1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
mtn. biking 101
2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
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  1. #1
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    Question About Tire Sizes???

    So i just bought a Trek 4300 a few weeks ago and was looking at different tires online. The stock size is 26 x 2.0. I know the 26 is the size of the rim but if i got a different width size would it fit on my rim. Looking at tires i see sizes from 2.0 all the way to 2.6 etc. My question is will any tire fit on any rim or is there a certain limit to what width tires you can get. The stock rim on the 4300 are Bontrager Camino's, also, if anyone knows the maximum tire size the camino's could fit that would be great Bit of a noob question but i want to get tires a little wider since i tend to downhill more then climb so the extra width would work out better. Also is there an all around good tire size to get, maybe the 2.0 is fine but i would like to know more about tires since it is something i don't know much about when it comes to components. Thanks a lot
    Last edited by jet429; 06-28-2008 at 02:31 AM.

  2. #2
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    This is a huge subject...

    First lets start by saying there is no one tire that works for all conditons. Some tires are better on hardpack, some do well in mud, some are better for rocky or rooty terrain, etc. and there are some that do pretty well as all around tires. So when picking a tire it's usually best to consider where and how you ride. The best way to get a good idea of what will work in your area is to look at what local riders are using. If you see local riders using a specific tire there's usually a good reason.

    Tire size is a big subject as well. You can fit just about any width tire on your rims that you want. The limiting factors are your frame and fork. Just because it fits the rim doesn't mean your fork or frame will have the clearance to handle it. That and when you start puting really wide tires on narrower rims you change the tires tread profile, i.e. the way the tread makes contact with the trail. Tire manufacturers design tires with a specific profile in mind so that the knobs make contact with the trail surface in a certain way for best performance. There are center knobs that you run on most of the time when going straight, then as your move out to either side there are transition knobs which make contact as you start to lean as in a corner, then there are shoulder knobs or cornering knobs that dig it at full lean in a corner. If you put a big wide tire on a narrower than intended rim you round out the tire more because the narrower rim forces the beads of the tire closer together than intended. This in turn moves the inter mediate and shoulder knobs further from the trail. This can create extra space between the knobs and make the tire feel sketchy in the corners and unstable when riding a straight line. So you have to be careful not to go to wide. Not a problem though in your case as your bike won't likely handle a wide enough tire to create this problem.

    Now as to what will fit. Lets start by saying that tire sizes vary quite a bit between tires. There are tires out there that are listed as a 2.1 that are true 2.1's, some that are a bit narrower than listed size, and some that are a bit larger, so always be cautious when going to a larger tire size. The 4300 is a cross country/trail hardtail, so you are safe in going with a 2.1 to 2.2" width tire. If you want to go bigger don't even try anything bigger than a 2.3, and that will depend on the manufacturer and the tire. There are high volume 2.3's out there that won't fit between the chain stays of your bike, tires like the Kenda Nevegal 2.3 are just too big. If you want to go bigger than 2.2 I would highly recommend hitting the local bike shops and taking your bike along and having them "test fit" the tires before you buy to check for proper clearance. That covers the rear, now to the front. Your fork is the limiting factor up front. Just because the tire fits between the fork legs doesn't mean it's safe! Wider tires are also taller when inflated. The limiting factor in a fork is crown clearance. When the fork is fully compressed, i.e. bottomed out, the tire MUST NOT make contact with the crown of the fork, and most fork manufacturers recommend a minimum clearance of 3 to 5mm between the bottom of the crown and the top of the tire with the fork bottomed out. If you don't pay attention to this one you could get hurt badly. If you'r bombing a down hill and take a big enough hit to bottom the fork out, and the tire is too tall, and the crown slams into the top of that tire, you are in for an endo to end all endos! And you're likely going to break something. It's better to be safe than sorry here.

    So being the 4300 is an cross country bike the fork isn't likely to be designed to handle much more than a 2.3" tire. But with out knowing the exact spec I'd say stay UNDER 2.3" due to the size variation between tires that I mentioned earlier.

    So with all that said. A 2.1 or 2.2 inch wide tire would likely fit your frame and fork just fine. The rims will be no problem at all as you won't be able to fit a wide enough tire in the frame or fork to make a difference anyway. From there to learn more about tires, check out the "wheels & tires" forum on this site. There's more information about tires there than you could ever want.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  3. #3
    spec4life???..smh...
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    dont think we need anymore post on this thread Squash has it covered

  4. #4
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    Wow, thanks a lot for taking the time to type all that out. Answered all my questions. Thanks again.

  5. #5
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    I was just going to say I have 2.65" tires on my Norco but it hit the chain so I just went and took a bit off the side lugs and it works fine now, so if the tire is just a little to big you could try it it still works fine too.

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