The pinnacle of performance… with some constraints
When I heard that Laid Back Bikes were stocking the M5 Carbon High Racer I had mixed feelings. Partly excitement, but partly trepidation too. With the possible exception of the Cruzbike Vendetta, it seems like there are no production bikes that challenge the M5 CHR for sheer performance on open roads (especially with the demise of rivals like Zockra, Velokraft, Troytec) so one way or another, I was about to discover how good things were going to get for the foreseeable future!
The CHR was introduced at Cycle Vision 2006, so it’s all the more testament to the design that nearly a decade later, largely unchanged, it still sits at the top of the pile. M5 have produced a few one-off bikes for the hour record, and of course there are bespoke options (like John Morciglio) and the barely-useable out-of-production VK Nocom… but that’s about it.
The winning formula seems to be dual 700C wheels paired with what is conventionally a lowracer frame design – keeping seat height down to just 48cm (a bit over 19″ – without pad) and shielding the upper half of each wheel (where effective airspeed is highest) in the dirty air around the rider’s body. The M5 Carbon High Racer is actually lower than many midracers, and much lower than US-style stick bikes. Combine that with a massive all-carbon construction for ultimate stiffness, and away you go.
Aesthetically the M5 CHR is not great, in the eyes of this beholder – side-on is definitely the “best side” of this design – in the flesh it looks boxy and ungainly. The free flowing shapes of a Zockra or VK frame are much more pleasing, but you can at least admire the fact that the CHR was modelled and built for a specific purpose – to go fast, rather than merely to look fast!
In a strange way, it has something of the awkward kit-car feel that I got from the Milan velomobile I reviewed a few years back. There are options such as paint or a more traditional carbon finish, but then you’re talking about a nine month wait and significant upcharge from the factory.
If you want a really nice factory finish, the Schlitter Encore is far and away at the top of the pile (full review coming soon).
M5 make some bold claims for the all-up weight of the M5 CHR. I’ve now handled three separate examples but didn’t disassemble them to weigh the components separately – the one pictured tipped the scales at just over 10kg (22lbs) including seat pad and pedals, and there are some obvious weight savings that could be made if money was no object.
However, Aussie randonneur Andrew Heard has disassembled and weighed his CHR and the parts are heavier than you might think: 2600g for the frame, 500g for the boom, 670g for the seat, 440g for the fork, 200g for the bars.
Taking only the frame and boom into consideration, that means my High Baron is only 500g heavier than the CHR, while the fabulous Schlitter Encore (at 1900g) saves 1.2kg over the CHR (and the Schlitter is also cheaper… bonus!)
Weight isn’t everything – especially when the bike is very aerodynamic and the extra weight is providing a super stiff platform for power application. The front of the High Baron is noticeably soft compared with the CHR, especially in the small ring. However, a whole kilo saved on the Encore does contribute to measurably faster climbing: ~0.14mph extra on a 10mph hill with power and all else equal. Does the aerodynamic edge of the CHR (if any) outweigh this?
The CHR is very stiff compared with anything else I’ve ridden – and no wonder when you consider the enormous cross section of the frame:
When it comes to speed, I did put the M5 head-to-head with my High Baron and the Schlitter Encore in this article. The take-home message is that without optimising the Laid-Back demo CHR for my purposes, there was nothing much in it at the low power levels I can sustain for multi-hour rides.
The M5 CHR could certainly be significantly sped up with a flatter seat, and I have set a couple of downhill Strava segment PRs on it, so there is definitely potential beyond the High Baron, which is slammed as far as it can go. Note also that the flat course deliberately isolated the aerodynamic component, further flattering the High Baron (which is heavier and more flexible than the CHR and Encore).
The best independent figures I’ve seen for the CHR are from this old post by Sean Costin where he gets 25.6mph for 200W in a velodrome with an aero wheelset – that’s a 3mph step up from my own speed at the same power and compares well with Larry Oslund’s recent 100 mile ride (25mph for 194W on an open road loop) on an optimised Cruzbike Vendetta.
As ever, be careful about ranking bikes based on the performance of their riders. CdA and Crr are objective measurements, and you don’t have to check many race reports to see what a massive difference the rider’s condition makes – see Maria Parker’s Hoodoo 500…
Adjustment, Comfort and Handling
First and most important, the long wheelbase and slack head angle of the M5 CHR make it quite a limiting bike in terms of rider height.
