Tuesday, June 24, 2008

The new Robusta

The bike was delivered within the time range they estimated. (8-12 weeks.) The bike was as spec'd (except for the tires which were spec'd as 25c, and came as 28c's.) Co-Motion did ship the wrong seatpost, and left out a shim for the stoker's stem. This was discovered Monday afternoon, and replacements were Fed Ex'd and delivered Tuesday morning.The Bike is going to fit correctly when its all dialed in, so the measuring/ordering process worked well. .The Bike is beautiful.

In my personal opinion the 2 tone fade worked out really nicely, and was worth the $100 upcharge. Unfortunately, there's a slight chip in the paint. I'm not too worked up about it. It was going to happen someday anyway. The LBS, however, is going to see if Co-Motion will do something by way of compensation. (ended up comping Deb a pair of shoes, )Weight is just about what I expected at 29lbs 14oz. Co-Motion specs it at 27.7. I'm sure they measure off a 21/18, and ours is a 22/19. Also, I'm sure they weighed one without an adjustable stoker stem.) Considering the slightly larger frame size, and adding 396 grams for two sets of speedplays (and the heavier 28c tires.) would indicate that Co-Motion's claimed weight would be in an acceptable tolerance range.

As for riding it, it is Night and Day between the Co-Motion and the Burley. 20lbs lighter and markedly stiffer, really shows up in accelerating the bike from stops and out of corners. The Burley is like a Dodge Durango, and the Co-Motion is like a Porsche.Cornering, it definitely turns in much quicker. The combination of the Alpha Q tandem fork, and FSA bar and stem is way more stiff than the Burley's setup. The Rolf wheels also feel plenty stiff even with the low spoke count.The Dura Ace brakes stop the bike extremely well, and I'm doubting the need for a disc now (but will reconsider that after some mountain rides.)I tried to purposely induce "stoker wag" (jumping on the pedals, intentionally leaning out of synch) and I really couldn't get the frame to flex, at least to any degree comparable to the Burley.So I guess this report tells you that a 2008 Co-Motion Robusta is light years ahead of a 1994 Burley Duet, which you probably could have guessed.Perhaps after some more rides I can post something a little more insightful.

We've put approximately 600 miles on the Robusta now, including some group rides with the Hammerheads, and some real climbing and descending, and we're starting to get comfortable with the bike.Some further impressions. It definitely handles more quickly than our previous tandems. I'm past feeling that it's twitchy, and starting to appreciate the quicker handling.It is definitely stiffer than the Burley.

At first I thought that the aluminum CO-Motion, with a rigid aluminum frame had a a harsher ride than our previous steel tandems. After getting used to it, the ride does not feel objectionally harsh at all, including riding on dirt roads. I would still likely opt for steel, ti, or possibly CF, if comfort was my number one priority.

Movement by the Stoker definitely has more of an effect on the Co-Motion than on our previous tandems. A little squirming form the back has more of an influence on direction, and is more perceptable to the Captain. I attribute this to 1) the bike's quicker steering, 2) being 20lbs lighter, and being stiffer (thus the movement is transmitted more directly.)As we ride the bike more it's not an issue, but I think it might be initially unsettling to inexperienced teams or people used to a more stable bike. I read one review of a Robusta where the reviewer was complaining about "Stoker wag" and lack of stiffness. In our experience the bike appears to be very stiff. I'm thinking that rather than experiencing flex in the frame, the other reviewer may have been experiencing the effect that the Stoker can have on a very light, stiff, quick steering tandem.

The bike is fast. 20lbs lighter, and wheels that are substantially more aero makes a perceptable difference. We've been able to pretty much keep up on rides with the local fast guys (including Cat 1-2 racers) that we wouldn't have a prayer on with the Burley.As for the Rolf Prima wheels so far so good. They seem acceptably stiff, and tough for our 350lb team weight. Cornering descending, and on fast group rides I haven't noticed unacceptable wheel flex. We also have ridden about 30 miles on them on mountainous unpaved roads without incident.The only time I noticed any flex in the wheel was muscling up a 15-20% grade out of the saddle, the front wheel seemed to be flexing under my effort/weight, but it also could have been the tire squirming.

As for the brakes, the bike brakes fine. However on a couple of descents the rims got very hot. The descents where the rims really heated up were the very first descents on bad pavement, and descending on a dirt road with some 17% sections. I'm thinking that in both of these instances I was braking a lot more than I would routinely do. At this point I'm still undecided on putting on a rear disc.
.All told, we love the bike, and would highly recommend it to anyone that wants a fast, light, quick handling tandem.

No comments: