shorter cranks muni = great but super exhausting??
So yesterday I had one of those “cloud with a silver lining” experiences…
My muni skills have improved over the last few years and I’ve moved from 24" to 26" to now 29+ (30.5") and both my uphill and downhill have really improved. So for yesterday’s ride I switched out my 150mm cranks for 127s… and technically I did incredibly great: I was able to ride up almost all uphills that I ride on my 26 with 150s and my 29+ with 150s. As expected short/fast uphills were easier but even super steep slow crank-and-pause hills went great (that was really amazing and a great feeling!). And downhill I was able to ride (almost) as well as with the 150s. Only for hops and drops did I really feel the difference. And, as expected I was WAY faster. It was amazing.
However, there was a major down side:
But what I couldn’t believe is just how incredibly tired and exhausted I was. I’ve thought about it a lot and the only theory I can come up with is: b/c of the shorter cranks I am forced to spin fast all the time. Uphill I must use high force to keep riding and downhill I must spin fast. And slow-speed/technical then requires concentration and force on the pedals to stay on the uni. And (duh) as there’s no freewheel there is no rest or recovery time at all.
After the first hour or so I had to stop and take a break and then for the next 3+ hours I had to get off and take a significant break about every 20 minutes or so because I was so thoroughly exhausted. This was on my normal 2-4 hour route that I’ve been doing 1-2 times a week for the last 2+ years and am I usually never forced to stop for recovery although I usually take 1-2 breaks just because and to eat/drink. But my level of tiredness was crazy and near the end of the ride, even after taking a break for 20 minutes I would get back on and ride up one hill and 10 minutes later again feel like I was about to die… (I’m guessing I had already massively over-exerted myself so I had no reserves left at all)
I’ve done lots of enduance sports over the years (mtb, road/trac/crit biking, trail and mountain running, etc.) but I’ve never been as thoroughly exhausted on a fun/training ride as I was: ok, maybe at the end of some multi-hour races where I pushed myself really hard, but never from a training ride. Or maybe a few times due to high heat in >95F (35C) high humidity, but yesterday was around 22C(72F). And I’ve bonked due to lack of energy, but that is different and was not the problem (after taking a break and eating and drinking it was not significantly better).
Anyone ever experienced this when dopping down crank length? I had a simliar experience about 6 months ago when I had dual hole 150/127 cranks on my 36 and had had them at 127 for a road tour and rode to the trailhead and just thought, “It’ll never work, but I’ll try and ride the trail with the 127s…” With the 127s on the 36 I wasn’t able to ride everything, especially the steep uphills (but my technique has also improved since then), but I was also totally exhausted after 15 to 20 minutes.
So I’m not sure:
Do I leave the 127s on and expect (hope) that my fitness will improve with time?
Or do I switch back to the 150s as all-in-all it is more fun to not feel like I’m about to puke out my guts from exhaustion? (and today I still feel like I got hit by a truck)
Maybe I’ll break out my heart-rate monitor again. However if I remember correctly from my last attempts with muni, the correlation of the HR with exertion was not nearly as informative as in cycling or running (I assume because you do a lot more then just push the pedal/feet but also have to balance). And then what do I do if I find I am riding in too high % zone? I can’t switch gears or slow my footspeed?? With the short cranks it is either 95% effort or get off and walk…