Speed Hack - no more limited by 27MPH cutoff ??

[MarcD]

If you want to actually calculate some scenarios you can here: http://www.kreuzotter.de/english/espeed.htm

I've posted this before, and it is useful. For example, a 5'10", 180 lb rider on a MTB requires about 89 watts to maintain 12.5 mph on flat. The same rider requires 556 watts to maintain 25 mph. So 2x mph requires 6.2x the energy using this model.

To travel at 35mph requires 1,451 watts. Given that a fit, amateur cyclist can usually sustain about 125 watts or 150 watts, a 1,000 watt motor isn't going to cut it.

More importantly, a 25 mile range would require the following: 25 miles / 35 mph = .714 hours of run time. .714 hours x 1326 watts = 946 watt hours. 946 watt hours is a 20 amp hr battery at 48 volts. A huge battery. And this doesn't allow for motor and drivetrain inefficiencies.

Just something to consider.

Marc

 

[Brambor]

I totally agree with the last sentence. Above 30mph you better have smooth and predictable surface to ride on. You might survive a 'one of' but doing this on a daily basis I think karma would catch up with you soon.

 

[James]

My Stromer had no problems at those higher speeds. I head down a steep long hill everyday and get to 65km/h every time. She handles it no sweat! I can't get there on my own (gearing, motor top speed) but if I somehow had a motor ad battery combo to get there my bike could handle it. I will say that wind resistance is the enemy at anything over 35km/h... Draft any big truck at those speeds and you'll see what I mean!

 

[Bike_On]

There is a bike, in existance, that allows you to pedal, gives assist of around 1000W, can maintain an average of 28-30mph for 22-24miles. It is the Optibike 1100R. The weight of 62 lbs, fatter tires and quality full suspension provides a solid ride, and feels comfortable with the 35-40mph downhill speeds.

I'm not trying to sell any Optis, just give credit where some riders want to be, and almost every OEM can't be: high speed, long range and safe handling (on/off road). Motorcycle class? At 62lbs? Hardly. Many hubs can be designed to go faster, but are heavier and less safe. The 1100 Watt mid drive thru the Rohloff opens the doors to the upper line of ebikes. Too bad it does not have PAS option.

I can see how the Stromer will feel solid as well at higher speeds with the 2" tires and good c-o-gravity The difference is the unsprung hub weight and no rear suspension.

 

[MarcD]

That's fair, Bike_On. I was thinking of a generic hub motor set up. High end Opti's are in a class by themselves. But even that shows the added engineering and expense for those higher speeds.

I guess my argument after reconsideration would be: "The practicality of a 35 mph bike by simply upgrading a hub motor is fantasy."

Maybe the equation is that you need 3 to 4 times the engineering and build specs rather than looking at simple watts.

Anecdotally, I can say that over 20 mph on a rough or unpredictable road with an unsprung bike gets dicey. If not only from a safety standpoint, from a comfort standpoint. If I did 1.5 hrs on the turbo on rough roads my back was wrecked until I installed a Thudbuster ST.

 

[MarcD]

Of course, you can always find more speed with a larger chainring.

 

[Shea N Encinitas]

There are some electronic hacks for the Bosch and other motors out there too. -S

 

[oilerlord]

Glad to see this thread resurrected. I checked out that link...seems to be limited to Bosch & Panasonic motors; not the Dapu motors in our Neo / Jumper bikes. I'd just like the ability to get to 30MPH comfortably instead of having to pedal like a madman. BH service dealers probably have a software mod they can do...but liability concerns would prevent them from doing it.

 

[Shea N Encinitas]

One of the hacks is almost funny, the magnet on a small disc to reduce the apparent speed of the bike. I'd love to try the speedup ghost ($158.50 Plus btw) on the Haibike RX. If the BH line is hackable someone will crack it. Maybe a slight overvoltage in a modded battery. Reminds me of camera firmware hacks. -S

 

[Peter]

It Can Be done. You need a booster battery pack on Bh 36v bikes

 

[biknut]

Look at the chart at the bottom of this page: (Link Removed - No Longer Exists) also here: http://www.electric-bikes.com/velomobiles/winddrag.html and finally wind resistance and other losses here: http://mccraw.co.uk.



As far as 35 mph, I don't think anyone here has a bike that can be safely ridden at that speed... not enough bike structural strength or mass to adsorb all that vibration. Can we revisit "death wobble" ?

I hate to disappoint you, but that's not the case at all. I've made many motor bicycles with gas engines that go 40 mph using cheap Walmart bicycles that have lasted for years. Most of the ebikes I've seen are superior to the Walmart bikes, so I seriously doubt 35 would be any problem, especially when you consider the lack of vibration.

I also know several people with eBike conversions made from Walmart quality bicycles that do 40 + mph and they haven't suffered any major frame failures either.

 

[Craig Morrison]

I hate to disappoint you, but that's not the case at all. I've made many motor bicycles with gas engines that go 40 mph using cheap Walmart bicycles that have lasted for years. Most of the ebikes I've seen are superior to the Walmart bikes, so I seriously doubt 35 would be any problem, especially when you consider the lack of vibration.

I also know several people with eBike conversions made from Walmart quality bicycles that do 40 + mph and they haven't suffered any major frame failures either.

It's not the bike frame i'd worry about, it's how much damage they'd do to themselves if they had an 'off'. So hope they're wise enough to wear body protection at that speed on an e-bike...

