Like this site? Help us to make it better.


J.Laverack R J.ACK Disc



Sporty performance, silky smoothness and all the benefits of disc brakes

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.

What the scores mean

Good scores are more common than bad, because fortunately good products are more common than bad.

  • Exceptional
  • Excellent
  • Very Good
  • Good
  • Quite good
  • Average
  • Not so good
  • Poor
  • Bad
  • Appalling

The J.Laverack R J.ACK was one of the standout bikes last year. We were so impressed, in fact, that it made it to the Superbikes of the Year against a field made up entirely of carbon fibre rivals. For 2018 the young British company has introduced a disc-equipped version of the R J.ACK and managed to retain the velvety smoothness and composed handling with all the benefits of disc brakes and increased tyre clearance, though there is a weight penalty.

  • Pros: Smooth, comfortable, fast, nice handling, looks good
  • Cons: Weighty, pricey

Titanium is a wonderful, if expensive, material from which to build a bicycle frame. With the J.Laverack R J.ACK it provides a nice balance between stiffness and compliance: it has the necessary stiffness to ensure direct handling and responsiveness for energetic and pacy riding, yet is composed and compliant over the rough roads that are a regular feature around most of the UK.

> Buy this online here

Adding a disc brake option was a no-brainer. Disc brakes are increasing in popularity, becoming more widespread even on bikes designed for racing or high-performance riding, as the J.Laverack R J.ACK is. There are pros and cons to disc brakes, and they're not for everyone, but all I will say is if you do try Shimano's latest hydraulics, you might find it very hard to go back to rim brakes with carbon wheels. With the J.Laverack R J.ACK, you now have the choice of rim or disc.

Ride and handling

Much of what I wrote about the original R J.ACK holds true with this new disc brake version. It's a fast and smooth bike, covering ground swiftly and doing so with the high refinement you'd expect from titanium. The smoothness is its big highlight, and really does wonders to transform my local roads into something a little less harsh and jittery.


It's no marshmallowy ride, though. There's evidently enough stiffness in the frameset, bolstered by the carbon fork, to ensure it's a thoroughly entertaining ride when you want to go fast. The geometry gives the R J.ACK a touch slower steering than some race bikes, which sees it being very docile at high speeds. It never once got skittish even down some of my steepest and rattliest descents, and the Shimano hydraulic brakes make it easy to control your speed. If you want extra confidence, this bike offers it.


If there's a downside to the new bike, it's the weight increase over the rim brake version. This bike is, more or less, a very similar build to the one I tested last year, but it's giving away about 600g. That does sound like a lot on paper, but to put it in perspective, it's about the same as a full 500ml water bottle. So ask yourself, do you feel faster when your water bottle is empty or full?

Frame details

Ignore the disc brakes, and visually the new frame is identical to the rim brake model.

There's the same 3Al-2.5V double butted titanium tubing with a squashed top tube, tapered head tube and threaded bottom bracket. The stays are a lot curvier, though, necessary to ensure the flat mount brake calliper is in the correct place and provide adequate heel clearance.


Even the 'race' geometry of this test bike is essentially the same, though you could choose the 'classic' option which uses J.Laverack's new carbon fork and has slightly more relaxed geometry if you want race bike performance without the back pains.


As usual, the attention to detail and quality of the finish is first class – very much what we're used to seeing from this young company. J.Laverack is big on customisation, with a choice of finishes and other options to choose from, so although not a bespoke bike as such, you can tailor it to an extent.


As already mentioned, some of the details on this bike are carried over from the previous version. That includes internal cable routing, which on this bike has been optimised for the electronic groupset, and the external threaded bottom bracket, but you could choose a press-fit if you prefer (ha!).


Where it is different is in the fitment of the Enve Road Disc 2.0 carbon fork and the new stays and dropouts. J.Laverack has developed new cowled thru-axle dropouts with a flat mount on the non-drive side. It's very nicely done, all clean and tidy. Lever-less thru-axles require an Allen key to operate but do leave nice clean axle ends, which I like.


Switching to disc brakes has boosted the tyre clearance on this bike. There's space for up to 32mm tyres, up from the 28mm limit imposed on the previous bike by its rim brakes. With a growing interest in wider tyres, it's great to see this increased choice, and speccing 28mm tyres on this model is a smart choice for helping to smooth poorly surfaced roads.


An interesting deviation from the original rim brake version is the development of the two geometry types, mentioned above. We have the 'race' version with the most aggressive geometry and a stock Enve fork, as tested here, and the 'classic', with slacker, more relaxed geometry and the company's own fork. The classic actually sits a bit closer to the company's original J.ACK road bike.


"We wanted to translate the proven geometry, speed and agility of the original R J.ACK to a disc brake model in order to a create a spirited and elegant bike for the discerning road rider," explains Oliver Laverack, designer and founder of the company.

Each frame comes with a 10-year warranty with the original owner.


J.Laverack will happily sell you a frameset for £2,380 or a complete bike customised to your needs, with full bikes starting at £3,650. If you're feeling flush and want to blow your bonus/pension/inheritance/student loan on an £8.5k superbike build, this Shimano Dura-Ace Di2 bedecked beauty could be yours.


Dura-Ace Di2 is the current benchmark groupset, slick of shifting and strong of braking, with arresting looks and flawless durability. The hydraulic brakes with the new Freeza rotors offer highly impressive braking, powerful and easy to feather in any situation, whether tackling a tricky descent or weaving along the road in a fast-moving peloton.


