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Intro

Intro class notes
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Intro

[T] Course overview, parts of bike
[T] Safety check
[T] Adjustments, ABCQChk/3S's
[T] 3L's, Quick release, clockwise, lock-nut theory
[T] pedal removal, chain issues (limits, breakage)
[T] General fit
[T] Seatpost, stem height
[A] Threaded stem adjust, lube
[A] Seatpost height adjust
[A] Mounting and dismounting
[T] Chain lube (and replacing onto gears), air tires
[A] Chain lube (and replacing onto gears), air tires, safety check (instructor check)

Greetings and Intro (to the intro)


Some people are usually late, so as people are coming in I will run through what the curriculum covers in each week, and what people can expect to get out of the classes - nothing that anyone is going to regret missing, but a good way to get people ready to listen.

Once everyone is assembled I say a little about the co-op and what we do, for those who might not know. I sometimes run over the three Rs, sometimes not - I am more likely to with a bigger crowd or people who are less familiar with the organization (or people who are not volunteers but might become them).

Respect (treating others as you want to be treated),
Resourcefulness (doing the most with what you have), and
Reciprocity (getting out what you put in).

That aside, I lead into the safety check - this is just a demonstration, but you will lead the students in a safety check at the end of class so that they see everything twice.

Safety Check — this needs clean-up


I like to do the true safety parts of the safety check first, emphasizing that they are the really important part. I then quickly run through all of the non-safety, "don't wear out your parts" sections to give people an idea of how much there is to check, but really gloss over them since no one will understand them at this point anyway.

The true safety parts are the steering (tight stem, other steering aspects fit into security), stopping (brake levers not touching bar, pads on rim, pads tight, brakes attached properly), and security (bars/levers tight, seat tight, wheels on with tight skewers, bearings not dangerously loose, tires not about to blow out, reasonably inflated)

  • 1 Hold front wheel between your knees and try to turn handlebars (sideways and down, including bar ends) and brake levers, and check for loose grips or tape.
  • 2 Squeeze brakes – lever should not contact handlebar. Pads should touch rim, not tire. Rock bike with front brake on – it should not rattle.
  • 3 Grip wheels by tire — they shouldn’t rattle. (check quick-release or nuts). Spin wheels — they shouldn’t wobble. Squeeze spokes – they should be tight.
  • 4 Grab seat – it should not twist or tilt. Jiggle cranks and pedals — they should not rattle too much. Is chain rusty? kickstand, rack, or other parts loose? Are seat or grips torn or derailer bent (crash damage)?
  • 5 Check tires for cracks, bulges, or cuts. Press heel of your hand down on tire – it should be hard.

How to use pump: Lever down (next to hose) is open, up is closed
(to lock on valve). Hold valve with one thumb while pressing and
twisting chuck down – if air won’t come out of pump, try again. If air
comes out of pump but won’t go in tire, tap chuck while pumping.
To remove: open lever and twist chuck side to side while pulling.

Check helmet fit: it should sit level, with junction piece just below
ear and little slack under chin. Should not be able to push it down
on nose or up off forehead. Suggest rubber band for pant leg.

Three Ls - basic principles of bicycle maintence

  • Lubrication - To make things turn smoothly and not rust.
  • Leverage - Not just getting more power, but using the right tool generally - makes the job easier and reduces the chance of damaging parts
  • Love - Pay attention and understand what is going on, do the right thing now so you don't have to apologize and buy the bike flowers later (yes, I really say that)

Seatpost height

Explain why seatpost height is important and that people often ride with their seats too low. Correct seatpost height allows more efficient pedalling, with the leg operating in the range where it is stronger, and lowers stress on the knees, greatly reducing the damage done to the joint.

Seatpost height adjust

Explain the process of getting the seatpost loose, that greasing the seatpost is done to prevent corrosion, and how to find the proper seat height. Mention the max height line. A good starting rule is to make the rider tiptoe to the ground when sitting on the seat, and another method is to raise the seat 5mm at a time until it's a little too high, then coming down a notch. The "too high" feeling is easily reconigzed as a feeling of rocking back and forth on the saddle and stretching for the pedals. This is as opposed to some riders' feeling that they should be able to keep the bike stable at rest without coming off of the seat. Students remove their seatposts and grease them, then set them at an appropriate height.

Mounting and dismounting

Since some students will not be used to riding with proper seat heat, demonstrate (and have them try), proper mounting and dismounting technique, including moving the pedal into position before starting. Students may try this on their own bikes if their seatposts have been raised.

General Fit

Explain the primary dimensions of bicycle fit: the distance from the bottom bracket spindle to the saddle, and the distance from the saddle to the handlebars, and how these can be varied: frame size, stem length, seatpost adjustment. Also discuss fitting the type of bike to the type of riding, which includes gearing concerns, handlebar type, and tire size.

I generally tailor fit to the type of riders in the class. I always explain the difference between flat-bar bikes and drop-bar bikes. (Flat bar are generally more upright, more casual, for shorter distances - fit is more of an approximation. Drop bar are more stretched out, requires conditioning to be comfortable, fit more precisely) I don't personally dwell on fit methods that fit a person exactly using measurements and tools, specifically because these are tailored toward racer needs and are not optimized for comfort (and I say so). -PG

Threaded stem adjust

Explain the way threaded stems are secured into steerers, and show how to remove stems and grease them for corrosion prevention. Mention the max height line, as with the seatpost. Students should remove and grease their stems, if cables do not prevent it.

If anyone has a threadless stem, I will quickly show the difference and explain that they are different, but leave the detailed explanations for the bearings class. If no one has one, I'll just mention that there is a different kind on newer bikes and leave the detailed explanation.

Quick release theory

Explain how quick releases work, using the demo quick release where the cam shape is easy to see. Emphasize correct tightness, where the skewer is adjusted so that friction is felt halfway between open and closed, and so that it leaves a mark on the hand. Also mention that it is important to make sure the skewer is completely closed, since the cam is designed so that tension actually decreases at that point, making it harder to open accidentally.



Created by: JSheehan. Last Modification: Thursday 23 of April, 2009 06:35:39 UTC by jsheehan.