Mountain Bikes Frames

Looking for the proper material for your frame depends on the biking involved. Many factors play a part in choosing the right frame material for you. Different alloys means different properties in strength or weakness so choosing the stead for your ride depends on a culmination of budget, style and landscape.

Ongoing progress in light weight and ultra-durable materials have continued to keep up with the curve and the growing number of mountain bikers throughout the world. It will be interesting to see the evolution of current materials into other synthetic or combined alloys that will push the limit with strength, consistent maneuverability and featherweight design. Typically the three major compounds riders deal with are carbon fiber, aluminum and titanium. These metals make up most of bicycles on the market, but vary in prices and attributes.

Titanium is among the more expensive but it has powerful corrosion resistant properties that rival even platinum. Titanium can be guaranteed to last past expectations and continue to maintain the same durability and appearance it did the day you bought it. This kind of high density metal provides support in those sweet spots on the bike that absorb the bunt of the impact. Light weight coupled with strength makes titanium a favorite among bikers. Titanium actually has the "highest strength-to-weight ratio of any metal." There are also no known health risks with titanium. Since the alloy is almost always pure, lead and other contaminants are taken care of. These traits together make titanium a smarter choice for all terrain riders.

Aluminum is vital for any bike, especially for those who intend to ride at night. It reflects light better than most metals and can help in safety. Chemical or physical vapor deposition is a process that can add a coating of aluminum to any metal to reflect light, so even if you don't want the entire frame made out of it, you can add a good shine to any other alloy or metal. The bike may not end up being as immortal as a titanium frame but aluminum holds its own as a decent alternative. The problem with this material is that the quality is never a sure deal and the purity changes from place to place. Aluminum will likely deteriorate faster than titanium and will be more prone to dents or contortions in the frame.

Carbon fiber is light weight and resilient to rain, weight and long term use. It is also malleable and able to move or bow according to suspension needs. The material is often found in shoes and helmets because of it's dexterity and flexibility. Carbon fiber frames do fail on being consistent with managing stress and the compound needs more studying before it is used to its best ability. This compound has the possibility of becoming an essential for long term cyclists, but as of right now has little success in the bike frame industry. It is simply not strong enough to conduct the large amounts of pressure put on a bicycle frame. A reinforcing composite material can be added to other materials, though, for added support and impact absorption. This has had solid success in skateboards, motorcycles and some mountain bikes.

Choosing the right compound for a bike frame can often take trial and error. Weight, density and stiffness all play important roles in the way the bike operates and responds to the rider. Titanium is the most dependable choice, but the other two should not be exempt from brainstorming for improvements in ergonomics and handling. There is an exciting future in store for riders and entrepreneurs in the bicycle world. Breakthroughs in materials and manufacturing will likely continue to be faster, cheaper and more durable than ever before. As of right now, I'd recommend going to your local skate park to ask around and maybe test ride a few frames.




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Mountain Bikes

Other than spending a small fortune on a hybrid car or electric car, commuting by bicycle is probably the best way to save gas and improve the environment. When selecting your next (or first) bicycle, it’s pretty important to understand the different bike types. Here’s a few tips about the most basic categories.

Road bikes, also known as racing bikes, are usually, if not always built for speed and riding on smooth surfaces like pavement. Because of this they are equipped with very narrow tires, drop handlebars (to put the rider in the most aerodynamic position), and multiple speeds (12-24 gear positions is common). Racing bikes follow the same basic layout, but with a very lightweight frame. Although road bikes and racers can be used for commuting, most casual riders opt for comfort rather than speed.

Mountain bikes are built less for speed and more for durability and control. These bikes have much larger tires, raised handlebars that put the rider in a more upright position, and are generally (but not always) heavier. Since mountain bikes are intended to be used on trails and steep inclines, the gear ratios are generally lower than that of road bikes. Some mountain bikes have up to 36 gears, advanced suspension systems to handle bumpy trails, and it is now common to find disc brakes on one or both wheels. These bikes are great for commuting, especially if some of that commute is over uneven and rough or rocky roads.

Hybrid bikes attempt to combine the best of road and mountain bikes, and are intended to handle most commuting situations. These bikes come equipped with narrower tires than mountain bikes, suspension systems for the occasional bumpy road, comfort grip handlebars and comfy seats, and often come with pre-fitted fenders and luggage racks for bicycle saddle bags. Many hybrids are geared much like road bikes, while others limit the number of gears to a minimum (5-7 speeds) or have the gears “sealed” in the rear hub (3-5 speeds). Hybrids are generally the best selection for most commuting situations, and are a great choice for casual riders.

