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IrishAyes

(6,151 posts)
Mon Jun 8, 2015, 05:48 PM Jun 2015

Looking for McGyver (Cross Post)

No, really.... I have a pressing personal problem for which there might or might not be a viable solution. Since I'm only 5' tall, my bike's wheels are 24" - otherwise I can't touch the ground with my feet on both sides at once. You don't want to know how many times I wrecked a 26" bike. Well, if you do want to know, I'm not telling. Can't count that high. And I don't trust cable brakes so mine are coaster.

Also with the passage of time, I'm less able to deal with the hills around here, I need some kind of AFFORDABLE pedal assist. I've spent hours hunting a suitable rig online and have finally decided to admit defeat.

So any bike enthusiasts and/or engineer types out there who can help me solve this, I'd appreciate the help. I'd prefer something electrical or at least solar or battery for the noise issue. I know systems can be found on eBay for instance, but I never know for sure which would work with MY bike and they're pricey anyhow. There's one beautiful rig that turns any bike into assisted and all you have to do is just pop it on - But if I can pop it on, somebody else can easily pop it off too when I blink. Plus it costs close to 6 times what I paid for the bike. At that price I'd have to walk.

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Fumesucker

(45,851 posts)
1. Are your hills long and sustained like in the mountains or more like rolling hills?
Mon Jun 8, 2015, 07:35 PM
Jun 2015

What range do you need, five miles round trip, ten, twenty?

What do you and the bike and everything you carry or want to carry all together weigh?

How fast do you want to go? Fifteen mph? Twenty?

The heart of an ebike or e assisted bike at this point is the battery and a decent one that has a proper charger and the other necessary electronics is probably going to cost more than the rest of the electric system put together (motor and controller).

It's a very confusing thing for a newbie putting one of these rigs together, I'm glad you asked for assistance because otherwise you were almost guaranteed a bad experience.



IrishAyes

(6,151 posts)
3. On rare occasions
Fri Jun 12, 2015, 01:56 PM
Jun 2015

I've been known to look before I leap. Against nature but it happens.

I'm not sure how much the bike itself weighs. It has wide (not fat) tires. I want to have heavy duty adult size training wheels welded on. But with maximum load, I'd imagine we'd hover in the 175 lb range, surely no more than 200! Not interested in going very fast, especially under load. 10 mph would more than suffice. So far anyway I'm not concerned about more than an assist either, for the hills which are more rolling than sustained. This place is really more near the top range of foothills. Couldn't afford to move to the mountains or I would have.

As for range, 5 miles would be plenty. I'm town-bound on a bike, of course, and the geographic area's no more than 12 square blocks. (To give most people an idea how remote, I usually tell 'em the nearest Walmart's 65 miles away.)

Thanks for any help you can offer. As you can see, this is wayyyy outside my wheelhouse.

Fumesucker

(45,851 posts)
6. A shade tree motor drive is a major project, there's a lot to get right
Sat Jun 13, 2015, 06:50 PM
Jun 2015

A bolt in front wheel motor drive would be your best option but we are talking $500 before you start riding most likely and I get the impression you don't have that kind of money (I don't either right now).

If I were you the first and cheapest option I would try is get a bike with 6 or more gears and pedal in a very low gear. You have a single speed which means you are having to push the pedals hard. I have painful knees if I push hard too, so I gear down and twirl the pedals rather than mashing them. Considering your size I'd look for a kids 20" mountain bike with gears, 6 should be fine on a bike that small. I see them at our flea market every month or so. 24" bike is hard to find, there are a lot more 20" and 26" than 24". Extended seatpost and handlebar support will get the seat and bars where you need them. The smaller bike will have a shorter stroke on the pedals so you won''t have so much motion for your knees.

The longer you wait to get an ebike setup the better they will be and the less they will cost, it's like cellphones, getting better very quickly. Don't be impatient if you can possibly manage.


Blanks

(4,835 posts)
2. I've always wanted to use a car starter...
Tue Jun 9, 2015, 08:22 AM
Jun 2015

They have a lot of torque. Of course then you'd have to put a car battery on the bike too, and that would add quite a bit of weight to the bike so that it would be difficult to pedal without the assist.

