Hitting the road with J.ACK

It has been a very busy fortnight since my last post. Amongst a lot of work I’ve managed to maintain my training plan and follow up on the foundation sessions at the velodrome. Last week I also arranged a meeting with Dave Clow of J Laverack, the small independent titanium bike brand. Their J.ACK model was on my shortlist for the TCR bike build and I was keen to get a test ride in before I left for Japan.

“Aluminium, steel, carbon, titanium. Each have their benefits, drawbacks and enthusiastic fan clubs.”

Ultra-distance presents some fairly unique challenges, so I have a few requirements of my race bike that are probably worth explaining now. The key materials for bike frames are aluminium, steel, carbon and titanium. Each have their benefits, drawbacks and enthusiastic fan clubs. A quick poll among the 2016 TCR riders shows a fairly even spread across all materials. My preference is for titanium, which has the strength of steel at half the weight. Most importantly it has a degree of compliance that makes for a more comfortable ride; comfort being the most critical factor in ultra-distance riding. Carbon is much lighter and offers the best performance but isn’t as durable. Titanium bikes don’t fatigue over time, as steel does, so a titanium bike is a bike for life.

I consider disc brakes essential for the race, which is why I won’t be using my Canyon Aeroad. Traditional rim brakes are rubbish in the wet, wear quickly and can also suffer from overheating on longer alpine descents. None of these things are good for the Transcontinental. Hydraulic discs also require much less effort to pull. It’s common to lose hand function over ultra-distances so this is a useful thing. Similarly, having electronic gears makes for physically effortless changes. It also allows me to add shifter buttons on the extension bars, which means I can stay in a good tuck for longer and avoid wasting any energy (or exposing myself to danger) by moving around on the cockpit when I want to change gears.

Option 1: The Kinesis GF Ti Disc v2

These things all combine to provide a relatively shallow shortlist of potential frames, which I’ve since reduced to two. J Laverack are a new company, launching their debut model in 2015. This is in stark contrast to long-established Kinesis, who produce the other bike on my final shortlist. Their GF Ti Disc is a disc-braked variation of an established frame that has been refined over many years and consistently reviews amongst the best bikes around, in any category. On paper the Kinesis is an easy choice. But building up a titanium bike is also an exercise in cycling romanticism and that means the heart has some say in the matter, which complicates things. I find myself drawn to the J.ACK, where the Kinesis has yet to stir any passion. To be fair to it, I have not yet been able to test one and all reviews swoon over its ride quality. The chaps at Kinesis have been enthusiastic about me riding one to Turkey but have struggled to build or source a test bike in my 60cm size for several months now. There is a lot of post-build testing to do and luggage to make up etc, so time is running out for the Kinesis. In some ways I’ll be relieved if that doesn’t work out because then I can follow my heart without guilt, ignorant of any advantages I might be giving up.

“On paper the choice is easy, but building a titanium bike is also an exercise in cycling romanticism, which means the heart has a say in the matter.”

Two days before I met Dave to test the J.ACK I was on track at the Olympic Velodrome, taking my stage 4 accreditation test. Stage 3 was a flawless pass and I was feeling very confident. This session, however, was disastrous. One cantankerous old chap broke ranks during the first stacking exercise and refused to listen to anybody in the group, insisting we were all riding too slow everytime he rotated to the inside line, oblivious to the pace of the riders on the outside. He kept surging far ahead and shattering the formation, which led to some dangerous situations going into the changes. It can’t have looked good to the assessors.

“My helmet is deformed in two places and cracked in another; evidence of the violence of the crash.”

Later, during pairs changes, another chap executing a change panicked and slowed dramatically on the banking. Inevitably that led to his bike slipping out from under him and he slid down into the formation, taking out six riders. I was at the back of that formation and seemed to come off worst. Riding inches from the guy in front, there’s really no way to avoid joining the crash and I launched over the first rider, landing head first on a contorted heap of bikes and riders – like some demented game of cycling Twister gone horribly wrong – before flipping over to land on my back on another bike. My helmet is deformed in two places and cracked in another; evidence of the violence of the crash. Immediately I found myself clutching my arm, feeling very similar to previous times when I’d broken it. That now seems unlikely but the whiplash took a few minutes to make its presence felt (and a few days to reveal its full effect). The migraine took a few hours longer. I’m not sure this track business is wise if I want to have a healthy season.

Option 2: A custom-built J Laverack J.ACK

I arrived in Peterborough in a bit of a mess, worried if I could even ride a bike let alone have the capacity to judge the frame’s ride quality. The oft-mentioned ‘magic carpet’ quality of titanium was apparent from the first few revolutions though. I pedalled out of the car park in search of some rotten surfaces to try my luck. I didn’t have to look that hard to find some junk roads, as bad as anything I expect to find on my way to Turkey. The tyres – the largest contributor to comfort – were 28mm in size but pumped up to 90psi. That’s quite firm for 28s, which made the comfort I was experiencing even more impressive. Going tubeless should add even more comfort.

