Auto Ads by Adsense

Tuesday, September 26, 2017

Long Term Review: Co-Motion Triplet

We've had our Co-Motion Convertible Periscope for more than two and a half years now. With multiple conversions back and forth between triplet and tandem mode, and with a tour under our belts, it's time for a long term review.

It's a human tendency to focus on things that go wrong, rather than things that go right, so before I jump into the review let me state that if you've not ridden with your kids on the back of a tandem, you're missing out. It's been a pleasure to have Bowen grow out of the child seat into the back seat with crank shorteners. I've also had some of his (older) friends ride the back seat before he grew into it. Now his brother can ride the middle seat and hearing them sing and laugh as we ride never gets old. There's no doubt in my mind that while the trailer cycles are cheaper, they're by no means a good substitute --- I don't think we would have even attempted our 350 mile bike tour this summer on anything other than a tandem. We've even done a 25 mile club ride with the bike club in triplet configuration with Boen in the middle.

My biggest disappointment so far has been that the indexing fails when switching between tandem and triplet mode. After every transform, I've had to tweak the derailleur's indexing. My solution now is to replace the right shifter from a Shimano 10 speed shifter to a Rivendell Silver shifter. That way, all I have to do is to get the tension in the derailleur cable to the correct ballpark and then I'll have access to all the gears correctly. (The stops on the derailleur have to be set correctly, of course) By accident, I seem to have found a happy medium by which I no longer have to dick with the anchor bolt between triplet and tandem, so hurray for friction shifters!

In tandem mode, the bike behaves pretty much like you expect a tandem to behave. In triplet mode, the bike becomes quite a bit heavier, and much tougher to maneuver. You certainly can't weave it through a barrier easily the way a tandem could. Climbing is also much much tougher in triplet mode, much more than you expect: 3% grades feel like 6% grades, and 6% grades feel like 12% grades. I made use of the 24x36 drive train, and frequently wished for a 42 or 50 tooth rear cog. I suspect I'll have to build a new wheel for that to happen, so that's not in the cards until I wear out the set of wheels I built for the tandem. In triplet mode, I also have to check the couplers every ride to make sure they're not coming loose. This doesn't happen in tandem mode, so the extra length of the bike is what's creating torsion and loosening up the couplers.

People frequently ask if the kids actually contribute. The bike's slower without the kids than it is with the kids, so yes, they pedal. I also feel it when they fight me on the pedals, so it's not like I'm turning their legs in addition to the wheels.

I haven't tried the tandem in quad mode. Until the kids get older, their friends would need crank shorteners as well. Each set of crank shorteners is $116.26, and I'm not inclined to buy them for other people's kids, so that'll take a little more time. Yes, I'm expecting it to be even tougher, but hopefully, the kids will be stronger and help more as well. I think if I had it to do all over again I wouldn't bother with the quad: it might be fun once or twice, but it's just not practical.

I've actually converted the bike from tandem to triplet and back again a number of times. When I first bought the bike, I expected to keep it in triplet mode most of the time, but what's happened is that for commuting by bike, the tandem mode is faster, delivering Bowen to his school in less time than driving would (because of traffic and the lack of need to deal with the school dropoff craziness). But for weekend rides with the family it's way more fun to have Boen in the middle seat. I've gotten to the point where I can convert the tandem to triplet in about half an hour, and about 15 minutes going the other way.

Finally, transporting the triplet is currently a pain, requiring disassembly and reassembly. It's not difficult, but takes quite a bit of extra time. I need to get a trailer to tow it behind the Honda Fit. I'm not sure how I'm going to get it onto the plane when we finally decide to tour with it: it's going to take a lot of suitcases and quite possibly extra charge.

But for now it's been a pleasure riding it with my 2 kids. It's stupid expensive, and we'll only get to use it for 10 years or so, but it's worth it. If you're in the area and want to borrow the bike for a ride please ask.


Unknown said...

Hi, will you sell you co-motion triplet bike?

Piaw Na said...

Still using it nearly daily, so no.