Yamato72

Interesting that you say that, as I definitely feel like I am pedaling toes-down, even though I set (checked) my saddle height with my heel on the pedal. I'll check out the video and investigate further.

Thank you for the warning based on your experience, yes I'm way too active to risk messing up my feet!

Carbonfiberboy 

Brand/model doesn't much matter as long as they have coded transmitters or are a different brand. We use two Garmins for navigation and my HR and then Stoker has a Polar watch for her HR. All ANT+ units that I know of have to be paired with their receivers, so anything ANT+ should work for both positions. Or one ANT+ and one Polar for the stoker's position like we have, however one wants to arrange that. Stoker also has to have some idea of LTHR and cruising HR, etc., for both people. Our team works best if Stoker usually runs ~5 beats ahead of me. Most women have higher HRs than men.

We go by breathing for a rough guide. If I hear her panting and I'm not, I tell her to back it off. If I'm panting and she's chatting I ask her for a little more power or I just say, "Are you with me?" Starting a hill using HR, Stoker will always lag my effort because my HR takes a while to come up. OTOH, after my effort her power stays high a little too long. So it's not perfect, but kindness and understanding helps, as always. Following another bike, she holds steady power and I vary mine to keep the right distance. That works pretty well.

Carbonfiberboy 

You may remember the tandem team we used to have on here composed of M-F track racers. Their tandem time on Mt. Diablo was the average of their single bike times. I don't know where you got the efficiencies for captain and stoker, but whereas a tandem (with the exception of BBs) has one of everything, 2 singles have 2 of everything. So I don't get that a tandem is less mechanically efficient than the sum of 2 singles. I do get that a team that isn't well synched will definitely suffer power losses. Even after lots of practice, we still don't climb well out of the saddle. OTOH, my stoker can't ride out of the saddle at all on her single. So we are definitely better on the tandem than on 2 singles.

Carbonfiberboy 

Just feel for that heel cup all the time. You could be pointing your toes even if your saddle is at the perfect height, whatever that is. It's an easy habit to fall into. I do it myself when I'm distracted. We climb stairs toe-down, after all.

merlinextraligh

the 7% power loss for the captain has been referenced on several previous BF threads. IIRC it comes from one or more studies. The explanation for the loss is the captain's power has to be transferred through 2 bb's and two chains to get to the hub. It's one of the arguments for making the stronger rider the stoker.

I didn't find the reference in a quick google search, but it's somewhere in BF archives.

merlinextraligh

Found the reference. Testing by BF's own ASU_GT, found a 6% loss for the captain, and a 1.8% loss for the stoker. So I was off by a percent.

https://www.bikeforums.net/tandem-cy...nsmission.html

noglider 

And also two chains. This is a good argument for putting the stronger rider in the back. Too bad it doesn't work most of the time. Often, the weaker rider isn't strong enough to hold the bike up.

Leisesturm

For a conventional tandem drivetrain that does not have IPS, it should not be the assumption that the Captain's power is anymore impacted by the drivetrain components than the Stoker. Even if a tandem were locked in a trainer and the Stoker assessed separately for power output they would still activate the Captains bottom bracket and the timing chain. The only explanation for the measured difference in the combined power of a tandem team vs the Captain and Stoker separately is due to the difficulty of synchronizing independent powerplants. Triples are worse, Quads even worse. That's why 8 man tandem craft have never taken off. 8 man rowed shells compete with a non-rowing Coxswain who functions mainly to coordinate the efforts of the Crew. Even so, the primary benefit of pairing, trebling and more of individual efforts is social vs performance. An 8 man rowed shell is not 8x faster than a single scull, not even close to that. The aerodynamics of the close drafting position of the Stoker behind the Captain should outweigh all of the drivetrain inefficiencies. What is left is Companionship and Sociability. A fair trade, I think.

Chancy

There is the loss of efficiency (of the captains power) thru the timing chain and drive chain, plus the (loss) flexing of a longer frame, and the flex of the boom tube as the captain pedals. These things rob some of the captains power before it gets to the rear wheel and not in play (other than the drive chain) for the stoker's power delivery.

I am not an engineer, so if I am missing something here, please comment.

Tailwinds,
Charlie
Charlie

Leisesturm

I am not an engineer either but it is obvious to me that things aren't as neat and tidy as "the Captains power flows through the total drivetrain but the Stokers power just flows through the drive-chain". There are times when my Stoker does not get the memo to cease pedaling(!) and tries for a quarter revolution or so to keep going. Why only a quarter revolution? Because her efforts are quickly resisted by the uncooperative timing chain and if we are going to go there then boom stiffness is a factor in exactly what is felt at the Stoker cranks. Even if the more powerful person is at the Stoker position they can only do what is 'allowed' by the weaker rider otherwise they waste energy trying to drive the Captains feet around. Clearly the Stokers power, rather than flowing entirely and directly into the drivechain must of necessity interact with the power (or lack) generated by the Captain.

dragonlord76

Totally agree with you.

Carbonfiberboy 

All the above said, yesterday a steel CoMo tandem in our group with a well-trained but ordinary 50's team knocked out a 5800', 55 mile ride with no problems. They had a great time.

WrenchSpinnr

There is an interesting thread under this topic ("Different Spin Rates Causing Problem") you might want to check out. There are ways you can adjust to make your stoker more comfortable. I'd guess you might both be happier if you worked on that and rode your tandem more.

Dean V

I also have found climbing to be a bit slower on the tandem.
One of my stokers is of similar ability to me and if we ride with our usual group of singles on the tandem we definitely struggle more on the hills than usual. It isn't a huge difference but definitely noticeable.

noglider 

Our power difference is huge, and we have a heavy cheap tandem, so hills are HARD for me. But it's OK. I'm riding with my sweetie.

zonatandem

Mid-60 is old??? Really!!!
At that age we were still riding lots of centuries on tandems.
Now at ages 85/83 we've mellowed quite a bit but still get out once or twice a week.
Agreed, not as fast and not as far! Go for it!
We've ridden over a quarter million miles TWOgether on tandems since 1975. Now on tandem #5 and this one has over 45,000 miles on the odo.
Pedal on !
Rudy and Kay/zonatandem

124Spider

To bring this up to date, we just got home from the Ride from Seattle to Vancouver plus Party (RSVP), 106 miles/4000 feet of climbing the first day, and 81 miles/2600 feet of climbing the second day. We rode the tandem. It was a blast.

Thanks for the encouragement!

zonatandem

Told ya you two could do it!
Pedal on TWOgether!
Rudy and Kay/zonatandem

Alcanbrad

124Spider

I hope it works out well!

Paul J

Wishing you a speedy recovery! Better to be off the bike in January/February then spring/summer/fall. :-)

Alcanbrad

Thanks folks. I did schedule surgery for the off season, but when you ride year round, it is still frustrating to not even be able to use the trainer.. This soon should pass