Safe's Electric Bike Project #001

[safe]

I barely clear 3'' inside the swing arm. What about them spokes though?

You just have to buy new spokes. And you might try the "24 X 2.35 Kenda Krusader" tire if your tolerances are really tight. Reducing the diameter slightly is not a big deal.

But before you get too excited... are you running disk brakes? If not forget it because you will never find brakes for 3" tires. (and don't forget that the 24" rim is further away from the brake mount than on a 26" rim)

 

[RatoN]

I still don't have a rear break period (long story). I will have a disk break though, so that does not add to my e-broblems lol.

For the tire whit, i could get away with 3'' no prbs.

Now, stop with those great ideas! It's gonna cost me

Thx


EDIT: Btw, about tire maximum load and speeds. Got the Maxxis reply

Maxxis replied to your email 1/24/2007 at 10:46:15 AM, The reply is as follows:


We do not have that type of information.

Our tires are designed to accomadate people of all sizes on a bicycle.

They are not designed for any other use.

Best Regards,

Maxxis-USA

To reply to this message, you must follow the link below.


Thank you!
Maxxis International

 

[Toorbough ULL-Zeveigh]

So yer hot-n-sweaty4 the phat black booty... tyres.

Here's another idea that's sure to pop your tent



As I recall, each wheel was built up from a pair of bike rims.
So you can make any wheel as fat as you need.

 

[safe]

If those tires are light weight that would be perfect on sand. (like in the picture) A brilliant idea to adapt to a specific environment. 8)

 

[xyster]

It's a pedal-powered amphibious hybrid!

 

[D-Man]

Safe, what kind of materials is your bike made of? Is is just plain steel? Any specific guage? Where did you get the frame material at? Welder used?

 

[safe]

Safe, what kind of materials is your bike made of? Is is just plain steel? Any specific guage? Where did you get the frame material at? Welder used?

There was an online steel company and I just bought the tubing that I needed as regular mild steel. With 86 lbs of batteries I used some pretty thick rectangular tubing for the forks and rear end, but the "cage" in the middle is only 0.75" mild steel. If I were to do it over again (with that design) I'd use a higher grade of steel because this stuff tended to warp too much while welding.... with an ordinary oxy-acetaline torch.

The entire frame and fork weighs about 20 lbs so it's not bad as far as weight...

 

[D-Man]

Got any pictures of the gearing?

 

[safe]

The "transaxle" was welded together from a #25 chain scooter sprocket, a steel bicycle hub (for the ball bearing assembly and axle) some 2.5" tube and a couple of coaster brake rear sprockets. It was then simply painted gold.

In order to get up hills I run in the lower sprocket most of the time, but if you want to go for a "speed run" you have to get your fingers dirty and lift the chain onto the larger sprocket. They are 14 tooth and 22 tooth sprockets. The other gearing is 10 / 80 I think... (then there's the 14-28 six speed freewheel)

 

[xyster]

I see a derailleur so I imagine you can change gears? You're always talking about that.

Only a single, lonely gear available while riding!?!? I'm shocked to see gear-obsessed Safe not practicing what he preaches! Hmmm....that bike could make a nice platform for a hubmotor conversion

 

[safe]

Only a single, lonely gear available while riding!?!?

No it's a six speed... it would be nice to have it be an 18 speed (add a front derailler and one more front gear) and it could be done, but I'll be getting a wider gear range on the newer projects that use internal hubs with 8 speeds and "direct drive" from motor to hub with just one chain (305% verses the current 200%). That should be about 95% efficient and with all those gears it "amplifies" the efficiency of the overall bike. I can "pick and choose" torque levels and rear wheel speeds and that means if I ride well I can do a lot more than a one speed.... um.... hub motor...

 

[xyster]

Sorry, Safe, I missed the six speed freewheel. You've been duly acquitted of the implied charges: "do as I say, not as I do hypocrite"; and the technical offense, "argument not internally self-consistent"
I've charged myself with the equally serious offense, "filing charges without due diligence".
I found myself guilty and have been sentenced to a grueling, 5-mile bike ride today without the benefit of electricity.

 

[D-Man]

Thanks for the pictures Safe. Thats quite a machine you have there. Looks like a lot of welding and time spent on that. Excellent Job.

 

[safe]

Thanks for the pictures Safe. Thats quite a machine you have there. Looks like a lot of welding and time spent on that. Excellent Job.

It took about a solid month of work to get "running" and then the debug/enhancement/testing phase is still going on. Every ride is a test still, though I think it's pretty much "done" once the new wiring and new controller are finished. It's still too cold to even think of working on it now and actually this morning I shoveled about 4" of snow off my driveway...

 

[Toorbough ULL-Zeveigh]

A'm I the only one that's impressed as hell that the frame with fork weighs in at only 20 lbs on something that size!

Thin wall & oversize, that's the way to go. At such a minor weight penalty, this has convinced me to no longer even consider Alu as framing materiel.

Nice work & thanx 4 the pix & your contribution generally!

 

[safe]

Thin wall & oversize, that's the way to go. At such a minor weight penalty, this has convinced me to no longer even consider Alu as framing materiel.

It's funny that you say that because I've often pondered about going towards an Aluminum frame on a future project.

Imagine this scenario...

Top of the line Lithium battery pack that is "excessive" in size like Xyster has done.

Lightweight Aluminium frame with a "Deltabox" design.

The seat (with fairing) is suspended. (just thought I'd throw that in)

DC Brushless OR AC powered motor for maximum efficiency.

