Folding mountain ebike - The Big Dilema

The Stig

The Stig

100 kW
Joined
Nov 15, 2008
Messages
1,032
Location
Boston
I'm relatively new to the ebike scene and I've been awaiting some time for my Puma motor to come from Brett White. But I still can't decide which of these two folding mountain bikes too get, and convert to ebike.

The bike must be:
-light and fold small for portability (I travel a lot: car bus train plane)
-dual suspension for comfort and versatility (on road/off road/snow)

Electric conversion:
-Puma motor in 26" rim, infinion controller(or so promises Brett)
-48v 16Ah Ping battery, 45A max discharge, 32A cont discharge. The single part of this build I already have. Thanks Li Ping!
-Battery box mounting: either right on the back of the seat post as low as possible, or right in front of the seat post as low as possible. I'm really not that sure how best to do it! WOULD REALLY LIKE SOME BETTER IDEAS ON HOW TO MOUNT THE BATTERY AND WHAT BOX TO USE! Ideally I would be able to lock the bike outside and not worry about it getting stolen, but still be able to easily take it for charging.
This build is all about flexibility/versatility - freedom.

I've pretty much boiled it down to two contenders.
In the corner to my right, at $537 shipped, we have the Bazooka Navigator.
Navigator-for-web1.JPG

navigator-silver-foded21.JPG

http://www.bazookasports.com/viewproduct.php?cat=1&product=2608
Pros:
-Lighter 15kg (33lbs)
-decent components (front fork, brakes, other components wont give me trouble)
-decent saddle
-folding pedals
-confidence in integrity of folding joint of frame

Cons:
-Will need fenders installed
-pricey
-quite quite pricey


In the corner to my left, at $203, we have the Lock N Roll folding bike.
RVXDF2604_large.jpg

There are a lot of good close up pictures on their website.
http://www.rvtoyoutlet.com/large/p-RVXDF2604.html

Pros:
-cheap
-could be given a better front fork than the bazooka
-I'd probably be saving a lot of money
-could recommend the setup to more people and friends, helping spread the word (big plus)

Cons:
-weighs a tad heavier 16.8 kg (37lbs)
-would have to change suspension fork and saddle for sure, possibly brakes as well.
-how tough do the Chinese make their mid-frame folding joints... with a good fork at a soft setting though I should be safe. I only weigh 63 kg (138lbs)
-iffy components + rust


There was a third contender but he got knocked out due to weight problems. 19kg :?
http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=250301967818&ssPageName=MERC_VI_RCRX_Pr4_PcY_BIN_Stores_IT&refitem=250320385099&itemcount=4&refwidgetloc=active_view_item&usedrule1=CrossSell_LogicX&refwidgettype=cross_promot_widget&_trksid=p284.m184&_trkparms=algo%3DCRX%26its%3DS%252BI%252BSS%26itu%3DISS%252BUCI%252BSI%26otn%3D4
I liked it's disc brakes and acceptable components for ebiking, but its just too heavy.

Imagine my financial situation is such that I'm quite torn between the two. I'm leaning towards the Bazooka but I'd really like to hear reasons to get the cheaper one. If I could get away with justifying buying the cheaper that would be nice because I really am interested in "spreading the word."
Any feedback would be much appreciated.
 
The bazooka looks like it has components to match a lowend bike store bike. Shimano, Tektro, RST, Truvative are familiar names. The cheaper bike doubtfully has anything name brand, and is what I call cheap Chinese. Heh, I just bought a cheap Chinese 24" folding bike myself not long ago. The bazooka fork is probably much better than the other.

If you don't need full suspension and are willing to do some tune up work, you can size a crazy amount of money by looking into this $25 Orange County craigslist ad - http://orangecounty.craigslist.org/bik/1011392401.html. Same exact company. caveat emptor. buyer beware. I am merely mentioning it as an option; I take no responsibility for anything ...
 
Mount the battery on a good seatpost rack, and hunt down a metal toolbox to lock it into. Most of the toolboxes now are plastic, so the flea market and garage sales are the place to look for it. Other lockable options include camera boxes, and other small hardcase luggage. But it needs to be small enough to fit the pack well. The weight on the back rack doesn't matter that much, like it would if it were a bunch of sla's.
 
