By Zap


Although my first recollection of meeting David Turner is a bit hazy, what I do remember is that it was at some NORBA National in the late ’80s, and he was this baby-faced, up-and-coming racer whom I’d yet to take notice of, as I was busy stargazing at the likes of Ned Overend, John Tomac and Juli Furtado.

Over the years, however, as I got to know David, I came to not only appreciate his technical savvy in talking about mountain bike designs and the primitive days of suspension, but also his simple, kind and honest replies to my frequent questions.

More than anything, though, it was the level of gumption, courage, intelligence and self-confidence he must’ve had to fight for a slice of the full-suspension bike market against such mega-corporate brands like Specialized, Trek and GT—that was impressive. As cliché as the David-versus-Goliath metaphor has become, in this case, it fits.

Facing growing frustrations making carbon suspension bikes, in the last year David decided to chart a new path and instead dedicate his time to making titanium mountain and gravel bike frames. Here’s his story.

Back in 1990 David Turner (L) was an aspiring pro racer, here lined-up next to Daryle Price – back when XC riders rode multiple events. Also note the use of both a curved and straight bladed fork which at the time was the topic of another flaming tech debate. (That’s young Jimmy Donnell in the DWC jersey getting ready to race in the background).



MBA: When did you get started riding and racing?

David Turner: I got hooked on mountain bikes in 1983 when I was ski-bumming in Colorado. All the cool skiers in town had these awesome Euro road bikes that they trained on during the summer—Ciocc, Colnago, Masi, Battaglin, Moser, and so on. Growing up on dirt bikes in SoCal, skinny tires just didn’t seem that cool to me. The seasonal bike shop had a couple—and I do mean a couple—of mountain bikes, and they looked like more fun. At the time I could accurately guess who was on the trails ahead of me by the tire tracks, as there were only a few mountain bikers in town.

After two summers of riding the local trails and logging roads, I saw an advertisement for the 1984 National Championships in Eldora, Colorado. A riding buddy and I drove over the mountains to spectate. We walked around the course in the snow and mud, and I fell in love with the sport. I had to try mountain bike racing!

Over 30 years later, David is still an avid rider and racer and personally developed his new titanium hardtail.


MBA: You raced for Mongoose when they went from hardtail to full-suspension bikes that had been developed by Horst Leitner. How did all that go down?

DT: When I raced for Mongoose, suspension forks were quickly becoming a must-have. In talks with my boss about what developments would follow in the wake of the suspension-fork explosion, we decided to look into rear-suspension designs.

Something to keep in mind, though, is that there were a slew of developments happening all at the same time. Mountain biking was new and exploding. Already in development were disc brakes, multiple front-fork ideas, a myriad of full-suspension frame designs, fat experimental tires for snow riding, suspension stems, suspension seatposts, oversize steerer tubes to decrease flex, alternative front-gear systems, dropper seatposts, and on and on. It was crazy!   

Of course, in the early’90s, the predominant bike at the time was still a fully rigid hardtail with a short top tube, steep head angle and long stem, with massive 2.2-inch tires. Having grown up riding dirt bikes and reading Motocross Action and Dirt Bike magazines, I had read about Horst Leitner and the ATK motorcycles he designed and built.

Horst’s motorcycles weren’t based on traditional concepts like all the other designs on the market; they worked better. Horst’s theory was that suspension needed to work independently from the forces generated by the drive and braking.

Back in the early 90s, these were the main players in the suspension fork market.


At the time, none of the other bicycle suspension was nearing that Holy Grail between too much chain torque being applied to the suspension to “resist bobbing” and complete marshmallows that would compress at the slightest movement of the rider.

If Yamaha or Honda would have had such a notably better functioning system, I don’t think I would have had the courage to approach a massive company with a proposal regarding use on a mountain bike. But, Horst’s company (AMP Research) was local, so I reached out, got a meeting, jumped in the Team Mongoose van and drove to the biggest meeting of my life.

