How can I build a 30mph e-bike?

[full-throttle]

Any of the brakes I listed can lock the front wheel at speed, so strength is not an issue.

In you 40s an still a bike mechanic. No wonder you're so grumpy :lol:

Anyway, since you are so experienced and knowledgeable, answer this simple question:
Why in the most brake-demanding cycling competition, mountain biking, rim brakes weren't used for over a decade? Surely the racers could benefit from this great brake system that has such superior strength and according to what you say is virtually fault free :lol:

And what about other vehicles in the last 5 decades?

Oh, and I wasn't your average school kid :wink:

 

[dogman dan]

Brakes aren't his primary problem anyway. Make them as good as you can inside your budget. His big problem is an affordable battery big enough. $1500 budget would make things much easier to do.

Good brakes or bad, you will be screwed when that car pulls into your path, thinking you are a bike going 15 mph. Too late is too late. The car is 20 feet away, good brakes will stop you in 30 feet. If you have 30 feet, you have time to turn and miss the car.

 

[wesnewell]

The larger the disc, the less power it takes to stop the wheel. You can't get a larger disc then the rim. Therefore, simple physics apply. It takes less force to stop with V brakes. I wouldn't say rim brakes are best because some caliper type rim brakes really suck simply because you can't get enough force to the rim with them. But you can with V brakes.

 

[TonyReynolds]

To the OP:

Well, lotsa good advise here, as has been said, main problem is battery capacity for speed and distance. If interested, I've been trying to do roughly the same thing. This is my build thread:

http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=33819

Steel frame with disc brakes and an A123 in-frame battery as you've been looking at.

Build isn't quite finished yet, as my wife passed on last year, many life changes, serious injury kept me from riding all last fall, yadda, yadda...

BUT, I *can* do 35MPH on a flat while peddling. That's not the goal though. The goal was to AVERAGE 20-25 mph, while peddling the entire way (except coasting downhill), with the greater speed available as a safety factor for merging with traffic, getting across intersections, etc.

Best of luck with the build.

Tony

 

[full-throttle]

I have created a separate thread discussing brake systems
/viewtopic.php?f=48946
Feel free to redirect unwanted conversations there

 

[bigmoose]

I moved a post over to the brake thread... and then pruned a couple of posts so the merged thread made a little more sense.

A quote I read today might have a bit of insight for all of us here on the sphere...

''When a man knows something, he really knows - deep down in his heart - he doesn't have to prove it or argue - just knowing is enough.'' --Ben Cartwright from the series Bonanza

Bonanza was one of my favorite shows as a little guy. I always looked up to the wisdom of Ben.

 

[Chalo]

''When a man knows something, he really knows - deep down in his heart - he doesn't have to prove it or argue - just knowing is enough.'' --Ben Cartwright from the series Bonanza

Not exactly the driving philosophy of an online information forum, is it?