knobby problem from the knees thread or nomomoto

[buyagain]

Conversion Kit Brag Board seems the logical thread to continue the conversation with Rearengine and his neat engine. And yes ultimately this is about knobby knees. LOL I can't tell you how I'm disappointed that apparently he saw fit to remove said motor from his bike. Rearengine's complaint was that the vibration was too much plus noisy. I don't know about the noisy part but I'm I the only one who can perceive a guaranteed vibration problem with knobby tire? Rearengine, I'm surprised you didn't crack a few teeth with those tires. Or perhaps you just got a good back message. Seems I read somewhere that those spindles on friction drives are meant for anything other than knobby tires. Correct me if I'm wrong Rearengine but I think that accounts for your vibration.

I'm not admitting to it for now but sometime in the future I might benefit from a little motor assist up some hills when I get as old as Defjack. So let me clearly define that I'm not just interested in hanging another motor off another bike. That's been done to death. Go to any you tube demo and you see this guy who has just put a motor on his bike and the next shot he's going by at no less than 40 or 45 mph on a public street. I can't believe my eyes at the sheer stupidity. I don't even want 20 or 25 mph (although I would not turn it down). Most interesting to me is the possibility of a smooth almost transparent assist just when you need it kind of motor design. A trip to http://www.bikemotorparts.com/ illustrates perhaps the closest to what I'm talking about.
Note at this site that all have centrifugal clutches (missing from Bill's bike). Though perhaps the wrong tire I genuinely admire rearengines placement and execution as a whole. Our Conversion Cruz bikes offer quite a unique and advantageous place to mount such an engine as illustrated by Rearengine. The only real diffence would be using the channel piece from the BMP kit. Please leave all comments about electrics from this thread. I've looked and studied electrics extensively and I still see the engineering advantages falling to 4cycle engines for now (yes, even ecologically too). Maybe even the 2 cycles also. I hope this describes the type of set up others will find appealing.

Special note here; I dont' mention the Sofrider, Freerider, and certainly not the Silvio for one very good reason. As far as I can discern they are all pedigreed low weight bicycles that would be degraded by adding any additional weight. Just my opinion.
So finally; If your knees get too knobby, you too may need a little power assistance someday.

Regards
Bob

 

[Mark B]

buyagain wrote: Special note here; I dont' mention the Sofrider, Freerider, and certainly not the Silvio for one very good reason. As far as I can discern they are all pedigreed low weight bicycles that would be degraded by adding any additional weight. Just my opinion.

I am in agreement.

Mark

 

[John Tolhurst]

John Tetz is a great exponent of the merits of judicious assist.

 

[buyagain]

johntolhurst wrote: judicious assist

That's it, that's says it perfectly.

Also thanks for the steer, John.

 

[John Tolhurst]

If you make the vehicle efficient, a tiny motor will do a big job. That is what I do, I design ultra-efficient vehicles. My car is 6 cyl, and can output 150kW, while I can output 150W. The car has a 1000 times more power, but it not 1000 times faster than me on my bike. My 7 year old son can ride 15km an hour, but even the world's best athlete cant do just 5 times that, not even the most extreme testosterone monster athlete, nope.

 

[Mark B]

I can see both sides of the power assist debate. I lean towards being more of a purist; if you're going to pretend to be a cyclist, then work at getting faster and fitter on your own. There are no shortcuts and in my mind, a motor of any kind other than your own heart, legs and lungs is defeating the purpose. However, I can see where there are practical uses for power assists:

- Transporting heavy loads on a transport bike or bike and trailer. I think a powered trailer for hauling loads would be really cool. Atomic Zombie has plans for homebrewing a powered trailer and I can see that being a good thing.
- Velomobile, where you are competing with cars for the lane and it's important to get up to speed quickly. I can see power assist being a good thing here.
- Recreational Vehicle? Why not? Atomic Zombie is currently working on building a HPRV (Human Powered Recreational Vehicle) that will be power assisted. Sure, that's cool.

For a single, two wheel bicycle, be it recumbent or upright, I just have a hard time wrapping my mind around power assist. But.... That's just me.

