Use Watts instead of W/kg to categorize group rides?

Hi, as a lighter D cat recreational rider (60kg, 132 Watts - 2.2 W/kg) I usually struggle to keep up in group rides, even if they are ones I should in theory be able to keep up with - for a 1.5-2 W/kg ride I usually have to ride at around 2.5 W/kg or higher, so can only keep up for part of the ride, depending on the weight of the ride leader (usually heavier!) and how close they stick to the advertised ride difficulty (not often!). While I get a good workout it becomes a bit demoralizing to drop off and ride by yourself after a while and it seems I’m not the only one with this issue.

After looking at various discussions it seems to me that is an issue that would be solved by using Watts instead of W/kg to categorize the difficulty. At least that would take the weight of the ride leader out of the equation and it would make it easier to choose a group ride that I could keep up with - not that I imagine too many rides would be around the 130 Watt mark given that most Zwift riders are stronger than this but at least I could go in with a better idea of what to expect. What do people think? Is this too simplistic an idea or something worth pursuing? I’m not talking about racing here (which seems to have its own can of worms), just group rides or at least Cat D group rides…

Hi Ann,

One way we negated all the physiological challenges is by stating a specific speed for flatter courses and wkg only for ramp ups.

The idea of watts is plausible but I beg to differ. Why? Everyone is different - weight, FTP, muscle endurance, skills to ride in a group etc.

I have in many parts used speed as a balancing medium. I will let everyone know okay this is how “slow/fast” we travel together on the very flat courses. Coming to climbs, I will state estimated w/kg to achieve but always try follow the beacon who will keep to it. So far these methods have helped me lead many group rides successfully.

Finally, do research on group rides that will meet your expectations and has positive reviews. That way you can be assured of a positive experience from joining it.

All the best, #rideon.


Admittedly it is always variable. Somewhat heavy, I find it relatively easy to keep up on the flats but really have to go hard on the climbs. Sometimes, based on the people who show up, rides will be slower or faster.

Unfortunately I don’t think wattage alone solves this because people will be going potentially very different speeds depending on their weight.

I think speed would be a better metric, and some groups do this particularly on the flats by setting a target speed as opposed to w/kg.

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Hi Ann,
I too am a light rider Cat D and initially struggled to find group rides that met my training intent for the day using w/kg. Based on advertised w/kg, I would often find myself doing Zone 4 work when I was looking for recovery. It was a good workout, but the wrong one for the day. Over time and with experience as my research with different groups (as Patrick mentioned) I have found rides that meet my expectations for the level I want. There are some great leaders who keep the pace and work hard to control the group’s tendency to fly. If you want some recommendations, let me know.

On a related note, I have definitely found that speed on flats seems like the most clear metric for group rides as it takes weight out of it. I am curious why more groups and ride leaders don’t use it more in their ride descriptions and during the ride. Any thoughts on that?


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I’m 65kg & have Raced D & C. I have done TT @ 3.7 (Cat B, 26mph), yet find myself having to do 3-3.2 just to keep up on a D, 2.2-2.4 Grp Ride! Also, why do I only have to do 2.0 in Front of Fence, but 3.0 in Group Behind the Fence. Can someone explain That!

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w/kg is a fairer way to split categories than watts, but it is also hugely flawed. The physics is too complex and variable (based on terrain, aerodynamics etc) to categorise in this way, and that is why ultimately a performance based category structure has to be the way to go. For example, there may be 10 categories and you move up through them as you win races, or get relegated if performance versus your peers is poor. Smaller races may combine cats (e.g. 1-3,4-6,7-10) and larger ones may have separate races for each category. Either way, your score which determines if you should be promoted or relegated would depend on the level of those you beat or lost too.

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I think many riders pick group rides above their current ability.

A group ride should be in your Z2 if you want a recovery ride.

So if your FTP is 200w and you weigh 70kg then you should be comfortable at 1.6w/kg so you should pick a group ride where the range top at 1.6w/kg (ie 1.2-1.6) then you will be able to ride in the group.



You should pick group rides at a lower range. If you ride a 1.5-2w/kg group ride than you are in Z3-Z4 (Tempo and Threshold) that is not the effort for a group ride.

Also knowing that you are on the lower end of the weight spectrum you need to pick rides that have a event lower range to account for leader weight difference. A good heavy leader will ride at the lower range and a good light leader will ride at the upper end of the range.

See below the w/kg requirement for your weight and FTP


Thank you all for your insights. I can see that speed would give what I am looking for - a better idea how how a ride would be when you don’t know the leaders weight. However, it also looks like I’ll just have to get fitter! After looking at Gerrie’s useful tables its no surprise I can’t keep up with most rides for the full ride. Not that I mind riding with others in the group who are also slower, it would just be nice to keep up with the main group for longer. There are very few, if any rides lower than 1.5-2.0 (at least in my timezone), so I’ll just have to suck it up :smiley: