Can anyone explain why..

Roger Davies · June 2007

Tandams are faster on the level but slower uphill? I've never ridden one but know people who do. That's what they say. I cant figure why.

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Old bikes are better

Mystique · June 2007

Going uphill it's weight - flat or downhill it magically becomes momentum (especially with a fatty in the rear gunners seat...).

I've not been right since my karma ran over my dogma

alecstilleyedye · June 2007

more weight has more effect on climbing the hill. for example, in the tdf big, heavy cyclists can pull the peloton along at 50kph and put in a good TT but die a death on the mountains, while the elfin lightweights can dance up the cols with ease but cannot TT and of limited use chasing down a break.

if i had a better signature, i'd use that instead

Mosschops2 · June 2007

Hmmm. Momentum though is just weight x speed.

And on the basis that a rollercoaster full of, as you put it fatties, would not go any faster than an empty rollercoaster, I don't think your answer is correct.

Having said that, I do not know the answer either.

I might expect flat / downhill speed to be higher as you have the same air resistance, but much more power. (Since air resistance is the greatest force "holding you back").

As for uphill.... heavy bikes?? Not sure why that would make that[/] much difference.....

Have you ever tried pressing Alt+F4 ??

somekindofwizard · June 2007

Surely wind resistance comes into it? There is no bigger area of air
resistance for the two riders compared to one with lots more power?

Roger Davies · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Mystique

Going uphill it's weight - flat or downhill it magically becomes momentum (especially with a fatty in the rear gunners seat...).

I've not been right since my karma ran over my dogma
<hr height="1" noshade id="quote"></blockquote id="quote">

Thanks but I still dont get it. Power to weight on a tandam should be higher than on a single because there is less bike -right. So shouldnt that have as much effect going uphill as level?

********************
Old bikes are better

wherryman · June 2007

wouldnt the person behind go faster by being in the slipstream.........hee hee

Richrd2205 · June 2007

http://www.mayq.com/Best_european_trips ... d_math.htm
Downhill & on the flat, power is about twice that of a solo & wind resistance is roughly equal, so the tandem is faster. Uphill, power is still about double a solo, but mass/weight is prob a wee bit more than double, therefore the solo might be faster...
In fact, power is likely to be less than twice that of the solo since finding the perfect cadence for both riders is going to be difficult.
Hope this helps...

simbil1 · June 2007

Haven't ridden a tandem but I expect the position is different?

On a bike, the rider can apply weight down over the pedals for maximum power. If the position is laid back like in a recumbent, driving the pedals is all down to muscle effort without any assistance from the riders weight. That's fine on the flat where you just apply a little force to maintain speed, but up hill it is not enough power.

That's my guess

<edit>
Damn it, where is my brain?! I read 'Tandem' as 'Tricycle'. Must get more sleep, must get more sleep...

http://picasaweb.google.com/thefirstsimbil/Bikes

Mister Paul · June 2007

We got a good speed up on the tandem yesterday going down a hill, and kept much of the momentum going up the other side. We passed an MTBer struggling to get up on hte granny ring. We were knocking 30mph. the look on his face was priceless.

__________________________________________________________
Road Safety Expert

Adam_57 · June 2007

From the CTC website:

Tandems

In tandem means one behind the other and in cycling that confers several advantages, most of all with regard to wind resistance. On a tandem you have the power output of two and only a bit more drag than one, so tandems go better into a headwind, downhill and on flat roads. Since their weight is also less than double, tandems ought also to go a bit better uphill; but they don't and this is a source of much debate. The most likely explanation is that you don't actually get double the power, especially uphill, when each rider tries to move the bike in his own particular way and must instead reach a compromise with his partner. This theory is confirmed by the observation that well-matched riders can go uphill as fast on a tandem.

Simon Notley · June 2007

Yep, the CTC have it I'd say. In theory, the tandem should be faster all round, but climbing requires a lot more technique and subtle changes in effort meaning the riders are unlikely to be able to co-ordinate perfectly and end up not being able to use their full potential.

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If I had a baby elephant, I'd fit right in here.

Roger Davies · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Simon Notley

Yep, the CTC have it I'd say. In theory, the tandem should be faster all round, but climbing requires a lot more technique and subtle changes in effort meaning the riders are unlikely to be able to co-ordinate perfectly and end up not being able to use their full potential.

