Cruzbike/MBB theory vindicated (anecdotal evidence)

[billyk]

I've been enjoying riding no-hands for much of my commute, and go for miles without needing to touch the handlebars. I know I'm slower that way, but it's fun. With my hands free, I can text, take photos, eat lunch, ... (not really).

Lately it occurs to me that this gives a test of the theory that MBB bikes are more efficient because they involve the whole body. Riding no-hands means power is applied like a normal recumbent: between the lower back cupped into the seat and the pedals, like a leg-press machine. The arms and upper body do nothing.

So I've been testing the difference when I hold the handlebars, riding in a very relaxed manner, cruising on the flat. Just the very minor-seeming pull-back that happens naturally and the bike seems to jump forward. I immediately want to shift one or two gears higher. It's something like a 10% increase in speed as I feel the tightening of muscles through my shoulders and trunk.

This is obviously not an objective test, but it really feels like the involvement of the whole body matters a lot.

BK

 

[Charles.Plager]

Hi Billy,
Huh.  That's

Hi Billy,

Huh. That's actually a pretty clever test!

I'm not sure it "resolves" the question, but it is very suggestive (and it is consistent with my own experiences).

Nicely done,
Charles

 

[Vargas]

Is there any explanation why

Is there any explanation why some people simply can't ride no-hands?
I could NEVER do it on my DF bikes.
Looks like I could do it better on my SR, but didn't try it hard enough, and think it is safer to keep my hands on the handlebar.

 

[marshall2389]

I think a lot of the reason

I think a lot of the reason your power output goes up when your hands are on the bar has to do with control. With no-hands riding you must pedal and steer. This limits your ability, or at least makes it very hard to, put out high power through higher torques. Instead you must limit your torque in order to control your steering.

 

[bladderhead]

I agree.  On the

I agree. On the conversion-kit, I can't yet do no-hands. I can do open-palms, but with hardly any power. Too much power gives you pedal-steer, whether you want to go round the corner or not.

 

[ak-tux]

            ..I can do

..I can do open-palms, but with hardly any power...

@bladderhead If you can do this then I believe you can ride hands free. Look for a flat or gentle incline less than 1% grade then start with open-palms while coasting and then slowly lift the opens palms off the bars for a few seconds at a time.

Repeat three or four times, but each time increase the time off the bars.

Take a break and do the open-palms for some time and try again the next time. If you practice this for a few days, you should be able to coast hands free. Once you are comfortable, then try gentle pedaling ?open-palms ?then slowly lift the opens palms off the bars for a few seconds at a time as before. Let your legs feel the feedback of the pedal induced steer a few seconds at a time. Soon you will be able pedal away hands free.

 

[Charles.Plager]

I think a lot of the reason

I think a lot of the reason your power output goes up when your hands are on the bar has to do with control. With no-hands riding you must pedal and steer. This limits your ability, or at least makes it very hard to, put out high power through higher torques. Instead you must limit your torque in order to control your steering.

That's actually another good point.

I'm sure I'll actually add something to this conversation at some point...

 

[counterpoint]

uphill pulling works on my recumbent

I have a Carbent Sea Dragon 650c: when I really need speed up hill I will grab and pull on the horizontal part of the handlebar. It somehow changes the dynamics because the upper body is now less reclined. In that more egg shaped position I can bring more power to the pedals.