Thursday, September 5, 2019

1991 Carbonframes Onyx

Walking the expo at this past weekend’s Dirt Fest I couldn’t help but marvel at all the killer new bikes on display. As a fan of vintage bikes a vast majority of my experience with frame construction materials is mostly constrained to steel, aluminum and titanium. Carbon fiber, at least as we know it today was not widespread in the early days of mountain biking. Early attempts at composite bikes started coming on the scene with bikes like the 1987 Kestrel MX-Z and the 1988 Trimble Carbon Cross. Those bikes (which I will discuss in an upcoming web article) were considered a composite construction and unlike today’s true carbon fiber bikes had fiberglass and other materials incorporated into the carbon weave, which was often applied over a core, foam for the MX-Z and Douglas Fir (yes that’s a tree) for the prototype Trimble. These early attempts at building a composite mountain bike were novel and unique but in my opinion fell short of the label of carbon fiber bikes. While it’s hard to pin point with total certainty the first time all carbon construction was applied to mountain bikes this Carbonframes Onyx is certainly a strong contender for that title. 

Carbonframes was the first commercial venture of one Craig Calfee who went on to start Calfee Design who are well known for their organic looking carbon and bamboo bikes. While not his first carbon bike, that honor goes to the Sapphire road bike, the Onyx was his first and only attempt at building a carbon mountain bike (oddly enough Calfee makes off road cabon tandems these days). The Onyx is one of the more striking bikes I’ve ever seen, I think it would look equally at home in a modern art gallery or as prop designed by H.R. Giger for the set of Alien. 

The mix of organic curves of the frame and the way the carbon tubes are bonded together is contrasted by the sharp corners of the reinforcing gussets, making you think it was not design by an engineer but rather an artist. Turns out this isn’t far from the truth. Craig Calfee gained most of his practical knowledge of working with carbon fiber while working on Olympic caliber composite sculling boats and eventually sailing boats, while pursuing a sculpting degree at the New York City art college.  Craig combined those skills with his passion for cycling and started building all carbon bikes around 1988. The Onyx was a revolutionary bike at its time, and seeing it for the first time at the 1990 Interbike in Anaheim must have been breathtaking,  . Not only was the frame made of CF and weighing in at around 3.4lbs without a fork (at a time where most frames were over 4 lbs), but it also seamlessly incorporated elevated chainstay technology (I use that term loosely here) which was the new ‘it’ trend in the late 80s. The beauty of carbon fiber is that it is isotropic, and allows you to create structures that have physical characteristics that depend on the direction in which it is laid up. Craig understood this very well and set out to build a frame that is both rigid but has built in damping characteristics. I think if you compare it to the frames of the time you would agree with that to a point, also I imagine it helps being a spindly XC racer. However, with the benefit of 30 years of hindsight and for a guy who tops 200lbs the bike is not what you’d call confidence inspiring. As I write this I’ve not logged many miles on the Onyx, but the few I have combined feedback from others who have ridden it paints a slightly different opinion. The Onyx is a fine bike for an average XC jaunt on your local trails. It’s a fair climber and handles pretty well (courtesy of the short wheelbase). However it’s a different story when you point it downhill and toss in some obstacles, and things go a bit sideways quickly. Basically, if you watch your speed and keep things in check you’ll be fine, but my alarm bells were ringing anytime speed crept up into the double digits. So, while it wasn’t the best bike in the long run it was a true milestone in the development of today’s carbon bikes. As I gear up for the larger carbon story the thing that rings true for me about carbon is that it in terms of mountain bikes it was a technology without a real application that is until full suspension came along. So, bikes like the Onyx, Trimble, MX-Z and the famous Yeti C-26 were early explorations into a world of what could be, and what would eventually enable the radical machines many of us take for granted today.

The handmade, limited quantity production aspect of this bike comes through in the way the dropouts are integrated into the carbon stays.

Wednesday, August 28, 2019

1992 Mantis XCR EC

  1. 1.
    made up of various parts or elements.

