Sevencycles Sola TiA Long Term Evaluation by Casper |
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Introduction
This is a long term evaluation of my Sevencycles Sola Ti, a custom-made titanium hardtail. It is hoped that this review will be useful for cyclists who are contemplating the purchase of a new bicycle by outlining the factors influencing my choice and by outlining my evaluation of the outcome of that choice. There will be a considerable amount of subjectivity (and probably bias) in this review. My personal experience with reviews by owners of equipment is that there is a tendency for them to be slightly self-congratulary in nature, affirming the owner's infinite wisdom in making the purchase. I will attempt to avoid from falling into this trap. This hypothesis also suggests that, in general, bad reviews by owners are more reliable than good ones!Background
In 1998, I owned a 4-year old 16.5" Litespeed Obed. This is a fine bike: a lightweight and nice handling titanium hardtail. Coming from a high-tensile steel Bridgestone CB-3 city bike that was pressed into off-road duty, I found its compliant rear triangle a revelation: I remember my amazement at how smooth-riding the bike was when I rode down Boner in Bukit Kiara. (Back in 1994, the last section of this trail was a bone-shaking, white-knuckled yeehah of a descent, which was the main reason for its name, and not as is sometimes suggested, a reference to the excited state of the rider who successfully negotiates this sinuous and bumpy high-speed descent.)But of course, the Obed was not perfect. My holy grail of mountain bikes should be a bike that can do anything: a quick handling, lightweight, durable yet compliant bike that can handle loaded touring, technical descents like Mondo Cool and steep ascents like Pondok to Pondok with equal aplomb. It should have eyelets for a rear rack, which the Obed did not. There was vanity: the Obed is nice and extremely well made, but it was not a work of art in the way that an Ibis Ti Mojo or a Merlin XLM was. At a certain level, the bicycle is tool, an efficient transportation machine. But to those afflicted with the Disease, the bicycle also affects them on a deeper, emotional level: it is a precision-made, perambulating exhibition of artisanism, a confluence of functionality, efficiency and aesthetics that displays not just the care and attention of the builder but also the good taste and individuality of its owner.
It was clear what was required: a lightweight, durable, agile handling, vertically compliant travel bike frame that could be pressed into touring duty when needed. Some of these goals were clearly divergent; was the result the best compromise?
Choosing a builder
The usual suspects were scrutinised: Ibis, Merlin, Litespeed, Moots and Sevencycles. In the end what swayed my decision was the fact that Seven offered a customisation service for no extra charge, and that they had re-engineered their whole bike building process in a way that made ordering a custom frame effortless for the customer. Even if you lived half the globe away in Malaysia! (Sevencycles is located in Watertown, Massachussets.)By contrast, Ibis and Moots do not offer bespoke framesets. Merlin did have a custom service, but at a hefty premium over the already stratospheric price of an XLM frameset. So does Litespeed, but even a stock Tanasi costs more than a custom Seven. Which is not to suggest that these other brands are inferior in any respect: Ibis, for example, are reknown for the jewel-like finish on its frames and the artistry of that oh-so-cool headbadge. Moots has a similar cachet - I once had the good fortune to fondle a Moots YBB SL (superlight) at Two Wheel Action, leaving behind a pool of drool on the shop floor. Merlin, one of the pioneeers of production titanium frames, share the distinction with Ibis of making one of the lightest, butted Ti framesets.
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Why custom?
The advantage of a custom frame is evident for riders who have peculiar needs (or in my case just plain peculiar). If you, like me, have a longish torso in relation to your height, then you'll need a longer top tube. Want an agile, quick-handling bike? Specify steeper geometry. Need a compliant, shock-absorbing feel? Thinner gauge seatstays. Rigid drivetrain to minimise bottom-bracket flex? Thicker chainstays.But should you get a custom frame? This is a difficult question to answer, primarily because only you can answer it. You should consider a custom frame if you have had difficulty finding a good fit on stock frames. Riders with injuries or disabilities (such as a bad or inflexible back) as well as those freak-show refugees (eg. bow-legged Malays with short femurs like me) fall into this category. Note, however, that precise fit on a mountain bike is less critical for comfort than on a road bike. This is because your positioning tends to be much more dynamic - you tend to move around a lot more - on a mountain bike. Secondly, consider a custom bike if you want features not normally found on stock frames, such as a 3rd bottle mount, funky cable routing, unusual geometry or a parang holder. The third and most compelling reason to get a custom frame is Narcissism. Little else compares to a titanium frame made to measure, just for you to fan the flame of your vanity.
