Is this safe? (bike question)

I could be wrong, but my guess is that it's always been there, as with the rear tire.  However, since a rear tire typically wears faster than a front tire, the "mold seam" (as the previous poster described it) has likely worn/smoothed out faster.  That tire looks like a Bontrager Race Lite.  If you look at the picture of a "new" tire in this link, you will see this seam:  http://bontrager.com/model/00443

Probably nothing to worry about at all.  Maybe rotate the tires once in a while, so that they wear evenly.

Thanks for the responses.

hm, that picture is interesting.  (You are correct in the type of tire.)  But, in looking at my tires again, both front and back, it doesn't seem like it's a seam which has always been there.  The back tire doesn't have it going all the way around, just indication of "dry" (?) cracks in random places.  The back tire looks like it could be getting there in terms of a line around the entire tire.  On closer inspection of the front tire, it *seems* like something that "formed," i.e. not something like in that picture... Also, I would have also thought that the back tire would wear out more quickly which is why I am also confused as to why it seems like the front tire is in "worse" shape...

Could you post a couple of pics of the rear tire (maybe in a few different places)?  Also, IF it is wear, and the back tire doesn't have it around the entire tire, it might be that you've had to hit the brakes hard at some point, and skidded - that would certainly wear a section faster than other areas on the tire.

Or, you could just send a couple of pics to Bontrager Support, and they coud tell you what's really happening to your tires.

Same type of tire, less miles:

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 Well they do claim to have "triple flat protection"!  So I guess I can vouch for that?!  I've never had a flat...

So I guess I'm wondering if this is a disaster waiting to happen??  It would be very awesome if I could just finish off September on these tires, and with winter approaching, I could then figure out what I want to do with the tires/bike.  This bike has a few problems that (I have been thinking) are non-(overly-)problematic so I've just been dealing with it... but now with another, more potentially serious, problem, I might look into a replacement bike...

Thanks for the input!

You're welcome.  I'm going to try that approach with my wife... my tires are worn, so I really need to buy a new bike!  I'll let you know how that goes...

No one can answer that for you based on the pictures.  I'd get a new set of tires myself as my hospitalization insurance deductible would be a lot more than a set of tires

Even if you trade/sell the bike you can always keep the tires and put the old ones on it (just let them know)

Duane

Tires are constructed around a casing that consists of a 'fabric'.  The threads are strong and woven in to a sheet and then rubber is laminated around that casing.  Even if the rubber cracks, the casing is still holding everything together just fine.

I've never known tire tread to just delaminate from the casing (unlike what sometimes happens to car tires).  I have a pair of Michelin PR3s that have been in service for 8 years now.  There is far more cracking in the rubber than on yours.  Yet despite that, I would say it's only cosmetic since they work as well as ever.

The only reason you would retire those tires now would be if the casing is compromised (which it's not).

As for the line appearing....it's certainly possible that the manufacturing process laminates rubber on the tire in layers and that the top layer did not have a molding line here, but the layer immediately under it did.  Again, not problem until you either see threads, or the casing is damaged (which is evidenced by a bulge in the tire).

I think you're tires are OK.  That "seam" is often called "mold flash" and is a result of the way the tire is made.  The mold used to make tires must have two pieces that come apart so you can get the tire out after it is made.  The little gap where the two pieces fit together gets filled with rubber and the result is what you see in the first pic.  Chances are, the rear tire had it too, and you've worn it off.  The other tires you showed probably had it also. 

If in doubt, go to the bike shop and look at a few new tires, and you'll probably see evidence of mold flash on all of them. 

Nothing to worry about IMO.

Looks like there is a fair bit of dry rot cracking in both tires, but all that is going to do is give you flats eventually. I highly doubt the tire is going to catastrophically fail and cause a crash.

I'd finish the season on them then look for something new.