Saturday, October 18, 2008

Something Simple

How often do I hear, "I need something simple, like an old English bike. Them new fangled De-Rail-Eurs is to complex for me to handle" (Tip: A bunch)

So I point them to the one bike, in the shop, that has an internal hub. When they see that the "simple" bike of their dreams cost eighty bucks more than the one with a derailleur, they run screaming from the shop. No doubt in search of two sticks with which to light up their next Marlboro.

Now look, the first thing is that an internal hub only seems simple because you cannot see all of the stuff inside the hub.

(Note, this is what you see if you break even one of those hair springs(They look like hairs in the shot)and need to replace it.
ALSO, this is the simplest internal hub, it is a three speed. Most modern hubs have twice the gears and twice the parts)

A derailleur is much more simple in construction and is as easy to adjust(if you know how) on the rare occasions that you might need to do so.

(Note, this pic is far more "apart" than you ever see your der. because the most likely thing to break is a pulley which involves only the removal of a single screw. You do not even need to take the wheel off)

An internal hub uses a set(or sets) of planetary/ring/sun gears to give several different gear ratios. This makes for lots of little gears and springs and pawls, and a couple of more springs then a separate gear carrier. Oh, and then you have the shift action that is part of the hub. And if you want the "simple" brake, the coaster or foot brake, add another spring, some friction material, a drum and a screw engagement. And an indexed shifter.

A derailleur just uses a properly length parallelogram setup that indexes to the shifter.

Pay no attention to the exposed derailleur. Its apparent complexity is a LIE.
If you set up a der. right it will work without flaw for years.
To be fair, so will an internal hub. Until a hair spring fails and you have to completely disassemble it(see picture above)

But here comes the fun part:
You want the internal hub because it is simple and you want a simple bike when you ride back and forth to work.

What happens when you get a flat?

Well first you unscrew your carefully adjusted cable and unhook it from the hub(It shifts thru the end of the axle(Sturmey) or thru a mechanism on the hub shell(Shimano). Then you remove the cable guide, undo the nuts, take off the axle index washers, and hook the chain over the dropout so it does not lay in the dirt while you repair your tire.

To reinstall: you slip the axle back into the dropouts, making sure to line up the chain, reinstall the index washers(after remembering where you laid them down) by twisting the axle to the correct angle(with your fingers), finding the nuts(near the index washers, in the dirt, by your foot)you install them, while trying to keep the wheel straight and the chain properly tensioned.
If you also needed coaster brake "simple", include: Line up torque arm and find torque arm hardware(in dirt by foot).
Flat tire repair time: twenty minutes. Wait, you are the guy that wanted a "simple" setup. Actual Repair Time: How long does it take you to call some one on the cell and get them to haul you to the bike shop and have the shop fix the flat for you?

Now if you have a derailleur equipped bike:
Shift to small-small gear combo.
Open quick release, remove wheel. The der. will hold the chain in place.
Fix flat.
Slip the wheel back in to place and re tighten quick release.
Repair time: Ten minutes, (I can do it in three, you are just slow)

All I can figure is that people looking for a "simple" set up have a vague recollection of three speed "English bikes" back in the mist shrouded by-gones of friction shift road bikes.
All bikes are index shift now. Click and shift. If you can read this column, you can operate a modern thirty speed bike(Unless you have some kind of inner ear balance problem).
Modern bikes have a better range of gears. This means smaller jumps between gears as well as a lower low gear and taller top gear.
So go ride a derailleur equipped bike before making some kind of silly judgement based on vague recollections of bikes you never rode in the first place.


Ben said...

Tellin' it like it is as ever :)

Also of note people who look at my bike and say "you have too many gears"

No, I do not have too many gears. You ponce to uni at 2 km/h. I smash my way through the woods at 30. My number of gears is just fine, thanks :D

(and it's only 21, christ.)

Chuck said...

When you calculate the ratios out, it does not even come to 21. They overlap and you have some redundant ratios.
If people could really see how complex some of the "simple" things they take for granted are, their heads would explode.

Old House Gazette said...

Don't forget that people seem to think that if you have 30 gears, that you have to start at "1" and go to "30" every time you start riding. I always tell them "It ain't a f@#$ing Toyota!"