Sandy wrote:
> 531Aussie wrote:
> > it's basically this guy: http://www.bsn.com/Cycling/cranks.html (Ed
> > Zimmerman), who presents a traditional view with some very convincing
> > points.....
> >
> > verses
---8<---cutting a bit
> With all the answers, just think about this : if you properly keep the same
> saddle to pedal axle distance, then at the top of your pedal stroke, you
> find your thigh a full centimeter higher, if you switched from 170 to 175.
> Your initiating muscle groups change, and the timing changes. Your recovery
> muscle groups work longer, and the timing changes.
>
> That said, it's up to you to feel whether these real changes improve or
> degrade your pedaling. They may not have much effect, also. But if we know
> that the change of a centimeter in your horizontal extension makes a pretty
> palpable difference, it may well follow that pedal lengths do influence your
> performance.
>
> Personally, I think they do. Finding which length is your most effectiveor
> efficient would take a lot of time in each to evaluate. I think Leonard
> Zinn has done some of that work, but he has his own biases, people say.
>
> --
> Sandy
I'll share some of my experiences. Original cranks 172,5, inseam length
85 cm (33,5 in), have had occasional knee problems previously, more
related to running. Pedalling with seat slightly low, cleats moved back
towards centre of foot, typical cadence ca. 105.
Bought 177,5 cranks (C-Rec), lowered seat 5mm, moved it forward 7mm.
Should've bought a longer stem but didn't bother. Rode 400 km over 3
weeks, typical cadence appeared to drop to ca. 93. Knees stayed OK,
since I pedal short gears at highish cadence. But my back muscles (at
pelvic level) were already fatigued due to overtraining in the period
before the crank switch. These muscles got worse, probably due to the
cranks, so I had to switch back to the shorter ones to do one of the
classic rides here (Sweden, Vättern Rundan, 300 km).
Now I'm going to spend the summer riding the longer cranks *nice and
easy*, allowing my back muscles to get used to them. I am also choosing
a higher saddle position which feels a bit easier when the foot's just
past the top of the stroke. This change in saddle height addresses
Sandy's point pretty well I think.
What I like about the long cranks is that I tend to reduce cadence to a
more reasonable level without me feeling I'm stressing my joints. My
hill climbing is so much better too, both sitting and standing. But I
wouldn't recommend a crank change to everybody; it's a bit of a
borderline case with me. But I'll try them for 2-3 months more, and
re-evaluate.
Sandy, can you pls explain "recovery muscle groups", I'm a novice at
this.
BR /Robert