Ordering a frame
Seven makes it extremely easy for you to custom order a frame. Visit their website at www.sevencycles.com and download their .pdf form. Fill in your body measurements by following the instructions in the form. The form itself is clear, well-designed, and goes a long way in making a custom frame accessible to the average rider. For example, you may be an experienced rider who can easily ascertain how a bike feels, but may not necessarily obsess over the head tube angle of your bike or the rake and offset of your fork. The Seven order form effectively demystifies this custom bike ordering process.Customising allows you to choose how your bike rides. You can specify, on a scale of 1-10, how agile you want your bike to handle, with "1" being stable and "10" very quick. This choice is benchmarked against your current bike where you are asked to name your existing bike and to give it a rating.
Seven also determines your preference on how vertically compliant you wish the rear triangle on your bike to be. "Vertically compliant" just means flexible or springy, but in an up-and-down direction. (The bike industry dislikes the term "flexible" and avoids its use. But it seems to me there's good flex as there is bad.) A vertically compliant bike will give a comfortable, shock-absorbing ride that is typical of titanium frames. If you tend to pedal through corners, Seven will raise the bottom bracket height for you. Seven also claims to be able to make a drivetrain rigid whilst still maintaining a compliant ride quality by manipulating the thickness of the walls of the chain- and seatstays.
I specified "9" for handling, "2" for vertical compliance, and "4" for drivetrain rigidity. (Note: the form has increased in sophistication since then, and now even includes a weight versus performance choice continuum.)
Additional features can be added at no extra cost: I added a third bottle mount under the down tube, a cable stop on the seatstays for cantilever brakes (for retro-compatibility) and a set of threaded eyelets for attaching a rear rack. I also specified for the head tube to be the same length as that of my Obed. In addition to allowing me to swap forks between the frames, the longer headtube is also supposed to reduce the leverage of the load of the fork on the headtube and the headset bearings.
The only minor gripe that I had related to the fact that the form asked the prospective owner on the width of the tyre to be used on the bike, without spelling out why this information was needed. I filled in 1.9", and now have less than ideal clearance when running a 2.1" rear tyre (which fortunately I do not do often). Mud clearance becomes an issue on trails like Janda Baik - Kg Chennah and Cameron Highlands - Gua Musang.
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Aaaargh! Someone sawed my bike in half! |
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Bike Torque Couplings
Here's a scary thought: what if your frame could be broken apart into two so that you could carry your bike in a normal-sized suitcase? But what if you could do this with no loss in structural integrity, no adverse effects on the bike's handling, and just a 0.5lbs weight penalty? S&S Machine can change this scary thought into a dreamy reality with their Bike Torque Couplings (BTC).Each BTC comprises two sets of interlocking teeth welded or brazed onto the ends of the two tubes that are to be connected. The end of one set is threaded to accept a locknut that is attached to the other tube. Sounds much more complicated than it actually is, so here is the animated .gif file to paint the thousand words:
(used with permission)
The teeth are machined out of 6Al-4Va Titanium, and the locknuts from stainless steel. Titanium BTCs add about US$500 to the cost of a frame. Here's a close up of the top tube coupling on my bike:
(The dark goo is marine grease that I hadn't bothered to wipe off before taking this shot)
Like everyone, I was at first a bit leery of the very idea of splitting a frame into two. In the end, the following factors were decisive for me:
- S&S, on its website, shows that in destructive testing of chromium-molybdenum steel (chromolly) BTCs attached to a length of Reynolds 531 chromolly tubing, the BTCs in fact increased the strength of the tubing.
