- News
- Reviews
- Bikes
- Accessories
- Accessories - misc
- Computer mounts
- Bags
- Bar ends
- Bike bags & cases
- Bottle cages
- Bottles
- Cameras
- Car racks
- Child seats
- Computers
- Glasses
- GPS units
- Helmets
- Lights - front
- Lights - rear
- Lights - sets
- Locks
- Mirrors
- Mudguards
- Racks
- Pumps & CO2 inflators
- Puncture kits
- Reflectives
- Smart watches
- Stands and racks
- Trailers
- Clothing
- Components
- Bar tape & grips
- Bottom brackets
- Brake & gear cables
- Brake & STI levers
- Brake pads & spares
- Brakes
- Cassettes & freewheels
- Chains
- Chainsets & chainrings
- Derailleurs - front
- Derailleurs - rear
- Forks
- Gear levers & shifters
- Groupsets
- Handlebars & extensions
- Headsets
- Hubs
- Inner tubes
- Pedals
- Quick releases & skewers
- Saddles
- Seatposts
- Stems
- Wheels
- Tyres
- Health, fitness and nutrition
- Tools and workshop
- Miscellaneous
- Buyers Guides
- Features
- Forum
- Recommends
- Podcast
forum
Power differences
Hi everybody, I wonder if anyone can answer this (daft?) question.
Does it seem possible that there is a 60w difference (160w and 100w) between the power produced by two cyclists on the same 10-minute segment, considering that both cyclists were on the same group ride and did the segment at the same speed? The only explanation I can think of is that one of the two cyclists was drafting much more efficiently than the other. Any other possible causes? Thank you
If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.
Latest Forum Topics
Latest Comments
- Benthic 0 sec ago
'Suitable advice' can already be found in the Highway Code.
- AidanR 3 min 17 sec ago
Fair point, although I have seen drivers go around other cars which he are stationary at the lights to jump a red!
- Secret_squirrel 42 min 46 sec ago
Im betting these come out of the same factory as the SG and the Grip grab gloves. Identical apart from the Silicon overlay....
- Steve K 48 min 1 sec ago
Oh, and for long rides (100 miles ish) a whole pack of fig rolls and a couple of jam sandwiches normally does my fuelling.
- stonojnr 59 min 41 sec ago
That "old lane" as you call it, is 1) very much open, some misguided cyclists still use it. I used it once, vowed never to again and I block ride...
- Backladder 1 hour 4 min ago
Confusingly there seem to be two Millicent roads which cross at approximately right angles, the one that is north-east to south-west is the one...
- Owd Big 'Ead 1 hour 14 min ago
Indeed....
- SaveTheWail 3 hours 16 min ago
"Although other neighbours were outside, nobody else had thought to alert her mum and siblings because there was no car on the drive so they didn’t...
- Tech Noir 3 hours 51 min ago
"Aldi apologised for the blocked bike racks and said "we have spoken with the store to make sure that the cycle bays are clear for use at all times...
Add new comment
5 comments
Thank you both. That makes sense. So a lighter rider on a carbon bike will need considerably less power than a heavier rider on a steel bike, say, to do the same stretch of (flat) road at the same speed. But their w/kg will be much more similar, I suppose.
Don't get hung up on bike weights. Its a marginal difference.
The build of the rider is far more varied and would make more of an impact.
The flatter the road, the less difference weight makes. Drafting will be much more likely to be the difference in this case. You can easily save a third of your energy drafting someone else. It can be proven by calculation and in the real world. I've been on rides with similarly fit people (i.e. similar power ranges), and they're doing tempo power on the front and I'm barely doing low aerobic. So could be say 270w on the front and 200w in the draft. As per other posts, rider size/shape alone will make an aero difference too.
Also, are the figures Strava estimates or genuine power data? Different power meters, even from the same brand can be a few percent different.
Yes, I'd say the variations in power within a group ride are very normal.
As Liam says, weight, aerodynamics of the rider/bike, drafting, plus if you really wanted to get into it, drivechain efficiency.
I'm hobbit shaped, I put out a lot less power than my more human shaped ride mates on the same sections on the same rides.
A far better measuring stick of 'fairness/fitness/speed' would be watts per kilogram, which is just more honest. (avg power divided by weight)
The big difference will probably be the weight of rider and bike. Then smaller factors would be differences in the aerodynamics of each rider and bike, rolling resistance and drivetrain efficiency. Drafting will make a difference, but it depends on the gradient of the climb and the speed at which it was ridden.
The difference between me and one of my training buddies is 20kg (in my favour). It makes a massive difference, not just on the climbs.