Moped muggers rob cyclist of e-bike in London’s Richmond Park

I could have a reasonable guess at someone's age-group and sex from their build, voice and possibly clothing. I'm not sure I could usefully ascribe race to someone in a full helmet and gloves: if any skin is visible (to a cyclist on a bike, while being mugged), I wouldn't confidently be able to distinguish between e.g. North African, South Asian, South American or mixed race of various kinds. If it wasn't (literally) a black and white situation, maybe it's better not to give the perpetrators an easy alibi?

Voice and build were not in the description. As regards the degree of variation and possible error being an issue, you could say the same thing for their age. But in the end it does not matter; what is being described is their appearance, not their date of birth.

I'm not sure what point you're making here. Their build will have been observed (unless they were wearing fat-suits), and their voices are likely to have been heard (source: I've never been mugged in silence). These inform a reasonable description of the perpetrators' likely age-group and sex, which are relevant to attempts to identify them. 
Their race(s) may not have been recognisable, either because they were mostly covered or because in the situation it was unclear which of many they were. 
If you're suggesting that the police deliberately withhold details of suspects' skin colour, that's simply not true. It's one of the first things they ask when taking descriptions, and routinely used in appeals for information. 

Yes, you're right, that is what I'm suggesting may have happened. I'd find it impossible to estimate a person's age if they were covered head to toe, and an aggressive voice through a full facial cover would give only a very approximate guide. At which point I'd have expected the description to centre on what was left to observe; height, weight, build. But they had enough to estimate his age.

I do understand there can be racial sensitivities involved in some cases, but I don't believe these should stand in the way of a clear sighted investigation. Asking people to look out for an approx 25 yr old male on a moped, isn't that all of them?

If that is the case, I'm at a loss to understand why the Met in Richmond are behaving differently to the Met where I am in south London. Here, the alerts for street robberies routinely identify suspects' skin colour where it's known: when it's not given, I don't automatically think "it must be a black/white/brown guy but the police don't want anyone to know."

I've never heard of the police witholding ethnicity as an identifier when known. What I suspect has happened here is that they have simply unquestioningly released the victim's best guess/impression as to age without  asking why they thought that was the case, and due to the helmets and possibly gloves/masks etc they couldn't make a guess as to ethnicity.

They should be pretty easy to spot, if they are wearing trainers on their shoes - that's a pretty distinctive.

Also are they coordinatinating their outfits or sharing a single set of clothes?

"The suspects were described as approx 25 years old, male, wearing a black coat, grey jogging bottoms, with a white or light grey helmet."

Trainers on their shoes?  That makes 'em faster I guess but I know how to escape from them!

I think it depends a lot on your bike. Both this robbery and last year's all seem to involve very expensive models. I was put off RP a bit last year but I spent two hours riding around it yesterday and the only annoying thing was bad driving, as usual. But then I don't think my mid-range women's bike is what they're after. They want your fancy Pinarellos or £5k electric bikes.

Maybe I dont credit them with enough nous to spot the difference, or RP has such a glut of obvious super bikes they can pick and choose.

But I'm always surprised at how often other riders who you would think know their onions, at cafe stops etc will compliment my bike as looking expensive (maybe its just trying to make small talk) and it ain't worth more than £500 thesedays, and didnt even cost more than 1k brand new.

Awavey wrote:

Maybe I dont credit them with enough nous to spot the difference

I've heard from a fairly well-informed source that gangs (thieves in general, not specifically moped-based ones, though I assume the same applies) frequently give their operatives who might not be au fait with which bikes are the most expensive a list of names of brands that don't do budget models, i.e. Pinarello, Cervelo, S-Works etc on the basis that if you get any of their models you're getting an expensive bike.