Archive for May, 2007

A Relationship With Your Tool

Posted in Tools, Daily Rant on May 30th, 2007

A multitude of folding bicycle tool designs fill our local bike shops. The relationship you have with your tool starts in the store, or web page, when you’re picking it out. Most people wouldn’t put much thought into it, and I don’t blame them. I wouldn’t expect anyone to sit and write a blog post about this sort of thing, but here goes mine.

1. What will be the means of transportation for the tool?

If a hydration pack, or some other large carrier is to be used, size may not be an issue. A seat bag can get tight with a tube, cell phone, CO2, and large tool. A jersey pocket might lead one to choose an even smaller multi tool. Remember the weight usually increases with size, and no matter what it’s in, you’ll be carrying it.

2. What will be a typical riding situation?

The company you keep on a ride can influence the decision. A well prepared group of riding friends can help one another fill in the blanks when it comes to tools. Solo missions would certainly require more preparedness and probably a tool that covers all the bases. The venue for a typical ride may also be considered. Stuck miles from anywhere with a broken chain and no chain tool is unacceptable. Even if you don’t know how to use a particular tool on the tool, someone nearby may, or you may just figure it out in a pinch. Pedaling around town might allow for a bus ride home or a quick stop at the bike shop when things go wrong, making your tool choice less important.

3. What are my bicycle’s needs?

Finding a tool that compliments your bicycle is wise. A road cyclist wouldn’t have much use for disc brake pad wedges or disc rotor torx wrenches. A multi tool with a decent set of tire levers may make more sense. Having your bicycle handy during this pain staking decision can help. One specific mechanical need might be the automatic choice maker.

4. How much is it?

Ahhh… the real deciding factor for most cyclists. A valid way to make a choice when other information is lacking. In the world of bicycle accessories, multi tools are cheap. This is hopefully a one time investment that will continue to retain value for years of cycling. Spending the extra $15 to get the tool of your dreams will rarely ever come back to haunt you.

Some things to consider in the world of bicycle multi tools. Being more prepared is usually the way to go about things. Having the right tool for someone else is a good feeling both for you and the person in need. Besides, buying the tool with the chain tool may just motivate you to learn how to use it, and that’s invaluable. Good luck.

Brake Set Up on Your Bicycle

Posted in Repair Tips, Mechanical Hints, Daily Rant on May 30th, 2007

The brakes on your bicycle are used to control the speed of your wheels, so you can maintain control of the bicycle. Having brakes that work properly is very, very important. Please do not use this entry as a substitute for a bike mechanic with knowledge of your brakes. That could be dangerous.

So….brakes help you control the speed of your wheels to help you maintain control of your bicycle. In this entry I will discuss the how and why of The Pedal Wrench brake set up. The goal is to achieve efficient and effective brake control over the course of the ride.

Before we go into the brake set up, I feel I should mention braking technique. Brakes are designed to perform best when used certain ways, and remember, control is what it’s all about. Think about when a cyclist may use the brakes on their bicycle. I mean really, really use them, depending on them to work best when the consequences are the highest. For a road cyclist it may be right in the middle of the peleton, or perhaps a rain soaked descent with heavy traffic. The mountain biker may run in to the loose gravel turn with sudden drop just beside it, or the slippery roots of a technical downhill. In these situations, control is key to staying upright and safe.

The more fingers wrapped around the handlebars while braking, the stronger the main connection to the bicycle will be. If you are using 3 or 4 fingers to squeeze the brakes, you are barely holding on to the handlebars. Most modern brake levers are designed around a 2 finger brake technique, but 1 finger braking works as well.

In the case of the road bike with drop handlebars, the rider’s hand position on the bars is crucial.  Riding on top of the brakes, or on the brake hoods, allows access to the brakes but with little control of the brakes or the bike. While riding on the brake hoods is a comfortable way to get around, it is not the position the brakes were designed to be used from. To get the most from road brake levers, a rider must get used to descending in the drop position on the handlebars. I can’t emphasize how important this is for roadies. You’ll understand more shortly.

Brake lever clamps move on 2 axes to the handlebars.  Getting the position correct will help cut down on rider fatigue, making it easier to brake longer into the ride. Archimedes said “Give me a lever long enough and a fulcrum on which to place it, and I shall move the world.”. We don’t need to move the world, but having a nice mechanical advantage is great. This is the idea behind the first of these adjustments. We want to use the brake lever as it was intended, as a lever, and the longer the better. The other adjustment will make the brake lever less of a strain on joints and muscles.

The bar tape on road bikes makes adjusting the lever position a bit more of a task. Having faith in the mechanic that built the bike is usually acceptable in this case, but I’ll go over some general guidelines for road bike brake lever position. The brake lever hood and handlebar will create a broad area for your hand to rest. The brake hood forms a continuation of the part of the bar that runs parallel to the ground, forward of the 90 degree bend, and just above where the bar drops to towards the ground. As the rider’s hand grasps the bars in the drops, the bottom of the brake lever blade should be in easy reach of the 2 braking fingers. If the rider has to drop their shoulder more than a little to reach up to the lever blade, the lever may be mounted too high, or the angle of the handlebars could be off. Once the height is set, the hoods tend to be more comfortable when they are adjusted just in of straight forward.

Fortunately, mountain bike brake levers are easier to adjust. I say fortunately because most of the time having faith in the bike mechanic doesn’t work out so well in regards to this. Most mountain bikes will come with what I call “showroom brakes”. “Showroom brakes” are made to be aesthetically pleasing, not so functional. In order to get the proper placement on the handlebar, the shifter may have to be moved in towards the center of the bar. A common mistake bike mechanics will make when building a bike is overlapping the shifters and the grips. The creates an unusable part of the grip, unless you have Grip Shift. The shift levers need to be within reach, but should not take up usable space on the grip. Once the shifters are out of the way it’s time to adjust the brake lever. The lever should sit in a way that the 2 brake fingers easily reach the end of the brake lever. Remember, we want to squeeze the lever at the point furthest from the fulcrum or pivot to gain the most mechanical advantage. The next adjustment is one I constantly change. The angle of the lever in relation to the rider’s hand and forearm should be set for the cyclist’s comfortable descending position. Adjusting the lever to be in line with the forearm works well, but riding positions change depending on the terrain. To accommodate the change, leave the brake lever clamp tightened to the point where the clamp spins on the bar when forced. This will allow for adjustment while riding and it also allows the brake lever to move instead of snap off, should the bike hit the ground. If the lever moves under the normal forces of riding, it is too loose.

Now the lever is mounted in the proper place on the handlebars. The next adjustment to consider is the reach of the lever blade. “Reach” is the distance between the bar and the lever blade. Not all brakes have this adjustment, but many will. Road bike levers can sometimes use wedge shims to move the starting point of the lever blade closer to the handlebar. These reach adjustments may affect the tightness of the brakes which is why I’ll discuss that adjustment last. The reach should be set so the braking fingers can quickly and easily contact the lever blade. Obviously cyclists with smaller hands and shorter fingers will have the reach set closer to the bar.

The last part of this bicycle brake set up theory is the hardest to swallow for most. The brake lever is set in position, now we adjust the “throw” of the lever.  “Throw” is used to describe the amount of change from the starting point of the lever blade to the lever blade under “full squeeze”. “Full squeeze” is relative to each specific brake. Flex and compression in a brake can allow the lever to pull beyond the usable brake squeeze. The “full squeeze” would be the point in the lever’s travel at which the wheel would have a tendency to skid.

The closer to the handlebar the lever squeezes, the more brake and bike control is gained. Here’s why, The more a rider’s finger wraps around the brake lever the more muscles are used in the act of squeezing.  If 10 muscle groups are squeezing instead of 3, that would be an advantage. This is also important when thinking about control of the bike. As the lever gets closer to the grip it acts as a handle to grasp. Instead of holding on with 2 fingers, now the rider is able to hold firmly with all 4 fingers. The lever becomes a useful tool in controlling the bike through better grip. A looser brake will also allow the index finger to rest on and wrap around the lever, thereby significantly reducing the reaction time associated with braking.

There is too loose. If the brake pulls to the bar before it stops the bike, that would be too loose. One must also consider pad wear when adjusting the throw. If the pads wear more than lever is able to account for before it hits the grip, that would be too loose. If the brakes don’t stop the bike, they’re not so useful.

These are the brakes we’re talking about here. They are very, very important. Making them anything less than fully functional would be unsafe and irresponsible. Don’t attempt any of my suggestions if you are not fully competent working on your own brakes. I suggest finding a savvy bicycle mechanic to discuss the matter with. Thanks for tuning in.

KC

NORBA National, Fontana California, A Bike Mechanic’s Story.

Posted in Daily Rant on May 11th, 2007

I like bicycles. So when Doug Dalton, of Cannondale Bikes, called and asked me to fly to Ontario and help provide race support for the Bear Naked/Cannondale Bicycles race team, it was an easy decision.

Race support is a different beast than the daily grind of a bike shop or fixing bikes in a garage.  On one hand, you usually have new parts on new bikes.  When something breaks, you replace it with a brand new one.  The bike shop life involves a lot more “making it work”, maybe to save the customer a buck, maybe because you don’t have a replacement part in stock.  Inevitably, things will break at the most inopportune times on race bikes, which will add to the level of stress to the situation.  I cross over into both worlds quite often, and I happen to enjoy the variety. 

While the weekend mostly consisted of replacing brand new tires with newer ones.  Most of the racers went through at least two pairs of rubber over the course of the weekend.  Maybe a little excessive, but also a reminder that I may run my tires a little past their usable life.  With the addition of Stan’s sealant, seating the XC tires on the rim was fairly easy, even with just a floor pump.  The Michelin guys had to show me a few tricks to get the DH tires seated, even with a high pressure compressor. 

Besides tires, I lubed lots of chains, adjusted many derailleurs, and tuned many shocks.  The excitement came on Sunday morning when one of our pro woman downhillers had a headset explosion shortly before the finals.  We wasted no time pillaging another headset from a spare Cannondale Judge we had sitting around.  Her bike was fixed in plenty of time and then it was on to helping the others get ready for the short track race.

For those that have never witnessed a short track race, it is a 30 minute sprint filled with suffering and pain.  I was suprised at the tire pressures the riders were running.  Some of the women ran less than 25 psi in their front tires while the men hovered around 30 psi.  The theory behind the lower pressure is it lets you run more air in the suspension, for a more efficieent pedal, but allow the tires to hook up on the short and steep climbs, soft and dusty corners, and it also mellows the harshness of the small, high frequency bumps.

All in all, a great weekend as a bike mechanic.  I’d like to thank Andy Schultz, Tonya Bray, Kevin Smallman, Amelia Colasurdo, Leanna Gerard, Thomas Turner, Wendy Reynolds, and the other people who made the weekend totally radical. Huge thanks to Courtney for his help with everything, even though he was there on a volunteer basis. Can’t wait to see you guys when you stop through for Deer Valley. Go fast, take chances.




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