Do you find riding a tandem easier or harder than your single?
03-25-23, 12:26 AM
#76
Newbie
Originally Posted by merlinextraligh
makes total sense that higher load equals higher rolling resistance. That doesn’t begin to say that for a given load, the rolling resistance of a tandem on two tires is higher than two singles on 4 tires.
Tandem two riders, load of 180kg, each wheel a load of 80kg. The test shows that the rolling resistance not rises linear with the weight per wheel, but increases with load.
So the rolling resistance of a wheel with a load of 80kg on a tandem is higher as the added rolling resistance of two wheels wit a load of 40kg.
Go to the link.and read the test. His tests are realiable.
03-25-23, 05:12 PM
#77
pan y agua
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I don’t understand your math. The study shows rolling resitance goes up 4.4 percent for an additional 40 pounds per wheel. However when you compare the rolling resitance of the tandem with 2 tires versus two single riders with 4, you’re starting with a 50 percent reduction by eliminating the rolling resistance of two wheels. For the tandem to have more rolling resistance the increase from weight would have to be more than 100 percent.
So yes the tandem will have more rolling resistance than a single, but it has the power of 2 riders, and less rolling resistance Than the 4 tires of 2 singles.
on a power to rolling resistance basis, the tandem with 2 tires is going have better watts/rolling resistance than two single riders.
So yes the tandem will have more rolling resistance than a single, but it has the power of 2 riders, and less rolling resistance Than the 4 tires of 2 singles.
on a power to rolling resistance basis, the tandem with 2 tires is going have better watts/rolling resistance than two single riders.
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Last edited by merlinextraligh; 03-25-23 at 05:21 PM.
03-25-23, 07:43 PM
#78
just another gosling
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These test results are interesting:
1) It has become accepted gospel on BF, based on the testing at bicyclerollingresistance.com, that CRR goes up as pressure is increased. This testing shows the opposite, which also has been my experience on smooth asphalt.
2) The tested loads do not go as high as common tandem loads do, simply because of the test equipment used. The graph shows they believe it's a straight line of CRR with loading, so it would be relatively simple to extrapolate to get the more usual numbers. That said, IMO the pressures shown correspond well to the pressures normally used by riders for that given loading.
3) The CRR for the light single rider using their normal pressure is .00452. The CRR for the tandem with extremely light riders using their normal pressure is .00378. Thus the tandem actually has a lower rolling resistance than one single.
Thus merlinextraligh is correct as usual in his post 52.
I think drivetrain friction losses are greater on a tandem than on a single due to the tandem's 2 chains and the much higher loading of the drive chain. Merlinextraligh points this out in post 50. However, the tandem has a huge advantage, having only 1.5 * the wind resistance of a single. In spite of our team's substantial age penalty and our stoker with about half the captain's power, we wind up towing fairly strong singles in a bad headwind. Going downwind, they pass us quite easily. In dead air, we're about equal. Climbing, we totally suck. CRR essentially has nothing to do with anything tandem-related. It's so small w/r to everything else.
1) It has become accepted gospel on BF, based on the testing at bicyclerollingresistance.com, that CRR goes up as pressure is increased. This testing shows the opposite, which also has been my experience on smooth asphalt.
2) The tested loads do not go as high as common tandem loads do, simply because of the test equipment used. The graph shows they believe it's a straight line of CRR with loading, so it would be relatively simple to extrapolate to get the more usual numbers. That said, IMO the pressures shown correspond well to the pressures normally used by riders for that given loading.
3) The CRR for the light single rider using their normal pressure is .00452. The CRR for the tandem with extremely light riders using their normal pressure is .00378. Thus the tandem actually has a lower rolling resistance than one single.
Thus merlinextraligh is correct as usual in his post 52.
I think drivetrain friction losses are greater on a tandem than on a single due to the tandem's 2 chains and the much higher loading of the drive chain. Merlinextraligh points this out in post 50. However, the tandem has a huge advantage, having only 1.5 * the wind resistance of a single. In spite of our team's substantial age penalty and our stoker with about half the captain's power, we wind up towing fairly strong singles in a bad headwind. Going downwind, they pass us quite easily. In dead air, we're about equal. Climbing, we totally suck. CRR essentially has nothing to do with anything tandem-related. It's so small w/r to everything else.
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Last edited by Carbonfiberboy; 03-25-23 at 07:48 PM.
