Tandem Cycling - more in depth Robusta Review. (w/ new pics)

We've put approximately 500 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 descent 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.

The front derailleur does not shift as well as I would expect. It really doesn't like to go the small ring under even light pressure, and it takes effort to get it on the big ring. I'm hopeful some tinkering will improve the front shifting. However, I also think that FSA chainrings don't shift as smoothly as Dura Ace.

All told, we love the bike, and would highly reccomend it to anyone that wants a fast, light, quick handling tandem.

And I lied about more pics, but will add them tonight.

.....And I lied about more pics, but will add them tonight.

Aaaaarg! :crash:

Kudos for a great looking build.


KRhea

...The front derailleur does not shift as well as I would expect. It really doesn't like to go the small ring under even light pressure, and it takes effort to get it on the big ring. I'm hopeful some tinkering will improve the front shifting. However, I also think that FSA chainrings don't shift as smoothly as Dura Ace.
...
And I lied about more pics, but will add them tonight.



Sure looks as though you can move the FD a bit closer to the big 'ring. Might help, might not.

WOW, thats a great looking tandem.

It's been moved since the pic, but it may still need some more tweaking.

Looks like you have an "illegal" gap between your big and middle chainring like we do. I suffered with the front shifting on my Speedster for about a year. Two things fixed it. The first was switching from an SRAM chain to a Dura-Ace chain early this spring, which made a significant difference. Then a week ago I changed the front derailleur cable and found that the housing was quite badly damaged where it entered the front shifter, causing extra friction. I think it was improperly installed. Now it shifts like a single bike.

It's been moved since the pic, but it may still need some more tweaking.

you need to only have 1mm clearance between the tip of the teeth to the bottom of the outer plate.

It's been moved since the pic, but it may still need some more tweaking.

Unfortunately that's the secret - some small tricks which help you to get it right without spending hours:
1. Use the limit screws to set the cage so it's exactly above the big chainring with the fixing bolt slightly loose, then
2. use an English 1p piece (about 1.5mm thick) on top of the chainring to set the front derailleur height.
3. set the cage to be parallel to the chainring using a steel ruler
Then in theory the deraileur is in exactly the right place. Tighten the fixing bolt - the deraileur will have moved, so fine tune until it's the deraileur is at the right height and rotation and bolt is tight.
4. Now set the end stops to avoid chain rub in top and bottom gear
5. Now set the cable tension to shift up and down cleanly - the cable is normally just tight when on the small cog.
In theory it should work perfectly then. If it still doesn't, cable friction or non-shimano rings may be an issue.

- Once the FD is set, use some permanent pen to draw one or two tiny lines between the clamp and frame - tiny lines will do. That way if you ever need to take it off or change the deraileur you only have to worry about cable tension and end stops, which reduces the number of variables to set the deraileur down to two independent ones.

Some more observations. After some more miles, and riding with the fast guys, we've been pushing the bike harder.

It corners extremely well, feely very close to carving a turn on a racing single bike.

We are definitely faster on this bike. We're hanging, even working at the front, with hammerheads, on rides where we would have been OTB on the Burley.

The bike has a lot lower BB than any of my singles. Twice yesterday scraped my foot on the ground pedaling out of corners. (in turns that I could pedal completely through on my Giant.) No big deal, but the lean angle where you can pedal through a turn is much less than on my road bike.

Not sure how it compares in that regard to the Burley because I don't think we ever pushed the Burley hard enough in corners for pedal strike to be an issue.

From the OP's first and most recent notes:


The front derailleur does not shift as well as I would expect. It really doesn't like to go the small ring under even light pressure, and it takes effort to get it on the big ring. I'm hopeful some tinkering will improve the front shifting. However, I also think that FSA chainrings don't shift as smoothly as Dura Ace.
...
The bike has a lot lower BB than any of my singles. Twice yesterday scraped my foot on the ground pedaling out of corners. (in turns that I could pedal completely through on my Giant.) No big deal, but the lean angle where you can pedal through a turn is much less than on my road bike.

Two bits of input, based on things I've learned/observed while "dialing" our new Co-Motion Periscope triple:

1) Changing to an Ultegra middle ring (from the OE FSA ring) definitely improved shifting to the inner ring. Current configuration is Ultegra triple front derailleur with generic 28, Ultegra 39, and OE/FSA 53 tooth chainrings. The initial downside with the Ultegra ring was increased contact between the chain and outer ring when on the smaller cassette cogs. Thin washers installed between the crank spider and outer ring restored original clearance with no loss in shift quality. IMO, front shifting is now about as good as it gets.
2) Are both BBs low, or just the front? I found that rotating the eccentrics on our bike to place the BB axles above the shell centerlines gives about normal cornering clearance. From your early photos, it looks as though your eccentric is rotated to put the BB spindle below the shell centerline. The rear-stoker cranks on our triple are only 140 mm long, so your results may vary.

Good luck -- have fun,

Dave

Height/position of eccentric can affect pedal strikes . . .
If you re-position eccentric shell, don't forget that you will need to adjust your saddle height accordingly.
Been there, done that!

dave and zona, moving the eccentric 'upside down' is a great tip. I will try it. Reason is my carbon forks are a lot shorter than the originals, meaning the clearance isn't as good as it was.