A Datum is a data point or a baseline; A line to which dimensions are referred on engineering drawings, and from which measurements are calculated.

It’s an odd name for a bike. I think it’s meant to invoke a spirit of adventure, it’s meant to be the tool with which you create the journey. Also the company had already used the rather better Longitude name for a previous model.

I bought this bike very quickly. The bottom of the range model was usually £1800 and I’d seen it on sale for £1300 and I knew that in a few months the price for the frame only was going to be £1500. I took the last one in the country in my size out for a spin on the same day at lunchtime and slapped down the debit card.

It’s not like I knew nothing about the bike. I’d read reviews and it had the thumbs-up from my favourite reviewer, Dave Atkinson of road.cc. I had already done that thing I do with new bikes; I had gone to the manufacturers website and, like an old astrologer, stroked my lengthy grey beard as I looked at the geometry chart and asked the question are these numbers favourable?

'The Astrologer' or 'Audax Rider Prepares' (Giulio Campagnola 15c)

The other star that had come into alignment was a bonus from my job - I had just convinced a public sector body they needed to spend a largish fraction of a million pounds on a website and a small sliver of that was due to hit the joint account soon. This was the first new full road bike I had ever bought. That seems quite remarkable given how many bikes I have had.

I already had a carbon bike, the Orbea racing bike that was accumulating guilt in the attic, so why another?

This one was one of the first carbon bikes that was fast and had disc brakes and mudguard mounts. And why was that important? Well back in the middle of my torturous failure at PBP I had got heartily sick of european riders on racing bikes looking like they were going on a short training ride overtaking me at pace as I plodded along.

Being rather tired at the time all I saw were the bikes. I ignored the fact that these riders were very fit Germans and Italians who had a camper van to collapse artfully into at regular intervals, had full meals laid on and had their spare kit ferried around for them. I was carrying everything I needed, from a spare gear cable up to two extra pairs of shorts to toothpaste. Oh yeah, they were also half my age. No, I didn’t see any of that I just saw that they were riding Carbon race bikes.

I seized on that. I thought I had to have a carbon bike. There is a (tiny) degree of logic there - if you can be just 1km per hour faster then over the 60-70 hours of riding PBP that gives you 3 hours less time elapsed, or three hours more sleep. An additional 5% of time to play around with.

In short I was looking at something that could take mudguards and sat halfway between the Tripster (supremely comfortable) and the Orbea (quick as hell).

I’ve had this bike almost two years now and if you asked me if it had lives up to its promise I would have to say I am not sure yet.

I know it’s an absurdly good commuter because I have ridden it to work quite a bit. The combination of carbon frame, big tyres and disc brakes make it quick and comfortable and, most importantly, safe in all weathers.

I know it’s a very good bike for blasting around the lanes on for a couple of hours. My favourite ride on this bike so far was an early spring ride up to Cambridge for lunch on a day after a lot of rain. The roads were covered in standing water and the back lanes were slippery with mud but I was able to blast them on the Datum, sprinting from one corner to the next and slicing around dodgy corners in a way that would be impossible on a race bike. It’s was the kind of ride the Tripster was excellent for, but the Datum is sharper and wants to get up and go in a way the Tripster never did.

Perfect Datum territory

But I have yet to ride over 600km on it in one ride, so I am not sure yet whether it is comfortable enough given it is meant to be fast distance bike. It was very good on that 600km, which included climbing and descending 4500m in the Welsh hills and lots of dodging cars on narrow lanes. Though it is not the magic carpet ride of the Tripster you do feel like all the power is going to the back wheel and it takes a corner at a good clip - and I have yet to find anything like its limits downhill.

The thing about comfort on a bike is that not many bike testers ride their bikes over 600km in one hit so they can’t really tell you if it is really comfortable or not. It’s not really something a lot of riders consider when buying a bike - will this be comfortable for 24 or 36 or 96 hours at a time? The short answer on current evidence is not really.

The Datum really is a very very good modern bicycle. But it lacks the comfort of the best long distance bikes and it lacks the soul of a steel frame. It is like an excellent teacher who will help you get all the right grades but never makes you think beyond the tests.

So while on paper this bike is perfect it’s not really ‘me’. Never the less I think I will choose to be happy with it and not regret too much that it’s a bit characterless. If I was really looking for pure character I would get that Salsa out of the attic and rebuild that, but then I am not sure I can live without disc brakes when it’s raining and it’s late at night and I’ve been riding a whole day and a whole night.

And the most important thing of all, this bike imposes no real limits and gives me no excuses. Those Germans and Italians on PBP will still sail past me but I will have to put the blame for that in the appropriate place - my legs, not the bike.

It could well be my last bike. And until I take my next big adventure on it I am not sure I have anything more to say about it. So…. it’s time for a confession.

A kiwi riding past the flag of Erkenswine, the first king of Essex, on top of a Welsh mountain that looks like New Zealand. Go figure.

Right at the beginning I said I would write about every bike that I had ever owned, but I haven’t managed that. I left a few out.

Quite a few.

I’ll list them below for completeness, but first lets ask ourselves a question that is never far from my mind…

How many?

How many bikes should you own at once? How many bikes is it reasonable to own at once?

Well obviously everyone should own one bike, something they can ride three miles on, something to turn an hours walk into a pleasant 20 minute amble.

