Now THAT Was a Bike: 1990 Mantis Valkyrie

Jun 30, 2015
by Richard Cunningham  

Some readers may know that I made mountain bikes back when the sport was in its infancy and the vintage bike featured here, a 1990 Mantis Valkyrie, was one of them. The bike was beautifully restored by the Vintage MTB Workshop in the factory racing color that customers affectionately dubbed, "Tree Frog Butt Green," and is presently on loan to the Pro's Closet's museum. I rode one that was the same color and size for a number of years and it remains one of my favorites to this day. It was one of those rare designs where the good and bad traits blend together to produce a magical ride. I find it a bit awkward to be featuring a bike which I created here on Pinkbike, but I chose to because the unusual configuration of the Valkyrie frame and its boutique component spec recall a much broader story - about a brief and rampant period of innovation when rivals often cooperated and a garage machinist or a man with a welding torch could compete on a level playing field with the industry's largest players.

An Unlikely Source of Inspiration

The X frame was conceived after Gary Fisher took offence to statements I had made about the failure mode of his Procaliber racing frames in an article that I had guest-written for Mountain Bike Action Magazine. To prove me wrong (which he did), Gary flew me up to his headquarters near San Anselmo, California, where he demonstrated the failure modes of his frames, and some other examples he had laying around. Using a load cell and a fork fixture that he had borrowed from Charlie Cunningham over at Wilderness Trail Bikes, Fisher duplicated the forces of a head on collision by cranking down on a huge turnbuckle that pulled a solid steel "fork" towards the frame's bottom bracket until the front triangle failed.
Gary Fisher Mountainbikes 1994 remake of the classic Schwinn Excelsior cruiser that launched the sport.
Gary Fisher's Klunker, a 1994 reproduction of Gary's post-war Schwinn Excelsior balloon-tire bike and its "cantilever" frame. MOMBAT photo

True to Fisher's word, the Tange Prestige Procaliber frames outperformed his chromoly models by double. As expected, the chromoly front triangles simply rippled and folded at about 350 pounds of tension when they failed. The heat-treated Prestige frames, however, would withstand over 700 pounds of tension and they didn't dimple when they failed. Instead, the tubes would nearly explode as they cracked apart somewhere near their midsections, where their butted walls were paper thin. Fisher had a welded, oversized-aluminum front triangle on hand that blew the steel frames into the weeds by sustaining over 1200 pounds tension without failure. But, the a-ha moment for me happened when Fisher, out of pure curiosity, grabbed a rusted, 1940's era Schwinn Excelsior frame off the floor and hooked up the apparatus to it. It was a cantilever type frame - the kind that has an extra pipe that runs between the seat tube to the down tube near the frame's steering head. The Schwinn, with its one-inch-diameter mild-steel pipes nearly reached a thousand pounds on the load cell, and when it failed, it could still support 300 pounds of tension.

The head tube junction of a classic diamond frame is its weakest point. I didn't need Gary's demonstration to understand that. The strength of the Schwinn, however surprised us both. I realized that by simply triangulating the head tube area of a steel frame that I could use smaller, lighter-weight tubes and end up with a frame that was immensely stronger than its predecessors. I started working on the design on the flight home.

1989 Mantis Valkyrie

Originally, the Valkyrie was designed with conventional chainstays, and the handful that we built have become very popular among collectors. We switched to elevated chainstays around 1989 as a work-around to escape the confinements imposed by narrow rear hub and bottom bracket standards of that period. Large-diameter chainrings and an inboard chain-line restricted the space available around the rear tire and the sprockets to a few millimeters for designers who wanted chainstays shorter than 17.5 inches. Redirecting the chainstays over the bottom bracket area eliminated those issues altogether and allowed us to use short stays and "big" tires without clearance problems - and to avoid frame damage due to chain fouling, which was then a common occurrence.

The twin tubes that triangulate the frame serve as reinforcements to the head tube area, and also function to provide stand-over clearance. Back then, the longest commercially produced seat posts were 280-millimeters and while longer ones could be had from a boutique parts maker like IRD, oversized seatpost diameters had not yet gained acceptance and frames with long, slender seatposts were as flexible as tent poles. Twin struts allowed me to dramatically slope the top tube to get the stand-over clearance I wanted, while allowing for seatposts of reasonable lengths. The same concept is mirrored by today's frame designs, although the braces are smaller and simpler shapes.

