DIY build prep shopping list advice

[hjns]

Sorry to bring the news, but "science" is ALWAYS overruled by reality. Every medication that should be adverse event free based on scientific research happens to be toxic in specific cases. For every 100 airplanes where science has shown that they all should be flying for at least 5 years, there is at least one crash due to something that science did not foresee.

So, although alu should be ok scientifically, reality has shown it is NOT. Please, take a bit more time and browse the forums. I know at least of 5 descriptions of broken alu dropouts, one of them of yours truly.

If it is aluminium you want, either stay below 30 or get a fully. If you don't do that, then reality will show you why you should have. And don't forget the torque arms.

 

[john7700]

Heck man, no compatition for whatever that means. Just a hot sweaty night and some insomnia

My point with the first part was just to show that aluminum will indeed fail. That and the fact that some of the guys on this sight are simply awesome . I have an aluminum push bike in my garage that I take off six foot cliffs but I would not put a motor on it. Not without adding steel in the form of torque plates.

On the weight thing, my background is primarily in mountain bikes but I remember when they first started production aluminum MT frames that were just copies of the steel predecessors, the difference between the two was less than a pound. But again, the point I was making here is that with the motor, the weight difference of even say five pounds doesn't matter all that much.

But here was my main point (I have a lot of points don't I ) Ausi jester has a cruiser and recommends front suspension, Spinning magnets has a cruiser and recommends a $140 thudbuster for rear suspension and has what looks to be a ~$600 down hill fork for front suspension on that fast cruiser. You can take a cruiser frame, throw much more than the cost of the bikes you have listed on to it, and make it in to a full suspension bike that it pretty safe at the speeds your talking. OR you can start with a full suspension bike that you could get used for ~500 and have a bike that will make a much safer and better handling platform for higher speeds.

You can build one of the bikes you listed and run them at higher speeds but you are going to pay a stiff price for choosing form over function. I run a fully rigid mountain bike with balloon tires and with a max speed of only 25 mph it still rattles my cage some times and I have had to replace my rear wheel after a year of use also.

Oh, one more thing, have you figured out how you are going to stop that Straight eight with a motor on the rear wheel?

Again, just my $.02

 

[casemon]

@hjns
That is very useful advice, and addresses my question perfectly (if not abruptly haha).

@john7700
Glad to see we agree on the awesome And you make valid points on the weight / strength issue.


Still on the fence about cruiser style or FS MTB, but there's more digging yet to do!

In either case, will go with a steel frame; from your help, now fully understand why

Knowledge is power! Thank you both!

 

[john7700]

Its not that aluminum is totally bad but you need to be realistic as to style vs. speed and address the weak spot with torque plates/arms.

If you insist on a cruiser style, you are going to need one with external gears and breaks unlike that straight eight.

This one was being talked about earlier. It is still aluminum but at least has 26 inch tires, v-breaks and 7 speed cassette. Keep it below 30mph and use some torque plates and it might be a good compromise.

http://www.norco.com/bikes/urban/urban-lifestyle/santiago/

 

[casemon]

Oh, one more thing, have you figured out how you are going to stop that Straight eight with a motor on the rear wheel?

Failed to reply to this: plan on installing disc calipers front back or both?

 

[john7700]

You have to have mounting bosses/brackets on the bike in order to put breaks on. Your barking up the wrong tree with
that bike son. It just wont work without HUGE modifications.

 

[spinningmagnets]

Some of the "more affordable" cruisers have a one-inch head tube, look for a model that has a 1-1/8th inch head-tube, that will give you lots of options, since you may want front suspension forks and a front disc brake.

Direct-drive hubs give you the option of using regen to aid braking. If riding under 30-MPH, I am of the opinion that V-brakes with salmon pads are "adequate" on the rear wheel. I always recommend front disc brakes, even if you can only afford a cheap version.

 

[boppinbob]

Reserved

 

[casemon]

All useful advice; thanks you ES!

Update on my end; am yet sourcing the base; wondering if I should go quality with some name brand frame like Electra, or if a $200 Mircagi would be just as good?

@boppinbob
Eh?

 

[RWP]

What's happening with your build?

Used Townie's in the LA to Santa Barbara area are about $300 for a 21D. Townies seem to hold their value very well!
Most FS mountain bikes have a wheel base of around 42 to 43" the Townie is about 48" - I think this will make a big difference in handling at speed.

 

[Farfle]

After doing several electric conversions on townies , I would say that it is one of my favorite conversion candidates. It has beefy drops that are easy to bolt torque arms to. The rear chainstays can take a pretty chubby tire (26x2.5 hookworm) with room to spare, and the frame in general is built like a tank, pretty thick and well gusseted. Plus, very comfy and rides well at speed.

 

[thickhead]

Update on my end; am yet sourcing the base; wondering if I should go quality with some name brand frame like Electra, or if a $200 Mircagi would be just as good?

I support going with the steel frame (with the caveat that I just built my first ebike, so I'm no "expert"). I just narrowly avoided a disaster with my old 7005 frame. Granted, it was an old frame. And, granted, in a racing bike the weight difference might be significant. But for a commuter/cruiser? I'd take the extra resilience of CroMo.

Regarding better vs. cheaper frames: I'm an incremental cost kind of guy when I buy stuff. If I'm forking out around 1500 bucks for the power train, and want it to be reliable transportation and not a perpetual prototype, then is saving a few hundred bucks on the frame really "saving"? Don't get me wrong: I spent about 3 grand for my X-troll-cycle, which was about 500 more than I had hoped to spend. But that's going to be my car replacement (I hope). Some of my future builds will aim for lowest cost using recycled components, but that's with a different sort of end use in mind. Of course, guys like dogman and amberwolf know how to do it cheap and reliable--but that's going to take practice and experience that I don't yet have.

Oh, and another thing: safety. Don't underestimate the danger of riding 25-30 mph on a bike. I'm not an athlete, so without a motor I'm going to be going 10 mph* with an occasional 20 down hill. With a motor, you're in the Giro d'Italia every day! I personally am a safety wimp, especially on a bike designed for commuting. After a while you'll be commuting on autopilot and not as attentive as you probably should be. It's especially important that a practical transport ebike be rugged. If I make a pocket rocket for fun, that's arguably different, because when I'm riding it I'll have a different attitude (I won't be bleary-eyed riding into work with too little coffee, or spaced out after a long day).

Looking forward to seeing your build progress!
_____
* OK, that's wrong. I just tested and I would be going more like 15-20 on a nice flat road. I'm not as weak as I thought.