Saturday, June 21, 2014

Contemplating Madness: Part 6

Late night switcheroo
Friday's little test session revealed that my knee was not 100% and I think I have diagnosed why. In my pedaling all Spring on "normal" bottom bracketed bikes, I have had several hours into strong winds. It has been that kind of Spring this year. I'm certainly no bio mechanical engineer, but it seems that stomping out the miles into the wind has refined my pedal stroke to work most efficiently with a narrower tread and not the wider stance of a fat bike's 100 mm bottom bracket width. My pedaling on the Ti Mukluk I think was where I got into trouble. My thighs and hips were trying t replicate the "efficiency" of pedaling my other bikes while my foot was outboard more and the discrepancy showed up in my right knee after two hours of hard pedalling into the wind on Wednesday.

So, as I said, Friday I figured out that pedalling a fat bike hard was not going to be a good idea, and with Odin's 170 miles of challenging terrain, I bailed out on the titanium Mukluk in favor of the Fargo Gen 1.  However; I had to make some tweaks! 

I had already refreshed the drivetrain and replaced the 2X set up with a lower ranged triple crank. Last night I swapped the On One Midge Bar to a Ragley Luxy Bar, re-taped the bars, and went for a test ride.

This will be much, much better on the knee!


Barturtle said...

to quote graeme obree

"the natural position for the feet to pedal in is one banana why do manufacturers make them two bananas wide" ...or in this case about 4...

Guitar Ted said...

@Barturtle: Well, obviously the tire size is at issue here. (The tire size designed for this titanium Mukluk, at any rate!)

You necessarily have to deal with chain line and the physical sizes and natures of the drive train for bicycles of varying purposes.

Again- I am not schooled in the ways of bio mechanics, but I've often wondered about the differences in cycling, running, and walking in comparison to things like the stances recommended for weight lifting, football, and the like, which are always wider.

Obviously- the more natural feeling thing to do is to keep your feet closer together when cycling. It's at what exact point do you have the best efficiency, and since we're limited by mechanical design, that may always be a compromise. Then it becomes a question of what one can tolerate, and in my case, right now, it isn't a 100mm wide bottom bracket!

Nick Pankhurst said...

Good case for a shaft drive bike?

Guitar Ted said...

@Nick Pankhurst: You still have to clear the rear tire, and I'm pretty sure at a minimum you'd have to use an 83mm bottom bracket, like the DH rigs use.

No matter- I used the Fargo today and I think that's going to be fine.