Interesting drive train, I myself have set a record and won a state champ in SoCal on a tandem whose drivetrain I designed myself. I want to warn you of a situation, because I had the misfortune of finding out the hard way. The timing chain and drive train can touch on your setup, and if they do, it can cause massive damage to the chains. If the timing chain is a bit loose, and if you go over a bump, the timing chain can bend sideways, causing it to touch the drive chain, at the portion where it's on the large chain ring on the front side of that ring. The way around this "interference problem" is to match the timing chain ring size more closely with the large chain ring size, or to place greater lateral distance between timing chain ring and large drive chain ring. I paused the video when there was a clear shot and it seems that those two chains would touch if there is just a tiny bit of slack in the timing chain, and if the timing chain were to wobble sideways going over a bump. On my particular setup I had only a single drive chain ring. It was a 55t and the timing chain ring was 42t, I could not go any higher on the timing chain ring due to frame clearance issues, didn't want to start modifying the frame AT ALL. Luckily during the state champ and during the Fiesta Island Time Trial TT we set with my stoker Patricia, there was not chain interference. It was during a club ride that we experienced, the hard way, what can happen to the chains if they touch. We had to get picked up and taken home in a pickup truck. When I ran for example a 50t large chain ring w/ 42t timing chain ring, there was no perceivable problem. In all of these cases I had the timing chain taught, but not too taught, it was just right. You should know of this sort of issue b/c a customer may be very unhappy when they learn this lesson the hard way. I subscribed to your channel. I like hearing about people's design ideas.
Super spectacular! Those chainstays look like what you and Kent put on my road frame, ovalized tubes curving out to a squared cross-section at the hooded drop-outs. It stunned me how that could be done with titanium! Riding it is like having your own mini-NAHBS roadshow.
Beautiful bike! We've been wanting a full suspension mountain tandem, but I've had a couple people tell me that those are very inefficient, and a fat tandem would be a better choice. I don't live in snow country. We would be on dirt roads and mild single track with minimal climbing. Our road tandem has the excellent Kinekt seat post, but it doesn't stop my stoker from complaining when we hit a hard bump without my warning her. Your thoughts? Full suspension or fat bike? Thanks.
Yes, it's way more efficient because the power transfer does not put load on the bottom bracket bearings. It makes a huge difference for efficiency. However, it comes with caveats. You can read the long comment I left.