- The framebuilders who work with S&S BTCs include some well-known and reputable custom fabricators, whom I figured must themselves be convinced of the integrity of the BTCs before they would be willing to stake their name and reputation on frames bearing a 3rd party product.
- The testimonials and comments from owners and framebuilders on the S&S website were pretty convincing, and include that from cycling luminaries such as Greg Lemond. Hey, if it's good enough for a 3-time winner of the Tour de France, it's good enough for me.
Taking the plunge
So, on 17 June 1998 I put an order in through Soon Watt in Singapore (the regional distributor for Sevencycles) for a Ti Sola equipped with BTCs. On 20 July, I finalised the geometry of the frame with Rob Vandenmark.On 5 September 1998, I flew to Singapore to pick the frame up, which I carried through customs in KLIA in a Mavic wheel bag. Note that a mountain bike frame attracts import duty of 25%.
The rest of that Saturday was a fondle-fest: I brushed my fingers lightly over the satin smoothness of the frame. My eyes traced its elegant curves, stopping briefly at each tube junction to admire the weld beads, which were like still, limpid pools. That sort of thing, best done out of sight of your missus.
I won't wax lyrical over the build quality of the frame. Suffice to say that I felt that I was getting my money's worth of obsessive care and attention. The eccentrically machined head-tube, the elegant, large diameter S-bend stays, the carbon-fibre seat tube insert, the distinctive seatpost collar, the neat drop-out junction and the consistent weld beads were the highlights. The frame weighed 3.8lbs with Chris King headset cups and bearings installed, suggesting that the BTCs added 0.4-0.6lbs to the weight of the frame
Components
| Component List | |
| Fuselage |
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| Drivetrain |
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| Brakes |
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| Front wheel |
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| Rear wheel |
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| Total weight of the bike is about 24lbs. In racing guise, with Rock Shox SID (the original, 1997 version), Easton CT2 bars, Crossmax wheels, Continental Twister Pro Supersonics tyres and Speedplay Ti Frog pedals, the bike weighs a shade above 21lbs. | |
Performance
A word on the riding conditions here in Malaysia. The heavy rainfalls, high temperatures and humidity and corrosive soils here result in extreme conditions that will put any equipment through its paces. All to often, we have found equipment that perform well and are rated highly elsewhere to be poor performers in the mud and grime of our equatorial climate.Since acquiring the Sola in September 1998, I have put it through robust use — lanyak, to use the Malay expression. I've flown with the bike on a number of occasions, including once to LA to ride the Aliso Woods and Canyon trails near Laguna Beach (while the rest of my travelling companions exhausted themselves in Disneyland), and to Sydney to ride on the 2000 Olympics course at Fairfield.
Without wanting to sound too effusive in my praise, this bike is everything that I had imagined a custom bike would be. The compliant rear triangle takes the edge of high-frequency bumps, although I feel that the Obed is slighty more compliant. This is unsurprising, given the 7/8" diameter stays on the Seven and the commonly acknowledged fact that the early Litespeeds were slightly flexy.
The resultant geometry provided a bike that is extremely responsive to rider input. Steering on fast singletrack just requires you to look where you want go, and the bike follows, responding to small changes in body positioning. Although the head tube and seat tube angles are fairly conventional at 71/73 degrees, the top tube is about an inch longer than stock, with a corresponding increase in wheelbase. (A stock 16" Sola has a top tube length of 22.38". My 15.5" (measured from the centre of the bottom bracket spindle to the centre of the top tube where it intersects with the seat tube) has a 23" effective top tube.)
The short 16.5" chainstays combined with the long top tube makes this bike a fool's climbing tool, especially on technical ascents like Pondok-to-pondok in Bukit Kiara. The long cockpit puts the rider's weight further over the front wheels, while retaining pressure on the rear wheel through the saddle. This helps in preventing the front wheel from popping up and the rear wheel from spinning on steep inclines. There is, however, a downside to all this agility. In soft and loamy terrain, it's easy to induce oversteer if you're inattentive. This is especially true when going fast, where bumps, ruts and rocks can deflect the front wheel sideways, and when negotiating steep uphill switchbacks at slow speeds. Which is not to suggest that this is a problem; I like living on the edge.