Beyond that even the most hardened and active road cyclist needs three or four: Good race bike, winter trainer/commuter, maybe a fixie and a time trial bike or track bike if that’s your thing. That has been the formula most cyclists adopted for decades. But then bikes became a significantly smaller ratio of the yearly income and the range of choice started to explode from the bike boom ground-zero year of 2012.

So now some people have maybe five or six bikes on the go, and they always seem to have their eye on something else. This state of continual unfulfilled bike hunger leads to the N+1 formula - the right number of bikes to own is the number you already have plus one. This formula acknowledges that cyclists will always want a better bike, for no good reason at all. That brilliant bike that you swore would last you ‘a lifetime’ five years ago is now getting a bit boring. You’ve been subjected to years of marketing and branding to which your superior intellect makes you immune, but never-the-less there is that new model that promises 10% more something. What really matters is being 10% less fat, or 10% more fit, but that takes time and dedication to achieve that, so 10% more aero will do instead.

N+1 is then balanced by the tolerance of your partner or spouse. This is where the formula s-1 comes in - one bike less than would lead to separation.

So here is the definitive formula and pathway for bike ownership.

1: Everyone needs one bike. N = 1

2: If you start to ride a lot then that one bike should be something that fits the purpose (fast bike, touring bike) (N = 1, improved)

3: When that bike is sufficiently precious, or you need to put a baby seat on it, you may buy an additional cheap bike for commuting on. N = 2

4: If you race you may own one extremely good road bike and one winter trainer. Your winter trainer should take the place of the cheap commuter. Most likely the winter trainer will be the bike that used to be your most precious bike, but it looks a bit crap now you have a nice bike. N=2

5: Maybe you start to ride on the track, or specialise in time trials - you can have a bike for each of those discipline that you take seriously. N = 3-5

6: At some point you will want to try the new type of disc brake, large-tyre road bikes; at this point you will upgrade the winter bike to a nice disc road bike. N = 4-6

7: This bike might be too nice to ride to work so you end up buying another commuter - ideally this last commuter is a single speed or a fixie because you are strong enough for that now. N = 5-7

Suddenly you have between five to seven bikes.

My five bikes with two family bikes in background.

The list

That definitively and for all time solves the question of how many bikes you should own at once. For the record the most bikes I had owned at once is, errrrr…. six. Plus parts in the attic for two and a half more. Thankfully even I have seen the madness in that and currently I have four. And one in the attic.

So let me complete the cataloging of my bikes. The bikes I left out were:

1: A GT mountain bike I bought when I very first got to London. It was hot too, and too small. I gave it to a flatmate and she eventually had it stolen. Karma.

2: A mountain bike given to me by a Scottish Laird (long story) which I rode for a couple of months before transferring parts to the Rock Lobster. It was too small but got me back on a mountain bike.

3: A Quest road frame. This was a cheap but very light scandium road frame. I had ridden it about five times before it was nicked out of the back shed at the same time as the Rock Lobster.

4: A Pinnacle road disc frame. I built this up and rode it once. It was the wrong size and way too high at the front end. I took all the parts off it again and put them back on the Salsa, which luckily hadn’t noticed my unfaithfulness.

5: A Pinnacle hybrid frame, a Lithium. This is actually a very good frame and I enjoyed riding it a couple of times but never really liked flat bars around town. It’s now Steph’s bike, so at least it stayed in the family.

6: A Giant Anthem X mountain bike. Now this I thought I would write a post about but I haven’t been moved to. It’s a very good mountain bike that replaced the Rock Lobster. But all I want to say about is that it is too good. It makes riding in the forest a bit boring. It is ‘overbiked’. And then I got into Audax - being over 50 I don’t bounce quite as well as I used too.

So that makes 31 bikes across the 45 years I have been riding. There are readers of this blog who have one bike for many many years (looking at you Brendan) and for whom that will seem profligate, and I guess there are a few who will not even blink at that figure.

The last one.

I haven’t bought a new frame or bike since the Datum in 2016 - two whole years - and I will try to get through another few years before I feel like something else. The reason for this is I have one of every type of bike I need according to my own formula above.

I have just rebuilt the Orbea for fast weekend runs and have the Datum for proper distance; the Flyer for fixed and commuting in bad weather and the Anthem X MTB for muddy miles. I certainly don’t need more bikes than that. Some good wheels, maybe. Riding longer distances makes good riding gear vital so I expect to spend a bit more on better clothing over the next couple of years where mostly I have made do in the past.

No, what I really what I need to do now is get off my arse and do some big rides. Or join a club and go for a race. Or keep my fitness up by riding everyday through winter. Or take my son out mountain biking more. I have the bikes do all of that.

And you can only ride one bike at a time. If I had to have just one of my cirrent bikes to last me the rest of my life? Gun to the head? It would have been the Tripster but now it’s the Datum.

But putting that down on paper makes me feel a little nervous. It means that I can’t rationally justify another bike until the Datum dies, which could be very many years in the future.

That makes me sweat. You see I can easily imagine a better bike, a better experience. And the next bike will not be from a shop or a website, it will distill my many many miles of experience, my own knowledge about my aging body, my need for comfort and a whole raft of aestethic judgements and biases and I will be working with a custom frame maker to achieve it.

The Datum is the pinnacle of an off-the-shelf all round bike. It’s last bike I need, but it’s not the the last one I want.

Next chapter: Interlude - The Passion and beyond