Tandem Pedalling Action

[ewep]

I don't know whether this has been discussed, and I'm too lazy too look for it.  One of the tandems in Sunday's race allowed the pilot and stoker to pedal at different angles and what looked like different cadences.  Is this possible????  How does it work?

[Sammajoor]

Something to do with the rear crankset........  where is JB when you need him

 

There was a thread on the hub a while back where it was discussed in depth.

 

sorry for bugging out on you just now mate internet dodgy in Afkakistan

 

[Guest Big H]

Some tandemmers believe that by not having the cranks in sync they can eliminate "dead spots" All that happens is two people that are out of sync and not much is gained. The different cadence could be attributed to differing cranklenghts front and back. The cadence does not change ...... it is an optical illusion. If the cadence does change the sync will also change.

[Guest Agteros]

Different size rings on the chain linking the two sets of pedals to affect the change of cadence (gearing?)

 

Crank length alone cannot affect cadence, The set of feet driving longer crankset just travel a longer distance around its BB than those on the  shorter crank length set in the same time surely?

 

[Speed Devil]

Different size rings on the chain linking the two sets of pedals to affect the change of cadence (gearing?)

Crank length alone cannot affect cadence' date=' The set of feet driving longer crankset just travel a longer distance around its BB than those on the  shorter crank length set in the same time surely?
[/quote']

 

For this argument the blades on the left of the tandem are the "timing blades"

 

Different size timing blades will lead to a difference in cadence. It would put both riders out of sync and at some time a "complete"dead spot will be achieved. So absolutely no advantage will be gained. If anything the riders will be disadvantaged because their different bobbing actions will put the whole bike out of sync. The only way in which it can work is that if one rider wants a lower/high cadence than the other.

 

Different length cranks will give an optical illusion that the two riders have a different cadence, as the pedals on the longer crank will have a faster circumferential speed to be able to complete a full turn.

[mdk555]

Just get a Q-ring.........

[decibach db]

Had mine put on my new RAVO...cant wait to feel tandem power again on Saturday!!

[eliminator]

There's been a post a while back or a friend sent me a link, can't remember (will try to find it) where some tandem manufacturer made independent tandem cranks. The stoker could coast while the pilot is pedaling and vice verca. In the reviews people who tried it said you won't go back to fixed cranks after you've experienced it.

[eliminator]

Found it!

 

http://www.davincitandems.com/dv2.html

 

I doubt that people in SA would have it though.  So those people must have changed the timing.  Maybe they set it 90 degrees apart.  I've heard some people do that.