Saturday, August 23, 2014

Long-term review: 2014 Santa Cruz Tallboy 2 Carbon 29er

Last year the stork was kind enough to drop off a fine new ride in XT build, although some bribery in the form of selling the Trance X0, time-trial bike, Zipp 808 wheel set, and Compu-Trainer, and then throwing in a can of sardines was needed to seal the deal.

Riding the Tallboy has been hugely rewarding in terms of flow and speed compared to my 26" Trance. While the Trance was a custom, high-end build from the frame up, it was no match for the five more years of technological advancement distilled into the Tallboy. It all adds up to a lighter, stiffer, more responsive bike that rolls over lumpy trails where a 26er bogs down. The Tallboy has made me a better rider.

However, not all is golden in the land of new bikes. Since I first started mountain biking back in the dark ages of Biopace chain rings in the 80's, there's no question that modern bikes represent an entirely different sport. Today's components from pretty much all the manufacturers perform so well, that the only real choice becomes a matter of taste. Unfortunately, the tradeoff has been reliability. Years ago, an XT set-up would provide at least a good season or two of hard use before parts needed replacement. By comparison, the XT components on my Tallboy barely eked out one season of only moderate use (oh, where did all my free time go?). This suggests that manufacturers should start trading back ultra light weight for more durability and serviceability. Fact is, few race at the elite level where shaving grams can make a difference. The rest of us who've dropped six grand on a dream ride that was not meant to be a helium balloon should reasonably expect to get a full year of riding before having to spend hundreds of dollars replacing prematurely worn components.  

Here's a summary of observations about the Tallboy. Some of these are things that Santa Cruz should consider fixing; others require manufacturers to step up.

1. Better swing arm protection. The right chain stay sits awfully close to the rings on a 2x10 setup. On several occasions I've had chain suck (on a freshly cleaned and lubed chain, no less) that resulted in jamming the chain into the tiny gap between the teeth. Once I even had to remove the crank arm to free the chain. Another concern is that at full rear compression, the front derailleur hits the top of the chain stay. I don't see how the setup can be changed to avoid this problem. Chunks are missing from the precious carbon fibre. The existing co-moulded metal protection needs to be reshaped to protect this exposed area.

If you look carefully, you can see the distinct dent from the derailleur on top, and the gouging from chain suck on the side. The moulded protector just misses the fun. 

2. Pivot designs that facilitate bearing service and replacement. The Santa Cruz pivots are a decent improvement over many other designs because they incorporate grease nipples to allow the bottom bearings to be be greased without disassembly. Inspection of the lower pivot bearings shows the concept works. However, the upper bearings are a pain to pull, as an earlier blog post details. I'd like to see a completely new approach to pivot bearing design that gives up just a bit of weight to allow the use of larger bearings. These babies take a lot of abuse, so make 'em bigger. 

3. Stiffer wheels. Overall these wheels have proven quite reliable. The hubs (DT350) are still silky smooth, the freehub is dead-simple to service, and the rims resist dents. But there's just a little too much flexibility. Spokes that are one gauge heavier would be preferable, especially on large frames like mine where the rider and gear is likely to be in the 200lb range.

4. Better tires. The stock CrossMark tires are, in the words of one rider I met in Kingdom Trails, "the worst 29er tire ever". While I didn't find them that bad, something without the almost continuous centre ridge line would be preferable. The Mavic Roams that I'm riding now are not hugely better, just different. Not sure what to suggest, because I ride a lot of clay and any small-block tire (for lower weight and rolling resistance) is going to suck in mud of any kind--especially clay mud.

5.  180mm rotor on the front. This is a major oversight on the stock build, which specs 160mm front and rear (XT in my case). 160mm simply does not provide enough stopping power--especially for larger riders. After trying metal pads, heat-sink pads, resin pads, and an Avid rotor, I finally gave up on finding any stopping power in a 160mm front or eliminating a horrible squeal, and changed to 180mm. It's a massive improvement. Incidentally, Fox rates the Float 32 CTD 29er shock good for up to a 200mm rotor.

6. Poor XT cassette durability. For the first time ever, I've worn out the rivets holding the middle cogs together before the cogs themselves. As a result the middle cogs jangle around and I'm just waiting to shear the rivets altogether. WTF, Shimano?! This should never be an issue. Try using a better rivet. This is clearly a design or manufacturing defect and Shimano should warranty it. And I'm not alone: my local bike shop has seen this problem many times and warranty coverage is not forthcoming.

Edit: Days after posting I actually sheared three of the five rivets on a moderate (flat) trail ride and couldn't hold the chain on the middle cogs. The broken bits fell out of the cassette when I disassembled it. Fortunately my new cassette arrived shortly after from Chain Reaction Cycles ($61 delivered to Canada from the UK, vs. about $115 from my LBS). Same part, identical construction. In the second pic you can see two of the tiny rivet heads that sheared off. The neck of the rivets is barely 1-1.5mm in diameter. Clearly not enough material to withstand normal riding torque. Shameful engineering.

7. Ridiculous failure of an obscure part inside the XT clutched rear derailleur. This optional feature turns a little cam mechanism that applies tension to a one-way clutch on the derailleur arm and thereby reduces chain slap. Great idea, but the internal cam mechanism incorporates a crappy stamped metal part that breaks. Inexcusable: this part doesn't move while riding, and isn't exposed to the environment. Again, WTF, Shimano?! This is absolutely a warranty issue and I'm not alone in seeing the problem. Fortunately a neighbor was able to MIG-weld a repair. Otherwise it would've been a two month wait for a replacement from Shimano.

Here you can see the one-way clutch and the cam (with square hole):

Below at top left is the offending part. It snapped at a bend. It holds the cam seen in the photo above, so when you move the external lever, the cam apply pressure to the brake mechanism wrapped around the one-way clutch, thereby preventing the chain from pulling and slapping up into the stay. Nifty idea. After the metal retainer broke, the derailleur still works but you can no longer tension the arm and so you get normal chain slap action. In the picture, you can see the tiny repair weld on the retainer. 

Despite what these gripes may suggest, I love this bike and have a blast riding it. The main shortcoming is my own technical riding ability. So far I haven't reached the limits of what the bike can do.

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