Topic: razor blade + tire = ??

[3ntr0py]

so i got home from riding the other day ('75 CB550), and noticed something sticking out of my rear tire. upon further investigation i realized that it was an old rusty razor blade that i guess i ran over. not sure how it happened, it seems like it would have to be standing straight up in the road for it to get in there like that. anyway, it looks like i will be replacing at least that tire, which leads me to a few questions for you guys/gals...

1. i have been reading a bunch of posts on here regarding tire brands and i THINK i have settled on the bridgestone spitfire S11's. they seem to be fairly popular and aren't as expensive as the metzeler's etc. however, on americanmototire.com, where the best prices appear to be, they have the proper size for my rear tire (110/90-18) but it is labeled as a FRONT tire. is this a problem or is the size all that is important (no pun intended)?

2. is it generally a bad idea to ONLY replace one tire at a time? my front tire (cheng shin hi-max) is still in pretty good shape, and i would like to be able to save some $$ if i can only replace my damaged rear tire.

3. i have attached a photo below of the cut in my current tire, do you guys think that it is a bad idea to continue riding on it until my new tire arrives? the tire hasn't gone flat because the cut doesn't appear to go all the way down into the tube. as far as i can tell it goes pretty deep but stops just short of cutting all the way through the tire. i JUST got back on the road after replacing my chain and sprockets and would hate to have to sit out again until i get my new tire. but, i don't want to risk life and limb.

-j

[eldar]

That is pretty deep. I dont know, I think it should be replaced. Looks to be a pretty new tire. If the front is just as good, I would say to maybe get the same tire top avoid handling problems from having different treads.

I suppose if you feel brave you could always put some super glue or rubber cement in there!

[TwoTired]

Pry the cut appart and see if there are any cords cut.  If so, replace the tire.  If it is just rubber, then you have bonus rain grooves.  As long as you keep the speeds below 95 ish, ride it.

Cheers,

[Bob Wessner]

not sure how it happened, it seems like it would have to be standing straight up in the road for it to get in there like that.

Many years ago I read an article in a cycle mag about the proportion of flats due to road hazards in front vs. rear tires. Most, statistically, occur in the rear. The theory is that whatever the hazard is, nail, razor blade, etc. which may be lying flat, gets kicked up by the front tire passing over it just in time to nail (no pun intended) the rear tire.

[smashme33]

 If it helps any, I am currently using Cheng Shin Hi-Max tires on my bike, and I used them on a Nighthawk 250, and have never had any problems with handling, or otherwise.  I am not riding for speed, either, just local and highway cruising, and these are fine for that. I've had these tires up to 130 km/h(approx. 80 mph) without problems. If you are constantly driving really fast, then I would recommend a high-end brand, and these guys can tell you what they like for speed.

[Noel]

Many years ago I read an article in a cycle mag about the proportion of flats due to road hazards in front vs. rear tires. Most, statistically, occur in the rear. The theory is that whatever the hazard is, nail, razor blade, etc. which may be lying flat, gets kicked up by the front tire passing over it just in time to nail (no pun intended) the rear tire.

As an old retired bicycle racer I'll second that. It's exactly right.

More flat tire trivia: you'll get more flats in the wet partly because rain washes crap into the street but also because wet objects cut rubber much more easily than dry objects. Standard practice in bio and chem labs is to wet one's scalpel prior to cutting rubber tubing or sheet, as it makes for a smoother, cleaner cut.

And while I'm boring everyone, it used to be standard practice to rub your bicycle tires whenever you rode over glass or other junk in the streets. Some folks used a glove palm and others just their bare fingertips. The idea was to remove any debris within the first few revolutions, before it had time to bury itself deeply into the tire. Those of you who have removed your rear fenders from your motorbikes might try this on your next ride. Don't forget to videotape the results for us!

[Green550F]

don't think I'd be pushing the bike in the corners, but as for in town riding, Chen's have been decent tires fof me. you do tend to get what you pay for...

[bryanj]

Now this is only my 2cents worth but back in the late 70's when i was actually earning a living at a dealers Cheng Shing tyres we would only fit to 50cc mopeds restricted to 30 mph they were really that crap!! BUT i have no knowledge about the newer tyres made by them. Considering the letigious nature of the US I suppose they have to be better now Dont they?

[TwoTired]

Aren't Chen shins made for countries with unimproved roads?  Such roads, gravel or stoney dirt, are pretty abrasive on tires.  These tires need a hard compound for longevity as good traction on pavement is not the buyer's major concern.

If you are using your bike off paved roads, or don't care much about emergency stops on paved surfaces, Chen Shins are probably a nice long wearing tire for you.

Rubber gets harder with age.  Old Chen Shins will have less paved traction than new ones.

Cheers,

[KB02]

If any of you are familiar with Fred Rau (he's a pretty famous motorcycle jounalist for those of you who don't), you can probably imaging him saying the following about Chen Shin tires:
(it's a rought quote from what I can remember him saying)
"Poor old Chen Shin has been helping more poor people get by inspection than any other tire manufacture."

The CS tires are decent. I wouldn't call them good, I wouldn't call them crap. They're just decent. They've been on my bikes in the past, they'll probably be on my bikes in the future. (actually, I have on one at the curent, as well).

If you're going to replace it anyway, might as well get a matched set, I guess.

[Noel]

I used a pair of Cheng Shens on my old CB750. I didn't die.

So what KB02 said. They work. They hold your bike off the ground. They last pretty well and don't explode just because you exceeded 67.3 MPH. They're not great for track days.

So it depends on what you're looking for. Canyon strafing and boy racing?  Buy some Avons. Commuting, beer runs, and hanging out at Starbucks? Cheng Shins are fine.

And right to the point: if you already had them on there and had no complaints, what are you worried about?