1989 Mantis Valkyrie
The union of the bridge that connected the seat stays to the seat tube proved to be a weak point, I calculated the stress there believing that jumps and G-outs would create the highest loads, but it turned out that chain tension was much higher - up to 1100 pounds. I had to repair a number of cracked frames. This one was fixed by another builder.

Valkyries were a bit of a retro design for me, I had already moved most frame construction at Mantis from steel to oversized aluminum, and most welding was done with a modern TIG welder. Valkyries were a step back to steel construction, and their triangulated look reminded me of the British-made custom motorcycles that I lusted after in the '70's. The tubes I used were very thin, so with the exception of the bottom bracket junctions, X-frames were brazed together using an acetylene torch. I did all the welding on those frames, often while speaking on the telephone with customers. Most frame builders who use the fillet (fill-it) brazing method finish-sand the joints smooth. Having had a torch in my hand since I was in high school, however, I was pretty good at the technique, so to show off to fellow builders, I left the welds untouched. (I am pretty sure that nobody ever noticed).

Cottage Industry Component Makers

Bucking the norm is guaranteed to create problems and the Valkyrie had its own list of issues, the worst of which was that the X-frame's compact rear triangle was too short to route the saddle wires of conventional cantilever brakes behind the seat tube, so the wires had to be guided around the tube and the saddle connected on the front side. Even when set up perfectly, cantilever brake performance was less than inspiring. Fortunately, I wasn't the only designer who ran into that problem and help came in the form of the purple parts makers - ex aerospace machinists, like IRD's Rod Moses, who recognized that bike designs and riders' skillsets were progressing as quickly as big name component makers were falling behind. They were riders themselves, so they got it - and together they re-invented virtually every component on the bike to fill the growing performance void. A number of side-pull type brakes appeared, like the IRD Widget and Rotary designs on our featured bike, which handily solved the problem.

Most of the components that Vintage MTB Workshop used to complete the restoration are aftermarket items which came from that brief cottage industry bloom, which gave birth to almost every important innovation that created the modern mountain bike: Wide hubs and bottom brackets with sealed cartridge bearings, two-finger levers, offset crankarms, oversized and threadless headsets, dropper seatposts, through-axle hubs, tubular bottom bracket axles, open-face stems, disc brakes, suspension - and the list goes on. Sure there were a lot of crap products, but it is indisputable that the mountain bike industry is still harvesting the benefits of seeds sewn by the rule-breakers of the late '80s and early 90s.

The Bullseye crankset is a welded chromoly assembly that could have been the prototype for the present Shimano XT and XTR, with its integrated tubular axle and drive-side crank arm, pass-through sealed bearing bottom bracket and splined left-side interface. One of the bike's rarest features is the IRD remote seatpost quick release, paired with a Breeze-Angel Hite-Rite dropper spring. Correctly assembled, the Hite-Rite would keep the saddle lined up while its owner manually operated the quick-release clamp. IRD's cable-remote arrangement, powered by an early Suntour thumb-shift lever, will silence any doubts that the dropper post preceded the freeride movement.
1989 Mantis Valkyrie
Interloc Racing Designs' (IRD) Rotary brake was actuated by a cam and could be configured for center or side-pull cables. Stiffening arches kept the pivot bosses from spreading under hard braking efforts.

1989 Mantis Valkyrie
IRD's Widget brake, featured on the front was a side-pull design with a progressive rate that created a large amount of squeeze force, while allowing the pads to retract farther to avoid rubbing the rim.

1989 Mantis Valkyrie
1989 Mantis Valkyrie
Add IRD's Remote Seatpost Quick Release to a Breeze-Angel Hite-Rite and you get the seminal dropper - circa 1989

