BigRider
10 mW
Hi all,
I've been researching for months and I'd appreciate any review of my current leanings to make sure i'm on the right path for my specific weird situation / disability / whatever you want to call it.
I'm near 700 lbs. Yeah, I know. I carry it very well for 700 lbs, but it's pretty hard. I can walk into work but I have to stop and catch my wind on the way in, etc. I used to ride at 450 lbs and got in pretty decent shape as I got down to 400. But, that was a long time ago and even then I was on a recumbent that I had to push up a lot of hills and the front wheel was so small I zig zagged all over the place going uphill.
I know that I need a trike and electric assist. I can't find anything commercially that I'm willing to take a chance on. Being a handy guy, I've been researching and designing. Here's what I'm thinking, and I'd appreciate any feedback. I'm still reading but I think I've settled on some stuff and want your thoughts.
0) Pushing a 700 lb man means that I don't need a 40 lbs vs. 50 lb bike. It can be heavy.
1) Custom frame - made from big strong tubing.
2) Tadpole trike
3) Motorcycle front tires - 100/90-19 wheels (Almost exactly 26" OD)
4) Rear drive (simpler)
5) 7 speed rear dérailleur, single speed front sprocket (don't care about speed, just hill climbing)
6) Rear drive with the "GNG big block alternative" (logic below).
7) Dual front 160 mm disk brakes
8) Custom seat w/ pipe and nylon netting - adjustable angle
9) Adjustable pedal position (obviously would have to adjust chain).
A few points that went into above.
Tadpoles are cooler to me than deltas. Also, the way it's currently designed it's easy to arrange the drive stuff and and use standard parts from an old bike and overall easier. Makes the steering harder, but I'm willing to bite that off.
My logic for rear drive is that I have very powerful leg muscles from moving 700 lbs around. I'm assuming that since I have in the past folded chainrings by accident that I have more than sufficient power to do it again if I'm not careful. I like the idea of a mid-drive, but I figure if I throw 1000W into the BB in addition to my major muscle power, I figure I'd destroy most normal chain gear.
I also like what I read (so far - the thread is enormous) about the BB motor - about the high amps at low volts for torque and then higher voltage for speed (the Tesla analogy in the thread). I'm still working out controller / volts / amps, etc. But I figure that the direct drive will be a good idea in hill climbing.
On gearing I figure I'm thinking a 14-34 7 speed on the rear and 32 tooth front (the normal mid ring). This gives 24 gear inches / 5.8 MPH with a cadence of 80. High gear gives 14 mph at 80 rpm cadence. Either that or 22 tooth front gear which gives 17 gear inch / 4mph low and 9.7 mph high.
So right now i'm after does this make sense so far? Which threads should I read up more on? (I have about 4 open right now I'm in the middle of and have been researching for months). My plan is to get out in the garage when the temps start dropping (fall). Build through the winter. Test ride as soon as things warm slightly. Start real riding ASAP in the spring.
I appreciate any pointers / thoughts / etc. that you have. Thank you for reading this and sharing your opinion.
I've been researching for months and I'd appreciate any review of my current leanings to make sure i'm on the right path for my specific weird situation / disability / whatever you want to call it.
I'm near 700 lbs. Yeah, I know. I carry it very well for 700 lbs, but it's pretty hard. I can walk into work but I have to stop and catch my wind on the way in, etc. I used to ride at 450 lbs and got in pretty decent shape as I got down to 400. But, that was a long time ago and even then I was on a recumbent that I had to push up a lot of hills and the front wheel was so small I zig zagged all over the place going uphill.
I know that I need a trike and electric assist. I can't find anything commercially that I'm willing to take a chance on. Being a handy guy, I've been researching and designing. Here's what I'm thinking, and I'd appreciate any feedback. I'm still reading but I think I've settled on some stuff and want your thoughts.
0) Pushing a 700 lb man means that I don't need a 40 lbs vs. 50 lb bike. It can be heavy.
1) Custom frame - made from big strong tubing.
2) Tadpole trike
3) Motorcycle front tires - 100/90-19 wheels (Almost exactly 26" OD)
4) Rear drive (simpler)
5) 7 speed rear dérailleur, single speed front sprocket (don't care about speed, just hill climbing)
6) Rear drive with the "GNG big block alternative" (logic below).
7) Dual front 160 mm disk brakes
8) Custom seat w/ pipe and nylon netting - adjustable angle
9) Adjustable pedal position (obviously would have to adjust chain).
A few points that went into above.
Tadpoles are cooler to me than deltas. Also, the way it's currently designed it's easy to arrange the drive stuff and and use standard parts from an old bike and overall easier. Makes the steering harder, but I'm willing to bite that off.
My logic for rear drive is that I have very powerful leg muscles from moving 700 lbs around. I'm assuming that since I have in the past folded chainrings by accident that I have more than sufficient power to do it again if I'm not careful. I like the idea of a mid-drive, but I figure if I throw 1000W into the BB in addition to my major muscle power, I figure I'd destroy most normal chain gear.
I also like what I read (so far - the thread is enormous) about the BB motor - about the high amps at low volts for torque and then higher voltage for speed (the Tesla analogy in the thread). I'm still working out controller / volts / amps, etc. But I figure that the direct drive will be a good idea in hill climbing.
On gearing I figure I'm thinking a 14-34 7 speed on the rear and 32 tooth front (the normal mid ring). This gives 24 gear inches / 5.8 MPH with a cadence of 80. High gear gives 14 mph at 80 rpm cadence. Either that or 22 tooth front gear which gives 17 gear inch / 4mph low and 9.7 mph high.
So right now i'm after does this make sense so far? Which threads should I read up more on? (I have about 4 open right now I'm in the middle of and have been researching for months). My plan is to get out in the garage when the temps start dropping (fall). Build through the winter. Test ride as soon as things warm slightly. Start real riding ASAP in the spring.
I appreciate any pointers / thoughts / etc. that you have. Thank you for reading this and sharing your opinion.