Dumb Tire Question...

[MakoMoto]

Hey everyone!

So...have a question for all of you. I have this 2008 Ninjette, just got it all fixed up over the last month or so (as some of you know from previous posts) and been riding it for a few weeks now. Well, these cracks have appeared on my sidewalls..I am assuming its some dry-rot from being on the concrete in my garage. I know they are older, but they were garage kept and still felt soft and had tread so I have been riding on them. I will be getting a set of Kenda K671's in a couple weeks however. My question is:

Can I ride on these in the meantime? I only will be riding to work and back...about 15 minutes each way at about 50 mph and no cornering needed (straight shot). Will they explode? Catastrophic failure?

[Triple Jim]

You shouldn't base decisions about your safety on others' opinions, but it I were in your situation, and if no cords are showing through the cracks, I'd ride the bike and put new tires on as soon as practical. I'd also be aware that old tires don't have the traction they had when new.

If your gut tells you that you shouldn't ride on those tires, then listen to it.

[jkv45]

That first shot looks pretty bad!

I wouldn't ride on them, but that's me.

The cracks are from the rubber drying-out over time, and don't have anything to do with sitting on concrete.

When deciding if tires are safe to use, always look at the production date. 4 numbers in an oval on the sidewall like "2609". The first two are the week of the year (26th week) the second are the last digits of the year (2009). Anything over 5 years for a cycle tire is considered "old" - no matter how much tread there is or how good the rubber looks. Yours are probably from 2007.

Don't think of needing decent tires only when cornering, like - "if i don't ride fast or corner hard I'll be OK". You do need traction for cornering, but a better reason to have good tires is to have adequate traction for stopping. An old tire is going to lose its ability to provide traction for stopping, and is going to lock-up much easier than it should. Not what you need when you need strong braking. You may never notice the loss of traction until you really need it.

Yours are WAY past needing to check the date to see if they are still safe to use.

[Triple Jim]

Originally Posted by jkv45

Anything over 5 years for a cycle tire is considered "old" - no matter how much tread there is or how good the rubber looks.

I've seen some manufacturers use 10 years as the guideline. For my own use, since I live away from big cities and have low ozone levels in the air, and since I store my motorcycles indoors away from UV light, I don't worry much if I get to the 5 year point.

Ozone is one of the main things that makes tire rubber degrade with time. It's in the air, and around big cities the concentration can get high. Also, UV in sunlight makes ozone from the oxygen in the air, so that's why I mentioned proximity to a big city, and sunlight.

[jkv45]

I always err on the safe side, so I draw the line at 5 years for a cycle tire.

I've tossed OEM cycle tires that were less that a year old and car tires that were 3 years old though. If I don't like them or they give me any indication they are questionable they are gone.

I just don't see the advantage in trying to get every last mile out of a tire, especially on a cycle. The penalty just isn't worth it for pushing it too far IMO.

[Triple Jim]

Originally Posted by jkv45

I've tossed OEM cycle tires that were less that a year old...

I agree there. I tossed a Kenda and a Shinko that were on my Ninjette when I got it, because they didn't stick well.

I just don't see the advantage in trying to get every last mile out of a tire, especially on a cycle. The penalty just isn't worth it for pushing it too far IMO.

Well, the original question was whether MakoMoto should ride for a couple weeks on the cracked tires, until he got his new ones on. I think he knows they're not something he wants to ride in the long term.

[MakoMoto]

Yes, I most definitely am aware I shouldn't ride lomg term on these. My new tires will be on in 2 weeks. My main comcern is a blowout. Is it likely for the GT501's to blow in this condition? The only reason i am even considering riding on it is because I am working on my car at this point in time so my bike is my ride to work. I dont ride aggressively (never even been over 60) and I am aware if the braking issue as well. Is this a blowout risk? Tire go boom? Thanks for the insight everyone!

[DannoXYZ]

Not likely to have blow-out. I ran 9-yr old OEM IRC tyres at Buttonwillow last weekend and they had similar cracks to yours.

[MakoMoto]

On subject...

What is everyone's favorite tire to use on our bikes? I've read Pirelli Rosso II...Super Demons...Kendas..Shinko...? There has to be a thread on this I can be pointed to or a page on this site...and I dont mean to veer from the original question..but..what does everyone think?