Mark

 

[trapdoor2]

If you search on the bentrideronline site, there is a "power assist" thread buried in there somewhere that has links to some great information. Basically, the poster built a system to allow him just enough power to assist him in climbing his local hills. Not intended to add speed, just a little extra "oomph" to get him over the steeper bits. I don't recall if his solution was electric or gas, machts nichts really, you want ideas.

While I'm intrigued by power assist, I don't want it on my bike...at the moment. Naturally, necessity is the mother of invention...when/if I need it, I'll do it.

 

[buyagain]

Mark B wrote: For a single, two wheel bicycle, be it recumbent or upright, I just have a hard time wrapping my mind around power assist. But.... That's just me.

Truth is I don't have enough experience to make a decision one way or the other.
At this point I can either spend the money to assist it or I can start spending to lighten it. As an avowed tinkerer I will do one or the other for sure. I would love to get opinions one way or the other. Just for the fun of it. Right now I'm going to pretend to cut the yard then go riding.

Regards
Bob
"Any boat plane train auto or bike is just a moving set of compromises. "

PS Johntolhurst, so far as I can see you, you do it very well. I thank you for your design.

 

[JonB]

power assist is for really old people living in steep high mountains. For the rest of us, we need the extra exercise to live healthy.

 

[Mark B]

JonB wrote: power assist is for really old people living in steep high mountains. For the rest of us, we need the extra exercise to live healthy.

I'll subscribe to that theory.

Mark

 

[rearengine]

-For a single, two wheel bicycle, be it recumbent or upright, I just have a hard time wrapping my mind around power assist. But.... That's just me.

Mark

Thats the attitude you should have, at this time ,and your ability.. I hope it lasts a long,long time for you, like it DID me.. Now the assist on the hills keeps me bikeing, and living the good life, Miller Beer... Take Care Bill

 

[buyagain]

I see some seconding of opinions about not needing a motor. Rearengine; I'm seconding your motion. LOL
For those considering an engine, I see an opportunity to engineer because most engined bike that I see on the internet just don't cut it. A motor on a bike is not new. There is a certain naivete that fails to realize the complexity and most attempts to motorize a perfectly good bike ruins it's peddling qualities. The excess weight might yield a fun bike but God help someone caught out trying to peddle home on one of those beasts . 90 Percent of motorized bikes end up as virtually useless for any extended peddling and for that reason are useless for serious bicycling. As with the mopeds of yesteryear the attempt to peddle or to rely on peddles were and to this day are just next to impossible.

If by chance could new and lighter motors and and some drive efficiency improvements yield enough lightness and power dispensation yield a truly peddle-able motor assisted bike?
All I can say is that ever since i put a "Golden Eagle Bike Engine" on my bike I can't wipe the smile off my face. I hope that answers the question. LOL I'm getting lot of exercise too. I tinkered around and added another 14 lbs to the bike. I think thats about it. Looks like hopefully the weight will be coming off me not the bike. The bike is about 64 or 65 lbs now.

 

[highrider]

I'm just starting out on a Cruzbike conversion but I currently have two electric assist bikes: 1st up is a Heinzmann kit on a rather heavy Dawes Street Vision hybrid bike of mid eighties vintage. I live at the top of a big hill and I got this after seeing someone effortlessly sail up our main street. It's that steep that there is an annual hill climb competition! I have had it for about 4 years and it's brilliant. 3000 miles to date. I've even made a trailer to go to the allotment with the lawn mower and for big shops, camping trips, even to carry my Brompton. There is no way I would be cycling as much as this if I used my old Claude Butler. Then two years ago I put a small Tongxin electric motor in my Brompton. This gives real versatility in integrated transport as I have taken it on trains and buses and I can still get up the hill to return home. I even took it to sea and used it at destinations: Cornwall, Devon and the electric assist was invaluable. I'm not that old but for utility cycling no sweat cycling is great. I get tons of exercise as well. I'm definitely considering putting it on the Cruzbike if I manage to get it together! Collecting the donor bike tomorrow.