At 5’10” with pretty average legs for my height (X-seam 42-43″) I can ride comfortably providing the cranks are cut down to 155mm. Regular cranks at 165mm would not be possible unless I went for a pedal with a higher stack height (i.e. effectively have slightly longer legs):
You can of course drop down to a smaller wheel, like a 650 or 26″, but beware! For mortal cyclists who are not putting in massive wattage, rolling resistance is a huge component of performance and it scales roughly in reverse proportion to the size of your wheels. In this great topic on BROL, we see a more aerodynamic Velokraft VK2 lowracer is not actually faster than a Zockra highracer until somewhere around 300W, way beyond the sustainable power for most riders. This is because 50% more rolling resistance is more than offsetting the aero benefit.
Leg length aside, there is a deep drop from the bottom bracket to the seat on the M5 CHR, which may or may not suit you as a rider (some find it gives them hot feet, for instance) but the low seat height above the ground can hardly be overstated as a handling advantage. It’s just so easy to get your feet down on the CHR and this promotes confidence in traffic, hill starts, and the rest. In that respect, this is far and away the most rideable performance recumbent I’ve had the pleasure of pedalling.
At speed the long wheelbase makes the bike feel incredibly relaxed, and it’s almost possible to ride no hands.
However, take a look at the amount of overlap between the chain and front wheel. Without running an extra idler, the M5 CHR can be an extreme handful to negotiate tight bends – if you venture onto bike trails, beware! It also adds an extra degree of difficulty to steep hill climbing, where you may be zig-zagging the bars. Pulling away from T-junctions on small country roads can also be quite a big challenge (I try to pre-position myself on the minor road, so I’ve got the first half of the turn done without crossing the give way line).
I run my High Baron with a dropped chain so am no stranger to this way of riding, which deliberately adds handling difficulty as a trade-off for drivetrain efficiency. The M5 CHR is an all-round harder bike to ride (chain dropped or otherwise) in exchange for the performance boost it gives you.
The carbon seat is narrow but very comfortable – the curve at the bottom should not bother the back of your legs unless you go for a wildly laid back seat angle. Note the cut-out at the front of the seat to allow it to be mounted far forward – without this it would be impossible to fit riders less than 6′ or so to the bike at all!
This bike was fitted with the obligatory Ventisit pad. Nothing much to mention there!
The seat angle is essentially fixed from the factory, to one of three different carbon “pillars” that hold the seat off the frame. (I believe it may be possible to get a new frame shipped bare with the pillars loose, if you want to experiment). The stock seating angles are not outrageous, at 18, 20, or 23 degrees. You can obviously pack under the seat to lift it, but vice-versa is not so straightforward.
Seat, Bars & Controls
Another distinguishing feature of the M5 cockpit is the short stem and tiny handlebars:
I have to be honest and admit that these are too narrow for me. There’s not enough room to rest your whole hand on the bar, which is fine if you’re riding hard and paying attention, but not great for longer rides at all. An implementation with different shifters could clear enough space to rest the whole hand, but not this one.
However, I did really like the fancy aerodynamic brake levers mounted under the stem – very comfortable (even if the implementation does slightly fail to live up to its promise). I gather these are out of production unfortunately – you can just about see on my dual-700c lowracer project page that I ran conventional brake levers staggered on my Rapto’s stem for a while…
The narrow width does promote a very tight and aerodynamic shape on the bike, which is its main advantage. Try holding the handlebar assembly of an open cockpit like Bacchetta’s out of the window of a car doing only 30mph and you will feel a surprising amount of resistance from all that tubing. The M5 solution keeps your computer and mirror close to your face and everything is tight for maximum efficiency.
In the interests of fairness, I will point out that a lot of US riders don’t seem to get on with this kind of bar at all, and ride open cockpit despite the disadvantages (or to be precise – for those riders the tiller bar has more disadvantages, so they made a smart choice). YMMV!
A nice touch is the front mount for lights – this saves attaching a heavy and potentially unreliable adaptor to your boom or derailleur post to carry illumination on longer events. (Ironically, this particular bike is fitted with an adaptor to mount a battery light, but standard European lights bolt directly to the boom).
The back of the CHR is singularly badly suited to fitting lights. You can get by using the headrest at a push, or whatever your luggage solution is, hang a light off it!
You can run your choice of drivetrain on the M5 CHR. This particular bike had a tighter cassette than I’m used to (for smaller jumps between gears) but a triple ring up front to allow climbs of 20% or more, as demonstrated by David Gardiner on the Tour o’ the Borders.
