Rear tire cracking

[moonwalker]

So I guess I should replace my back tire... 
Those are some pretty substantial cracks in the side wall, they aren't particularly deep but go most of the way round.
I've only had them about 3 years and have done maybe 4000 miles on them, and there's loads of tread (don't use the bike that often).

Its a Pirelli Speed Demon 140. Are these known for cracking? I remember when it was installed I had to go back to the garage as it was leaking air, they told me it was a difficult to seat properly because of rust in the rim. Should I replace with the 130 next time? I know the 140 can fit on the GS500F, but if the rim isn't in perfect condition maybe it would be safer to go back to stock size 130. I just like the wider look the 140 gives, even if its only an extra 10mm! Also it may be no different but psychologically a 140 tire gives me more confidence with leaning.

Final Q - should I replace front tire same time as replacing this rear? It was installed at the same time and is also a Speed Demon but is in much better condition without the cracking.
Cheers all.

   

[Suzuki Stevo]

They may have been old when you bought them?
Alloy rims don't rust, so how old are the tires?

http://www.chaparral-racing.com/blog/2013/01/16/tech-tips-read-motorcycle-tire-date-codes/

[fetor56]

Danger Will Robinson.
It would help if u had your purchase receipt so u could go to the garage(then Pirelli if necessary) and explain your situation.This garage must have a receipt copy.
3 years/4000 mls with that tread felt is bad value for money;dangerous for continued riding.
What tire pressure do u run?

[lucas]

Yeah the tire might have been several years old when you bought it or perhaps just a manufacturing defect.

If you bought it from a decent place they might replace it for you.

[Big Rich]

After following all the above advice (and I'll add that your tire should definitely be replace), definitely contact the manufacturer. Generally, a tire manufacturer really likes to be aware of one of there tires failing with unknown causes. Not only for your (and our) safety, but for their standards not being met. But be sure to have all kinds of info handy in case they ask - date of purchase and location, date stamp on tire, miles on tire, load weight, general riding temps, etc, etc, etc, etc...

[moonwalker]

They may have been old when you bought them?
Alloy rims don't rust, so how old are the tires?

Thanks for the replies all, helpful. So after following your tips I've found the date stamp and its 3510, i.e. August 2010, so I suppose the tire was sitting with the retailer for 2 and a bit years, to account for the fact it is approaching the 6 year life mark. On that time scale maybe the cracks are not that out of the ordinary  but it is disappointing given how good condition the tread is in 

Interestingly the tire also looks to have been manufactured in Brazil and says for US use only on it - I bought it from oponeo.co.uk, who are a European (polish) online retailer - they've got generally favourable reviews and have done a lot of business, but clearly there's a reason their prices are the best... I won't waste my time trying to get any sort of compensation from them!

Disappointing to have to discard the tire when the tread wear is so minimal but I definitely won't be taking any more chances and will get some new tires in.
I didn't check the front tire yet but if its the same date stamp I'll just replace that too in spite of it looking in near perfect condition.

Thanks again folks

[moonwalker]

Danger Will Robinson.
It would help if u had your purchase receipt so u could go to the garage(then Pirelli if necessary) and explain your situation.This garage must have a receipt copy.
3 years/4000 mls with that tread felt is bad value for money;dangerous for continued riding.
What tire pressure do u run?

Tire pressure was 36 psi on the back - the same as the stock tire. It's never had much of a heavy load on it, only very occasionally had a pillion rider.