alancoles
Dress for fall & avoid it
I take offense to baseless assertions. If they were founded on anything factual that would be different, but they don't appear to be. As for your quote above, it doesn't actually appear from anyone who tried to be of help to you.
No one here was rude enough to suggest that your question didn't warrant a polite response, even though you failed completely to provide any of the basic information/parameters needed to provide a compete answer (bike make and model, tire manufacturer and model, etc., etc.). Instead, everyone tried to answer your question politely and you have the nerve to state "you are insulting not only my intelligence, but also your own" and then sugggest we (or me) are being "ludicrous and somewhat naïve"!!! That is so rich that it stands on its own with no response necessary.
Reagarding the article you quoted, you may have misread it. It supports what I said.
My passing mention of no issues raising alarm bells from driving in the Middle East was, as stated, to provide the perspective that ambient temperatures were not typically an issue. If you prefer to ignore information, that's your problem, but sticking one's head in the proverbial sand never enlightened anyone as far as I know.
I'm not sure how you missed my advice.
If those are your news sources than you definitely should think about expanding your horizons. If you actually read my post you would have recognized that I was absolutely not saying anything of the sort. You are completely misunderstanding what is being written here by people trying to help you.
What I said was basically that you should be more concerned about the cause of the temperatures which is most often under-inflation. Barring that, you would then look to the next (but distant) most likely issues of overloading the bike, prolonged speeds above the tire's speed rating, an issue with dragging brake pads or a bad wheel bearing.
As I, and others have said, that is information that the manufacturer has call them.
Kent, under-inflation accounts for approx. 90% according to studies of any size and professionalism.
My only addition to what you wrote would be that most everyone misunderstands tires, tire-pressure, proper diagnosis, and proper adjustment. It can be almost worse than an oil thread. One of these misunderstandings is the manufacturer's "Maximum PSI" on the sidewall refers to Maximum Cold PSI only. In case someone misconstrues what you said, it does not refer to hot PSI, it refers to Cold PSI settings. Outside special conditions (racing, off-road, etc.) one should not take hot PSI into consideration for private street vehicles.
Paul and other mentioned TPMS that take temperature into account and have alarms. As mentioned, these have mostly been removed from sale for private road-going vehicles and are mostly used for off-road, commercial or tractor-trailers. For the tractor-trailers, this is so that they can have extra warnings regarding tires that are often re-treads and that can't always identify a wheel bearing issue on the inside front wheel of the four tires on the rear of the cab. That and other specialized factors make temperature readings very helpful. But for the average Joe with little to medium tire knowledge, it can be as misleading as an accurate oil temperature gauge. There is a very good reason why most street-going cars and bikes have significant dampening on their oil temperature gauges. This moves the gauge to the centre quicker than it should and keeps it there rather than allowing it to fluctuate so that the dealerships aren't constantly hampered with customers unfounded concerns over things they really don't understand. Very much like the hundreds of LC Boxer water-pumps needlessly replaced (some did need replacing) because they wept. This was a natural function of that bearing and actually a necessary one. BMW has fixed the issue by placing a tube (a sponge or wick tube in some cases) in the crankcase so that the coolant isn't seen to weep and simply evaporates.
Mike, if your cold PSI is correct, you aren't overloaded and aren't riding for continued periods above their speed-rating, I really would not worry about tire temps, especially with a quality top-tier tire like the SmartIII. I have not run the SmartIII so don't know where they are "happiest", but you can't go wrong with the using the bike owners manual PSI recommendation. Some tires will do a little better adding 1-2 PSI above that, but that is too specific for here.
Paul has hit the nail on the head, Although, I would venture to say that if the cold-tire pressure were taken the next morning it would likely read in the low-mid 20's and possibly lower still. I'll explain at the end.
Paul has also identified where you, Wethead, and to be fair, many others make their worst mistakes.
You say you want empirical data, but completely ignore the empirical data you have at hand. Every passenger car, motorcycle and passenger tire manufacturer specifically states:
- only read your tire pressures when they are cold
- never remove air from a hot tire
This has, like I said, the horrible potential to become akin to an oil thread, but I'd like to set a few parameters down so that folks can get a better idea of what they should be looking at and concerning themselves about.
- Ambient temperature has very little effect on healthy, properly loaded and inflated tires run within the parameters set out on their sidewalls
- Underinflation is the biggest cause of tire failure by a factor of 10x compared to all others combined. The next biggest is overloading.
- Tire temperature is the result of load/PSI/speed/ambient-temperature (ambient-temperature is the smallest factor in generating "high" tire temperatures)
- If a healthy, properly operated tire shows too much pressure gain (Hot vs Cold) then the cause is virtually always under-inflation
- If a healthy, properly operated tire shows too little pressure gain (Hot vs Cold) then the cause is virtually always over-inflation
- High-performance motorcycle street tires don't give their best traction until the are at ~200ºF
When I was racing cars nationally (my BMW M3 took two National Class titles) we spent a lot of time maximizing the performance of the tires. Michelin was one of my sponsors and we took the first National Title for them with one of their brand new performance street tires.
On the race track, we would use a $400 Longacre Probe Pyrometer to measure tire temperatures.
- If we were below our desired temperature range we would remove air
- If we were above our desired temperature range we would add air
Note: Removing air from a hot tire is not recommended ever for the street. It should only be done for track situations where you have proper baselines logged, are using professional and calibrated equipment to measure things and have a thorough understanding of tire technology.
Someone mentioned seeing truck tire pressures never varying more than 3-4 PSI. I'd venture to say that you were just on the side of being slightly over-inflated and likely saw very good wear with just a bit quicker wear in the centre of the tire vs the edges. Could be wrong as there are tons of variables there but "typically" you would want to see an increase of 50%-to-double that for a truck tire between cold and hot. A change of 3-5 PSI is more common for a motorcycle tire.
YMMV ;-)