[DannoXYZ]

Originally Posted by MakoMoto

On subject...

What is everyone's favorite tire to use on our bikes? I've read Pirelli Rosso II...Super Demons...Kendas..Shinko...? There has to be a thread on this I can be pointed to or a page on this site...and I dont mean to veer from the original question..but..what does everyone think?

What is your intended purpose?
What kind of riding are you doing?
What is your budget?

Need more info to make proper suggestion; there's no one right answer, depends upon your usage. It would be irresponsible to recommend slick/semi-slick race-tyres for someone who will never be on racetrack, yet may ride often in rain and snow. For example, these suggestions may not be applicable to you:

https://www.ninjette.org/forums/showthread.php?t=302910

[MakoMoto]

I use her for riding to work and back and around town and nearby towns. I dont race as I am relatively new to street riding (rode parking lots for months...completed MSF...got licensed). I will be riding in the rain at times I assume but only if I get caught out in it. No way for snow. I would never risk a bike in a Michigan winter ��

[MakoMoto]

Budget is tight , id say $200 for a set would be around the top end I would like to go. However, Od prefer to not put a budget on my life. I have seen Kendas recommended on here before I believe, mostly for riders that bog around town and go 60mph tops and just cruise.

[Z1R rider]

You can't just say "I'll get Pirellis because they have great grip" or " don't use Shinko cause they're cheap and no grip" as a blanket statement. The manufactures make all kinds of different compound tires for different jobs, you have to consider the tire model #s also. I've used Shinko 740 and 741 on the track and touched down the foot pegs and side stand bracket numerous times on a pregen. That being said, I'm sure their "drag tires" wouldn't feel very good doing that. Pirelli also makes touring tires that wouldn't be to much fun at the track, but great on the highway.

As for life of a tire (before it starts showing cracks) has a lot to do with storage. Soft tires don't like the cold, as in don't let them freeze, (good suppliers won't ship while it's freezing out) or the rubber cracks right away. I've got a set of Hoosier drag tires off the car and the rubber cracked to the cords (where the tread meets the sidewall) in the first winter, nobody told me to store them in a heated space. Those tires are now 25+ years old and we still use them on occasion, up to 120 mph without a problem.

I know, I know, it's not the same with a car as a bike, but I've had a "rapid deflation" not really a blowout, hit a piece of metal in the roadway at 70 mph and put a gash in the tire, it wasn't a real big deal....back end squirmed around as I came to a stop, just keep your cool and the bike will almost always save the day. Ever seen race bikes do all sorts of crazy chit until it spits the rider off, then rights itself and goes forever till it losses too much speed and just falls over? That said, this is just my experience, yours may vary!!

All this said....most tires are better than you give them credit for when it comes to traction, even sport touring tires.

[DannoXYZ]

For your needs, I would recommend only radial tyres. They have better grip due to supple casing, longer-life, get better MPG, and are overall better value. In that price range you can't go wrong with:

Continental Motion or
Michelin Pilot Street tyres.

Get the 110/140 combo, the bigger rear will last longer and may wear out more evenly with front.

People like to look down on Shinkos for some strange reason; I'm on my 3rd set having tried their Podium, Advance and now Stealth radials on my CBR600RR and they've been awesome. Too bad their radials aren't made in smaller sizes.

Vast majority of reviews from people who've actually used them have been overwhelmingly positive. Here's some guys I used to ride with almost every weekend when I lived in San Jose. They love Shinko tyres and they ride hard!

Link to original page on YouTube.

[Triple Jim]

The reason I said that if the cords aren't showing, I'd ride them is that the cords provide the strength. The tire isn't likely to blow out just because the outer layer of rubber is cracked.

[Triple Jim]

Originally Posted by JacRyann

People like to look down on Shinkos for some strange reason; I'm on my 3rd set having tried their Podium, Advance and now Stealth radials on my CBR600RR and they've been awesome.

My only experience with a Shinko was the front tire that was on my 250 when I got it. In a hard stop, it would skid. When I switched to Bridgestone BT45s, in a hard stop the rear wheel comes off the ground before the front tire skids. I don't remember what Shinko it was, but I think it started with a 7.

