Tuesday, May 11, 2010

Gear me up

ACCESSORY 31: Freewheel $27.50 @ Nomad Cyclery

The climbs are really killing me and I have trouble admitting that it's my poor health and fitness that's to contribute to my pain and burning quads. These road bicyclists have something up their sleeve that I don't know about.

It's the gears! I called up a bunch of bicycle shops (since my mechanic, Justin from Nomad Cyclery won't be in until 12:30pm) and asked how comfortable they would be in modifying a recumbent trike.

Most are reluctant b/c of their unfamiliarity with them, but they're basically the same as bikes. Others don't want to touch it b/c it takes up too much store space. Why let a trike take up the space of 5 paying customer's bikes? From a business perspective, I get it. But it's frustrating. Justin's boss hates having the trike in there, but at least Justin's cool with it at the shop and since he's the one working on it, I'm liking the place.

I learned from Mike at DD Cycles this morning that my trike is hard to modify b/c it has a freewheel as opposed to a cassette that can easily be modified. Cassettes pretty much replaced the freewheel setup since the 80's. Mike said it would be hard finding a freewheel better geared for hills. They're just not as available anymore these days.

It was time to pay a visit to my mechanic, Justin and my trip paid off! Justin hooked me up with a hard to find, now discontinued part! It's a freewheel geared for hills! The original freewheel (above photo) is 13-28. This new one, the Shimano Mega Range is a 11-34! What does this mean?

After researching the web and talking to a couple guys, I sort of figured it out.

We all know to shift a car into low gear when climbing hills. We never see the actual gears in the car, so it may be a bit hard to understand the mechanics behind it.

First off, some definitions I learned. The cluster of gears on the rear wheel is either a cassette or in my case, a freewheel. Each individual ring is called a cog.

The lower gears in fact are the larger cogs- not the smaller ones. It's a bit counter intuitive until you think about the physics of it. The easiest way for me to think about it is to just remember that the larger cog provides more help to the pedals or chain ring up front - the big cog is for big hills. The largest cog with the red MegaRange writing on it in the photo is the lowest gear used for climbing steeper hills. This particular one is a 34t cog (t in 34t stands for tooth).

This 11-34t has two benefits over the 13-28t and all for only $25 plus tax! I'm still having a hard time getting over the price tag. So cheap. I've seen others in the hundreds. It's my favorite mod so far (for my trike AND my car).

1. The 11 gives me better speed on the flats compared to the existing 13.
The non-discontinued, readily available, order-it-from-the-internet-and-get-it-in-five-days freewheels that would fit my bike are 14-34t. That means I would actually lose speed on the flats (since 14 is higher than 13 and therefore a larger and slower gear). I'm lucky I got a hold of this Shimano freewheel. I originally left the freewheel at the store for Justin to install it next week, but after researching how hard it is to find, I went back to pick it up so it doesn't accidentally get sold to someone else.

2. The 34t cog gives me tons better hill climbing capabilities compared to the current 28t cog (hopefully).
It'll be like having three extra low end gears. I can't wait to put this bad boy on and see how well it works. Notice that the difference between the largest cog at the bottom (lowest gear) and the second largest is really extreme. There's a big difference in diameter and it's not gradual like the remaining ones stacked on top in an upside down cone shape.

The high end and low end it good to know, but I'm curious how many teeth the middle cogs have. I just counted and the number of teeth for each of the 7 cogs and it is:


The higher gear cogs are spaced closer together - 2 teeth apart. The low gear cogs are spaced a bit higher at 3 teeth apart. Interesting....

The trike will shift down fairly smoothly from gear 7 to 2, but once I hit the final "bail out" gear, I'm expecting to feel like Superman. If I can climb hills more easily, I'm up for the AIDS Life Cycle! ALC, here I come!

1 comment:

  1. Good job on finding that Shimano Freewheel. I am looking forward to hearing how much better it is vs stock on both the hills and the flats.

    I have a 11-32t freewheel that I have been wanting to mount on my Tornado, (Not a Shimano but a Chinese copy - looks pretty good though). I called Ashley Guy @ Utah Trikes and he informed me that there are NO 11 tooth freewheels that fit the mag wheel on the Tornado. I will be very happy when you prove him wrong :)