Bicycle Mechanics - Tire Help.
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05-19-09, 02:46 PM
I have a hybrid currently with 28 x 1 3/8 tire. I was curious if I would be able to go to a thinner road tire? I am looking to use this as a road only bike and wouldn't have a need for knobby tires because I also have a mountain bike.
Would the Forte GT2 Kevlar 700c by 28 work?
I have no idea what the 700c is, but im assuming its the standard road tire width and the 28 is the overall inch of the rim?
Thanks again for your advice. I am real new to road setups.
No, 700 mm is the approximate overall diameter of the wheel with tire. "c" is the rim type standard specification used on most modern road bikes. A 700c X 28 is a road tire with a maximum internal cross-section of 28 mm. Actual tire sizes vary between brands. A 28 is about right for a hybrid that will be used mostly on pavement. Fully inflate your tires before each and every ride.
05-19-09, 03:26 PM
That's not correct, Al1943. The 700c designation is not 700 anything, and the C is not a unit of measurement. When Europe tried to name the existing standard sizes, they lined them up in size order and called them 600A, 600B, 650A, 650B, 700A, 700B, 700C, etc. 700C came to mean a rim with a 622mm beat seat diameter. It's slightly smaller than a 27" rim which is the name for a rim with a 630mm beat seat diameter.
Think of 700 and C as arbitrary designations which mean a specific diameter.
For reasons too insane to mention, 700C is occasionally called 28" even though it's smaller than 27". Oy vey.
silvershark, you want a narrower tire? There's no telling if it will work, but it probably will. Try it.
First, though, check the sidewall of the tire and verify that it says 622Xsomething. The 622 is critical.
05-19-09, 04:05 PM
It does have a 37-622 on the tire. The current tires are vittoria tires. They are just old and warn, and it seems like a good time to switch them to smaller thickness if I can.
Thanks for all the info.
That helped me understand a lot better.
05-19-09, 05:11 PM
OK, you're in luck. That's 700c, one of the most common bike tire sizes. As I said 28mm will probably work.
Silvershark .... what rims are these tires for ? Brand and inside width would be great.... but I understand you likely don't have calipers.... just the model would suffice.
You want to make sure the rims are suitable for 28mm tires. A 28mm tire needs a 19mm rim or smaller. This is a good general chart. The width is for the inside of the rim. http://www.schwalbetires.com/tech_info/tire_dimensions#rim
If you need wider one, the Forte Metro K 700x35 works for me. It's about 34mm actual on a 19mm(inside) rim. Nice ride, yet still fast enough. Lots of room for punishing roads.
700x32 would likely feel zippier than 700x37, all else being equal. And, especially if you go for a style that is lighter, higher pressure, slicker tread, etc.
05-19-09, 10:20 PM
I went to my local bike shop with bike in hand and they suggested I stick with my 700c x 38 because of my build. I am not a typical road biker weighing 160lbs or so. I am 210lbs and look more like a football player. She said I might be able to get away with a 700x32 at the max, but she said I would probobly be happier overall with the 38's.
So I took her advice. They are made by bontrager.
05-19-09, 10:56 PM
Their advice doesn't make a whole lot of sense. Many folks in the 200 lb. class are riding 700cx25mm (and smaller). Many tandems with teams upwards of 350 lbs. total weight are running 700cx28mm. You'll almost certainly get a plusher ride from the 38mm, but at some point you probably sacrafice speed and almost certainly sacrafice handling by having too wide a tire. Your weight should not determine that you need to stick with the wider tire.
05-19-09, 11:21 PM
I own a Trek Hybrid from their FX-series, which had 37C and 32C being offered in different models on the same wheels. I put 28C tires on this and they fit like a glove. But I'd draw the line at 28C on these rims. 25C might not seat properly. I'd have to see your wheels to know for sure - but I'd say go ahead with finding some 700 X 28C tires.
A good and relatively inexpensive 28C tire is the Panaracer Pasela TourGuard - which has a Kevlar (or similar) belt. Their one drawback is their sidewall. This can be a bit thin, but where you're likely to get a puncture is protected.
05-20-09, 02:47 AM
To give you a comparison to your current tire, 28mm is about 1 1/8" and that's pretty thin for an upright hybrid style bike, but still, it could work. I'd consider 700 x 32mm also, which is equivalent to a 1 1/4" tire, probably the standard width for 27" road tires back in the 60s and 70s.
Btw, my Continental Contacts claim to be 32mm wide but only measure 28mm with a set of calipers. It is common for tires to measure thinner than the spec, because it makes a lighter tire, which drives a lot of purchasing decisions. So what I'm saying is 32mm may not be a big honking tire, it may be just what you're looking for - depends on the brand and model.
I just switched from 700x38Cs (almost the same like you) to 700x28Cs (Continental Ultra Gatorskins) on my hybrid last weekend, I did have a little trouble caused by my own incompetence (which you can read about it here http://www.bikeforums.net/showthread.php?t=536071) but in the past four days they've held up very well. Expect a MUCH bumpier ride, but 28Cs are quite a little faster (in terms of acceleration too) and I was happy to trade comfort for speed.
Just a word of warning, with 28 mm tyres do not under any circumstances ride them inflated below the recommended pressure. You may damage your rim (happened to me) and get a pinch flat (happened to me too :D).
By the way I have 21 mm rims, so I was sceptical as to whether they would take 28 mm tyres. All these guys here said they would fit (see above link) so I went for them. They fit pretty well, even though it looks as if the rims are almost as wide as the tyres themselves.
I've taken some pictures already, I'll try and upload them if you want to see how 28 mm tyres would look.
05-20-09, 09:50 AM
I have seen/heard many reports of 28C tires o hybrids that came with 32C and above. They say they work great - but if planning on carrying a heavy load (touring), most would opt for 32C.
05-20-09, 06:16 PM
I'm sure 28s will work fine. I'm also sure you'll notice a difference in handling and road noise. You might want to try out a bike with 28s before you buy. It's a big jump.
05-21-09, 10:24 PM
My buddy has 23's on his road bike. He said I could give it a whirl tomorrow, so I will give it test run and see how it is. He said he notices the bumps etc a lot more.
I've run 700 X 25's for years on my Raleigh hybrid city rain commuter that originally came with 32's. These have never given me any problems. I usually run these 110-125 PSI depending on if I fill them at home or work. I will swap the 32's back on for a week of camping and limited "off-road" use.
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