Tag Archives: Dynatech

My rides: Raleigh Dynatech Mission (Dynacurve)

One of my projects is a 1990 Raleigh Dynatech Mission. I’ve heard great things about this frame, and I’m rather looking forward to getting it built up, when time permits.

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The frame is of an unconventional construction, having butted Reynolds 653 mang-moly steel main tubes (531 material, after heat-treatment), a Reynolds 531 Mang-Moly fork and rear triangle, and an aluminium head tube.

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Look closely, and you’ll see the frame is lugged. But unlike most lugged frames, this one isn’t lugged and brazed. In fact, the main tubes are joined by bonding (using high-tech aerospace glue) into lugs. This actually makes for a stronger join than could normally be achieved through welding or brazing – the heat from which can reduce the tensile strength of heat-treated steel – and allows different metals to be joined (aluminium and steel in this case, but Raleigh also bonded titanium and metal matrix to steel and aluminium).

Raleigh often didn’t publicly acknowledge which tubing was used in their Dynatech ranges, preferring instead to invent their own tubeset designation. In the case of the Mission, Raleigh’s mix of Reynolds 653 and 531 was designated ‘2070 performance enhanced tube set’.

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For comparison, my Dynatech Voyager‘s 2060 tube set has Reynolds 531 main tubes instead of 653, and a chrome-moly fork.

Check out the unusual design of the lugged head tube  in the photo below

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But what really sets my Dynatech Mission apart from other frames is its ‘Dynacurve’ top tube. Dynatech Missions are not exactly common, and frames with the Dynacurve top tube are even more of a rarity – so I feel pretty lucky to own one.

As the name suggests, the top tube has a noticeable curve, so as to “ensure maximum support for the seat tube while keeping the head tube at the optimum length” on larger models of the frame.

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However, it’s not obvious why the Dynacurve is really needed at all. Other manufacturers managed to build large frames without the need for curved top tubes, but perhaps the issue is related to the bonded construction of the Dynatech. Regardless, I think it looks really cool!

See the photos below, linked from retrobike.co.uk, for a few more examples of Dynacurve frames.

Dynatech Voyager with Dynacurve:

Compare the above to the non-Dynacurve (smaller) bike below:

Dynatech Voyager without Dynacurve

And another example of a Mission, again from retrobike.co.uk:

Photos of my own build will follow at some point in the future … watch this space!

Vintage steel Raleigh Dynatechs

Often overlooked in favour of the lighter titanium models, Raleigh made some really nice bonded steel Dynatech frames during the late eighties and early nineties.

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Cover of a Dynatech catalogue

The innovation made by Raleigh for this range of bikes was the bonding together of the main tubes, often from different materials, to build a frame that is light yet strong. The Raleigh brochures of the day boasted that bonding gives stronger tube joins, compared to welding or brazing.

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I really love the very visible engineering on these frames in the form of lugs, and the absence of messy welds (although the rear triangle is still welded). Let’s have a look at a couple of the bikes.

Dynatech Voyager

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Dynatech Encounter

Check out the Girvin Flexstem ‘suspension’ stem!

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Dynatech: awaiting trial

Unlike for some brands, surprisingly little information exists on the internet about the Raleigh Dynatech brand – despite being one of the coolest serious mountain bike ranges from a British manufacturer during the early nineties. To remedy this deficiency, over the next few months I plan to catalogue and showcase as much of the Dynatech range as possible.

To get things started I give you the 1991 Raleigh Dynatech mountain bike catalogue’s front page, whichhas to be one of my favourite catalogue front covers of all time:

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Depicting a Dynatech Encounter handcuffed on a dank backdrop, the imagery evokes danger and subversion, and the bike screams ‘ride me, as though you stole me’.

Check out this thread at retrobike to see a surviving Encounter close up.

I too have a similar Dynatech Mission frame and forks at home, awaiting trial, which can only happen once I’ve decided exactly how I’ll build them up… And I have every confidence it will be as fun to ride as my Dynatech Diablo STX or my M Trax 300 or 400.

My 1993 M Trax Duo Tech 300

Way back during the early 1990s, Raleigh’s Special Products Division (or RSP for short) came up with the novel idea of bonding titanium or cro-moly steel tubes into steel or aluminium lugs, to build mountain bike frames that had a fairly low weight, a rigid rear triangle, and some of the damping and flex of titanium.

In its day, this was something of a genius idea, insofar as it allowed ownership of a hand-built titanium bike, with prominent ‘Titanium’ decals, for a fraction of the price of a welded, full titanium framed bike. While there’s little doubt that some clever marketing, along with a generous sprinkling of ‘titanium aura’ tinged hype, played a role in the relative success of RSP’s ‘Duo Tech’ framed mountain bikes, their performance and ‘ride quality’ was also usually quite highly regarded by those who rode them.

Originally branded as part of the Raleigh Dynatech range until 1994, and part of the Raleigh M Trax range from 1993 to 1995, the demise of the Duo Tech frameset came when the cost of materials and fabrication rose to such a level that the frameset stopped being profitable — at which point Raleigh switched to more conventional designs and materials.

My 1993 Raleigh M Trax 300 Duo Tech

As the bottom of the range model of the newly introduced M Trax brand, the M Trax 300 was the cheapest titanium framed mountain bike you could buy, retailing at about £350 back in 1993. Bought for the princely sum of £50 from retrobike.co.uk, this is my best value for money bike purchase to date. It’s getting common to rebuild retro bikes to their more or less original specifications using parts collected from ebay, but my M Trax is a true survivor: all original parts (down to the tires, grips, and brake pads), very little use at all, and carefully stored for 20+ years, albeit with some conspicuous rust on the bottle cage bolts and brake bolts.

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Raleigh M Trax 300: unpacked and ready to ride

After removing the reflectors and adding modern SPD pedals, at 27.5 lb it is not unduly heavy by modern standards, but is close to the upper weight limit that a self-respecting 90s mountain biker would be able to tolerate. The bike has potential for some easy weigh savings, such as replacing the steel stem, bar and seat post with lighter aluminium versions, and fitting lighter tires.

The good

  • The bike feels lively and springy (less so than a good all-steel framed bike, however), with noticeably more trail-buzz being soaked up by the steel controls and titanium tubing than I would usually expect with the 90s standard set-up of aluminium controls and an all-steel frame.
  • Steel controls and seat post give added confidence (at least for a taller/heavier rider like me).
  • The Shimano Deore II thumbshifters and hyperglide cassette shifted between gears remarkably smoothly, which some may find surprising for a bike of this age. The ability to shift across the entire block or chainset in a single movement was appreciated.
  • Reasonably light in weight.
  • Metallic turquoise paint job looks the business.
  • Titanium at the price of far-east steel.
  • Ostentatious decals on the top-tube emphasize that this frame has TITANIUM.
M Trax 300: destination Nun's Cross
M Trax 300: test ride, destination Nun’s Cross

The not so good

  • The gear ratios are a little on the high side for the steepest off-road riding, with its lowest ratio being 1:1.
  • A design fault in the Altus chainset’s non-replaceable inner ring makes chain-suck episodes all too frequent.
  • The plastic four-finger Dia Compe brake levers look ugly and lack power.
  • The bar is just slightly too narrow to steer the bike properly over technical terrain.
  • RSP’s Duo Tech frames were known to de-bond, and there are anecdotal tales of having a tube pop out of its lug mid-ride, in the middle of nowhere. Thankfully, this seems not to be an especially common problem.