Good bike to motorize

fechter · Jan 23, 2007

Always thinking of the next project, I saw this on Craigslist for $300. It looks way better than what I could get for the same money at Costco.
The square section frame looks cool and would be easier to bolt things to.

Oh well, it will probably be gone before I can get around to making space for such a thing. Craigslist is a great place to shop for bikes I've found.

xyster · Jan 23, 2007

Always thinking of the next project

Build a hubmotor into a mag wheel, patent the method and make a ton of money!

Ebikes are not, I think, going to become popular in the U.S. until the common, niggling issues like broken spokes are remedied.

safe · Jan 23, 2007

25 lb rear hubs are a lot of "unsprung weight". That's what's killing your spokes... bring that hunk of iron on board and you can eliminate the spoke breaking problem. (and make the thing handle a heck of a lot better too)

I'm such an "on board motor / gear freaK' that I'm too biased! :lol:

xyster · Jan 23, 2007

Well Safe, you make a good point. But for me the fix is not to ditch the hubmotor, but improve its implementation. If Knoxie's glowing reports of the 8lb BMC Puma geared and brushless hubmotor are accurate, it'll make an excellent replacement later for my overweight hubmotor. Affixing the 5304 to a mag wheel somehow is another solution.

Hopefully the issue is mainly weight, and not rotational forces, else spokes won't last long on the Puma either.

Sorry for peeing tangential, off-topic dribbles all down your thread, Fechter

safe · Jan 23, 2007

Getting back to the bike, yes, I like the fact it has disk brakes and if you can stiffen the suspension to handle the extra battery weight it would be good. You can get similiar bikes at WalMart for next to nothing. (of lessor quality of course) It's just amazing how cheap bikes are now.

$189.74

http://www.walmart.com/catalog/product.do?product_id=3610588

$159.37

http://www.walmart.com/catalog/product.do?product_id=2513014

joystix2 · Jan 23, 2007

Fecht, I was looking at the same bike and others on Craigslist. Now that my BD36 bike is all done I am starting to look at my next project bike. On that type of bike with the dual suspension do you think those racks that fit on the seat post will hold Nimh batts (36/48v 10/13ah). Or do you think we'd have to go to Lithiums? The only Lithiums I have seen for decent prices were the ones from Batteryspace.com but they can't handle too much amps.

http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=911

By the way. I am Ric the larger brother.

knoxie · Jan 23, 2007

xyster said:
Well Safe, you make a good point. But for me the fix is not to ditch the hubmotor, but improve its implementation. If Knoxie's glowing reports of the 8lb BMC Puma geared and brushless hubmotor are accurate, it'll make an excellent replacement later for my overweight hubmotor. Affixing the 5304 to a mag wheel somehow is another solution.

Hopefully the issue is mainly weight, and not rotational forces, else spokes won't last long on the Puma either.

Sorry for peeing tangential, off-topic dribbles all down your thread, Fechter

Yo Xyster

Yes I agree I also think safe is right as well about getting the motor on board as well, driving the wheel by attaching a motor to the hub or any way where there are forces applied that would never normally applied will loosen spokes.

Most of the Chinese wheels come in with very poor spokes fitted, Mark always just buys the motors in and has them laced by a pro with stainless top quality spokes, he has never had 1 failure on a chair in 5 years which is good going.

Like any bike you do need to keep on top of the spokes, I check the tension on mine every week or so and adjust when needed, with the extra weight its important to do this.

Standard bike components don't last very long once you start pumping more than 800 watts in to them unless you keep on top of the maintenance of them.

Even if you put the motor on board you are still applying the same amount of rotational force to the wheel that you would had it been in the wheelor clamped to the spokes, it is this force on-board our outboard that will loosen the spokes, the motors weight doesn't really have much to do with it, although the Puma is a lot lighter at 4lbs which will make a great difference overall.

Cheers

Paul

safe · Jan 23, 2007

A really heavy hub (25 lbs) is a lot of "unsprung weight" in a really terrible position. When the wheel hits a bump and it has to overcome 25 lbs of inertia and combine that with torque stresses and you have a multiplication factor going on that puts much more stress than if it were the torque alone. The answer it to get the weight down... so the Puma sounds like the way to solve "most" of the problems...

patrick_mahoney · Jan 23, 2007

Maybe I'm missing something but where are the reports on the Puma motor? I did a forum search..?

