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# A question of Mathematics

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# A question of Mathematics

12-01-09, 01:55 PM
#1
stevegor
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A question of Mathematics

Does anyone know a formula that accurately compares mileage/time spent between different disciplines of cycling, as in:

50 miles on a solo road bike = ? on a tandem = ? on a Mtb = ? track?
12-01-09, 02:03 PM
#2
WebsterBikeMan
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Originally Posted by stevegor
Does anyone know a formula that accurately compares mileage/time spent between different disciplines of cycling, as in:

50 miles on a solo road bike = ? on a tandem = ? on a Mtb = ? track?
Wouldn't that be nice. Between tandem and road single it will depend on the bike and the team. Between anything and Mtb will depend on the terrain, and between track and road bike will depend on the roads ridden, including the terrain, and the wind, and...
12-01-09, 07:10 PM
#3
sch
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Stokers experience differs from pilots experience judging from observations made by local teams with fairly strong riders.
ATB bikes require a good bit more energy to push the knobbies over terrain, so a 50mi ATB ride would be considerably
more challenging.
12-01-09, 07:28 PM
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JanMM
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Way too many variables to have a neat formula for this.

And don't forget that 1 mile = 1 mile.
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12-01-09, 11:36 PM
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professorbob
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I was told once (some guy... i read on the net.. they say...) that a 50 mile mountain bike race is roughly the equivalent of a 100 mile road race.
12-02-09, 04:59 AM
#6
stevegor
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I ask because, after a 2hr MTB ride, I'm knackered and a 2hr Tandem ride, I'm knackered, but a 2hr solo, not knackered.
12-02-09, 07:23 AM
#7
DCwom
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As others have said there are way too many variables, however different bikes usually mean different terrain so unless you're comparing a mountain bike on a road or a road bike on a muddy trail (funny sight) nothing really compares.

When we first bought our tandem I did a totally unscientific test between my hybrid single and our new "roadish" hybrid tandem; I spun the front wheels as hard as I could and timed how long it took before it came to a complete stop. The single was something like 2 minutes, while the tandem was over 5 minutes! Apples & oranges I know (700cc vs. 27 inch, etc.), but still the new tandem wheel spun for more than double the time, so it is likely a better rolling bike, at least where the wheel bearings are concerned. I imagine that the 32mm tires also have less rolling resistance than the 1.75 inch tires on the single hybrid.

If I had to make a guess for myself I'd say I'm about 1.5 times better on the tandem than my single, but my stoker might argue that she's 33% less efficient YMMV
12-02-09, 08:58 AM
#8
blamp28
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Originally Posted by stevegor
I ask because, after a 2hr MTB ride, I'm knackered and a 2hr Tandem ride, I'm knackered, but a 2hr solo, not knackered.
Now there you go. If you simply ride until you're "knackered" and do the math, you will have a formula that works within the variables in your situation. We all have our own variables we bring into this as well.

I ride two MTB endurance events every year and I can tell you that the 28 mile and 48 mile events take me 2:45 and 4:15 respectively and are nothing at all like 3 or 4 hour road rides due to the terrain and pace. I do find that pushing hard on the tandem with my wife gives me a better workout than I had expected even if we are not going fast. I'm guessing it is the "resistance" of taking more than 50% of the load. It works for both of us and we get more time together.
12-02-09, 11:09 AM
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Hermes
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I do not know of a formula per se other than comparing power numbers. As a captain, I find that riding the tandem and riding on my road bike are about the same. I have done a little mountain biking and find it requires much more torque in pedaling and the uneven surface, even with full suspension, uses energy to absorb the bumps. I ride and race at the track and it requires high cadence and high power for short efforts. A sprint tournament with a warmup and several sprint competitions is very tiring.

I have power measurement on my road and TT bikes. And if you load the power data into Training Peaks software, it will calculate a training stress score or TSS. In the book, Training and Racing with a Power Meter, TSS is discussed. Essentially, the more one is close to, at or above threshold power, the higher the TSS. A 40K time trial at threshold power is equal to a TSS of 100.

So, if you ride your road, tandem, time trial, mountain or track bike for an hour at threshold power (not easy to do) the TSS score will be the same or 100. Training Peaks will not know which power meter or bicycle is providing the power data.
12-02-09, 11:59 AM
#10
Retro Grouch
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I don't know about comparing a tandem to a single bike but I know that stoker's don't ride as far as captains.