If you've ever turned over an engine without the clutch engaged, you know that it has enough juice to move the vehicle.

It would need adapters, and a little beyond the capabilities of someone who doesn't do a lot of DIY projects.

Here's a link to a site where someone did something similar to what I'm talking about.

http://m.instructables.com/id/How-to-build-an-electric-bike-for-less-than-100/

Blanks

(4,835 posts)
5. Another powerful electric motor...
Fri Jun 12, 2015, 02:09 PM
Jun 2015

Are the ones that power those treadmills. They are ubiquitous at thrift shops. It might require a transformer but if you got a good deal on an old treadmill, they would come with quite a few materials to help fashion something. This video is kind of interesting.

mackdaddy

(1,526 posts)
7. This sounds like this is your primary transportation, so you might consider other options.
Sun Jun 21, 2015, 10:43 PM
Jun 2015

I know you already have this bike, but if this is your primary transportation you might consider what the complete package that is best for you is. As you have discovered, the bike is really one of the smaller parts of the electric vehicle you need, especially if you are talking about adding stabilizing wheels to what you have.

An option would be to look for a new or used Schwinn adult trike. These are stable and come with a carrying basket and can be set up with electric assist. Occasionally they will show up on craigs list for very cheap.

Here are a couple of YouTube videos of a guy who set one up with quite a bit of detail. I know it is tempting to try one of the conversions like the starter motor idea, but the Asian made hub motor and controller sets are going to be much less hassle in the end. There are quite a few independent bike shops out there that do the electric conversion for you, although not cheap. I did find that there are a lot of people who have done conversion YouTube videos, and several electrical conversion groups.

Here is one I found interesting:

for the basic etrike conversion,

and this one where he has a bunch of bells and whistles, and a place for his dog

 

happyslug

(14,779 posts)
8. your problem is to small a bike
Sat Jun 27, 2015, 06:04 PM
Jun 2015

Last edited Mon Jun 29, 2015, 11:00 PM - Edit history (4)

LEED gas an electric,as sit for less than $1000 dollars but requires a 26 inch front wheel. At 5 foot you have to go with small frame 26 inch bicycle. They are hard to fine. My sister had special order hers and she is 5 foot 4 inches tall. You need a 48 cm frame or smaller frame equip with one inch tires.

Now I did check the LEED web cite, they sell electric kits for 24 inch bikes:

http://www.e-bikerig.com/products/PBJ-e-bike-kit-samsung-li-ion-front-wheel.html


Here is E-bays recommendations for bike size, they recommend the 46 cm for people who are 5 foot tall:

http://pages.ebay.com/bikesizingguide/road/

Bike Frame Size: 46 - 48 cm
Height: 4'10" - 5'1"
Inseam Length: 25.5” - 27”

http://www.amazon.com/CFG-Cycle-Force-Cro-mo-Cyclocross/dp/B00HPKVVBK

If you go with a LEEDS, read my report from last year on their electric converstion system:

http://www.democraticunderground.com/1207413

Please note since that time I have managed to destroy the battery and had to order a new one. I do not think I came close to what LEEDS said the battery should be able to do, but it did failed me after about a year of off and on use do to my own errors in installing it.

AS to the bike itself 26 inch bikes with frames below 18 inches/46 cm are are to come by.

You can get them even in cheaper bike but such small bikes are rarely stocked. Thus you have to special order them. Please note the 46 cm is a guide not a rule. Fitting is important. A front shock increase the height thus you may want to avoid a front shock or if the bike comes with one replace it with an steel front fork.

Bike wheel sizes are set by diameter of the tire on the wheel at the size it first came out in. In 26 inch tires that was 2 1/2 inch tires in the 1930s. You can get smaller tires for most 26 Inch bikes and that can drop the height of the seat almost an inch.

Sounds like you need a 46 cm frame with 1 inch wide tires on 26 inch wheels. Anything bigger is just to tall. The corresponding frame size is the most important thing when it comes to a bike. There are ways to work around a to small a frame but not to large a frame.