What still amazes me about Horst’s vision was that he had already sketched out a mountain bike frame design sometime prior to my reaching out but had shelved it. It was obvious that Horst never quit thinking about “active” suspension, even if bicycles were something he had no personal interest in.

A couple of keys to working with Horst on the Mongoose project were his steadfast focus on designing lightweight parts and that the suspension was always “fully active.” It was really exciting to be a part of a massive change in the sport. I knew that full suspension would dominate mountain biking in the future. What I did not know was that it would take so long for full suspension to become the norm of mountain biking and that there would always be a notably sized market for hardtails. I really thought that the full-suspension mountain bike would exterminate rigid bikes.

The Mr. Dirt PBF inverted fork was ahead of its time.



MBA: How long did your racing career last, and then what prompted you to quit and start your own bike company?

DT: I first rode for Team Marin in 1987, then Kona for two years, and finally for Mongoose from 1990 to ’91.

The real reason to start my own company was wanting to make what I thought was best. What I personally wanted to ride did not exist at the time. I had always been picky about so many aspects of a bike—from the first mountain and road bikes I bought myself, and then my team bikes, I always wanted changes. Making my own bikes seemed like the best way to go.

While I was racing, I was also helping Horst develop his bike designs, but one day we had a disagreement and I quit. The very first thing I did after I walked out was go down to the local arts and crafts store to buy some vellum paper, colored pens and a T-square. Next, I borrowed a sheet of plywood from a construction company, hauled it up to my apartment and started designing bikes. I launched my first bike in 1994, and it was made in America.

MBA: How long did you produce carbon frames?

DT: The first carbon frame was the XC Czar in 2014. The next model was the RFX, a 160mm-travel enduro model, and the final was the Flux, a 120mm-travel trail bike. From 2014 to 2019 was the timespan we were selling these carbon models. All the carbon frames were made in Asia.

The AMP full-suspension bikes were lightweight wonders—sometimes too lightweight.


MBA: What is the cost of a closed-mold carbon frame, and what were the lead times?

DT: For Turner Bikes, the cost of developing the design, including the molds and prototypes to test for the lead-up to production, was in the $150K range. Each company and each model are unique, and the price range is certainly broader than my experience. A not-so-fond memory of developing these models is the hidden costs of tooling. For the Flux, we used two different factories to create the three models, and one of the factories just kept adding on more tooling costs.

For example, we were using the common post mount. A rear brake-mount alignment tool is something that a factory making bikes should have, right? Not in their minds. Either Turner Bikes was the only one checking brake mounts or all the customers were getting billed thousands extra for the tools to make sure the brake caliper fit on the rear end straight. And this went on and on.

And speaking of “on and on,” probably the hardest part of the process are the lead times. I have heard from a guy I know at Giant that they can bring a completely new model to market in half a year. Amazing but not surprising, as they are a fully integrated brand and factory. I have also heard that Specialized plans on 18 months for a new model to be developed, which is reasonable, as they don’t own their own factories. But, in the case of Turner Bikes and the factories I have experience with, it was taking over 24 months to go from the initial meetings to getting the molds done and ready to produce.

And that $150K for the minimum number of molds (one each for small, medium, large and XL rear triangles) included no production frames—nothing to sell at this point. So, depending on a factory’s MOQ, it was another $100K +/- for production frames and another three to four months for production to be completed. Trying to plan that far in advance with an ever-changing market was challenging to say the least.

MBA: Was there a particular moment when you said “enough” and made that turn to only making titanium frames?

DT: When I started Turner Bikes, we were building in aluminum. As geometry standards changed, it was relatively easy to adjust to the changes by readjusting the welding fixtures and the tube-mitering schedule.

Carbon molds, on the other hand, are like a very big waffle iron and far more complicated. So, when the market wanted steeper seat tube angles for longer reach, lower standover height for longer dropper posts and slacker head angles to make longer wheelbases, flush that tooling! Cha-ching!