Internal 8 speed rear hub.

3" Aluminum Rims with 24"x3" "Road Racer" tires.

Fiberglass fairings front and rear.

Anyway... steel is a good idea when building your prototypes because mild steel gives a lot of warning before failure. Normally you would feel excessive flexing and see signs of metal fatigue before a failure occurs.

Aluminum and Carbon Fiber are MUCH stronger and lighter, but they tend to fail "all at once" in spectacular fashion. Either you did it right and it never breaks or you did it wrong and hit the cement in a bad crash. So generally speaking you go about using the more "exotic" materials with a little more "concern" about their durability.

 

[knoxie]

I see a derailleur so I imagine you can change gears? You're always talking about that.

Only a single, lonely gear available while riding!?!? I'm shocked to see gear-obsessed Safe not practicing what he preaches! Hmmm....that bike could make a nice platform for a hubmotor conversion

Hi

Yes I love the work you have done on this bike, it would however make a great frame for a rear mounted X5 at 120V.. esp with some exotic battery chemisty and an X5 would scream at 120V! ha ha I dont think anyone has tried one that high though.

Still I like gears a lot so stick with what you have!! its cool

Knoxie 8)

 

[safe]

...it would however make a great frame for a rear mounted X5 at 120V.. esp with some exotic battery chemisty and an X5 would scream at 120V! ha ha I dont think anyone has tried one that high though.

If I had an X5 laying around to test I would. Buying one new is expensive and the alternatives are actually better on a dollar/performance basis. The PMG 132 would be my choice if I was going to go for insanely illegal power (like 15 hp) but for now I'm going to be a "good boy" and keep it legal (at least as far as horsepower) and stay in the 1-2 hp range. Plus, once you get above 1-2 hp you run the risk of blowing up the internal 8 speed hub or a 6 speed freewheel, so that makes me want to keep the torque down to "conservative" levels.

 

[xyster]

I'm going to be a "good boy" and keep it legal (at least as far as horsepower)

Like robbing half a bank, eh?

 

[safe]

Like robbing half a bank, eh?

If you rob a bank and they catch you with the oversized "motor money" then they can arrest you.

If you rob a bank and they can't find the oversized "motor money" then it's harder for them to know you're guilty. :wink:

 

[safe]

After completing the wiring upgrade and getting the new controller I managed to make 47 mph for 5 seconds after coming off a moderate downhill and onto flat land. The "self propelled" speed seems to be about 38-42 mph, but if you can get a "running start" from a downhill you can hold from 42 to 47 mph for a while... it just sort of gradually eases off until you return to about 40 mph. I actually tried this after I had already ridden about 15 miles so the batteries were not at their peak charge.

So the new (non-official) top speed for my bike is a 47 mph.

(38 - 42 mph for true flat land)

I still don't get to join the "50 mph Club".

 

[xyster]

Even in a tucked position, would a small fairing make sufficient difference to get you into the club?

Or it looks like you might have enough room to ride underneath, steering the handlebars with your feet

Anyway, at 44mph on the flats, my hubmotor is still faster! :wink:

 

[safe]

Even in a tucked position, would a small fairing make sufficient difference to get you into the club?

Or it looks like you might have enough room to ride underneath, steering the handlebars with your feet

Anyway, at 44mph on the flats, my hubmotor is still faster! :wink:

It's actually redlined (no load speed) in the top gear. It's possible that with one or two more teeth on the "transaxle" sprocket that I could get there. The other possibility is to go from a 10 tooth on the motor to an 11 tooth.

Hmmmmm.... that's easy to do... (and cheap at only $5)

When I build the new bikes I'll have "spare" fairings and could mount one on this "older" bike. That might get it to 50 mph... or probably just 49 mph just to tease me... Though by then the new bikes will be approaching 60 mph as their limit...

http://tncscooters.com/product.php?sku=106006

 

[safe]

Darn

I've already got an 11 tooth sprocket. And it looks like it might be difficult to even find a 12 tooth that would fit. (but not impossible)

After further review of the calculations here is what was "supposed" to have happened on this bike:

"Ideal" Top Speed if gearing were "perfect" for top speed - 48.1 mph

"Peak Power" speed as the bike is "actually geared" - 41.8 mph

Calculated best top speed with wind resistance included - 44.3 mph

So when I'm getting 38 - 42 mph on flat land that's about 2 mph off of what it "should" be if I had a full fairing.

As for top speed on a mild downhill it seems that at 47 mph I'm already 3 mph past the calculated wind resistance speed, so the power is FALLING OFF in that zone and it's nearing the "no load speed". There's no power and so I'm essentially coasting.

If I gear it up any higher then I wouldn't be able to climb the hills to get home... however, this is a BIG IMPROVEMENT over before when I had a top speed with the 14 tooth gear of only 31.4 mph. (I used to only use the 22 tooth for speed runs, now I use it everywhere)

The bottom line is that I'm able to go 10 mph faster just about all the time now... which is AWESOME!

 

[xyster]

Hey Safe,
Though I designed and sketched it to paper awhile ago, I posted this schematic of a 48v30ah --> 72v20ah switching circuit in part for you. See the second version at the bottom of the page.

http://endless-sphere.com/forums/viewtopic.php?t=278&start=15

It'd work great in concert with your planned 120-cell NiMH pack I think.

I'm hurt you haven't criticized... errr....critiqued...err...noticed it yet!