You may known that I'm a cheapskate. The budget is tight and I'm really inventive when it comes to saving money. What comes with this behaviour is that I don't buy high end bicycle components. No 'Durace' or 'X9' for me. 'Tiagra' and 'X7' is where it ends for me. What's the point of having a carbon dérailleur? I know that the high end components tend to last longer, but 'above average' probably still is pretty good. My 'bent's components don't have to withstand a 3000km trip to the Arctic. Partly because I'd rather spend my money on a vacation to BC, and partly because I don't want to die from hypothermia. I don't tend to demand exceptional things from my shifters and bearings, so I don't bother paying an exceptional price.
There is however, one part that stands out above the other. This is the only part that costs five times more than the 'just above average' part would do. This part then, must be very special and important. The standard idler of a Mango velomobile is, how do I say this, crap. Well, it used to be when I bought mine. It could be different nowadays, it probably is. If not so, do the same as I did, only sooner. I contacted Terry Cycle after about 7000km of noise and drag. We e-mailed a bit back and forward and came to the conclusion that a 13 tooth idler, with titanium sprocket, would be the best for a Mango. (warning! Tall people often do not have enough room for this slightly larger idler)
Since I upgraded to this little work of engineering art the Mango felt much smoother, especially when pedalling hard. I often do traffic light sprints and, apparently, I seem to be very good at sprinting. It used to sound like something was being cut in half when I accelerated, now it's sounds and feels very smooth and direct. You want some figures to go with that? This may sound meaningless, but it takes me 11 seconds to accelerate from 5 to 45km/h. I don't start at 0, to prevent me from damaging things like knees and frames. My gut feeling tells me that the TC idler helped to bring that time down from 14 to 11 seconds. The feeling, the smoothness, the sound, all as it should be in a, anything but cheap, velomobile.
Another great thing about the €100,- idler is that it lasts long. Mine is know 17,000km old and still looks and feels good. Yes it's shielded against the things that usually ruin chains and alike within one winter, but is has to deal with horrible stress loads. And don't forget, every watt you put in at the front must pass that little wheel under your seat.
So, is it worth costing five times more than just above average? Yes, it very much is. You could even make it more expensive by buying the ceramic bearing version, but that gives you the same speed advantage as using a fart for jet stream propulsion. Imaging how hot a little bearing would become if it would cost you 5 watt efficiency. Just touch a hot halogen bulb and you'll know what I mean.
More photo's can be found here. Terra Cycle is here, or here for European readers. And no, I'm not being paid for this, I'm just sharing my experience, although a TC t-shirt would be nice ;-) A nice video about a recumbent race can be found here. I do a fabulous standing start in Yavixa at 2:07.