Time for new tires?

[bkhan]

Hi folks,

I want to ask about the state of my tires. I bought a GS500 two years ago and it had to sit until this spring when i finally got around to rebuilding the carbs. The bike runs great, but I have no idea how old the tires are. There is plenty of tread left. I rode it a bunch this summer, but the previous owner didn't ride it that often. I'm asking specifically because the weather is changing here in New England and I'm trying to ride it as deep into winter as possible. Last weekend, on a completely dry piece of road, going at a moderate speed around a corner I've taken at that speed a million times, my bike lost traction and slid out from underneath me. I'm basically fine other than a bad scrape that's still healing, but I'm nervous my tires' age may have led to this and I want advice whether this was because of the combination of old tires and cold weather.

What do you think? If I'm going to make it through to December (January if it snows late into the season), do I need new tires?

Khan

[DoD#i]

Take pictures. If you get nice, sharp, in-focus pictures of the code numbers molded into the tire, someone can probably tell you how old your tires are, or you can look up tire codes and figure out for yourself. We'd also be able to see if they had any signs of cracking or dry-rot. Replacing them is probably a good idea, but won't be a magic solution to all issues.

There are many reasons you could slide out on a corner you've taken many times. Colder weather without proper adjustment of riding technique for colder weather is one - tires stick less in the cold, and don't heat up as much when ridden in the cold. As such, less extreme lean angles are needed to maintain control. This will be true even of new tires, and you won't (as far as I know) find any snow tires for motorcycles with special cold-weather-sticky rubber.

Oil, anti-freeze, sand, leaves, etc. on the road surface can also cause you to slide out. If we skip over the first two since you said "completely dry" that still leaves at least a couple of options.

[Gary856]

Lots of unknowns to us:

Year of the bike? Your riding experience? Brand/model of the tires? Tire pressure? Type of road (pavement type, camber, uphill/downhill, left/right turn)? Cleanliness of road surface? Ambient temperature? Other factors involved in the crash? Time of the day and visibility? etc...

Date code on the tire sidewall would tell you the date of manufacture. Unless you were going balls out in the corner on 10-year old tires, I dobubt it was just the tires that caused the crash.

[bassman]

Just how cold was it the day you lost the bike?  Here in the UK the days are getting really short now and the road surface is geting colder and colder.  There is very little traction when the tarmac gets cold and it can get very slippery very quickly when the dew starts forming.  Black ice is a very real problem and can form very quickly even when the air temperature doesn't seem too cold.  I've got a brand new Bridgestone front tyre in the cupboard because I was convinced that I had a slow puncture.  I was riding home from work  one evening last winter and I could feel the bike describing slow lazy 'S's as I rode along.  Very disconcerting!  I pulled over several times and could find nothing wrong.  I thought I might have a slow puncture but when the weather warmed up for a few days the problem went away.  I've experienced this lots of times and so I know to take it easy.  You've just got to be extra cautious when venturing out in cool/cold weather.

That said, sorry that you had a spill.  Hope your better soon and don't let it put you off riding!

Bassman

[bkhan]

Thanks. I'll try to get pictures up soon, but I tend to leave the digital camera in my classroom since I use it more often to take pictures of my students than I do personally. The day I slid out was one of the colder days we've had here in CT so far and I'd guess it was about low 40s or upper 30s. The tires must have been pretty cold, I was only riding for about ten minutes before hitting the corner. I've been riding for three years, but I usually have the bike put away by the beginning of the school year because I rarely get to ride it this late into the season due to work. However, I'm trying to keep it out on the road as long as possible for the first time, so I'm new to cold-weather riding. I suppose it was too vague a description, but I think I may just settle up for new tires anyway. Better safe than sorry. I probably should have replaced them when I first got the bike, but the tread looked fine and I haven't had any concerns until now.

[gsJack]

Check the DOT number on the tires for date of manufacture.  The last 4 digits of the long number starting with DOT are the week and year of manufacture.  If it was 3705 for example the tire was made the 37th week of 2005. 

[bkhan]

Thanks gsJack. How old is too old? I imagine there's a general rule of thumb for something like that.

Khan

[Roadstergal]

Dirt riding cures traction problems.  Or, at least, makes them less dramatic.

You'll hit the traction limit of any tire, at one time or another, and it's best to have the tools in your mind and body to handle it properly.

[gsJack]

The rule of thumb on bike tire age is quite variable due to the bike usage being so very different for various users.  High milage or low milage users, very spirited riders or those just cruising along or touring, etc. for example.  It doesn't pay to get expensive long life touring tires to ride a couple thousand miles a year since they will be old before they are used up and it gets very expensive to use the short life very sticky supersport tires if you are a high milage user and will need more than a set per season.  It's well worth the expense to some though.

Opinions vary on the max shelf life permitted before they are sold to the user, I don't like to buy new tires that are more than 2 years old now that they can last me a couple years but when I was riding 15-20k miles per year on my 1st GS I rarely had a tire last thru one season.  Most say about 4-5 years max shelf life before sale but some say as much as 6-7 years.  Slower selling sizes can get too old in the dealer's stock.

And there are those that say a motorcycle tire shouldn't even be used after it's 5 years past manufacturing date but I'd go with the 6 or 7 years for that for my usage.  A tire isn't likely going to fail dangerously as much as it will just slowly get harder and loose traction as it gets older and be more likely to cause a mishap that way.  I think tires deteriorate much faster on bikes just sitting in storage than they do in continuous usage.  I bought my first GS a 97 model in 99 that had sat on the showroom floor for 2 years and the tires were dry rotted with small cracks in the sidewalls and in the tread grooves.  I put a quick 8k miles on them in 3 months and then replaced them, I think I'd replace them sooner now though under those conditions.