1989 Mantis Valkyrie
Roger Durham designed the prototype of modern cranksets in 1979.

Technical Details

• Year: 1990
• Serial number: VK1912
• Frame: Mantis Valkyrie
• Fork: Mantis Straight Blade
• Stem: Salsa Moto
• Headset: Shimano Deore XT
• Bottom Bracket: Bullseye Sealed Bearing
• Handlebar: Salsa Merlin Titanium
• Shifters: Shimano Deore XT Thumb shifters
• Front Derailleur: Shimano Deore XT
• Rear Derailleur: Shimano Deore XT
• Brake Levers: Shimano Deore XT
• Front Brake: IRD Widget
• Rear Brake: IRD Rotary
• Crankset: Bullseye
• Chainrings: Sugino 26-38-48
• Pedals: Shimano Deore XT M731
• Hubs: Bullseye Cartridge Bearing
• Rims: Matrix Mountain Titan
• Tires: Onza Porcupine
• Wheel QR: Ringle Cam Twist
• Seatpost: IRD
• Saddle: Selle Italia Turbo
• Seatpost QR: IRD Remote
• Grips: ODI Tomac Attack
• Cogs: Sachs Freewheel
• Chain: Shimano HG
• Remote seat clamp shifter: Suntour

1989 Mantis Valkyrie

Closing Thoughts

bigquotesValkyries had a sort of magical feel. The frame had a little give that took the edge off of the bumps, which was a wonderful thing during the pre-suspension era. And, they looked beautiful just leaning against a tree. The frame's slender tubes did not afford much in the way of lateral stiffness, and while that could be easily sensed, the bike tracked quite well at any speed. I raced one at the Mammoth Kamikaze DH and it was easy to control the endless drifts that were the course's signature move. Those who loved the Valkyrie most, however, were riders who put in long singletrack miles, which is something that I also enjoyed. It's time on earth was short lived, though. Paul Turner's RockShox eliminated the need for "vertical compliance" and by the mid-1990s, big brands had sorted out frame, crank and bottom bracket standards that worked with conventional frames. I was busy making dual-suspension bikes, titanium and aluminum were the metals of choice, and steel would soon be relegated to the craft beer of cult bicycle builders. Today, when I think of the Valkyrie, it makes me smile. It reminds me of a brief moment when the mountain bike community was united, fertile and chaotic. The wild West on wheels. - RC

