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13 Bikes Intrinsic Lambda



Looks good, feels good, rides well and won't break the bank

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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On a smooth, straight section of downwardly sloping tarmac, with a touch of tailwind, 13's Intrinsic Lambda feels as good as just about any bike I've ridden – and better than some. Maybe it's the aero touches in the design, maybe it's lowering expectations in a snobby, superior, I-normally-get-to-ride-much-more-expensive-bikes-than-this way, but this £550 offering from the Halfords brand spins along very decently on the flat, deals with rougher surfaces quite well, and its wide gear range means hills aren't too much of a bother. You could certainly do worse.

The Intrinsic is one of 13's new range of women's bikes. It has an aluminium frame, 8-speed Shimano Claris gearing, and Tektro brakes. So far, sounds pretty standard. But the two new road bikes in the range, the Intrinsic and the £850 Intuition Lambda (there's also a flat-bar model, the Intuitive Lambda, at £499.99), have spent time in the wind tunnel on their way to the high street, and both incorporate aerodynamic tube shapes and aero brakes tucked behind the fork legs and under the chainstays.

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Do these aero details work? That's hard to say without heading into the wind tunnel myself (and seeing how it compares with the non-aero version, which doesn't exist...), but it's certainly a pleasant enough ride – until you have to start climbing. Less fun then.

13 Bikes Intrinsic Lambda - Riding 4.jpg

On the flat, and downhill, I was expecting a lot more pounding of the backside and hands. Aluminium isn't best known for its comfort-giving credentials, and adding aerodynamics into the equation doesn't tend to help. Topping it off with tyres that are only 23mm wide and I was prepared for the worst. And yet... there's not a lot not to like. It's not as smooth as the lovely steel bike in my stable (well, side extension), but it's not overly harsh, and I'm not sure some carbon bikes costing twice the price have been twice as comfy (though they have had better brakes and bits). The main drawback to my mind is the weight.

Even a longish last-minute emergency ride in my least comfortable commuting shorts didn't have any negative effects, and I found myself thinking that, for half a grand, this more than decent ride would be a good choice for daily commuting if you have a posher bike whose parts you want to preserve for weekend outings – as well as being good enough for all sorts of other activities if this is your max budget. It might even do for racing, given the aero details, at least until your results/wallet could move you on to something lighter.

Frame details

The Intrinsic has a triple butted aluminium frame, which means the tubes have three different thicknesses within each length, balancing strength where it's needed with lightness and thinness where it's not. The aero down tube is deep and narrow throughout its length, at its deepest and narrowest in the top half, widening as it reaches the bottom bracket. The top tube roughly maintains its width all the way along, but reduces in depth towards the seat tube.

13 Bikes Intrinsic Lambda - top tube detail

It's a big ol' down tube, and the chainstays are quite deep too, but thinner, round seatstays and a full-carbon fork (though with teardrop profile legs) seem to help stop the ride being harsh. You get feedback, but it's not beating you up. It also has a 27.2mm seatpost, which will provide more give than an oversize post, although there's not a huge amount of flex going on; it's definitely a semi-compact frame rather than compact (where the top tube joins the seat tube way down), so not a huge amount of seatpost sticking out.

13 Bikes Intrinsic Lambda - rear

Despite having the rear brake positioned aero-style behind the bottom bracket, there's still a brake bridge (or mudguard fixing point – plus eyelets on the dropouts) between the two seatstays, which will help create rigidity rather than comfort. The seatstays join well below the seat tube/top tube junction, too, and short'n'straight tends to mean stiffness rather than flexiness. And yet...

13 Bikes Intrinsic Lambda - seat stays

Overall I think it's a good looking frame, and I know there'll be plenty of women out there who like the fact that it's not all pinkified. The internal cable routing keeps it looking tidy, and the welds are semi-smoothed, though a bit halfway house. 13, do you want the welds showing or not? Decide one way or the other!

The bits

As for the kit and components, although £550 might seem a lot of money for a bike for some, you can obviously spend a whole lot more, and we're talking fairly entry-level as far as components go. Shimano's 8-speed Claris gearing works fine, and I opted to test this model rather than the more expensive Intuition, with its 10-speed Tiagra groupset, because of the gear range. Both bikes have 50/34-tooth compact chainsets, but the Intrinsic's 11-30 cassette provides a slightly lower hillclimbing gear than the Intuition's 28t largest sprocket, and I need all the help I can get in the hilly part of the country where I live.

13 Bikes Intrinsic Lambda - rear drop out

I do find myself twiddling the gears quite frequently, front and back, to find the right cadence, but it's worth it when the time comes to shove it into its lowest setting and start grunting and grinding. Home. Every day.

The direct-mount TRP Aero brakes, hidden away beind the bottom bracket and tucked behind the fork legs, might reduce air resistance so they let you go faster, but slowing down isn't anything to shout about. They work, though you need to give them a bit of notice in wet weather, but they certainly aren't up there with the likes of Shimano Ultegra. They're also going to be a bit more fiddly to work on than non-aero brakes (I haven't needed to), and the rear brake position means it collects plenty of road gunk (and mud if you head on to less-well-surfaced cycle tracks/paths).