The same hill completely defeated me on the Schlitter Encore and I was barely able to manage it on the High Baron, but of course you can choose your own gears, so YMMV! The bottom bracket is a standard threaded fitment. No press-fit here…
Perhaps because of the boxy carbon frame, I found the M5 Carbon High Racer to have a fairly loud drivetrain. The short length of chaintube was OK (although my own bike I would remove this and have a dirty leg) but the power idler really rattled. It wasn’t any better or worse than my High Baron, but I would pay a lot of money for a totally silent recumbent drivetrain
This bike had a return idler fitted to the headtube which helped make the bike more steerable in tight sections and also reduces the chance of slipping the chain from the front end. Again, you’re trading a straight and efficient drivetrain for handling convenience.
I gave the brakes their own section merely to emphasise how much better they are than the brakes on my High Baron. These are the exotic M5 super-light Brams brakes, tipping the scales at 80g. (Not quite enough to offset the 1.2kg weight penalty over the Encore frameset, but pretty nice all the same).
The brakes are plenty powerful even with the thumb lever on the handlebars, allowing you to ride with confidence. The rear caliper is mounted under the frame, protecting it from road spray and improving the cable run:
Tyres and clearance
The M5 Carbon High Racer has disappointingly small tyre clearance – 25mm tyres are the widest I could fit, and even then it required a tight and true wheel. My favoured 28mm Schwalbe One was a complete no-go!
The pictures here are showing a 25mm tyre, with basically no clearance at the front or rear:
This is one of the few areas where the bike shows its age. Now that the peleton is moving even to 25mm tyres (wider for the Spring classics) it’s a bit awkward to have a recumbent that won’t run to 28mm. We don’t need the massive clearance of a Metabike frame here, but unless you ride perfect blacktop asphalt, it does put the CHR at an unnecessary disadvantage.
Don’t get me wrong – the CHR is a fantastic descender with the super stable long wheelbase and slack head angle. However, on quiet Scottish roads, it’s certainly losing out without the ability to run a more forgiving, faster-rolling tyre.
Mudguards and luggage
A front mudguard is not so easy, but a rear one can be fitted too much trouble. And as for luggage… you can fit a rack and do some touring if you can only get over the limited tyre size. In fact, as one visitor to Edinburgh demonstrated, you can go crazy on your touring luggage!
In the end the M5 Carbon High Racer is a bit of a mixed bag.
When I first rode the High Baron, I was instantly hooked. It handled perfectly, it was super smooth and easy to live with (except the terrible brakes!) and put out a mean turn of speed for a very reasonable price. I expected to get on the M5 CHR and feel like I had “gone to 11″ but in the end it was a much more incremental experience. Perhaps the hype is so great that I was inevitably going to be slightly let down.
If you aren’t tall enough, handling could be badly compromised, or you might have to compromise the spec of the bike itself to get on it. Once you’re on, if you can put up with the sometimes challenging low-speed handling, the minimal tyre clearance, the tiny handlebars, and the fact that it’s surprisingly heavy for a fully carbon bike… you’ll be on a super stiff and aerodynamic speed machine!
While there are certainly lowracers with a more aerodynamic profile, only the most powerful riders can hope to put in enough watts to overcome the higher rolling resistance of those designs. The average guy (and anyone doing brevets!) will experience better performance on a big-wheeled bike, and pretty much the best performance of all on the M5 CHR.
Don’t get me wrong – the M5 Carbon High Racer *is* the fastest bike I’ve ever ridden over mixed conditions on real world roads. It’s really quite tempting as a prospect to replace my High Baron for a big year of riding in 2016, if not the step-change in performance that I hoped it would be (and at considerable expense!)
For casual riders, I’m not convinced the M5 Carbon High Racer is such a good choice, especially if it would be your only bike. It’s a bit of a hassle, and it punishes mistakes in a way that would simply never happen on a Nazca or Optima design. As a first recumbent this would be a very courageous choice indeed.
In my opinion the Schlitter Encore (and perhaps the carbon Metabike or Performer HR) is a massive challenger for our money if you are looking for a better *all round* experience. See Rob Williams’ (aka Darkersider) short review of this same M5 CHR for perhaps a more positive outlook.
Available to demo now via Laid Back Bikes, and I honestly wouldn’t recommend this bike without trying it out first… you have been warned!
- My main Laid-Back reviews page – all recumbents on one page