Thinking back to the days when everyone raced the Mammoth Kamikaze on hardtails reminds us of how good modern bikes are.



MBA: So much good and bad technology has come and gone over the years. What do think were the best tech breakthroughs?

DT: Disc brakes: Mostly because they are just great! They are so much easier to get dialed in perfectly, and that means consistent power, month in and month out. Oh, how about stopping power? I’ve done a lot of brake adjustments in the last 40 years, and once the bleeding process is learned, it beats trying to toe in brake blocks any day. With rim brakes, the slightest bit of moisture and Voila’, your braking goes away. Oh, and using a very expensive piece of equipment (the rim) as a wear item, yeah, that’s right, the rims as consumables. Simply ludicrous.

Tubeless: Forget the last decade of rolling-resistance performance mumbo jumbo—from a “downtime” and from a cost perspective, tubeless crushes inner tubes. Remember when changing mountain bike tubes was a regular part of riding? It seemed like someone was getting a flat all the time! Another tube, another tube, and on and on. I still see this on group road rides where about half of the bozos refuse to go tubeless because it’s easier, then their tires get punctured from goat-head thorns that grow along the road—easy holes for sealant to fill.

As fellow back-in-the-day veterans, David Turner and MBA have enjoyed a long history of bike tests and interviews

Is it really easier changing a tube on the side of the road with sweat running into your eyes with your friends sitting around watching than it would’ve been to set up tubeless in the comfort of your garage? Even patching tubes to cut one’s cost was a time suck, and of course patches and glue are not free. At one point, I had over 20 patches in one tube alone, nursing that $6 tube along as long as possible.

Index shifting: From beginners to pro racers, it revolutionized the operation of a bicycle. I still remember the short spin on Joe Murray’s Fisher race bike equipped with a pre-production index shifter. It was game-changing.

Clutched rear derailleurs: In one word, amazing! Remember all the dropped chains? And, of course, the “experts” recommending putting the chain on the big ring/big cog to take some slack out of it in an attempt to keep the chain on the cogs. Between index shifting, clutched rear derailleurs and modern 1x chainrings, mountain biking has become so much more enjoyable.

Bigger wheels: Some have heard the story that the pioneers wanted to start the mountain biking revolution with a 650b oversize winter tire from Hakkapeliitta, but the Soviet army bought them all up. And, with the then-recent release of the Ukai 26-inch aluminum rim, the pioneers went with what they could get.

The 26-inch wheel was a second-rate piece of equipment from the start. Don’t forget that the old-fashioned bikes that the pioneers were riding were juvenile bikes. All the big companies making them never considered that an adult would ride them except to cruise along the boardwalk.

Fast forward to Diamond Back when they made an off-road bike in the mid-‘90s for Dave Wiens to race with 700c wheels. What was it? A city bike for dirt? Then fast-forward a few years to when Wes Williams from Willits bikes started building custom Ti bikes with 29-inch wheels and mocking the rest as building “kiddy bikes.” Somewhere along the way, Gary Fisher caught on, and the rest, as they say, is history (or at least Trek’s version of it).

Born from a race bike originally built for Geoff Kabush, the Flux was half XC racer and half trail bike. The aluminum Flux rolled on 27.5 wheels and had 120mm of travel. It was Turner’s last American made model.


MBA: Okay, what about the five worst?

DT: Hmmm, in a free-enterprise system, if no one likes it, the product dies. But, some trends are pushed so hard by the behemoths that we have no choice. Some stuff I love to hate on.

Center-lock brake rotors: Great for high-production environments but stupid for home/trail use. Every mini tool on the market has a T25 on it. None of them have the multiple lock-ring sizes.