Make a turn after riding through a puddle. The back wheel always cuts the turn short.
12-02-09, 02:50 PM
#11
Stray8
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Originally Posted by stevegor
I ask because, after a 2hr MTB ride, I'm knackered and a 2hr Tandem ride, I'm knackered, but a 2hr solo, not knackered.

Well, then there you have your personal power exertion equation (independent of mileage) for your particular situation:

2 hr MTB riding = 2 Hr Tandem riding = 2 Hr Solo riding x 1.25 bike weight penalty x 1.25 tire rolling resistance penalty.

So according to this theory, if you just increase the weight of your solo bike by 25% (e.g. put enough rocks into panniers) and swap over to MTB thick knobby tires, you should then become equally knackered after a 2 Hr Solo ride in the dirt...LOL.

.

Last edited by Stray8; 12-02-09 at 03:17 PM.
12-02-09, 03:19 PM
#12
Murf524
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You forgot to throw a trainer into the mix. I've heard people state that riding a trainer for an hour equates to 45 minutes on the road since you don't have traffic signals and such to contend with.

Gotta agree with the observations about too many variables...
A 45 mile ride with my wife and an 18 mph average on the tandem and I'm feeling great. The same ride at a 15 mph average with my 15 year old I'm whupped for the rest of the day.

Last edited by Murf524; 12-02-09 at 03:19 PM. Reason: spelling error
12-03-09, 04:30 AM
#13
stevegor
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OK, maybe I've asked a dumb question here.

I do find that pushing hard for 2+hrs on the tandem hurts the legs more than my solo.
Doing a hard MTB ride also hurts more...maybe I just need to "Harden up?"
12-03-09, 07:35 PM
#14
Hermes
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Originally Posted by stevegor
OK, maybe I've asked a dumb question here.

I do find that pushing hard for 2+hrs on the tandem hurts the legs more than my solo.
Doing a hard MTB ride also hurts more...maybe I just need to "Harden up?"
It was not a dumb question but you need to HTFU anyway. As we all do.

However, if you, as captain on the tandem, try to provide all the necessary energy to hold speed on slight climbs and accelerate without help from the stoker, then it is a tougher day in the saddle on the tandem than on the single. I find it is more perception. You think you should be going faster and put in more power. In essence, you are producing more energy on the tandem than on the single.

Conversely, if you do not increase power and the stoker does not either, the bike slows down. That is not bad per se, it just seems wrong to the captain compared to what one would expect from a single.

Other issues could be fit or Q factor. If the tandem is a triple and you are used to riding a double, the triple is wider. Some riders are more sensitive to this than others. My tandem has 175 cranks and my singles have 172.5 so there is a difference in Q and crank length.
12-04-09, 06:27 PM
#15
Dean V
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Originally Posted by Hermes
It was not a dumb question but you need to HTFU anyway. As we all do.

However, if you, as captain on the tandem, try to provide all the necessary energy to hold speed on slight climbs and accelerate without help from the stoker, then it is a tougher day in the saddle on the tandem than on the single. I find it is more perception. You think you should be going faster and put in more power. In essence, you are producing more energy on the tandem than on the single.

Conversely, if you do not increase power and the stoker does not either, the bike slows down. That is not bad per se, it just seems wrong to the captain compared to what one would expect from a single.

Other issues could be fit or Q factor. If the tandem is a triple and you are used to riding a double, the triple is wider. Some riders are more sensitive to this than others. My tandem has 175 cranks and my singles have 172.5 so there is a difference in Q and crank length.
This is pretty much how it feels for me on the tandem. As I am a stronger rider than my wife it seems that I tend to push harder than I normally would solo, just to get the tandem going what feels "right".
This is compounded somewhat due to me having a faster spin also. So when the cadence drops it suits my wife but I feel I need to push to get on top of it. When cadence increases her output drops, along with bike speed.
We are both riding 170mm cranks and I know that it will improve if I put 175s on for me. Just haven't got around to it yet.
As for comparing to time on the MTB. It depends a lot on the sort of terrain being ridden.
12-05-09, 09:31 AM
#16
stevegor
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I borrowed a MTB tandem to take my VI stoker for his first off road ride the other day, half of the ride was on a trail the other was on the road, best leg workout I've had for awhile, in fact it wrecked me for a few days.

My guess the sum would be if you rode a tandem, solo roadie, MTB and track bike on the same flat road for 20 miles each...

20m solo= 25 tandem=30 MTB= 22 track?
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