"What about that new timing belt system instead of a tandem timing chain?"
We're happy to oblige. We know that there are a lot of tandems out there with these, so on the surface it seems to be really sweet. But, as you may know by now, we at Rodriguez and Erickson Bicycle company feel it is important that you know the drawbacks as well as the benefits to any product that we use on your new tandem. Keep in mind, we only intend to inform, so please don't shoot the messenger. We'd love to build your next tandem, whether it's equipped with a timing belt or a timing chain. We have nothing against the Gate's timing belt, and we sell quite a few of them. But, since we deal directly and personally with every one of our tandem customers, we have heard a lot of direct feedback, and feel that you can benefit from their knowledge.
So, let's strip away the hype and get down to business on the Gate's timing belt.
Benefits:
1.) The first benefit of this product is easy, right? No greasy legs because the belt requires no lubrication.
2.) Because it requires no lubrication, that makes it very low maintenance.
3.) The only other benefit that I can muster up right now is the cool factor. It is newer therefore cooler, and has 'carbon' in the name.
4.) ......there is no 4. They list a few more on their site, but the ones I've listed are the only true benefits our customers have experienced.
Many people assume that the belt will be quieter than a chain, but that's not true. There are many situations that cause the belt to make a considerable amount of noise, and require attention to solve. Gate's even has an FAQ on noisy belts, causes and fixes on their site. A quick web search of 'gate's belt noises' will render many results that will shed light on the types of noises that one might experience.
Drawbacks:
1.) Proprietary design: A lot of customers find that being able to get a part easily, even when touring in rural or third world places is a very important consideration. The Gate's timing belt is not the product for someone who has this concern. It requires parts that are much harder to find (belt and belt rings) than a timing chain.
2.) More time consuming for travelers: If your tandem is going to be a travel tandem, and designed for convenient packing into a suitcase, then the Gate's timing belt works against your goals. You see, you will have to remove your timing belt (or chain) when you pack the bike, and then reinstall it during re-assembly. A timing chain can be taken off in 2 seconds without the use of any tools. It can also be reinstalled the same way with no tools. To see how easy it is to remove a chain on a tandem, watch the first 30 seconds or so of this video.
On the other hand, great care must be taken when removing or reinstalling a Gate's timing belt so as not to damage it. It cannot be 'rolled' or 'forced' off like a chain with your hands. It will require the use of tools to loosen the eccentric bottom bracket so there is no tension to contend with during removal. Then, during re-assembly it must be carefully installed and then brought back up to tension with a spanner tool before re-tightening the eccentric bottom bracket.
One could argue that "it's only a few extra minutes on each end", and that would be true. But, it is adding time to a procedure that you might be performing on the floor of an airport somewhere, after a long flight.... so keep that in mind.
3.) Cost: The Gate's timing belt/belt ring system is quite a bit more expensive than a conventional chain/chain rings. Not so much that it puts it out of reach, but still it is an additional cost for few benefits.
4.) Stoker Compartment Limitation: By far this is the biggest drawback to the Gate's carbon timing belt, and it is permanent to the bicycle. Gate's only makes one size of their timing belt (a chain can be any length we need). In order to use this product, the stoker compartment must be designed to a length that fits the belt system perfectly....no longer....no shorter. At Rodriguez, we prefer to design the stoker compartment to fit the stoker perfectly. A limitation wouldn't necessarily be a problem except for one big issue. They made their required stoker compartment length way too short to fit 90% of stokers comfortably.
"Why did they make it so short?" You ask? So did we. Back when it came out, we called them and asked just that. You see, Gates is a huge belt manufacturing company, and not a bicycle or tandem company. They make belts for cars, machinery, washing machines and such. In order to determine how long to make the belt, they spoke with a tandem manufacturer (we'll call them comapany X), and asked them what the distance between the 2 cranks should be on a tandem. Unfortunately, company X makes all of their tandems with the same 'very short' stoker compartments. Now, had they spoken with some custom tandem builders who make every bike to the length needed for true fit, they would've made the belt longer to fit more people....but, they didn't. So, the original belt was designed for a stoker compartment length of 72.4cm (the only length that Company X offers)....no longer, no shorter.