Interesting that you have to take the handlebars off the Bazooka and stow them in the loop on the center post. Doesn't look like a "quick release" process, judging by the hardware (and how secure the stem needs to be in order to ride safely).

Also caught my eye that they left the peadles (yes, dogman, "peadles" :)) off the cranks to make it look that much more compact. In reality, they'd detract from the overall "flatness" of the thing when folded. Unless it comes with the kind of folding pedals that the "Everest" model you posted the eBay link to seems to be sporting.

I've thought a bit about a folding bike project (for another family member who doesn't have much space), and the idea of a "go like stink" little motor in a 16" or 20" wheel sounds more fun than trying to get a full-sized bike to collapse...

I wouldn't split hairs about a few pounds, either. The 4 or 5 pound difference between the eBay bike and the much more expensive Bazooka is NOTHING compared to the 10 or 12 pounds the Puma will add, let alone the batteries.
 
It has to be a full size MTB so I can do reasonable off roading, and feel pretty stable on the road. Options for dual suspension 20" folding bikes look like they don't have much suspension travel up front.

Hmmm $50 is tempting for the same bike with a couple problems. That way I could just try it out. If only there was some way to tell if that seller is legit. http://orangecounty.craigslist.org/bik/1011392401.html
Edit: It says nothing in the post about shipping so this may not be an option. The shipping would also have to be from coast to coast.

You can get a carry bag for the bazooka navigator. It also comes with folding pedals.

The main problem with the cheap Chinese one is that I would have to change the front fork, which raises these questions: Would that add weight? Could I find matching components? Could I find a reasonably priced, relatively long travel, suspension fork?
 
I think all forks are pretty standard be/w the main two choices. I think they're the 1 1/8" and 1", threaded and threadless. I am guessing the chinese is 1" threaded, which has less choices. However, I still think there are available ones out there that will be better than stock Chinese.
 
Found a nice source of battery boxes. Waterproof, lockable, and can come with watertight wire seals.
http://www.fuertecases.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=fuertecases&Category_Code=Seahorse-Hurricane-Cases
Is there a battery box thread I should post this link in?
 
Suspicious similarities between this bike and the "Everest" being sold on eBay. Apart from the disc brakes, it's looking like a "relative", if yer followin' what I mean...
 
Hi Stig,

Those bikes, the Bazooka in particular, look similar to the folding MTB I converted.
I too wanted 26" wheels. The biggest single problem was mounting the battery; I ended up building a special box and mounting system. Mind you, it is a fairly serious battery.

http://www.re-voltage.eu/integratedtransport.html

Crystalyte 406 in rear wheel
24 x Headway LifePO4 10 Ah cells (72 V, 10 Ah)

Nick
 
Tiberius said:
Hi Stig,

Those bikes, the Bazooka in particular, look similar to the folding MTB I converted.
I too wanted 26" wheels. The biggest single problem was mounting the battery; I ended up building a special box and mounting system. Mind you, it is a fairly serious battery.

http://www.re-voltage.eu/integratedtransport.html

Crystalyte 406 in rear wheel
24 x Headway LifePO4 10 Ah cells (72 V, 10 Ah)

Nick
Click to expand...

Wow that is just what I'm looking for! Do you have a build thread? How does it work for you? Your frame looks suspiciously similar to the frame of the Chinese bike I'm considering.
 
Glad you liked it. Sorry there isn't a build thread, but I can try to answer questions. The main effort went into the battery and its mounting and that was a long story of 1 step forward, 2 steps back.

The original bike came from ebay in the UK. It doesn't seem to be available any more, but here's the pic I saved at the time. urbanitefolder.JPGNow I see the pics in the same thread, it looks exactly like your Lock n Roll one rather than the Bazooka.

I have a Xlyte 406 rear wheel or a Suzhou Bafang rear wheel to go in it, each with a 6 speed freewheel. They are set up with standard connectors for easy change, but so far I've only tried it with the Xlyte, which is the more powerful motor.
The bike frame is aluminium so I made some simple torque washers.
torqueplate1.jpg

torqueplate2.jpg

They hold nicely with the Xlyte.

Nick
 
It's exactly the same bike as the Lock N Roll except from your pictures I can see it has a better fork and a quick release handle bar. Did you add those? Have you ever weighed the bike?

