Bike Repair, 1-29-17

Bicycle Maintenance with Laurence, Third Class, 1-28-17

January 28, 2017  —  the agenda consisted of vocab review, new vocab – The Wheel – and the four steps of a bike tuneup.  Again, I left at 6:30 because of a dinner commitment so if anyone else present (Laurence, Annie S or Annie A) has material to add or wants to modify this, please chime in!

 

The wheel and other parts are below:

 

Other useful sites:

https://en.wikipedia.org/wiki/List_of_bicycle_parts

http://adventure.howstuffworks.com/outdoor-activities/biking/bicycle2.htm

 

What parts of the bike have ball bearings?  Pedals, hubs (front and rear), headset (fork tube), bottom bracket and free wheel.

You can help to true the wheel by adjusting the spoke nipples  which will move the wheel one way or another.

Tune ups

There are four basic steps, and Laurence likes to do a bump test where you pick up the bike up a few inches and allow it to bounce down and see what rattles, moves and what doesn’t feel tight.  It may be that your bike tuneup requires more than the basic four steps.  For instance, during my bounce test Laurence looked askance at the fork tube (the bike is old, 15 or maybe 20 years?) and it maybe that the ball bearings in the fork tubes are bad.  Consider that if water got down into the fork tube (looking at my bike, this looked very possible) then the bearing may have started to rust.  In any case, a perusal of the fork tube indicated evidence of stress and likely failure in the near future.

 

The Four Steps:

  1. Pump tires
  2. Oil the chain
  3. Adjust shifting
  4. Adjust brakes

 

1  . If you’re going to bike a lot, invest some money in a good pump with a gauge ; if the tire is new, go ahead, pump up to the recommend PSI, if it’s old, a bit below the recommended PSI

2  Oil the chain

  • Winter, use a winter lube made for bikes with a nozzle that allows you to put one drip on every link – hold a cloth beneath to catch oil that falls, move the chain along until you have lubed every link
  • Summer – use a summer type lube
  • Be careful not to get oil on the bike rims (Pat!!) that can impact on the brake’s effectiveness
  • Wipe the chain with a cloth to remove excess oil– chain should be glistening, no more
  • Frequency – about every 4-6 weeks (Laurence bikes 200-300 miles/month)

 

  1. Adjust the shifting/gear adjustment
  • Use a Phillips head screwdriver, find the High and Low limit screws

  • Turn clockwise to tighten

 

Background explanation from  http://www.bicycling.com/training/fitness/basics-bike-shifting

  1. Gears: Most bikes have two or threechainringsin the front and anywhere from 7 to 11 gears, or cogs, in the back. Moving the chain from the smallest rear cog to the largest eases your pedaling effort incrementally. Moving it between the chainrings in the front results in a more noticeable change—pedaling feels easier in a smaller chainring and harder in a bigger one.
  2. Shifter Savvy The left-hand shifter changes the front gears; the one on the right controls gears in back. If you get flustered on the fly, remember: RIGHT = REAR
  3. Avoid Cross-Chaining That means thechain is at an extreme slant, either in the big ring up front and the biggest cog in back, or the small ring up front and the small cog in back. This not only stresses the hardware, but it also limits your options if you need to shift again. (related to this is :  the chain is on biggest chainring in front and the biggest cog in back – this is a gear that bikes were not meant to shift into – so don’t put your chain in this position )
  4. Cheat Sheet: For: Uphills and headwinds
    Use: Small or middle front chainring + bigger rear cogs (uphill, low gear, less force on the pedal but you must peal faster)

For: Downhills
Use: Large front chainring + a range of rear cogs

For: Flat terrain
Use: Small or middle front chainring + ­smaller rear cogs

 

So when your chain is on the smallest cog in back, you are in high gear, and your bike is hard to pedal; this is the gear to be in on flat land; low gear are for the hills here in Ithaca.

You want to stand behind the bike and make sure the derailleur and cogs are s lined up , adjust  the High limit screw, if you tighten the screw too much, the chain wont be able to slide down to the smallest cog and that’s when you’ll need to loosen the High limit screw (counter-clockwise with the Phillips head.)

If you tighten the cable by loosening the screw, you go up to the next gear .  You want to make sure the chain does not hit any part of the derailleur.

Releasing the tension makes the cable housing longer and loosens the ????

Point: if you have just gotten a new cable, it will stretch in the first month, and you will need to adjust it.

Something about spoke protectors?

4  .Brakes    We did a front adjustment during the first class using a lock nut, but we did not adjust the tension of the back wire.  We did talk about the proper alignment of brake pads and if the pads indendations are worn off, the pad needs replacment.  Same with old  hard-rubber or cracked pads:  replace them.

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