Why not make a longer version? When we had them on the phone, we did ask them to make a longer belt. They informed us that the tooling to do so is too expensive (over $20,000), so they will only be offering the belt in one length. But, they did start to make the rings in a smaller design, which allows us to make the stoker compartment ever so slightly longer with the same short belt. The problem is, that the difference is only 12mm longer (1/2 inch) and that's still nowhere near long enough for 90% of our stokers proper fit :-( So, for that 90%, we're kind of stuck with either letting you know that you will have to compromise a bit to use the belt, or recommend against it.
What it Boils Down to is This
Designing the frame around this component means that stoker compartment can be a maximum length of 73.6cm. This is very short in modern custom tandem design. It is our philosophy that the stoker's comfort IS the most important component on any tandem. No matter how cool my tandem is (and it's really cool), if my stoker is not comfortable, the ride's over...period. A stoker compartment length really needs to be longer than 73.6cm in almost any application that we build. Even when we did build stock sizes, our stoker compartments were 76cm long, and we often found those too short.
Every Rodriguez or Erickson is completely custom for its riders.
This is one area that we are different than every other tandem company. We've built every tandem custom for the riders since 2006. I cannot stress enough how much we've learned about fitting customers to tandems since we've made this change. Since then, we discovered what Glenn Erickson knew even in the 1990's. Even stokers of average height almost always need a stoker compartment of 78cm or longer or they have to sacrifice their comfort and convenience.
Here's what I'm talking about. Every Rodriguez and Erickson tandem design starts with a fitting. Then the results of the fitting are drawn in a CAD program and the stoker's seat and bars are positioned where they found the most comfort. Then the captain's seat is drawn into the picture at the appropriate height. It's at this point that the stoker compartment length can be determined. In a perfect world, we like to design without restrictions from component manufacturers. This way we can ensure that the rider's comfort is what we are designing for, and the rest of the bike can fall in place where it will.
When we design a Rodriguez or Erickson tandem for a couple that would like to use a timing belt, we start off the same way. We draw the stoker's seat and handle bars in their perfect position. Then, we draw the captain's seat at the appropriate height, then move it to the required 73.6cm distance from the stoker seat. Often, at this point, the captain's seat and the stoker's handle bars conflict with another severely, and the belt will just not be possible without major fit compromises by the stoker. Sometimes, there's no compromise at all and the 73.6 works just fine. Often, while not ideal, a few compromises in the stoker's fit will allow the use of the belt if it's a deal breaker. In these cases, we make a second drawing that shows how we would build the bike for a perfect design. The team can then decide if they can accept those restrictions/compromises or not. Below are parts of 2 drawings that I just finished for just such a couple. See for yourself.
Gate's timing belt design
Image 1 shows the maximum stoker compartment length of 73.6cm. The bars and seat are positioned exactly where they need to be to achieve the comfort the stoker experienced on the adjustable fit bike here in the shop. As you can see, drop bars may not even work on this design as the captain's thighs will more than likely hit the stoker levers. If she decides to use drop bars, they will have to be very wide (that is a fit compromise). No matter what bars she ends up using, she will not be able to raise them further, nor install accessories like a phone holder, computer, or bell, unless she move the bars back (also compromising her fit). Her face will also be very close to her captain's back, limiting her view of the road ahead.
Exact same fit but with timing chain
Image 2 shows the bars and stem in exactly the same position as far as fit considerations go, but with much more room for the stoker to raise her bars if she ever wants to. She can also use narrower bars for less stress on her elbows and shoulders (as her fit calls for), and she has plenty of room for stoker accessories. Being further behind the captain also opens up her view of the road ahead. This is something that many recent Rodriguez stoker converts say they really love. I know that my stoker noticed a better view right away when we had our custom tandem built a few years back.