 

[calvin]

I hate to disappoint you, but that's not the case at all. I've made many motor bicycles with gas engines that go 40 mph using cheap Walmart bicycles that have lasted for years. Most of the ebikes I've seen are superior to the Walmart bikes, so I seriously doubt 35 would be any problem, especially when you consider the lack of vibration.

I also know several people with eBike conversions made from Walmart quality bicycles that do 40 + mph and they haven't suffered any major frame failures either.

I have begun to see more gasoline powered bikes around. Speeds attained would have them classified as mopeds here in AZ. Can't ride those on bike paths here. Is there any documentation around to support your position? Anyway, the proof is in the pudding. I would ask anyone who wishes to try and go 35mph on a standard bike to try and do so. Simply find a long and steep hill and give it a shot. Does it feel safe? It sure doesn't to me.

 

[biknut]

I have begun to see more gasoline powered bikes around. Speeds attained would have them classified as mopeds here in AZ. Can't ride those on bike paths here. Is there any documentation around to support your position? Anyway, the proof is in the pudding. I would ask anyone who wishes to try and go 35mph on a standard bike to try and do so. Simply find a long and steep hill and give it a shot. Does it feel safe? It sure doesn't to me.

Calvin, come on man, you sound like you don't believe people are actually building bicycles capable of 35 mph? I assure you they are. Here's 2 different motor kits out of hundreds, made to fit any standard bicycle. Don't bother trying to prove the claims real or not, because I can assure you from experience they are. It's actually very easy to make a motor bicycle that can go 35 mph. Even the slowest ones, with the smallest motors easily go 30 mph.

The next question you may ask is, how common are they. Allow me to answer that too. They're very common. Thousands of these china girl motor bicycle kits are being sold every year. No one keeps accurate numbers of total sales, but there's about 100 different brands being sold online. The popularity of china girl motor bicycles is pretty surprising considering we hardly ever see one in the flesh. A good gauge of how popular they are, besides the number of places you can buy them, is the size of the forums dealing with them. The biggest, and most popular is motorcycling.com with 47,000 members. If you spend a little time looking around there, it might be an eye opening experience for you. I think this should clear up the question of, if people are actually riding bicycles as fast as 35 mph, but you also question does it feel safe?

As far as I know, no one in history has ever made the claim that riding a bike is safe lol. Doesn't matter if we're talking about a bicycle, or a motorcycle, safety is relative. A Kawasaki ZX10 can do 180 mph out of the box. Is that safe? I don't think it is, but that's not hurting sales any.

I was just looking over a website the other day that offers eBike conversion kits. This site was actually recommending Walmart style bikes as being good candidates for conversions, the argument being that cheap bikes are usually heavier, and therefore probably stronger than more expensive lightweight bicycles.

You specifically asked about a standard bike. What's a standard bike? There's bikes, and then there's bikes. All bicycles are not created equal. Some have better brakes, some better wheels, some better frames. I can tell you from experience these things get sorted out quickly when you start running above 30 mph. It won't take you long to find out your brakes are crap. Your wheels are weak. These are things that definitely need to be addressed, but that's very easy to do. How much money do you want to spend? You can make any bike safer, but there's no such thing as safe.

http://motorbicycling.com/


http://www.sickbikeparts.com/Manuals/Shifter kit.pdf

This will allow you to climb the steepest hills and still hit top speeds in excess of 40 mph without straining
your engine.

http://www.ebay.com

Go up to 38 M.P.H

 

[Brambor]

I agree with Calvin. I think, if I understand him correctly, he said that riding bicycle at 35mph doesn't seem safe to him. (he said: ...to try and go 35mph on a standard bike to try and do so. Simply find a long and steep hill and give it a shot. Does it feel safe? It sure doesn't to me.)

I agree with Calvin: Riding a bicycle at 35mph does not feel safe to me. Heck I have 2 Vespa mopeds with suspension and I don't think riding those mopeds at 40mph and hitting potholes you encounter on an average road is very safe.

 

[opimax]

Maybe I am selling my Stromer short, I go do this hill on a 4 lane rd , sometimes can hit 32-33, wish I could do more, feels very secure no worse than my Subie going over 70. I am not sure about hitting the brakes and skidding if someone were to cut me off tight but that too is the same with my Subie at 70 and someone cuts it too close

 

[Shea N Encinitas]

35 mph on a Haibike feels quite stable, safe. Not sure if that is a standard bike but it represents my search for a safer ride above 30, stiff frame, large headset bearings, hydro brakes VS the Dash for example lacking in all those categories. Happy Friday yall! -S

 

[biknut]

Stromer's are very sturdy bicycles so it's not too surprising they're stable at higher speeds. Some bicycles are better suited for high speed than others, but claiming they're all unsafe is rather uniformed. People that build a lot of motor bicycles know what it takes to make them suitable. It should be easy for a factory that builds electric bicycles to make one capable of 35 mph with reasonable safety, and some in fact already do.

The paltry speeds of eBikes has little to do with equipment safety considerations, and everything to do with ridiculous laws.

 

[Brambor]

I have a stromer and a turbo. Except for nice, non potholed road I would never want to drive them above 30mph...more importantly I would never want to crash a bicycle above those speeds no matter what the surface or surroundings. To each its own... I thing faster than 30mph is for motorcycles.

 

[biknut]

I have a stromer and a turbo. Except for nice, non potholed road I would never want to drive them above 30mph...more importantly I would never want to crash a bicycle above those speeds no matter what the surface or surroundings. To each its own... I thing faster than 30mph is for motorcycles.

Just out of curiosity, what would you want to crash at those speeds?