There are some minor gripes, which I mention for completeness. None of these would have affected my decision to buy the Sola. First, as mentioned above, is the less than ideal clearance on the chainstays should I run a wider rear tyre. This is entirely avoidable: just inform Sevencycles that you like riding in mud (Sicko!) and would like to fit large rubber. (Note however, the Land Rover philosophy adopted by some riders that propounds the use of narrower tyres in mud on the basis that they are better at penetrating the mud to reach the substrate beneath.)
The second gripe relates to the diameter of the brake bosses. I fitted a pair of Avid Arch Supreme direct pull brakes and found the fit between the brake bosses and the cartridge bearing pivots to be very tight. The very same brakes slid onto the studs on my Rock Shox SID effortlessly. On the other hand, a pair of XTR V-brakes fit the frame with nary a problem; so it might be down to that particular combination being at the opposite ends of the tolerance range.
Finally, I have found some chemical reaction of some sort taking place on the seatpost collar when comes into contact with certain types of soil, notably the smelly reddish clay that we sometimes get on logging tracks. The seatpost collar looks like it's Nickel plated. It's now blemished with spots. Not pretty, but it's only a bike, and it serves me right for not washing the bike and flossing it after every ride.
Using BTCs
The BTCs are extremely well made, lending a functional, industrial appearance to the frame. As an added bonus, its shape echoes that of the Seven seatpost collar. The interlocking teeth of the couplings are tapered. This ensures that, should there be wear in the interface, the joint remains tight. The couplings are loosened and tightened with a minimalistic, 6" spanner that looks a bit like the old-style pre-Shimano bottom bracket tools of yore.
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The black rubber sleeve is a section of old inner tube that I slip over the coupling when riding to prevent tropical muck from getting into the joint. |
Travelling with the BTC-equipped Sola has been a revelation. The bike and all my mountain biking gear (shoes, Camelbak, helmet) fit into a large suitcase, 26" by 32" by 9" in measurement. The whole shebang weighs in at 22 kilograms, well within the 25 kg or so limit that most airlines will let get away with in economy class.
To fit the bike into the case, I need to remove the seatpost, the right pedal and the forks. The frame tubes are then wrapped in foam tubing (air conditioning foam insulation tubing) to prevent scratches. Packing takes under an hour. Re-assembly can be accomplished in just 25 minutes. A sealed cartridge bearing headset is nice to prevent the need to chase loose bearings around. Cable splitters can further help to prevent tangling of the gear cables, but they are not absolutely necessary and I do not use them. Complete disassembly and re-assembly takes just 3 tools:
- 5mm allen key
- 15mm pedal wrench (Speedplay) or 6mm allen key (Time ATAC)
- S&S spanner for the couplings
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Everything, including smelly shoes and Camelbak, goes into the suitcase, which I bought in 1-Utama for RM350. The S&S case is much nicer, but costs US$350! (US$1 = RM3.80). |
Upon reaching my destination, the hotel staff will often look on with amazement as I proceed to re-assemble a full-sized mountain bike in their lobby. After storing the suitcase in the luggage room, I'll be on my merry way, whistling my happy tune, content that I am on my personal rig set up just the way I like it, rather than having to put up with the ignominy of riding a rental pig-iron bike with the responsiveness of an overloaded vegetable truck.
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Gnarly descent on the Seven Sola in Gunung Nuang, in the Ulu Langat area. |
BTC Performance
I can't detect any way in which the BTCs adversely affect the handling of the Sola. In the 3 years that I have used the bike, I have never felt any flex or looseness in the front triangle. S&S recommends that you check the tightness of the couplings before every ride. Each time I have done so I have never found the nut loose.Although the Sola is set up in what you may call a cross-country set-up, I use it to ride any trail that I can get my grubby hands on, sometimes with injurious results. And when the trails get scary, you must have complete confidence in your equipment. I have full faith in the integrity of the BTCs. Were this not the case, I doubt that I would ride my Sola as I do.
