MY "TEN SPEEDS"

 

 

MY "TEN SPEEDS"

 

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MY "TEN SPEEDS"  

MAINTAIN WHEELS - INTRO

WHEEL CHOICES

TIRE MAINTENANCE

RIM MAINTENANCE

DENTED RIM REPAIR

HUB MAINTENANCE

WHEEL TRUING

 

RIM MAINTENANCE

Vintage road bicycle rims were made from three fundamental materials - wood, chrome plated steel and aluminum alloy.  Steel and alloy are the common choices for most vintage road bicycles of any quality, with alloy being the choice of choices.  The wooden rim was popular, in the early days, but is no longer in common use, having been replaced first by the steel hoop, and later by the extruded alloy rings, common in today's bicycle world.

In addition to the material used to make the hoops, the hoops can have vastly different characteristics.  Many Old School steel rims had patterned braking surfaces.  The theory was the such a surface would improve braking efficiency.  Perhaps but one thing the patterned surface does for sure.  It makes a lot of noise when the brakes are applied.  For my money, if I never ride a set of patterned rims again, be they steel or alloy, that would be just fine with me.  I hate, both the looks and the results of the pattern.

A bicycle rim must be round first (eliminate "hop") and then true (eliminate wobble).  Wheel rims must also be positioned properly in relation to their respective hubs.  The front rim is centered over the hub while the rear wheel is "dished" (offset) to one side to make up for the added width of the freewheel.  Generally, both hop and wobble can be eliminated when frame truing a wheel.  Out of position will require a special tool that probably doesn't show up in every tool box.  The special tool is as you might have guessed, is a dishing tool and can be purchased if interested.  I built my own out of scrap aluminum angle bar and machine screws.  Works pretty good and matches my home-made truing stand.

Round is simple.  Look at the rim closely and carefully.  All the way around - both sides.  Are there any spots that are obviously damaged?  The area of concern might look to have a small dent.  The damaged area might extend for an inch or two, appearing to be "flat", when compared to the normal curve of the rim.

A rim that is dented, or has flat spots is, more often than not, trash and should be discarded.  The dent or flat spot likely occurred because the tire was under inflated!  I ensure that my bicycle's tire pressures are bang on BEFORE EACH RIDE - EVERY TIME.  This practice helps to prevent rim, inner tube and tire damage from occurring!

Flat spots can also be caused by improper spoke installation and improper truing.  It is quite possible to build a wheel out of round, simply by adjusting spokes, in a given area of the rim, too much.  To much spoke tightening,  in a give area of the rim, will cause that part of the rim to be pulled closer to the hub, resulting in a flat spot on the wheel.  This kind of flat spot will cause the wheel to hop with each revolution.  Unlike the flat spot, or dent, caused through damage, improperly adjusted spokes create flat spots, that are difficult to see with the naked eye, and will need to be identified during the wheel truing process.

Vintage road bicycles are designed to be light in weight.  In order to achieve this lightness, components, including tires and inner tubes, were built to be as light as possible, often times sacrificing durability to achieve that light weight.  This lightness is the road bicycle's bane to dependability and durability.

In the case of the inner tube, lightness is achieved by using less material to make the tube.  The inner tube's wall are very thin.  So thin, in fact, that air can actually pass through the, somewhat, porous material, allowing tire pressure to drop dramatically, between rides.  It is the air pressure, coupled with volume, that serves to improve rider comfort by offering some cushioning effect, from road irregularities.  It is these same two characteristics that serve to protect tires, inner tubes, and wheel rims, with that same cushioning effect.

Riding a road bicycle, with inadequate tire air pressure, is inviting trouble in the form of a mechanical failure - a flat tire or worse yet, a flat rim.  However, sooner or later, you will end up riding with an under inflated tire and damage just might result.  A flat tire is easy to deal with, but a flat spot on a rim is a different story.  A story that can frequently have a happy ending, though, if you know what to do.

Get rid of the dent or flat spot!  Simply bend it back into shape.  This does not mean start beating on the damaged spot with a hammer, rock or stick, although those unusual tools will, and have, worked for me in certain conditions.  Bending the rim back into shape, means getting whatever will work, as a tool, and then gently, with great attention to what you are doing, and to what you are doing it to, force the part back into shape.

NEXT - REPAIRING A DENTED RIM

 

 

 

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