The gears in a mountain bike just keep getting more and more intricate. The bikes of today have as many as 27 gear ratios. A mountain bike will use a combination of three different sized sprockets in front and nine in the back to produce gear ratios. It can all seem a bit complicated for the newbie.
How Mountain Bike Gears Work
The idea behind all these gears is to allow the rider to crank the pedals at a constant pace no matter what kind of slope the bike is on. You can understand this better by picturing a bike with just a single gear. Each time you rotate the pedals one turn, the rear wheel would rotate one turn as well (1:1 gear ratio).
If the rear wheel is 26 inches in diameter, then with 1:1 gearing, one full twist on the pedals would result in the wheel covering 81.6 inches of ground. If you are pedaling at a speed of 50 RPM, this means that the bike can cover over 340 feet of ground per minute. This is only 3.8 MPH, which is the equivalence of walking speed. This is ideal for climbing a steep hill, although bad for ground or going downhill.
To go faster you’ll need a different ratio. To ride downhill at 25 MPH with a 50 RPM cadence at the pedals, you’ll need a 5.6:1 gear ratio. A bike with a lot of gears will give you a large number of increments between a 1:1 gear ratio and a 6.5:1 gear ratio so that you can always pedal at 50 RPM, no matter how fast you are actually going.
On a normal 27 speed mountain bike, six of the gear ratios are so close to each other that you can’t notice any difference between them.
With actual use, bike riders tend to choose a front sprocket suitable for the slope they are riding on and stick with it, although the front sprocket can be difficult to shift under heavy load. It’s much easier to shit between the gears on the rear.
If you are cranking up a hill, it’s best to choose the smallest sprocket on the front then shift between the nine gears available on the rear. The more speeds you have on the back sprocket, the bigger advantage you’ll have.
All in all, gears are very important to mountain bikes as they dictate your overall speed. Without gears you wouldn’t be able to build speed nor would you be able to pound pedals. The gears will move the pedals and help you build up speed.
There are all types of gears available in mountain bikes, all of which will help you build up a lot of momentum if you use them the right way.
How To Lube Your Mountain Bike
A mountain bike is a lot of fun although it does require some maintenance. You should always lube your bike 15 hours or so before riding, as quick jobs right before you take off normally doesn’t get everything lubed. Some lube jobs will last for more rides, although if things get loud or shifting gets sticky, it’s time to lube.
Here is how to lube your bike:
- The chain
Apply a generous amount of mountain bike lube to your chain as you move the pedals around backwards. It also helps to find a spot to steady your hand such as the frame while you move the pedals around and around. Make sure you watch out for the cranks and chain rings as they move around.
- Front Derailleur
On the front derailleur, lube the pivots. Use a spot of lube everywhere you can see movement when you move the shift lever.
- Rear derailleur
Just like the front derailleur, lube the pivots.
There are some types of clip less pedals that will need to have the release mechanism lubed. You should only lube this mechanism if you have this type of pedal.
- Everything into motion
Pedal around, shift your gears, and bounce your bike around. If you hear anything squeak, there’s a moving part there are it should be lubed immediately.
- Wipe it all clean
Once you’ve lubed everything and wiped it all around, simply wipe it all back off. Use a rag to wipe away all the lube you used, including all the lube off the chain. Wiping it away will leave the lube in between the parts but clean it away from everywhere it isn’t needed. This will keep your bike from collecting dirt while you ride.
How To Use A Chain Tool
Once your mountain bike chain becomes damaged, you should immediately replace it with a new one. It is possible however, to repair a broken chain using a chain tool. For this very reason, most mountain bikers travel with a chain tool.
Your chain has three basic components – the metal side plates, the rollers between the side plates, and the rivets, or pins which go through the rollers and help to hold the plates together. These pins allow the rollers to freely turn as the chain moves around the cogs.
If your chain happens to break, you’ll need to remove the broken link and replace it with a spare link. To do this, simply reattach the two ends of the broken chain and ride on a shorter chain until you can get it replaced.
To remove a broken link of chain, place it in the chain tool. Now, turn the tool counter clockwise until the rivet pin of the chain tool touches the chain rivet. Continue to turn the tool until the pin pushes out of the roller. Be very careful, as you want to stop turning when the pin is right at the edge of the roller, before it moves through the outer side plate.
Now, turn the tool in the other direction, and back it out of the roller. Set the tool to the side, then work the chain very gently from side to side and extract the inner side plates and roller.
Now is the time to re-route the chain through the bike. You may want to have a chain retaining tool or some to help you hold the chain in the right spot as you route and repair it.
Now that the broken link has been removed and you’ve re-routed the chain, you’re ready to insert a new link or simply connect the links that were beside the broken one. The process here is the same – align the two ends so that the link with the inner side plates will fit inside the link with the pin and outer side plates. Now, use the chain tool to push the pin inward until it’s positioned evenly between the side plates.
The easiest way to learn how to do this or feel comfortable doing it is to have someone show you, then actually practice with a chain and a chain tool. You’ll have no trouble at all making a temporary repair in a mountain bike chain once you’ve seen it done by a professional and practiced it yourself a few times.