Many other specialized types exist, from single speed cruisers to very specialized off-road “rock riders” and BMX racers. However, most cyclists will do alright to start from the list above. Use this guide as a starting point, try out a few models of each type to see what’s a good choice for you, and then start riding. You won’t regret it.

Tires/Wheels: You’ll note that the terrain for ‘cross races is not nearly as technical as your typical singletrack trail. With that in mind, super knobby 2.2 tires are only going to slow you down. Switch to a narrow pair of semi-slick tires such as the Kenda Short Tracker (1.90) or the Kozmik Lite II (1.75). Low profile tires with good side knobs for cornering work best.

Tires are easy to swap as conditions/needs change, but you could go so far as having an extra set of wheels with your “cross ready” tires already mounted. If you were sticking with the typical 26″ wheel size, any lightweight cross-country wheelset would be fine.

If you’re running disc brakes, you COULD put 700c (29′er) wheels on a 26″ mountain bike frame. As long as you use true 700c cyclocross tires, there should be enough clearance on MOST frames/forks. If you’re running linear pull brakes you still have options. Mavic makes a nifty adapter (Mavic 700c Brake Adapter) that attaches to brake post mounts and changes the brake’s position to allow for larger wheels. I have a pair of these on my commuter bike (regular 26″ hardtail mountain bike now with 700c wheels and cyclocross tires), and they work great. If you’re a weight weenie, you might balk at the additional grams but you can always drill holes in your frame to offset that (kidding, of course).

Before you switch wheels, be sure to double check the spacing between the rear dropouts. Road wheels might have rear hubs that are 130mm wide while mountain bike hubs are usually 135mm wide. Check out the late, great Sheldon Brown’s Web site for more information about frame/hub compatibility, or check with your local shop.

Drivetrain/Brakes: First, choose a clipless pedal that functions well in the mud, such as those offered by TIME and Crank Brothers. Make sure you’re adept at getting in and out of your pedals quickly, as you’ll be doing that quite a bit in a ‘cross race.  To some newbie riders, platform pedals and running shoes may seem like a good idea (considering the running sections), but think of it this way: if that system worked well, everyone would be doing it. The positive connection between clipless pedals and the shoe cleats still reigns supreme.

When it comes to making changes to cranks, derailleurs and shifters, I’d say that in most cases you could leave these alone. You could switch to a rear cassette with taller gears as you’re probably not going to need a 12-34 in the back. You could also remove your granny gear, to save a little weight, and limit the front derailleur. I’m lazy so I didn’t do any of that to my converted mountain bike. Truth be told, I’m close to having all but my road bike be singlespeed, so gears and derailleurs bore me.

My original converted mountain bike had linear-pull brakes and they worked fine. I hear the arguments for cantilever brakes, but my personal opinion is that when V-brakes hit the scene they worked better and were an improvement over canti’s. Also, I’ve ridden plenty of muddy mtb courses and even with my fat tires I still had enough mud clearance. Enough said there because I think disc brakes are even better. The UCI still has its bizarre ban against disc brakes, but for the vast majority of local ‘cross racers, UCI rules don’t apply. If you’re racing on a national or international level, well, you’re probably not doing so on a converted mountain bike.

For the rest of us, this is where you’re going to have to make some serious decisions as to really how far you want to go to convert your bike. If you want to swap out your flat bar for drop bars, you’re going to have to change your shifters/brake levers. The shifters should work fine (road shifters with mtb derailleurs or vice-versa), but road brake levers will not work well with linear pull brakes, nor will they work optimally with disc brakes. Personally, I say stop here and use whatever handlebar/brake/shifter setup you’ve got. If you go much further with the conversion, why not just take the next step and buy a ‘cross bike?

Well, that covers: frame, fork, wheels, tires, cranks, brakes, shifters, levers and pedals. That leaves rider cockpit items such as your stem as well as your seat and seatpost. If your fit is good and you’re comfortable on your bike, don’t change a thing. A more stretched out position may be better in the long run but, unless your mountain bike is set up so that your back is straight up when you’re riding, you should be fine. After a couple of races, you’ll know if you need to make any fit changes.

There you have it, now you’ve got no excuses. So toss your bike in the stand, grab a Duvel and ring that cowbell like you just don’t care.

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