Which leads me to another huge pet peeve: more and more proprietary tools. How is it that a couple more or a couple fewer teeth on a BB tool makes it better? There are so many BB tools. Anyone introducing a new BB can easily pick one, but oftentimes the BB has a new wrench interface. More money, more stuff to put in the toolbox.

First designed in 2004 after he raced the Downieville Classic, Turner designed the 140mm travel 5 Spot to be a “rough terrain trail bike” that was a fast descender that could still climb well. Sounds like an enduro bike!


Boost frame spacing: For a lousy 6mm of added width, the whole industry has been disrupted. What’s up with that? It did not even change “dish” substantially. Cannondale does that better with Ai, a direct take of what pioneers Doug Bradbury and Charlie Cunningham did, who built custom wide and dish-less hubs/wheels with their custom frames. Wider hub spacing only helps in part; asymmetry is the second part. Or, are the powers that be saving that for another year to send the industry scrambling with the “latest” and “bestest” marginal gains?

Elastomers for springs: Although this is a really bygone matter, it still irks me. I understand all the reasons that all the effort was spent pursuing elastomers to use as fork and shock springs, but they never worked well. All those elastomer-sprung forks from the early days were terrible when compared to today’s oil-damped standards. RockShox were the best engineered package; then they put a lousy kitchen sponge in it for a spring. Manitou forks were gorgeous, but they used pencil erasers for springs (for the youngsters out there, Google “pencil”).

The development cycle for full-suspension bikes has come far since the days when 3-inches of travel was considered “long.”


As for the AMP Research linkage fork that I raced with, for the record, I really tried to get Horst to do the right thing, but alas, he did what he wanted and the result was a beautifully designed, stupidly lightweight work of art that would hiss and wheeze when cycling through the travel. And worse yet, the kinematics led to abrupt and disturbing fork dive when using the front brake.

Mert Lawwill’s Leader fork was another crazy-smart linkage design that in use didn’t revolutionize the industry and was ugly as sin. But, the biggest advantage to the Lawwill Leader was the quality of the shock that it used. At the time, it had a real suspension with air spring and oil damping, and the construction was topnotch at a time when so many production forks were kind of janky.

Well, that was until the Marzocchi Bomber came out. Previous to the Bomber, Marzocchi forks were junk. And despite the air/oil damping, which Italy did design, the forks would flex all over the dirt road, and I wouldn’t even want one on my gravel bike! What I remember most about the Bomber was that its design came out of the U.S. office. And with that, the Bomber has a place in history as the first fork to give mountain bikers what they really needed. It paved the way for what we have today.

Bob Barnett was so far ahead of his time with his Mr. Dirt fork that most still don’t get it. The Mr. Dirt PBS fork smashed all the other spindly DH forks on the market at the time. If you watch the video of the Kamikaze eliminator race that shows Jeremy Purdy beating Myles Rockwell, you can see how well Jeremy’s bike was working. Bob’s was a one-man company. He didn’t own any airplanes or go to the races in a semi, but he did have some of the highest-profile racers in the world racing his forks. Bob tried to bridge the gap between the crappy mountain bike suspension and what the motorcycle industry was already riding. Not to take anything away from Jeremy, but his setup was superior to the pile that Myles was paid to ride, and both the Mr. Dirt fork and his chain guide were a huge part of that race bike. 

Remember the days when tall seat posts, long stems and triple chainrings were the norm?!


MBA: So, how about a then-and-now analysis?

DT: Compared to the bikes of just the last few years, old bikes suck. The last 10 years of mountain bike development have been huge. Not as huge as the decade before that, or certainly not even close to the decade before that, but the refinements to the mountain bike as we know it have had a massive impact on what is available today. Everything today is much stronger due to the “A-Line” influence, with much better handling through extensive (and expensive) geometry refinements.

And, of course, bigger wheels are now the norm, which unless you are a child or a dirt jumper, is inarguably better. The sprinkles on the cupcake, like the brakes, dropper posts and tires, oh, how much better tires are today—don’t even get me started! 

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