Tuesday, April 18, 2006

My Bike:

I've actually got quite a lot of time and effort invested in this bike of mine. I'm going to add a picture or two of it here when I take a couple and figure out how to upload them via the blogger interface. I'm going to modify this post and go into some serious detail about what I did and how I did it, but for now, I'll just put this placeholder post, and maybe one picture.


This bike of mine, is really a mid '80ies Raleigh ten speed that I got for free on craigslist. It had 27" road tires originally. First I put a more comfortable seat on it, then, I flipped the handlebars around. I like to ride sitting up straight, most often, so the handgrips still weren't high enough. I put an extension tube on, and got some more mountain bikeish handlebars. After that, I found a derelict bike (also free) it had Shimano shifters and SRAM mountain bike derailleurs, so I put them on my bike.

I got a triple front crank and finally got a seven speed rear cassette (actually, a freewheel) the rear goes from 11 to 34 and the front goes 54,38,26. This is quite a spread, so I had to modify my derailleurs to handle this. The rear, I added larger pulley wheels, and moved the bottom wheel down as far as it would go. For the front, I tried just about everything, but I finally had to get a longer one, which I haven't installed just yet. But even as it is, it rockets down the road fast and climbs steep hills with ease!!

The last thing I did, was convert it to a mountain bike. I was tired of getting so many flats, so I got 26" wheels and put some Bell Dirtster's on them. With slime-filled, puncture resistant tubes and anti flat strips around those, I'm much better equipped to pedal around without worrying about flats. When you convert a road bike to a mountain bike there are a few adjustments you have to make. First, your brakes won't fit anymore--they won't reach down to the rims. So, what you do is get some BMX brakes and put them on front and rear. And, for good measure, you get the long cantilever-style brake pads--even though they're not recommended for that type of brake, they really do work much better and they're more adjustable as well.

Most importantly, you have to take the fork out back and hit it a bit with a dead blow hammer, because you need to increase the forward rake on the fork a bit, otherwise the newly converted bike will tend to turn to either side. I figured out an equation for this. Where R=Rake in inches, d=wheel diameter, and Theta=head tube angle from the vertical. Actually it's not all that accurate, and only presents a sort of starting point, or minimum bend that the rake should be. There's no major pull to the side at that value, but not a strong centering force that you need in order to ride with no hands, for example.

Anyway, I'm stylin' now!!!


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