neptronix said:
Well when i say MC tires i'm referring to the hutchinson spherus which is basically a thick bike tire with a harder motorcycle compound to carry high amounts of weight. I also have a Mitas MC2, used by solar racing teams, which has higher rolling resistance for sure.
The Mitas MC2 is the one I'm really interested in!
Shearing apart a trike front end with pedal is pretty impressive, although if you're referring to a KMX thunderbolt... well, KMX trikes do not seem study overall.. knowing that many ES members have destroyed the frames.. bummer.
It's just called a Thunderbolt, from Hellbent Cycles. Sets of plans to build them used to be sold in the 1990s. Chalo used to know Rick Horowitz, one of the designers. I thought it was a KMX at first, before and just after buying it, but it was something heavier and nowhere near as sturdy as a KMX. I bought it for $500 from a man from rural Texas who built it, and restored it(with some help from a bike shop and paying them for the share of the work they did). It was slightly cheaper than buying a used trike at the time. It lasted about 1 year, but in its defense, it was also repaired twice, after one of my roommates was thrown on it during a brawl when 6 people tried to break into our apartment also destroying a mold/plug and some fiberglass I was working on at the time and also run over by a truck while parked at a restaurant, so the frame was put through quite a lot. After the truck ran it over, it was never right again after that, even though I still put thousands of miles on it after it was mangled up and bent back into place as best as I could manage. Were it not for that, it is likely I'd never have bought the KMX and would have eventually built a velomobile off of it. Since it had indirect steering, making a velo off of it would have been a lot easier than the KMX, and with its narrow 32" track and with me seated in it a 31" height, it probably would have been a lot more aerodynamically efficient(my KMX has direct steering, a 39" track and with me sitting in it is 38" tall with the seat as reclined as possible).
My average time to a flat tire with a 'puncture proof tire' is about 10 miles here in Utah on various schwalbes versus your 5,000 miles.. i am pretty jealous.. and honestly i hate the extra drag because it really eats away at the advantage of the semi recumbent.. although there's no way in hell
I don't have to deal with goatheads. That's probably why. The roads where I am at are crap. For comparison, I'd get about 2,000 miles out of a set of Schwalbe Trykers.
The aero advantage of a semi-recumbent isn't huge, so a little bit of rolling resistance difference can mean the difference between reaping the aero gains and not. Now, if you were to go to a full-on enclosed streamliner, OTOH... with LRR bicycle tires, aero drag and rolling drag might be equal at around 30 mph, whereas moto rims/tires might bring that break even point up into the 40 mph range.
Yeah it would be nice to have CRR values on moto tires. I notice that difference in rolling resistance is very easy to 'feel' between tires. If you wanted to get kinda scientific, i imagine a bike trainer plus hubmotor would give you some friction values in watts that would be useful.
If I had the room to set something like this up, I'd do it. If I had a trainer to donate to you for that purpose, I would...
At some point, I'm eventually going to try them. My curiosity and desire to have a "bulletproof" solution for eventually cruising at highway speeds has gotten the best of me and it's just a matter of getting the cash together to have some 16" light-weight motorcycle wheels built up around a spare set of KMX hubs I purchased earlier in the year, and also getting the cash together to purchase a set of Mitas MC2s to go with them, plus an upgrade to hydraulic brakes. All of that will come after I convert it to electric and have the bugs worked out, which fortunately, I'm sitting on all the required parts other than some connectors to make my battery pack work with my controller. And when I do get around to using these tires, I will have to find a flat area, take some mass data, and do some coast down testing from low speeds in effort to try to derive some ballpark Crr numbers. I will have to account for the rear tire as well and derive a Crr number for it that is constant between the two equations, and obtain weight distribution data so that I can account for the rear tire's influence.
I'm looking forward to seeing what you do with the maxarya. Recumbents are so much more comfortable than normal upright bikes. You will probably end up using it for nearly all of your riding once it's built up, and may very likely increase the amount of riding you do because it is such a pleasure instead of a chore.
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