Bikes

What follows will be tips on how to maintain, setup and even purchase a bike.  If you have any questions that you would like answered send an e-mail and an answer will be posted.

All about tires.

OK, the season is going and you've got your bike all tuned up.  If you haven't then please refer to the "Pre-Season Check" article.  One of the most important part of your bike is the tires.  They are also the part that are thought of the least when checking the bike over.  So here is some information that should be helpful.

Tire pressure:

Tire pressure is very important as it can influence not only how the bike roles but how it handles on a track.  There really isn't a "correct" tire pressure as each racer finds something that works for them, however here are some guidelines.  The higher the pressure, the better the bike will roll, however the bike won't absorb the bumps as well.  If the pressure is too low, the bike will be harder to pedal and as you lean or go into a corner the tire can "roll" on the rim, making it harder to control in a corner.  Low pressure will also make the tube more likely to be "pinched" between the tire and rim, resulting in a puncture.  For heaver riders, 150 pounds or heaver,  a tire pressure of between 35 psi and 70 psi is where the tire should be.  Most riders in this category will use between 50 and 60 psi.  For younger riders, especially if they run the "skinny" wheels, the tire pressure should be between 60 psi and 90 psi.  Tire pressure should be checked every couple of races and in fact the "skinny" tires should be checked before every race as they hold less air and even a small loss of air can result in low tire pressure.

Tire tread:

Tire tread is very subjective and to be truthful most tread patterns work.  Large knobby tires will grip well if the dirt is soft, which isn't encountered that often, but it takes more effort to pedal the bike and the bike won't roll easy.  A tire with little or no tread will roll easier, but may not grip well.  Younger riders can get away with limited tread on most track surfaces as even the slightest amount will grip well.  For older riders, a "low profile" tread will be a good choice.  Tires by Supercross, Maxis, Intense, and Kenda offer a variety of tread patterns and sizes to choose from.

Tire wear:

The rear tire will be the one to wear down after use mainly because it's on the drive wheel.  Also the break on all BMX bikes stops the rear wheel so skidding is common.  If the tread is visibly worn, the tire could lose traction in a corner and should be replaced. Tires are one of the least expensive part on a bike so don't skimp on the tires.

Tubes:

Tubes get holes, it's a fact.  They are thin and we are riding on dirt, which may contain sharp rocks, glass (hopefully not) and thorns.  Patch kits are available, however tubes don't cost much (usually less then $10.00) and are easier and faster to replace then patch.  Always have at least two tubes on hand at races, even if you don't know how to change them.  It's not much fun not being able to race because of a flat and you should be able to find someone at the track who can help you change a tube if you don't know how, but you may not be able to find a tube.

Next time we will go over a discussion of gears.  

4-May-08 10:41 PM

Pre-season Bike Check

Welcome to the first Bike Check installment and because the season is almost here, this is what we will concentrate on.

Bikes are machines and like all machines they need maintenance on a regular basis in order to function safely and to perform at it's best.  Prior to every race season a BMX bike should be throughly gone over.  Before this is done, however, the bike should be cleaned.  If you don't feel comfortable doing this then this can be taken care of by your local bike shop.  Regardless of who does the work, these are the items that need to be looked after.

Wheels and tires.  

This is the part of the bike that makes it "roll" along the track.  Anyway, the spokes on the wheels need to be checked for tension and at the same time trued.  The hubs and axles need to be checked to make sure the wheels roll smoothly.  If the bearings are sealed then not much needs to be done, other then making sure they are clean.  If they are not sealed then the bearings should be cleaned and greased.  The tires should be checked and if there are any holes are cracks they should be replaced.  Also, if the tread is worn then they should be replaced, unless you want to skid and fall.  Finally the air pressure needs to be checked and more air added if necessary.  Air pressure is a personal preference but it should be between 35 and 60 psi for tires that are 1.5 inches or wider and between 60 and 100 psi for the 1 1/8 and 1 3/8 inch tires.

The drive train.

The drive train is what makes the bike go.  It includes the pedals, cranks (the pedals are attached to these), the chain wheel / ring, the rear freewheel or cassette cog (located on the rear wheel) and the chain.  The pedals should be tight to the cranks and there should not be any play in the crank arms where they attach to the bottom bracket (where the cranks meet the bike frame).  The chain wheel / rink should be clean and the teeth should not be damaged.  If they are, it should be replaced.  The rear freewheel or cassette cog should also be clean and the teeth should not be damaged.  If they are, they should be replaced.  Also, if your bike has a freewheel, it should not "grind" or "skip" when you pedal the bike.  If it does, it should be replaced.  In fact it's not a bad idea to replace the freewheel or cog at the beginning of each season.  The chain is simple, replace it.  They don't cost much and it does make the bike go.

The headset.

This allows the bike to turn.  This should allow the front of the bike to move easily, but not be loose.  If the headset is sealed, all you need to do is make sure it moves freely and isn't loose.  If it doesn't move freely then the assembly should be taken apart, cleaned and greased.  When you put the assembly back together, make sure its snug and moves freely.  If the headset isn't sealed, the bearings should be cleaned and greased.

The rest of the bike.

Make sure all the bolts are clean, lubricated and tightened.

Tips on lubrication.  

For unsealed, moving parts, a thin layer of bike grease should be used.  Don't use too much as this can cause the parts to not move freely.  For other parts like the wheel hubs (the part that the wheels spin around) and the chain, a spray on silicone lubricant works best.  One of the best products is Jig-A-Loo all purpose lubricant that can be purchased at Canadian Tire.  The reason this works better then chain oil is that it doesn't attract dust and dirt, which can cause the moving parts to not move easily and can actually wear out the parts.  Just spray on the lubricant and wipe off the excess.

If you are doing the work on your own, make sure you know what your doing or ask someone who does to show you what to do.  If you are going to take it to a bike shop, list what you want done and give it to the mechanic.

If you have any questions, send out an e-mail. 


14-Apr-08 8:42 PM

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