Slo Ride

[BiggKidd]

It would seem my motor has gone on round the world tour and now it's back in Greece. They claim to have reshipped it and complained about they had to pay postage a second time because they sent it wrong the first time. I'm beginning to worry it may never show...

 

[hillslayer@]

Goat makes a 96 volt 15000 watt e dirt bike for $5,000 it does 65 mph. I would not bother building something that would probably cost more than this.

 

[A-DamW]

It would seem my motor has gone on round the world tour and now it's back in Greece. They claim to have reshipped it and complained about they had to pay postage a second time because they sent it wrong the first time. I'm beginning to worry it may never show...

If the Lehner dosen't make it, Lightning rods sells some some nice honken' big motors:

Lightning Rods

I have a couple Toppower TP128, which is the equivalent to the LR XXL Motor:

XXL Motor

Serious motors.|

 

[BiggKidd]

Goat makes a 96 volt 15000 watt e dirt bike for $5,000 it does 65 mph. I would not bother building something that would probably cost more than this.

Some of us enjoy the process of building our own! I have done a cost workup at about 3K to 4k total depending on the battery with me doing the build but does not account labor costs since that's my hobby! Of course that's provided the motor I bought shows up for the price I paid. The largest problem I foresee at this time is cramming enough battery in to handle the 24kw nominal current load!

 

[BiggKidd]

If the Lehner dosen't make it, Lightning rods sells some some nice honken' big motors:

Lightning Rods

I have a couple Toppower TP128, which is the equivalent to the LR XXL Motor:

XXL Motor

Serious motors.|

Looks like a similar motor but I'm praying the one I ordered makes it. Yeah it did cost a bit more but it's also rated as a 100,000 hour motor and it only weighs 4.2lbs.

 

[BiggKidd]

Just sent an email to Grin to see if they would be willing to build me a rear wheel for this project bike. For some unknown reason I have my doubts about hooking a 24kw motor to a standard 16x4 bike wheel! Anyone know of any other places that might help or be less expensive?

 

[Chalo]

Folks who know what they're doing will tell you no. Folks who don't care will take your money.

 

[BiggKidd]

Folks who know what they're doing will tell you no. Folks who don't care will take your money.

I just wish I knew a formula to compare the torque of a 20,000rpm 24kw / 32hp electric motor to a 10,000rpm 37kw / 50hp gas engine! My gut instinct says the 24kw electric motor will have better acceleration than a 50hp gas motor. But I just don't know! The electric bike will likely weigh about 65% of the weight of the gas motorcycle I'm using as a comparison.

 

[Chalo]

I just wish I knew a formula to compare the torque of a 20,000rpm 24kw / 32hp electric motor to a 10,000rpm 37kw / 50hp gas engine! My gut instinct says the 24kw electric motor will have better acceleration than a 50hp gas motor. But I just don't know! The electric bike will likely weigh about 65% of the weight of the gas motorcycle I'm using as a comparison.

Consider that the poison motor will make max torque at 1/2 to 2/3 of max power RPM, and the electric motor will make max torque at zero RPM. So the more powerful poison motor, if correctly geared, will have a higher top speed. But the electric motor will hustle faster off the line.

 

[gromike]

As far as being lighter than a gasser you have to add in the weight of the battery.
An emoto with power, speed, and endurance is a heavy thing.

 

[BiggKidd]

That's exactly what I'm thinking except the top end speed will be almost identical if and only if my math is correct. @Chalo

True @gromike I will not have the extended speed ability of the E-motos. Believe it or not I expect to ride bicycle speeds 98% of the time. I just like the ability to go fast when I want too! There are lots of private places around here I can open it up when I get that feeling, including a private airstrip.

 

[bananu7]

That's exactly what I'm thinking except the top end speed will be almost identical if and only if my math is correct.

There's really not much math needed to see that it's quite hard for a 24kW peak power vehicle to match the top speed of a 37kW one. The weight has negligible impact on top speed, aerodynamics are much more important.

Believe it or not I expect to ride bicycle speeds 98% of the time.

I don't believe it for a second because riding a motorcycle at bicycle speeds is just completely unnatural. Once an open road segment happens I bet you'll just ride it accordingly to its capabilities. And it'll be very inefficient at slow speeds, too.

Plus remember what I said about suspension. You wanted a vehicle that goes up to 160km/h. Suspension setup for such speeds feels awful at 30km/h because the compression forces don't even start to bend the damping shims and it feels like it has no suspension at all. That's another reason why riding a sport bike in a city is a dumb idea.

Now, I know that there's a difference between a sustained cruise at 160 and an absolute maximum rating of 160 in perfect conditions (more in line with the 24kW power), and then we're looking at an equivalent of something like a 250cc bike. That could conceivably go that fast just to show it could, but you'd otherwise almost never use it at such speeds. Those are optimized for speeds in the range of 70-90 - much more reasonable for this power train, but still far more than any bicycle. The issue with electric powertrains is that they don't work like gas engines and they reach their peak efficiency close to their top speed, so if you gear it unnecessarily high, you'd be losing a lot of acceleration and range.

Long story short: a fast bike ridden slow will be harsh and inefficient. A slow bike ridden fast will be sketchy and potentially unsafe. Anything that tries to bridge those two will be a compromise worse than a vehicle designed optimally for its target use.

 

[BiggKidd]

Most of the many 250cc bikes I rode struggled hard to go 90mph and were more comfortable at 20-60mph much like I expect this to be. I may not have ridden bicycles for 40 years but I owned and rode a LOT of MCs on road off road and on tracks. I also daily drove many things that were as comfortable at 175mph as they were at 50mph. Then there's my old backyard built Z28 that once ran an 8.73 in the quarter mile and regularly ran 9's and 10's yet I drove it on the road everyday and never once in twenty years got stopped for speeding. The nasty bike I rode a few times was an old custom Harley with an air shifter, now that truly was a bit much on the street. My point being just because you can fly at any time doesn't mean you have too!

Grin already got back to me and they suggested an MC wheel...

 

[BiggKidd]

Alright I finally figured out how to get the shipping info translated to english. My motor is in America and is ready for release from customs. Looks like it should be here next week! I will rest a lot easier once it's in hand!

 

[BiggKidd]

I know I said I wasn't going to order anymore parts for the bike until the motor got here. I lied, although the motor is in Virginia according to USPS. There has been a NOS rear wheel for sale on E-bay for 50% of new that I've been wanting to order but had been holding off on. This morning I noticed it was in two other carts so I jumped and ordered it. Gotta save them pennies when you can! That's one more piece of the puzzle down. Still lots of pieces to go...

The downside to this wheel is it's color, it's mustard yellow! YUCK!!! That means I will have to try and remove the paint and polish the aluminum or go lame and paint it black.

My daughter just picked the motor up from the PO box.