View additional images in the Pro's Closet gallery

MENTIONS: @TheProsCloset

Author Info:
RichardCunningham avatar

Member since Mar 23, 2011
974 articles

  • 96 0
 That dropper is amazing!
  • 3 0
  • 75 13
 1989... Still more reliable and lighter than a reverb.
  • 3 4
 all they need is a lever for the clamp.
  • 8 0
 somebody really needs to make it and sell it, id buy it
  • 12 0
 I knew about the hite rite, but that remote binder just blew my mind.
  • 20 0
 Don't get too dewey eyed over the Hite Rite 'dropper'. You'll notice in the write up, that he specifically said 'properly assembled' This meant that not only did you have to have it installed correctly, but you also had to overcome the friction of the seat post sliding within the seat tube. Endless cleaning and re-greasing if you lived in muddy environs. Also, it is just a spring, so when the clamp was loosened enough to allow the post to move, the spring could twist on the eyelet through which the clamping bolt ran.
I had a couple of these (they came in longer and shorter travel versions) on different bikes, and ultimately went back to simply doing what I still do today... namely scratch my preferred insertion mark on the post itself and clamp it down. This way I could drop the post and then reset it by hand fairly quickly. I use a dropper post now... a reverb... and love it. It is incalculably better than its predecessor. Innovation though, the credit is due to those early visionaries who helped bring the mountain bike from klunker to the sweet rigs of today which allow us to ride terrain that would have demolished this frame, wheels and any rider foolish enough to guinea pig it.
  • 3 0
 I just love how simple it is.
  • 4 0
 reverend: I didn't have an issue with the spring induced seat twist, that I recall or noticed. Not to say you didn't. I really liked my Hite-Rite. Wish I still had it/ could get one.
To keep the seat post clean and the grease clean for longer, we zip tied an inner tube section over the insertion point. Long enough to be straight at the max extension. It just accordion'd up when dropped. Easy to replace when it wore out.
Would love IRD or anyone to start making the remotes again! Though, I'd probably need it to clamp harder as I'm not as svelte as I once was Wink
  • 3 7
flag Narro2 (Jun 30, 2015 at 15:22) (Below Threshold)
 or you could buy a modern dropper post, i have the one provided by specialized on my stumpy, I've done maintenance once in the last 3 years and it runs perfectly. MTB is my hobby i don't want to be spending time zip tying inner tubes the post, or any sort of jerryrigging on my bike. the Hite rite might've been nice back then but it has not comparison to current dropper posts
  • 4 0
 Well, it doesn't look like a session.....
  • 1 0
 Road cassette. as everything MTB was adapted road stuff back then. 28 tooth ring was all you got. I purchased a dura-ace free hub body so I could build my own cassettes and could up grade to a 30
  • 43 0
 Wow. I knew those legends about 26" bikes were true...
  • 9 0
 Love this articles! I have been into bikes my whole life and being able to witness the progression made on both bikes and riding is very cool. Back in the 90's I moved from a steel frame to the futuristic y frame from Trek. I don't think my stoke level has been as high ever after over getting a new bike. Please do a write up on that 1st gen Y-frame
  • 3 0
 Oh the hours I spent drooling over the Y Five-0...
  • 2 0
 I started with a shitty steel Trek 930, and drooled over the Santa Cruz Tazmon magazine cutout I had on my wall. Porn priorities.
  • 9 0
 A beautiful Mantis frame, IRD brakes, Bullseye cranks, a Turbo saddle, vintage XT with rubber-covered brake levers and dustboots over the barrel adjusters, Porcs...the only bad thing that I can say about this bike is that it does not live in my shed. If I had to choose between this one and the Yeti previously featured, I would definitely go for both!
  • 2 0
  • 14 1
 11/10. RC you the man.
  • 6 0
 this should be flagged for self promotion Wink
  • 8 0
 The 90's seems not too long ago for me. The internet was not widespread, mobile phones...heck. . not everybody has was not that complicated.. im waiting for the 90' to call back everything... .everybody.
  • 10 0
 Short, steep and high. New geo for 2016.
  • 7 0
 I'm sorry Richard, I didn't even read the words - the restoration job captured in those photos is just mesmerizing.
  • 5 0
 RC... to legit to quit! That impressive, i never knew your history. Awesome to see your still shredding it after all these years!
  • 5 0
 Big props to the guys at The Pros Closet for restoring this piece of history. I cannot believe the job they do bringing these amazing bikes back to life!
  • 3 0
 Saw a raw aluminum 'Cunningham' on display in San Francisco, I believe, in the late 80's or 1990 with a unique chain retention device, namely a tube through which the chain was threaded atop the chain stay. Was this Richard's design? First $10k bike I ever saw. And, despite the fact that there was no way I could even consider purchasing it, I lusted after it!

Some things never change.
  • 5 0
 That's an incredible bike! It was actually Charlie Cunningham's design. The collection in San Francisco was owned by Steve Banks, who has since passed away, but it's important that the history he curated is not forgotten and his bikes are still able to be viewed. We'll be photographing that Cunningham soon! Wink
  • 2 0
 Oh I look forward to that. Thank you for your attention to our history (short though it may be) and the wealth of innovation that has brought it so far in such a brief span. These photo's and discussions with builders feel like a reunion with long lost friends.

Thank you!
  • 1 0
 p.s. where can these bikes be viewed today? (Driving down to So. Cal to visit my in-laws in August, and stopping by to visit friends in the Bay Area on the way home...)
  • 1 0
 Unfortunately, not in CA, we're located in Boulder, CO. But, next time you find yourself in the Rockies, stop by and check out the collection.
  • 5 0
 that was one of the many bikes in MBA that I drooled over as a young mt biker.
  • 2 0
 So cool. I remember the hite-rite's but never the remote actuation, slick! Would be an interesting to have some WC guys throw around some 90's vintage bikes (canti's / 80 mm travel) down some trails back to back with their current rigs. Course dependent, but I bet they'd be 2x as fast, if not more.
  • 2 0
 Next vintage review... Nishiki Colorado Richard Cunningham design. I've got one in my stand right now cleaning her up. Virtually brand new. Robins egg spackeled blue paintjob, straight fork, biopace, canti brakes, cool cable routing guides, headtube gussets, white walls.
  • 3 0
 Back then, it was common to see canti on the front, and roller cam on the back. Does anyone know the reason for mix matching brakes?
  • 3 0
 Clearance issues with the shorter rear ends made the u-brakes popular… cantilevers didn't fit. RC mentions it in the article. It was a space issue.
  • 2 0
 Right, in this case makes sense. Why not using rollercam on the fork then?
But canti-front, rollercam-back was used on traditional frames as well.
I am wondering why.
Stronger brake on the rear?
Different fork design required for rc?
Either way I loved the rollercams, too bad did not take off.
  • 3 0
 Rollercam brakes were susceptible to grabbing so I am guessing it is the better modulation of cantilevers that kept them on the front. It would be cool to hear from @RichardCunningham why it was so popular…
  • 1 0
 Yeah, Rollercam... the real ones, made by cunningham and wilderness trail, had better modulation and power than any cantilever/v brake I had. And the used to cost a fortune! Not too hard to set up either.
Suntour made cheaper versions and some did not work too good.