As far as the original bike posted up, it looks nice.

NickF23 · Jan 23, 2007

the bike looks nice. I'd definatley recommend a bike with suspension for high speed riding. I don't have suspension and suffer a bit at 25/30 mph as result. All the bumps and vibration might not be too good for the controller aswell.

What kind of electric drive are you thinking of?

xyster · Jan 23, 2007

where are the reports on the Puma motor?

Knoxie's written quite a bit about it on other forums, and produced some vids I think are on youtube.

deecanio · Jan 23, 2007

hey all,
fechter the bike is cool - i'm hoping i can tell you all soon how f/s goes with a puma

jondoh · Jan 23, 2007

I found a hub kit at http://www.thesuperkids.com.

http://www.thesuperkids.com/500wabmcelbi.html

(sorry, i can't post the pic for some reason)

You think this is the same kit as the BMC Puma? If so-- and if it weighs only 8 lbs, it's totally worth considering!

I'd like to put together the ultimate, ultralight scooter bike using a light hub motor and a sidewalker scooter.

Scooter + motor + controller + batteries = 45 lbs

This would be pretty nice!

Ypedal · Jan 23, 2007

Hey Fetcher.. nice bike you found there !! looks good... but get specs on it before you get it .

I found out with trial and error that most of the " wal-mart" bikes that sell for almost nothing often come with less than quality bits and pieces :roll:

.. It's nice to get a bike for 200 $, but once you add better brakes.. better SHOCKS .. etc.. it all adds up quickly.

What's the problem with cheap suspension you might ask ?.. well.. how about very low adjustability. i found that weight of the batteries really tax the suspension, so careful consideration is required to avoid the pogo-stick effect.

Disk brakes are cool as you can modify the wheel size without having V-brake problems not reaching the rim.

RatoN · Jan 23, 2007

100% ^

They look fine, but you might bottom out the back suspension on one of those. Plus, I strongly suspect that replacement of the chuck with a better one might be difficult, as it is not the same size or not standard if you prefer. So consider these bikes only after inspecting them with a tape measure, insuring that you can replace the rear chuck with a REAL one.

Even then, geometry problems might occur with the way the swing arm was designed and the way it interacts with the chuck itself. They might have designed this bike with a 110 pounds rider in mind. So even after changing the chuck, it might bottom out :?:

ItÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s ok to bottom out a suspension in rough riding or when hitting a bump, but when riding on normal surfaces, the suspension shouldnÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢t hit, though, a Freeride suspension is soft to begin with. If you can bottom out a suspension just by sitting really hard on it, you have a problem.

ItÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s really difficult to explain WHAT IS the difference between a good bike and a cheap one, and what consequences it might have for our e-applications, but Ypedal, has pointed out well the most serious and most probable flaw. Other than that they look fine.

sabrewalt · Jan 23, 2007

I have to agree, Craigs list is a great place to find bikes. I found two Raliegh M20's on there and the guy wanted 100 bucks for both of them. I converted one and ride one moterless.

BiGH · Mar 29, 2007

xyster said:
where are the reports on the Puma motor?

Click to expand...

Knoxie's written quite a bit about it on other forums, and produced some vids I think are on youtube.

I've google searched, and can't seem to find any info :S

helpola? does anyone have a link?

deecanio · Mar 29, 2007

BigH,

there are vids of the puma at 36/48/72 v on http://www.teamhybrid.co.uk under "vids".

cheers,

D

BiGH · Mar 29, 2007

deecanio said:
BigH,

there are vids of the puma at 36/48/72 v on http://www.teamhybrid.co.uk under "vids".

cheers,

D

Thanks D,

I didn't realise they were the same hub motor - thats kind of insane! i'm not sure but seems to be the best all round motor. Now any ideas on how i can tell if i can carry enough battery power to do the range that i want to do? (60-70klm round trips)

Matt Gruber · Mar 29, 2007

BIG
just look up xyster's bike,
he gets your range.

BiGH · Mar 29, 2007

yeh i was hoping for a setup that i could remove the batteries from the bike at my destination ...

Matt Gruber · Mar 29, 2007

use wing nuts and velcro
no problem if u design it right.

Good bike to motorize

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