J.Laverack has decided to commit to producing its own carbon fibre wheels, and my impressions of the Aera AR|36 wheels are very positive. The wide profile works well with the 28mm Schwalbe Pro One tyres, providing a broad platform, and the aero performance, in so far as I can determine using speed, power and seat of the pants feedback, is commendable. They're laced onto Chris King R35 hubs which look and sound glorious.


I'm no fan of the Brooks Cambium saddle, though I know many people are; it's no bother to spec a saddle of your choice or simply change it.


The PRO Vibe carbon seatpost and handlebar with aluminium stem all look like good kit on a top-end build like this and functioned without flaw. I particularly like the shape and reach of the bar.


A set of J.Laverack's own titanium bottle cages completed the build – a good move as I don't think carbon cages would quite look right on this frame. What do you think?



I can count the number of disc brake-equipped titanium road bikes has tested on a single hand. Not many, but there have been some standout bikes.

> Buyer's Guide: 14 of the loveliest titanium road bikes we've ridden

Most recently there was the Van Nicholas Skeiron that offers high performance for the non-racer but is a fair bit heavier. If you want more of an endurace focus there's the Enigma Evoke Disc which also takes 32mm tyres and offers a delightful ride.

If you're not bothered about disc brakes, there is, of course, the rim brake R J.ACK or you could consider the Reilly T640.

And, just to show how light you can get a bike for the same money, there's the Specialized S-Works Tarmac SL6 weighing in at 6.3kg!


Apart from the stellar price, it's hard not to like titanium as a material choice for a bicycle, and when it's created with this care and attention there's really a lot to like. Okay, so J.Laverack doesn't craft the frame itself, few builders in the UK do these days, but it has produced a smart and distinctive looking frame with solid handling and nice attention to detail.


Sporty performance, silky smoothness and all the benefits of disc brakes test report

Make and model: J.Laverack R J.ACK Disc

Size tested: 56cm

About the bike

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

From J.Laverack:

Hand-made titanium road machine built for speed and comfort

'Race' geometry – Enve Road Disc carbon fork

'Classic' geometry – J.Laverack flat mount 12mm thru-axle carbon fork with or without mudguard lugs

Brooks Cambium C15 saddle – carved or standard

Chris King or Hope threaded or press fit bottom bracket & integrated headset

Flat mount brakes

Personalised bead blasted message

12mm Thru-axle as standard

Elegant design

Internal cable routing

Choose from two geometry options

Electronic groupset ready on request

Timeless bead blasted graphics

Optional threaded or press fit PF30 bottom bracket

Bespoke painting options

Available in brushed or Pavé finish

Tapered or straight head tube

Up to 32mm tyre clearance

Durable 3Al-2.5V titanium tubing

Hope seatpost clamp included

Tell us what the bike is for

J.Laverack says:

A timeless titanium road frameset, available in two distinct geometries, for the discerning rider

The R.J.ACK Disc, a thoroughbred with sleek, graceful lines and speed coursing through its veins. Exhilarating to ride, the frame is taut and agile, its handling precise and confidence-inspiring.

Frame and fork

Overall rating for frame and fork

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

Very hiqh quality build, neat welds and lovely attention to detail.

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

Double butted 3Al-2.5V titanium tubing.

Tell us about the geometry of the frame and fork?

Race focused geometry but you can opt for the "classic" which is a bit more relaxed.

How was the bike in terms of height and reach? How did it compare to other bikes of the same stated size?

I found the fit perfect with no changes required.

Riding the bike

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

The titanium tubing and 28mm tyres combine to provide a wonderfully silky smooth ride.

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

The front end has a reassuring level of stiffness when you're sprinting or chasing faster wheels.

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

It certainly won't rival a carbon bike but it's no marshmallow when you put the power down.

Was there any toe-clip overlap with the front wheel? If so


How would you describe the steering? Was it lively Relaxed and docile.

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

Quite relaxed and calm handling made it a doddle at high speeds.

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

I was impressed with the company's new carbon wheels, with reliable tubeless installation.

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

There's nothing I'd recommend changing, other than a saddle based on personal preference.

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

No changes.

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:

The drivetrain

Rate the drivetrain for performance:
Rate the drivetrain for durability:
Rate the drivetrain for weight:
Rate the drivetrain for value:

Wheels and tyres

Rate the wheels for performance:
Rate the wheels for durability:
Rate the wheels for weight:
Rate the wheels for comfort:
Rate the wheels for value:
Rate the tyres for performance:
Rate the tyres for durability:
Rate the tyres for weight:
Rate the tyres for comfort:
Rate the tyres for value:


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

Your summary

Did you enjoy riding the bike? Yes

Would you consider buying the bike? Maybe

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 overall score

It's a good choice if you want a fast and comfortable bike for high-speed riding, with all the benefits of disc brakes.

Overall rating: 7/10

About the tester

Age: 31  Height: 180cm  Weight: 67kg

I usually ride:   My best bike is:

I've been riding for: 10-20 years  I ride: Every day  I would class myself as: Expert

I regularly do the following types of riding: road racing, time trialling, cyclo-cross, commuting, touring, mountain biking

David worked on the tech team from 2012-2020. Previously he was editor of and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds, and you can now find him over on his own YouTube channel David Arthur - Just Ride Bikes

Add new comment


DaveBJones | 2 years ago

Lovely looking bikes but you will need to be very patient as I have been waiting for my GRiT frameset for 12 months and it still hasn't arrived.

kil0ran | 6 years ago

I'm really not a fan of the bent seatstay approach that seems to be prevalent at the moment. What's the purpose? Is it to shorten the wheelbase? Just looks like the bike has been rear-ended...

Latest Comments