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If I had a baby elephant, I'd fit right in here.
<hr height="1" noshade id="quote"></blockquote id="quote">

That sounds the most likely explanation. If so it follows that a practised couple on the right machine should be faster uphill as well.

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Old bikes are better

Buggi · June 2007

because the one at the back isn't peddling [:D]

_____________________________________________

To infinity... and beyond!
my epic adventure: www.action.org.uk/~Antonia

france · June 2007

Originally posted by simbil1

Haven't ridden a tandem but I expect the position is different?

On a bike, the rider can apply weight down over the pedals for maximum power. If the position is laid back like in a recumbent, driving the pedals is all down to muscle effort without any assistance from the riders weight. That's fine on the flat where you just apply a little force to maintain speed, but up hill it is not enough power.

That's my guess 

Wrong Guess about recumbents and tandems
leaping out the seat is not allowed ....
so you loose 5 points and now the other team has the bonus question
Why not ride one or two you might be surprised ....

A Recumbent team have won the RAM ride in the USA ?
Andy Wilkinson beat his own UK LeJog upwrong record on a recumbent.
A retired couple travelled accross the states on a tandem recumbent
and the wife managed to find time to knit two pullovers
whilst pedaling on the back ! .....
If you check the flat map they all had to ride up hills !
its all about using gears (big cogs little cogs )and the brain rather than the product sold in traditional butcher shops .

simbil1 · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by france
Wrong Guess about recumbents and tandems
leaping out the seat is not allowed ....
so you loose 5 points and now the other team has the bonus question
Why not ride one or two you might be surprised ....

A Recumbent team have won the RAM ride in the USA ?
Andy Wilkinson beat his own UK LeJog upwrong record on a recumbent.
A retired couple travelled accross the states on a tandem recumbent
and the wife managed to find time to knit two pullovers
whilst pedaling on the back ! .....
If you check the flat map they all had to ride up hills !
its all about using gears (big cogs little cogs )and the brain rather than the product sold in traditional butcher shops .
<hr height="1" noshade id="quote"></blockquote id="quote">


France, boooo, you quoted my post without my edit?! Who are you - Jeremy Paxman

So is a recumbent faster up a steep hill than a racer (same rider, just the hill)? I don't think anyone would doubt that a recumbent is faster over all due to the vastly improved aerodynamics - but specifically up a steep hill...?

I would argue that the main propulsive force of a race bike is the riders skill and strength to utilise their weight over the pedals on the down stroke. Without weight over the pedal (i.e. as in a recumbent position), your left with opposing torque and pushing against the seat to drive the pedals which has to be less efficient as it is all generated by muscle power without any assistance from gravity.

http://picasaweb.google.com/thefirstsimbil/Bikes

y tincp · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Simon Notley

Yep, the CTC have it I'd say. In theory, the tandem should be faster all round, but climbing requires a lot more technique and subtle changes in effort meaning the riders are unlikely to be able to co-ordinate perfectly and end up not being able to use their full potential.

---

If I had a baby elephant, I'd fit right in here.
<hr height="1" noshade id="quote"></blockquote id="quote">

So.....a fixed tandem would be the way to go then? Both pedalling smoothly together.

>^..^<

slowfen · June 2007

Having ridden a tandem, and still own one, one of the big problems is frame flex, you may have twice the power, but the frame really flexes. Also I don't believe a tandem is lighter than two solos, mainly because of the bigger diameter heavy weight tubes used to help try and counter the flex. (The galaxy twin feels more than twice the weight of my horizon)

Trii · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Buggi

because the one at the back isn't peddling [:D]

_____________________________________________

To infinity... and beyond!
my epic adventure: www.action.org.uk/~Antonia
<hr height="1" noshade id="quote"></blockquote id="quote">

That's the most likely explanation imo :P

Mark Alexander · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Mystique

Going uphill it's weight - flat or downhill it magically becomes momentum (especially with a fatty in the rear gunners seat...).

I've not been right since my karma ran over my dogma
<hr height="1" noshade id="quote"></blockquote id="quote">

Simple and brilliant explanation. love it[8D]

my elephant has more memory than my PC

Can anyone explain why..

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