The only shortcoming of the BTCs is its poor sealing against the build-up of grit. Which goes back to my earlier observation that some products that are designed and tested in sunny California may not be able to pass muster in muddy Malaysia. After a couple of months and many muddy rides, I found that there was a build-up of fine silt in the inside of the down-tube coupling nut. I spent a whole Saturday removing and re-installing the nuts. It was not easy. Each nut is held in place by two 720-degree circular clips. Removal and re-installation required the manual dexterity of a spine surgeon, the brute strength of an IGP, and the patience of an ISA detainee. Now, to prevent the ingress of contaminants, I slip a 4-inch length of old inner tube over each coupling . This low-cost, low-technology fix has worked surprislngly well.
Costs
A Ti Sola frameset costs US$2,595 (RM9,860). With the titanium couplings, expect to pay about US$3,000 (RM11,400) for the frameset.Conclusion
It's the last bike that I will ever buy. (It had better be, given the cost.) Then again, doesn't the Ibis Bow-Ti look just absolutely stunning? I wonder how it rides...
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Componentry included Speedplay Ti Frogs pedals, Avid Ultimate levers, Avid Arch Supreme brakes, Syncros near net forged aluminium crankset, Syncros Ti seatpost, King headset, Easton CT2 carbon bar, LP Composites carbon bar ends, and a pair of Suntour XC-Pro thumbshifters that I found while rummaging in the back of Tan's shop. |
Links and Further Reading
- Metallurgy for cyclists by Scot Nicol. Why choose titanium over any other frame material? An in-depth look at metallurgy and its application in making bicycle frames. (Nicol is Chuck Ibis.)
- Where Does Titanium Come From? by Gary Helfrich and Scot Nicol. How titanium is extracted, refined, then drawn into tubes. Helfrich, of Arctos Machine, is the pioneer titanium frame builder, and founder of Merlin Metalworks.
- Merlin Titanium Primer. Comprehensive article discussing, among others, the metallurgical properties of the various titanium alloys. Basically says that you're better off with steel than CP (commercially pure) titanium, and that 6Al-4V Ti (used by Litespeed in the Tanasi) is unsuited for bicycle frames because of its poor ductility and hence reduced fatigue resistance. It will be interesting to see whether this article will remain on the 'net now that Merlin Metalworks has been bought over by Litespeed's parent company. Learn about contractile strain ratio, and why engineers are no longer allowed to write marketing material.
- Merlin Extralight Review. An owner describes his thoughts on why he chose Merlin.
- Scandium Aluminium alloys. What about scandium? Well, actually it's aluminium, with a fractions of a percent of scandium as an alloying element. Scandium-Aluminium alloy frames promises to be as 10% lighter than existing aluminium alloy frames with better fatigue resistance (hence can be designed to feel like titanium or steel).
- Engineering for Bikes test of Scandium frames. This article, in German, describes a test conducted to determine the fatigue resistance of Easton's SC7000 Scandium tubing and Dedacciai's SC61.10 tubing. Result? Get a Cannondale!
- Leni Fried Designs. Customise your custom rig with anodised decals that won't scratch! This is sooo cool, folks.
- If bicycles were toasters...
Other Bikes to Covet
Ti Hardtails- Merlin XLM. The original Ti butted frame.
- Ibis Ti-Mojo. The original Ti frame made from drawn butted tubing. The Ti Mojo is unique in its use of tapered stays.
- Deep Cove Hummer. Be like Pat, eh!
- Moots YBB SL. The original soft-tail.
- Ibis Silk-Ti. 1.75" of travel on this soft-tail with a leaf-spring like plate for chainstays, rather than tubing.
- Ibis Bow-Ti. Incomparable. 5" of travel, no pivots.