13 Bikes Intrinsic Lambda - front brake
13 Bikes Intrinsic Lambda - rear brake

They're working to slow down 13's own RS aero wheels. These are referred to as 'deep section' by Halfords/13, but I won't be diving into whoever wrote that's swimming pool... With 32 spokes at the rear and 28 at the front, they've stayed true throughout testing, but I'd like to have seen them wrapped in 25mm rubber not 23. Everyone is going bigger in the tyre department these days, aren't they? Even 28mm and 32 can be seen on some road bikes, so 25mm would have been good, adding speed as well as extra comfort according to more scientific brains than mine...

Finishing comfort

I've been more than happy with the finishing points of the bike too. I'm quite fussy about my saddles, preferring extra width for my sit bones plus a cutout. The Velo-made women-specific model on the Intrinsic has a groove rather than cutout, with a bit of gel squish in the wings, and I've found it perfectly comfortable. On longer rides I've had to do a bit of manoeuvring to remain happy, but have always managed to achieve that.

13 Bikes Intrinsic Lambda - saddle

Bar width, access to the levers, and getting into the drops has all been perfectly acceptable, too. I've ridden women's bikes with 38cm handlebars and they've always felt too narrow, so I was pleased to find a 40cm one specced here (38cm on the smaller frame models), and it has a decent drop too, for when you want to get low and fight those inevitable headwinds; some 'female-friendly' bars are very shallow.

13 Bikes Intrinsic Lambda - shifter


Overall, I've enjoyed my time with the Intrinsic. It's a bit heavy when you're climbing – but that's good training, isn't it? – and you don't really notice the weight so much on the flat. It zips along well, and the handling/steering is neutral, not at all twitchy; I've even been practising my no-hands riding (while ignoring shouts of protest from husband behind). And I've felt confident on big, swoopy downhills, though I would swap out the 23mm Vee Rubber tyres for something wider.

13 Bikes Intrinsic Lambda - Riding 1.jpg

Otherwise, it's a good looking bike that rides well and copes with ups as well as downs. If £550 is your max budget, it's a good first road bike; if half a grand is what you can afford on your second bike, the Intrinsic makes a fast and capable commuter (add a rear mudguard to help in winter), so your posh carbon steed and its fancy parts can stay at home out of harm's way.


Looks good, feels good, rides well and won't break the bank

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Make and model: 13 Bikes Intrinsic Lambda

Size tested: 51.5cm

About the bike

State the frame and fork material and method of construction. List the components used to build up the bike.

Bottom Bracket: FSA Square Taper - 68mm Shell

Cassette/Freewheel: Shimano HG50 - 11-30t

Chain: KMC Z72

Chainset: FSA Tempo compact 50/34t

Frame: Lightweight triple butted aluminium, aero optimized with smooth welds

Front Brake: TRP T822/820 Aero brake

Front Hub: 9mm QR

Front Mech: Shimano Claris - 2 speed

Gear Shifters: Shimano Claris

Geometry: Female fit road - semi compact

Handlebars: 13 RS 31.8 - XS/S 380mm, M 400mm

Headset: FSA orbit No.10P - 1-1/8" - semi integrated

Quick Release Front Wheel: Yes

Quick Release Rear Wheel: Yes

Rear Brake: TRP T822/820 Aero brake

Rear Hub: 9mm QR

Rear Mech: Shimano Claris - 8 speed - medium cage

Rims: 13 RS alloy double wall - 28/32 hole

Saddle: Women's optimised saddle with gel

Seatpost: 13 RS alloy - 27.2mm - 350mm

Stem: 13 RS 70mm (XS/S), 90mm (M) - 31.8 with +/-7 degree rise

Tyre Size: 700 x 23c

Tyres: Vee Rubber 172

Tell us what the bike is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about the bike?

Halfords says: "The 13 Intrinsic Lambda Women's Road Bike is a bike that is only rivalled in its looks by its spec. With a triple butted aluminium frame and unidirectional carbon fork, the Intuitive Lambda is light and handles incredibly well. 16 speed Shimano Claris gearing provides an excellent range for blasting along the flats or up hills, and aero brakes provide an exceptional stopping performance."

That's a bit more exuberant a description than I'd give it, but it's a nice looking bike and I didn't dislike the ride. I didn't experience an 'exceptional' stopping performance though.

Frame and fork

Overall rating for frame and fork

Tell us about the build quality and finish of the frame and fork?

Nice paint job - pearly white. And no pink! Welds are semi-smoothed, so neither completely hidden nor particularly pretty.

Tell us about the materials used in the frame and fork?

Aluminium frame, carbon fork. So quite stiff in the body, with a bit of give up front for comfort. Semi-compact design, with the top tube near-horizontal, meaning no extra flex as you'd get with a more exposed seatpost.