Go to a bike shop and get a Giant or other bike with a frame no larger then 48 cm. I would like advise a better quality bike like a Trek or Cannondale but you may want to look in on a Terry which is designed by a female engineer for females. Go to DU'S bicycle forum for more information. The Terry is high end but sometimes the fugal act is to buy top end for it is cheaper for it cheaper in the long run.

Home Depot has a 46 cm frame for sale this the frame only no parts. Price is $129 just for the frame. No further details were given.

I did run across a 46 cm bike for $399.00 that came equipped. 46 cm is about 18 inches. 48 cm is about 19 inches. Frame size is based on the length of seat tube from the bottom of the seat to hub. Add about 6 inches for the difference between the bottom bracket and the ground to approximate inseam.

I also ran across a 46 cm frame only for $79 on overstock.com. Again that is frame only.

http://www.overstock.com/Sports-Toys/Bike-Parts-Accessories/2664/subcat.html?gclid=CjwKEAjw2cOsBRD3xNbRp5eQxzYSJADZGYbz0uB_ffn5xVcQWddV9hmx4DNUFpBCyz-i67xct2hjnBoCekTw_wcB&featuredproduct=8985076&featuredoption=12845594&cid=202290&kid=9553000357392&track=pspla&ci_src=17588969&ci_sku=16191088-000-001&utm_source=google&utm_medium=pla&utm_campaign=Sports+%26+Toys&utm_content=Sports+%26+Fitness&ef_id=VQBoMwAABe4rwwOR:20150630021541:s

Now Cr-Mo means Chrome-Moly (or Chrome Molybdenum) Frame. Cr-Mo was the wonder material of the 1930s. A Bike Frame made out of Cr-Mo is stiffer then one with high tension Steel (The wonder material of 1900). The stiffer the frame the easier it is to peddle (you can lose up to 60% of your peddle power to the frame, if the frame is High Tension Steel as compared to Cr-Mo).

If you buy a frame make sure it is Cr-Mo, Aluminium, Titanium or Carbon Fiber (That is the list of bike frame materials in order of Stiffness, the big improvement is between High Tension Steel and Cr-Mo, the other materials are stiffer, but marginal compared to the difference between Cr-Mo and High Tension Steel). Please note the above is not only the order of stiffness but also the order of price.

Most bikes made prior to 1980 were High Tension Steel (and most children's bikes are still High Tension Steel, it is a good material, can take a beating and can easily be repaired. Had the Titanic been made of High Tension Steel it would have survived the iceberg, the Steel used in the Titanic was crap). I bring this up for a lot of older bikes are still made of high Tension Steel, Cr-Mo is wroth the extra money.

Here are E-bays list of 46 cm 26 inch and 700 cc bikes:

http://www.ebay.com/sch/Bicycles-/177831/i.html?_dcat=177831&Frame%2520Size=45%2520cm%7C46%2520cm&_sop=15

E-bay had some 45 cm, which shocked me, but all of the bikes had 700 CC Wheels. The sellers suggest 42 cm bikes for people who are 5 foot:

42c has a standoverheight of 28" & fits most riders 4'11" to 5'3"
46c has a standoverheight of 30" fits most riders 5'4" to 5'6"

I suspect the reason for that is 700 cc are much taller then 26 inch tires and wheels. Thus these 46 cm bikes all sound TO BIG for someone who is 5 foot,

Something is wrong here, and thus why I recommend you go to a bike shop and ask about bikes for short people. Do NOT take a bike they have in stock, they gear themselves for teens and adults and that tends to be people over 5 foot 4 inches tall (Which is the minimum height to operate various pieces of equipment, a few years ago a Female Soldier who was shorter then 5 foot 4 inches lost control of a M113 Armored personal carrier she was driving and proceeded to get herself killed, the Commander was later Court Martial-ed for to drive a M113 you must be AT LEAST 5 fort 4 inches tall thus it was determined the accident was his fault for leaving her drive the M113).

Thus, you have to get to a bike shop (NOT a Walmart or other department store an actual bike shop) and see what they can get you in a bike that you fit. That is step one.
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