A no-holds barred park bike built in Christchurch
While many of us dream of building our own bike, designed to exactly match our desires and finished to the standard of a top-end production frame, the sad truth is that most people lack the skills and equipment on hand to make it happen.
Milton Bloomfield is not most people.
Milton is the owner of Dynamic Composites, a small Christchurch-based engineering, design, and carbon manufacturing workshop specialising in jobs other outfits consider too tricky. The company started up in 1997.
“If someone tells us it’s too hard, you can’t do that, that’s what gets me excited,” Milton says.
He’s a passionate mountain biker, and having all that gear and knowledge on hand meant the temptation to build his own rig was irresistible.
He’s come up with a gnar-crushing all-carbon freeride bike, running a high pivot suspension layout with a 63 degree head angle and 180mm front/190mm rear travel on 27.5” wheels—the perfect weapon for a huge day of laps at Christchurch Adventure Park. The rig is a real head-turner, drawing lustful looks and envious comments in the lift line.
When Milton feels a pedal is in order, he turns to the second custom bike in his quiver: a slack, long-travel carbon hardtail that’s nice and light for the climbs but ready to party on the way back down.
A meticulous craftsman, Milton designed and built the bikes himself, and the finish is on par with, or above, anything available on a bike shop floor. Careful attention to detail is on display throughout.
Soon, these no-corners-cut machines will be available to the general public; by the time this magazine hits shelves, Dynamic Composites will be taking orders for the freeride bike, offering a huge range of build kits. A 150mm travel, 26” kids’ bike will be added to the lineup in February, with others in the pipeline for later in the year.
Details on sizing, cost, or even the brand name the bikes will be sold under—the current name Zen is to be dropped—weren’t ready to be revealed at the time of writing.
The freeride bike was based around Milton’s desire for a simple and reliable setup, after spending too much time on his Whistler trips fixing rigs rather than lapping the mountain. That led him to the high pivot layout, which is simple but still performs well on the trail. The rearward axle path that comes with it—which makes the bike eat up square-edged hits, as the wheel moves out of the way—is an added bonus.
While the layout means the bike pedals well enough for the spin from the carpark to the chairlift, pedalling was never the focus—though the numbers suggest it should climb well enough for a bike this big, especially with the shock locked out.
“All the effort was put into a bike that had good suspension and good brakes,” Milton said.
Because he was building the bike for himself, Milton said he over-engineered it by putting in more carbon than it realistically needed. But the simple suspension layout means it still comes in at a respectable weight.
Spoke got the chance to thrash the freeride bike for a few days at Christchurch Adventure Park.
From the first run it was clear that the rig was an absolute monster, especially when things got rough and steep. That rearward axle path was part of it, as the bike was astoundingly composed through chunky sections with lots of harsh hits. It tracked really well through the rough stuff. Within a couple of runs I was taking rougher, straighter lines than usual through some sections of trail, while going faster and feeling like I was putting in less effort. I did manage to find the end of its suspension a few times but bottoming out was never harsh.
That doesn’t mean the bike is just a plough machine; it rides like a downhill rig but weighs a lot less so was easy to flick about, and was neutral off lips and stable through the air.
On smoother, flatter trails, the bike’s burly nature was apparent, taking a bit of effort to get up to speed and feeling slightly sluggish to turn in slower corners—but it wasn’t a chore by any means, and better than expected given the bike’s downhill intentions.
As far as the finish goes, it was equal to or better than any bike I’ve swung a leg over in the past—a truly production-quality finish. Details like the beautiful cable routing and the handy storage compartment in the top tube show that thought has gone into every aspect of the frame.
It’s hard to comment on durability after a short test, but there was nothing in the design that gave me any cause for concern, and I faced no issues while I had it.
All in all, I was reluctant to give the rig back. It would be a great choice for anyone whose regular riding is accessed by chairlift or shuttle.
Milton really got into mountain biking during a family trip to Whistler in 2017—and the bug bit hard. The following year while back in Whistler he took a hard crash, breaking his scapula.
A self-described tinkerer, Milton used his forced time off riding to think about the sort of bikes he wanted to get designing.
A rowdy hardtail was a must, after his brother-in-law showed up with a shiny Chromag frame. The other was an “ideal” park bike; something a little short of a full-on downhill rig but with enough squish to stay out of trouble.
He said he put about 200 hours of design work into the freeride frame, thoroughly modelling every aspect using design software, allowing him to test how the frame would hold up in a variety of conditions without having to build a physical prototype.
Another 15 hours or so went into the carbon construction of the prototype frame, with time in the paint booth on top. Milton has been largely happy with the result, though he built a second rear triangle which was made a bit stiffer after finding the first slightly lacking.
He was hesitant to say too much about how he makes the bikes, other than that the frame was still made with a bladder and mould, and cured at high pressure but done in such a way that they can make small batches of production quality bikes at a fraction of the up-front costs big manufacturers face. He said it did need technicians with a higher skill level than mass production methods.
The company plans to keep production in New Zealand and will be targeting the premium end of the market. Milton is aware that only a select group of people will be after a bike like this.
Dynamic Composites’ bread and butter is in the aerospace industry and medical devices, though they also spent time working on the Martin Jetpack (which wound down in 2018) and on the tech in Shotover Camera Systems, a company specialising in video camera stabilisers. Some of Milton’s structural design work for camera stabilisation went into the system used to film many of the aerial scenes in Top Gun: Maverick.
But Milton’s passion is for the outdoors, and has been incorporated into the business wherever possible. His first love is sailing, and he has built components for the Team New Zealand boats that competed in the America’s Cup—a carbon steering wheel from one sits in the workshop next to a picture of the boat in action.
Bikes first came into Milton’s life when he reached a crossroads in the late 90s: he either needed to move to Auckland to give sailing a go full-time and mount an Olympics campaign, or find a new challenge in the Garden City.
Originally based in Ferrymead, Dynamic Composites’ workshop sat next to a bike shop and Topsport Kayaking, so it made sense for Milton to take on the Coast to Coast, for which of course he built his own bike and kayak, as well as a hardtail with 70mm of travel up front for training.
From there he linked up with Sarah Ulmer, building the track bikes she used to set a world record and win gold at the 2004 Olympics in Athens.
He was working with the whole New Zealand team by Beijing in 2008. Hayden Roulston rode one of the bikes to a silver medal, at the time saying the bike made “a significant difference”.
More recently, Dynamic Composites helped prepare Winter Paralympians Adam Hall and Corey Peters for the 2018 event. Both came back with medals.
“We saved [Corey] just over one per cent in drag … when High Performance Sport went back and analysed the numbers, that was the difference between his bronze medal and him being sixth,” Milton said.
Milton said Dynamic Composites’ point of difference is that they can go from conception of an idea, through the design, testing and prototyping, and into small-scale production in house. It means they know any limitations of the build process and design accordingly, so they’re not trying to adjust the design late in the process.
If their track record is anything to go by, this venture into high-end mountain bikes will be well received by riders.