The Mantis Composite XCR mountain bike was one if not the first composite mountain bikes ever made. Well, maybe not composite in the way we might think of it today, but still no less true in the sense of the word. The original XCR released in 1983 as a fillet brazed steel frame was one of the first bikes made by Richard Cunningham under the Mantis brand [You can see two of the few known 83 XCRs here and here].  Then in 1984 Richard upped the ante and released the composite XCR. The idea behind this bike was the use two dissimilar metals where their specific qualities were best. Aluminum in the front for a stiff pedaling platform and chromoly steel in the rear for compliance. Since you can't weld the two metals the natural solution was to bolt them together. The early XCRs had a traditional double diamond frame design and it wasn't until around 1989 that the elevated chainstay design first pioneered on the Valkyrie made it over to the XCR. The elevated chainstay version of the XCR debuted at the 1989 Interbike show and stayed in production almost until the sale of the company around 1994. Towards the end of Mantis Richard started experimenting with full Aluminum construction on the XCR and a few prototypes were made for the race team. Though more rare and by that measure possibly more collectable those bikes were hastily made and in my humble opinion fall by the wayside when compared with the earlier composite XCR and lack a lot of the uniqueness that make this bike so fascinating.

What I really think is great about this bike is just the sheer creativity and in a way simplicity in it's execution.Sure you might say it looks all complicated, and weird but really if you think about it it's not. Let me explain, if you wanted to build a steel bike and make it really stiff, you'd have to get large tubing which for one wasn't available in a great many sizes and then it would be heavy. The opposite goes for Aluminum (which was rarely use on mountain bikes were rare in 1984) if you want it to be compliant you need to get fancy with butting and custom drawing of tubing which wasn't doable in those early days. So, if you want compliance you take normal thin gauge steel tubing and if you want stiffness you take straight gauge, oversize Aluminum tubing. The problem though comes when you want to marry the two. In case you didn't know, you can't weld dissimilar metals. So, you could glue it, but who in their right mind would do that on a mountain bike (turns out people did), or maybe make some sort of high tolerance press fit, or you could use the oldest trick in the book and bolt it together. Which is exactly what RC did in this case, using Sugino seat binder bolts no less. Can you imagine that order coming in??? I need 3000 seat binder bolts... the person on the other line would think you're really doing well selling that many bikes, only to find out you were using 4 bolts per frame. Then again, RC was known to use Sugino binder bolts as chainring bolts, so maybe they weren't surprised at the volume order. [Side note : anyone know the other example of a bi-metallic mountain bike built later on??? Hint : It's not a duck] The final result is really quite impressive if you take it at face value and rewind the clock to 1984. The bike actually rode pretty well, they weren't known to fail and were quite light by the standards at the time (this bike weighs 25.8lbs). The front fork is steel as well which in a way balances out the rear and makes for a fairly predictable ride characteristic.

The elevated chainstay version of the bike is a bit more flexy in the rear than it's non elevated counterpart, but it's not terrible. At the time of writing this piece I've done a couple laps on the local trails and found the bike pleasant, thought not immensely exhilarating in any way. These were shakedown laps and on old weathered 2.0 tires so I took it quite easy. I plan on putting bigger, modern tires on it soon and properly putting it through its paces. I'm not sure I expect to be surprised but I think it will go down as a bike that captures a point in time very well and basically does its job.

The build is full Suntour XC-PRO with Grease Guard, thought does not feature Micro Drive. When I first got the bike it actually had MD on it, but the rear hub was completely rusted out and I had to replace it with a freehweel version and I didn't have any MD freewheels around so I converted it to the standard or Power Ring version. Aside from that the only other notable feature on this bike are the Suntour made Pedersen Self Energizing rear brakes. These brakes used the motion of the rear wheel against the pads to twist an internal spring which effectively gave you more stopping power... or rather more power applied to the rim, what the tires did with that is a whole other story. In this case the rear stays are a bit soft for these brakes and the result is somewhat squishy and grabby non modulating feeling. Maybe it needs more tuning, somehow I doubt it.

One last thing I like or rather find uniquely interesting about this frame is the contrast between the beautifully brazed and formed rear end and the somewhat crudely welded front triangle with its massive reinforcing gussets. Richard was used to working with Aluminum (he built light weight airplanes) but his technique was not much more than practical, whereas he was quite skilled with the torch when it came to steel and was well known for his un-filed fillet brazed frame.

