonly used in pneumatic systems because of its oil resistance. However, if ozone gas is present, cracking will occur in the seals unless preventative measures are taken. Ozone attack will occur at the most sensitive zones in a seal, especially sharp corners where the strain is greatest when the seal is flexing in use. The corners represent stress concentrations, so the tension is at a maximum when the diaphragm of the seal is bent under air pressure.

The reaction occurring between double bonds and ozone is known as ozonolysis when one molecule of the gas reacts with the double bond: A generalized scheme of ozonolysis

The immediate result is formation of an ozonide, which then decomposes rapidly so that the double bond is cleaved. This is the critical step in chain breakage when polymers are attacked. The strength of polymers depends on the chain molecular weight or degree of polymerization, the higher the chain length, the greater the mechanical strength (such as tensile strength). By cleaving the chain, the molecular weight drops rapidly and there comes a point when it has little strength whatsoever, and a crack forms. Further attack occurs in the freshly exposed crack surfaces and the crack grows steadily until it completes a circuit and the product separates or fails. In the case of a seal or a tube, failure occurs when the wall of the device is penetrated.

The carbonyl end groups which are formed are usually aldehydes or ketones, which can oxidise further to carboxylic acids. The net result is a high concentration of elemental oxygen on the crack surfaces, which can be detected using energy-dispersive X-ray spectroscopy in the environmental SEM, or ESEM. The spectrum at left shows the high oxygen peak compared with a constant sulfur peak.

I have no idea what "distressed" CO2 is, but CO2 dissolves in tyre rubber, kind-of. It seeps into spaces between the molecules in the rubber, and can seep through the rubber. This doesn't normally do much damage to the rubber, but because of this seepage a tyre filled with CO2 will deflate quicker than a tyre filled with air.

That said, rubber in high pressure CO2 will absorb more CO2 - and if the pressure is suddenly released, as in a CO2 gun, the CO2 can bubble out, damaging the rubber, perhaps severely.

Another thing CO2 does is actually react with rubber, which can cause damage. However the amount of CO2 in normal air isn't likely to do much harm to car tyres - the normal oxygen in air will probably do more damage, long term - but it could well damage rubber in CO2 guns and airguns.

An aside, people put lampblack (carbon) in rubber for several reasons, but a major one is to slow the reaction with oxygen in the air. The oxygen still reacts, but (somewhere between greatly simplified and lies-to-children) reacts with the lampblack instead of the rubber... producing CO2, which permeates out to the atmosphere... But overall, the rubber lasts longer.

Rubber should not be used to seal CO2 long-term, especially under high pressure.

UV and O3 are very different animals!! Both will aggressively attack rubber. And almost anything else, including humans.

Peter Fairbrother

The carbonyl [C=O] end groups which are formed are usually aldehydes or ketones, which can oxidise further to carboxylic acids. The net result is a high concentration of elemental oxygen on the crack surfaces, which can be detected using energy-dispersive X-ray spectroscopy in the environmental SEM, or ESEM. The spectrum at left shows the high oxygen peak compared with a constant sulfur peak.

--------------------------------- That's slightly wrong like much of Wiki. Aldehyde implies an oxygen at the end but a ketone has oxygen hanging off in the middle. Chemistry is too complex for simple explanations. My 4 year degree in it qualified me only to understand further education which the Vietnam draft prevented, though the knowledge of matter, energy and quantum mechanics gave me a boost into other fields like semiconductor physics.

Sulfur is mixed into raw rubber to react with the C=C sites, but with different consequences, being less aggressive than its cousin oxygen it hardens and stabilizes, "vulcanizes", the rubber instead of enabling further degradation. It's the reason burning rubber smells bad.

Linseed and other "unsaturated" (double-bonded, -C=C-) plant-based oils cross-link and harden in air by a similar process. The fire hazard from a covered waste can of oily rags was caused by the feedback loop of oxidation releases heat and heat speeds further oxidation. The mineral oils that replaced them in machining have fewer double bonds and don't heat up. "Paraffin" is from Latin "parum affinitas" and means low reactivity.

Nobody likes to be wrong, so I did some look ups.

CO2 is said to contribute to the breakdown of rubber on several sites.

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You weren't wrong, we found confirmation, but the breakdown appears to be from physical expansion and tearing from absorbed CO2 expanding when high pressure is released, instead of chemical attack like ozone.