I remember when early dh parks stopped to allow rim brake bikes, i was still able to get in with the rollercams.
  • 5 4
 26 inch wheels with a 48 front ring...i sense a new standard, combine with a boost+ rear end (148.75), 41mm titanium rims and 1.9inch (400 gram) tires stretched like caitlyn jenner on a first date and you have the ultimate trail bike.....20mm through axle of course.
  • 1 0
 The first shop I worked in (circa 1996) had a lot of old stuff in the basement - one was an e-stay Mantis in bright green. I thought it looked weird and cool... still do. I bet when the shop closed in 2013 it was still down there.

Check out how close IRD got to making a v-brake with the Widget! Dang. Brakes back then sucked the big one.

Killer feature and hope to see more!
  • 3 0
 You don't see to many 237mm long stems anymore. Also we need more and these retro bikes, always a very interesting read.
  • 8 0
 I think the formula for stem length used to be bar width divided by 2
  • 4 0
 try applying that to modern DH bars. would be a areo timetrial position
  • 2 0
 I would like to see a 400mm stem
  • 4 0
 Wow a reliable dropper post!
  • 2 0
 Excellent article; thanks for taking me back to what was such a fun period in mountain biking history. Bikes now are amazing, but there is just something missing...
  • 2 1
 Diversity? They all kinda look the same.
  • 1 0
 I was going to say "character", but yea, they are related.
  • 2 0
 Great article "It reminds me of a brief moment when the mountain bike community was united, fertile and chaotic." so true - and evokes great memories!
  • 3 2
 LOL @ all the pussies these days who say a 30T ring is too hard on their 1x setups with a 36, 40, or 42 cassette granny cog.

This thing had 26-38-48 crankset and the cassette looks like it tops out no more than 28T.
  • 2 0
 And if u think this bike is cool, look up the non elevated chainstays version!
  • 1 0
 Great article and bike too. RC continues to inspire and cultivate the sport and life style of mountain biking.

Out of curiosity, had bar-ends been invented yet in 1990?
  • 2 1
 It looks like they tried making a full suspension bike, but then though "Ahhh screw it, we're making a hardtail". ;D
  • 1 0
 " when rivals often cooperated " man i wish they still did, we probably wouldnt have to deal with boost.
  • 1 0
 Another great historic bike article, thanks Richard. Love the dropper post.
  • 1 0
 What about the price back then? and todays price equivalent?? It looks really expensive
  • 2 0
 RC did you get any inspiration from a SE Quadangle by any chance ?
  • 1 0
 Just a simple but big THANK YOU, Sir R.C. This was and IS one of 'those' bikes. HUBBA HUBBA!!!
  • 2 0
 Looks like a Nishiki alien ;-)
  • 1 0
 So now I know what color my Banshee Rune is . . . Tree Frog Butt Green. What goes around comes around, I guess.
  • 7 7
 looks like the polygon enduro bike, oh wait in fact the polygon is yet uglier Big Grin
  • 2 1
 How did he create this bike on Pinkbike?
  • 2 0
 sold mine, doh!
  • 1 0
 Not my cup of tea but I whatever:-)
  • 1 0
 Really enjoy these articles. Keep them coming!
  • 1 0
 I remember those days. Still have my Diamond Back link 1.1 from 97.... lol
  • 2 0
 Looks like a session. :p
  • 1 0
 I was going to buy one of these but i punched myself in the balls instead.
  • 1 0
 looks like the early version of spez enduro...
  • 2 1
 Looks like .... nah
  • 1 0
 chain TENSION
  • 1 0
 Looks like a Pivot!
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