Why was the battery mounting so hard? I found a pretty nice battery box that I'm going to mount on a seatpost rack:) http://www.fuertecases.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=SE-520&Category_Code=Seahorse-Hurricane-Cases
 
Hi Stig,

The handlebars and fork are still as received. Its a cheap bike, there is play in the forks and the brake blocks needed changing. But a cheap bike is what I wanted; I was experimenting rather than trying to get to a particular solution. I already have another e-bike and this was to try out something different. I think the bike itself was about 15 kg.

One of the options I thought of was a seatpost battery mount, a bit like an old fashioned saddle bag. I'm glad I didn't though; after putting this together I learned a bit more about bike dynamics and handling and discovered the cross bar is a better place for the weight. There is a slight weave that I put down to rear frame flexing; its not a problem and it gets smaller at higher speeds, but I suspect it would be worse with the battery weight further aft.

What size battery are you planning?

Nick
 
Mine is a Ping 48v 16Ah. It's 7.8kg and the battery box will be another 1.5kg depending on which model I get. I may mount it to the seat post, and swing it around in front of the seat . How do you think you would like the the electric folding dual suspension mountain bike if the bike its self had no flaws (eg. if you had gotten the bazooka)? Do you think it would be worth building one with the bazooka?
 
Oh, don't get me wrong; I'm not upset with the bike, just aware that its not the best I could have started with. I've taken it up to 40 mph on tarmac and been off road with it. The hill climbing ability when you put 40 or 50 A into a Xlyte 406 is phenomenal, but both batteries and motor can get warm if I push it too far. With fat tyres, full suspension and a rear motor it copes with almost any surface. Everyone I've let ride it is just bowled over.

The only real issue I've had with the bike itself is the brakes. There were rivets concealed just below the surface of the blocks and I wore down to them very quickly. The front brake squealed terribly. These things were all fixed by fitting better brake blocks and carefully adjusting things.

BTW. I fitted a left hand throttle, which meant changing from the twist gear change to a lever one for the front derailleur. I kept the right hand twist grip gear change. With a motor, you don't really need the front derailleur - in fact, you really want a bigger chainring.

So the starter/donor bike turned out to be as close to requirement as could reasonably be expected. I guess the downside with a cheap bike is that things will wear out more quickly after its been electrified. I also think it might not survive a lot of off road punishment if that's what you were thinking of.

I'm doing something different for the next build for the sake of doing different rather than through dissatisfaction with this one. The new bike I've just got is steel frame, non-folding, no suspension. But its 26"wheels and some of the e-parts will be interchangeable.

Nick
 
How are the new brake pads holding up? I hope disc brakes aren't necessary if I'm going to be putting a lot of miles on it.

Do you find the bike useful for traveling? Or what features are practical and what could be done better... The only thing I can think of is your battery doesn't look like it comes off very easily and it doesn't look like you can park it and lock it when going places. All I'm trying to figure out is if this idea will really work for me as a way of getting around.
 
Tiberius, your bike frame doesn't seem to be available anywhere. I can't find it. Looking at the pictures on your website: the way the rear shock mounts to the swing arm is different to the bike in the picture you posted. Mystifying.

Anyway I think I'm going to go ahead and buy the Bazooka because I plan on making this bike work for a long time(chinese bikes usually fall apart unless modded or heavily maintained). Plus the quick release handlebar could be something for the bike thieves in Boston to steal.
 
Hi Stig,

I wouldn't worry too much about getting the same frame as I did, and spending a bit more for a better bike isn't a bad idea. Quick release handlebar and seat mountings are useful for folding/packing, though.

Didn't realise you are in Boston. I used to work there in the early 80's. "Can you hear us out in Needham, Route 128 by the power lines. Next to 50,000 Watts of power"* (Sorry, showing my age there.)

Nick

*Jonathan Richman and the Modern Lovers for our younger readers
 
The Bazooka will be arriving tomorrow and the next thing I need experienced input on is throttle type. I have a full twist from Brett, but the grip is hard plastic and I don't really like the idea of full twist on a bicycle.

Who knows what the best type of throttle is for use with trigger style shifters?

Feel free to point me to some threads or to starting a build thread.
Here are some pictures of the type of shifters:
251508708_185f6afcef.jpg

BPC307932.jpg


Pictures from the actual bike:
 

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