Riding the bike

Was the bike comfortable to ride? Tell us how you felt about the ride quality.

Comfortable. I was expecting harsher, the frame being aluminium, and with narrow 23mm tyres not helping with cushioning, but pleasantly surprised by how far I could ride without feeling beaten up.

Did the bike feel stiff in the right places? Did any part of the bike feel too stiff or too flexible?

All felt good.

How did the bike transfer power? Did it feel efficient?

Yes, plenty efficient.

Was there any toe-clip overlap with the front wheel? If so, was it a problem?

No overlap.

How would you describe the steering? Was it lively, neutral or unresponsive? Neutral.

Tell us some more about the handling. How did the bike feel overall? Did it do particular things well or badly?

No surprises. Followed the course I wanted it to. First bike for a long time I've ridden no-handed.

Which components had the most effect (good or bad) on the bike's comfort? would you recommend any changes?

Non-cutout saddle was surprisingly comfortable (I'm fussy about saddles). Bar width suited me too, not too narrow - as can be the case with some women-specific bikes.

Which components had the most effect (good or bad) on the bike's stiffness? would you recommend any changes?

Shortish length of seatpost showing, but that's down to the frame design (and my height).

Which components had the most effect (good or bad) on the bike's efficiency? would you recommend any changes?

Low gearing made it (me) more efficient on the hills! I'd still go lower if I had the choice.

Rate the bike for efficiency of power transfer:
Rate the bike for acceleration:
Rate the bike for sprinting:
Rate the bike for high speed stability:
Rate the bike for cruising speed stability:
Rate the bike for low speed stability:
Rate the bike for flat cornering:
Rate the bike for cornering on descents:
Rate the bike for climbing:

Low gears good, but they're countering quite a heavy overall package.

The drivetrain

Rate the drivetrain for performance:

It's Shimano Claris and it works, but 8-speed means a fair bit of twiddling to get the right cadence.

Rate the drivetrain for durability:

Tell us some more about the drivetrain. Anything you particularly did or didn't like? Any components which didn't work well together?

Claris is Shimano's entry-level groupset, so you don't expect the earth. It works, and it works positively, but when you're used to more sprockets in your cassette you notice their absence. I appreciated the spread of gears though - good top end, good low. Did experience some chain rub in the top gear, but a more competent mechanic than me could undoubtedly sort this.

Wheels and tyres

Rate the wheels and tyres for performance:

The not-very-deep 'deep section' wheels do catch crosswinds a bit, which suggests they're deep enough to have an aero effect.

Rate the wheels and tyres for durability:
Rate the wheels and tyres for weight:
Rate the wheels and tyres for comfort:

Upping the tyre width to 25mm would be an easy win.

Tell us some more about the wheels and tyres.Did they work well in the conditions you encountered? Would you change the wheels or tyres? If so, what for?

I was surprised to see 23mm tyres in this age of 'wider is better and faster'. Some road bikes come with 28mm tyres! It's the future!


Rate the controls for performance:
Rate the controls for comfort:
Rate the controls for value:

Tell us some more about the controls. Any particularly good or bad components? How would the controls work for larger or smaller riders?

I found the levers quite 'heavy' (as in, not light-action). Work fine though. The cable routing interferes with putting a light on the bar.

Anything else you want to say about the componentry? Comment on any other components (good or bad)

Not sure the aero brakes bring much to the party, other than difficulty in working on them. Then again, they might be a crucial part in the equation of how well the bike rides. They don't feel any more powerful than non-aero brakes, and aren't in the same league as Shimano Ultegra - but I wouldn't expect them to be.

Your summary

Did you enjoy riding the bike? Yes

Would you consider buying the bike? Yes

Would you recommend the bike to a friend? Yes

Rate the bike overall for performance:
Rate the bike overall for value:

Use this box to explain your score

I think this bike sits somewhere between good and very good. It's better than I was expecting for a £550 aluminium bike; I was 'looking forward' to a harsh frame, and feeling the weight on anything other than a descent - but I was pleasantly surprised. It's not overly stiff, it's certainly not uncomfortable, and though yes, it's heavy, that weight doesn't really make itself known until you climb - and then you're helped with the low gearing. It got me thinking about how much I'd spend on a bike that would cope with every-day commuting while also being a fun ride - and looking good too.

Overall rating: 7/10

About the tester

Age: 50  Height: 169cm  Weight: size 10-12

I usually ride: Vitus Venon  My best bike is: Paulus Quiros

I've been riding for: Over 20 years  I ride: Most days  I would class myself as: Experienced

I regularly do the following types of riding: commuting, sportives, general fitness riding

Tass is our production pedant, who boldly goes hunting for split infinitives, rogue apostrophes and other things up with which she will not put. She joined in 2015 but first began working on bike magazines way back in 1991 as production editor on Mountain Biking UK, then deputy editor of MTB Pro, before changing allegiance to road cycling as senior production editor on Cycling Plus. She's ridden off-road but much prefers on, hasn't done half the touring she'd like to, and loves paper maps.

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