Sunday, August 18, 2019

1992 Grove Innovations Assault

Grove Innovations are mostly known for their shall we say more unconventional bike designs. In my experience most people tend to bring up notions of heavy, overbuilt or quirky bikes like the Hard Core or X-frame when discussing the brand. If you've read any of my previous posts you may have caught that the Hard Core is one of my favorite bikes, though I can't deny that it does take some getting used to and it's not the lightest bike by any stretch. Unlike a lot of vintage bike collectors, I'm not a big subscriber to the "Steel is Real" motto and tend to prefer Aluminum and Titanium bikes for my style of riding. That being said I've been trying some more of the ferrous made bikes recently, with mixed results. Building on my affinity for Grove and my desire to try a more conventional design I set my sights on finding an Assault. Although I could wax poetic (and have) about the craftsmanship, innovative design or the hometown angle as the main reasons why I love Groves, I would be remiss if I didn't mention the paint jobs. Groves had among the wildest and most outrageous paint jobs of the late 80s and early 90s. While I've had many Groves pass through my hands, for some reason the ones that were in my size were more subtle. So, as I set out to find an Assault I really wanted one of those wild ones. Unfortunately I couldn't seem to find one in my size and in a cool color, so I nabbed the first one in my size and decided to make it my own.

I found this Assault frame in Florida back in 2015 or so when a fellow mountain bike collector  picked it up in trade and didn't really know what it was. He reached out to see if I could help identify it and we got to talking. The original color was long gone and although the fuselage was complete, it was painted rattle can green and devoid of any decals. We figured out it was an Assault but as it was too big for him and after some horsetrading I picked it up for a fair price. As usual personal projects end up taking a back burner and it wasn't until around 2018 that I finally decided to get this bike repainted and built up. I originally wanted a Neon Solar System Grove and so started working with Ollie from Dark Matter Finishing on recreating that paint job. Turns out the crackle effects have chained over the years making the task of faithfully duplicating the original nearly impossible. So, Ollie and I decided to change course and went for broke with neon fades and splatter. The result is nothing short of amazing and I think one of the coolest bikes I've ever had!

I saw this paint job on an early Hard Core and really fell in love with it. There is so much going on, but it all works, well at least in my opinion. This Assault features the full complement of Grove Innovation parts including an Assault unicrown fork, Hammerhead bar/stem combo and Hot Rod cranks featuring an externally greasable reactor core bottom bracket. As was the custom in those days this frame includes a pair of painted to match Specialized water bottle cages. 

The split top tube cable routing is a unique feature on the Assault model and reminiscent of the very early Yetis.

If you've been following my builds for a while you've probably noticed that I am fairly formulaic and tend to swim a fairly narrow lane in terms of component selection. For the most part I'm partial to Shimano and then tend prefer the M730/735 7-spd XT or the M900 XTR groups. That being said, I've wanted to do a Suntour build for some time (last time I used suntour was on the 1991 Potts CCR) and was planning on doing so with my 1994 Phoenix, but complications with compatibility made that impractical. I've been sitting on this near NOS XC-Pro MicroDrive grouppo for a little while now and decided to use it on this bike. Aside from a short term setback in the form of non MD compatible Hot Rod cranks (new spider in production at the time of the first post) it all came together nicely and should make for a fun bike. I really like Suntour and the XC-Pro group is really amazing. I particularly like the ergonomics and the feel of the shifters. The brakes are nothing to write home about, but get the job done adequately well. This particular set is an early version and does not feature Self Energizing rear brakes. This group was Suntour's first to feature the Grease Guard system which Suntour licensed from WTB and really makes overhauls very simple. Given I'm using Grove cranks I wasn't able to use the Suntour BB and in the end decided to forego Suntour's headset in lieu of a stylish Chris King 2Nut. So, that leaves hubs and pedals as the only GG enabled components carried on. In keeping up with how most Grove's that left The Bicycle Shop in State College the rims, tires and toe clips are Specialized and grips are Oury. IRD seatpost and Selle Italia Turbo saddle round out the build.

Small touches like forward facing seat binder, sculpted seat tube nicely complement the svelte brake bridge and brake stop and make for a tidy seat cluster. As with nearly every Grove made the welds are just gorgeous and practically invisible.

As I built this bike I realized that there were several versions of Hot Rods and this appears to be one of the later styles with a grease port integrated into the axle on the drive size. Earlier version had a hollowed out axle with an insert that served as grease port, while the first generation simply had a hollow axle. The Reactor Core bottom bracket features double bearings on each side and unique triangular interface between the spindle and non drive side crank arm. These really are some of the coolest two piece cranks ever made and in my opinion far superior to the much more popular Bullseye cranks.

Matching water bottle cages FTW!! Now I just need some Grove branded water bottles.

I have a bit of tuning to do and am still waiting on a MD compatible spider for the Hot Rods before getting this thing dirty. A quick ride around the neighborhood confirms the bike is a good fit and seems to be pretty comfortable. A ride review will be coming shortly!