[DannoXYZ]

FWIW, I think Kenda and IRC tyres are fine too. They just don't last as long as radials, especially under hard usage, so aren't as good value in a $$$/mile comparison. I worked in bicycle shop for 10-yrs while at university and we sold tonnes of Kenda tyres without issues. Interestingly, Continental bicycle tyres aren't that great of value.

[DannoXYZ]

Originally Posted by Triple Jim

My only experience with a Shinko was the front tire that was on my 250 when I got it. In a hard stop, it would skid. When I switched to Bridgestone BT45s, in a hard stop the rear wheel comes off the ground before the front tire skids. I don't remember what Shinko it was, but I think it started with a 7.

But you need to compare tyres of similar price-ranges and construction. A $40 Shinko 712 isn't going to be as good as $90 Bridgestone BT45. That was their entry-level tyre when they got started and it's similar to ~$60 Kenda or IRC tyre today. And have similar performance as well. On all bias-ply tyres, I've found running them about 5-10% lower-pressure than radials helps improve their grip. But yeah, I can slide all those tyres.

Even low-end radials have much better grip and performance than similarly-priced bias-ply tyres. Shinko radials I think have best performance in their price range, equaling tyres costing 50-100% more. Until their name gets more established... then their pricing will probably increase to match others.

I was looking at this really nice carbon-fibre racing frame from Carbonframes in Santa Cruz once... should've bought it! Very next year, Greg Lemond put his name on it and pricing increased by 400%.

[DannoXYZ]

Originally Posted by Triple Jim

The reason I said that if the cords aren't showing, I'd ride them is that the cords provide the strength. The tire isn't likely to blow out just because the outer layer of rubber is cracked.

Yep, rubber on sidewalls is really to hold in air. If you examine racing slick tyres, they're very similar to skinwall bicycle tyres, just barely enough rubber on sides to seal in air. This is one area where race tyres save weight over their street countreparts.

[Triple Jim]

The air is sealed by the rubber inside the cords.

[jkv45]

Originally Posted by JacRyann

Not likely to have blow-out. I ran 9-yr old OEM IRC tyres at Buttonwillow last weekend and they had similar cracks to yours.

Seriously JR - why would you ever do that????

Why would they ever let you do that? Don't they have Tech?

[DannoXYZ]

Tech-inspectors have list of areas to inspect based upon probabilities of them causing issues. In reality, cracks on tyre sidewalls are very low on likelihood of causing problems compared to bottoming brake-levers, stuck throttles, loose nuts & bolts, etc.

Apparently you've had more than average amount of tyre issues? Plenty of people have used inexpensive Kenda or IRC sub-maximum-grip tyres and have not died. I've ridden bikes since I was 14 and have never had a blow-out of any problems with tyres in 35-yrs. Heck, I've only had one nail in an auto tyre in all that time.

Cracks in tyres causes leaks well before the integrity of casing's strength is compromised. Tyre becomes useless from increasingly severe leaks well before there's any danger of sudden catastrophic failure. Those are caused by impact damage by rocks or metal to tread area and that's as likely with cracked sidewalls as without.

I think part of paranoia is cumulative and concentrated group experience. Looking at news all the time makes one thinks every other person in world is mugger, rapist and murderer. Real stats shows that's not true.

Same with tyres, if you poll 10 people with 10-years experience, maybe they've had 1 minor tyre problem each? But you add that up and you may conclude that there's a 100% chance that the next person will immediately have serious life-threatening tyre problem; which is not true.

Every tyre that's not a top-of-the line Pirelli is not going to spontaneously explode and kill everyone on the planet!

[jkv45]

Originally Posted by JacRyann

(SNIP)
Every tyre that's not a top-of-the line Pirelli is not going to spontaneously explode and kill everyone on the planet!

I never said it would - and some Pirellis aren't all that great from my experience (they dry, crack, and lose traction quickly, but...)

I've never had a blow-out or a tire come apart on me, and that's not what I was suggesting was the biggest danger with the OP tires.

When I decide to corner, maneuver, or stop aggressively (planned or otherwise) I need to know I've got the traction to do it.

I'm going on 40 years riding, 35 of it on the street and track. It's my belief that tires are one of the single biggest factors affecting safety on the road.

Considering your experience, I'm surprised you don't agree. Maybe your level of experience makes it possible to determine the traction of an old/dry/cracked tire and stay within the its limits, but I wouldn't want a less-experienced rider to read your opinion and expect to be able to do the same.