“I didn’t have to look hard to find some junk roads, as bad as anything I expect to find on my way to Turkey.”

Another major contributor to comfort is the saddle and this J.ACK – Dave’s own and No2 off the line – was wearing a Brooks C15 Cambium. It’s a great looking saddle that I’d spied in reviews but at 400g I had no intention of considering for my n+1 TCR build. It was quite something in practice though. I was wearing jeans for my short test so the saddle will need more testing in proper Lycra but it’s quite promising. And if there’s one area where it’s worth prioritising comfort over all else it’s the saddle. The lightweight touring bike I set out to build is quickly porking up!


The quality of craftsmanship in the metalwork is first rate. The J.ACK is possibly the most attractive frame I’ve seen. It’s a traditional material given a modern design; an approach I am enthusiastic about. I’m even impressed by the branding, but then I’d expect nothing less from a fellow Stamford design alumnus. Going back to the romance of building your dream bike; I’d also be keen to support a new frame builder from the area I grew up in.

The most negative thing I can say against the J.ACK is its weight, where it gives away around 250g to the Kinesis. The internal routing is where J Laverack claim this surplus lies, but it may also be that the Kinesis has been refined over many years, affording the opportunity to trim weight. 250g is not much when the total rider-and-bike unit weight it added up but it’s still a significant amount in isolation and every gram will be considered with such a mountainous route to Turkey! One suggestion from Oliver Laverack is to customise the frame to my own spec, reducing the seat post diameter to 27mm. This should shave some weight but a narrower seat post also flexes a little more, improving comfort to a small degree. This is the advantage of a customised built-to-order bike like the J.ACK.

I’m fairly sure I’ll be buying an excellent frame whichever way I go, but a decision needs to be made in the next few days. Kinesis have the ball in their court at the moment. If they can’t commit to a test date in the near future I’ll have made my decision.

11 thoughts on “Hitting the road with J.ACK

  1. Great looking frames and one year ago I probably would have bought one, I have a Salsa.
    Two points though;
    “Titanium bikes don’t fatigue over time” If only this was true. I’ve owned and seen several cracked Titanium frames, a lifetime warranty is the only way its a frame for life, still annoying when you don’t have it because its being repaired. Litespeed, Lynskey, Merlin, Nevi, Van Nicholas all makes seen with cracks. Yes Titanium is great, but it’s all down to the stress caused to the material during welding. (P.S. just Google images for “cracked titanium bike frame”)

    Try and get an extended (like 300Km) ride in on the Cambian. Yes they can be comfortable but boy do they make you sweat causing other problems, guess that’s the non absorbent rubber. ( I own 4 Ti frames and 2 brooks saddles though, so its all relative as to the level of your experimentation)


  2. Hi there – which forks did you go with on your J.ACK in the end? I note the present Whisky 9 forks don’t have the crown hole through to the front so making a crown mounted light a problem!



    1. They were a prototype pair from J Laverack. Best to drop them a line and make enquiries as I couldn’t find another option that ticked all my boxes. I’m sure they’ll be able to look after you.


  3. I am looking at building a bike for ultra riding events and came to the same point as you, Laverack or Kinesis. And the same conclusion (I think) as you for the same reasons! Reading your (excellent) blogs I take it that you now have a few miles under your belt on the J.Jack. Looking back was it the right choice, anything you would/have changed? thanks


    1. It’s approaching its 2nd birthday and, yeah, it’s got a few miles on the clock now. I’m still very happy with my choice and would make it again. There’s not much I’d change to be honest. Thru-axles would’ve been better – especially for ultras – but I think that’s standard (or at least an option) on all models.

      There are some tweaks I’d make to some of the parts I fitted myself (wheels, aerobars) but I’m working with J Laverack on those too (more on that soon). For the sake of disclosure: I’m an ambassador for them now but I only endorse a very limited number of companies whose products I’d choose anyway (awesome kit is better than free kit!). We’ve had many conversations about building the perfect ultra-racing bike so they’re well clued up on the demands of ultras and will be able to guide you too.


      1. Hi, Finalising the J.Ack build now. Can I ask what aero bars you fitted? I will be using clip on TT bars with them to. Decided on eTap I think in the end. Great ride at the weekend, and best of luck riding the TABR. cheers


      2. I use the Profile Design T3+ but there’s no universal solution. Aerobars are very personal. Syntace are popular with many racers.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s