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What is your general advice for somebody who wants to get an ebike?

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    What is your general advice for somebody who wants to get an ebike?

    I am copying and pasting an excerpt of a reply that I sent to a gentleman who was interested in having me sell or build him an ebike. He inquired about getting an ebike for hunting (225 pound, tall rider who wants to haul a lot of cargo).

    I took a long time to write the email, so I thought I would post it up here.

    What would you guys add to this? Anything that you disagree with?

    "Thanks for writing.

    So that I can best help you, can I please get all of the details about the application for your ideal ebike?

    For example, is the terrain flat or hilly? If there are hills, how long and steep are the grades? What is the ground like? Is it rocky? Gravel, sand, paved?

    What distance do you plan on riding between charges? Ambient temps? What max and average speed do you want?

    I live in a flat city, and I do 99% of my riding on paved streets. My fat tire bike was specifically designed for my 12 mile round trip commute on flat, paved streets in an urban jungle. I weigh 230 pounds and I carry only up to 15 pounds cargo. I have the power turned down on my ebike so the max speed on my commute is 39mph and the average speed is 27mph. Going faster than 39mph on this bike is terrifying (but exciting!) because I know the injuries caused when going down at these high speeds. There are a lot of cars and crappy drivers on my commute.

    Also note that my bike has no suspension. It performs terribly on MTB trails that have large rocks.

    Generally speaking, a plan for success is to start with choosing the pedal bike that is best suited for your specific application. This includes terrain (rocks?), bumps at speed (e.g. a motorcycle has a suspension to smooth out the high speed ride), budget, your aesthetic taste, gearing (e.g. tall gears for high speeds, granny gears for steep climbs), MTB/road bike or hybrid, etc. Make sure top choose a bike that you love because you may well spend a lot of time and money on it.

    Some no-no's in my opinion would include a carbon fiber or aluminum frame, tires any wider than your application calls for, cutting corners to save money (e.g. cheap Chinese parts that have an effect on safety), buying a battery on eBay, disregarding waterproofing if you plan to ride in wet conditions, using uncommon electrical components (I like to have easy access to replacement parts and service information), failing to consider corrosion, failing to consider motor or controller overheating, or making big compromises that will be expensive to correct (e.g. getting a small motor or a bike that you don't love).

    Important considerations include (1) trying to do as much of the build yourself as you possibly can (this is huge for troubleshooting down the road), (2) always keep in mind to minimize motor and controller heat (buy a huge motor and (24 FET) controller, minimize your (rider + bike + cargo) weight, limit the maximum current for your ride, (3) make great electrical connections when you build the bike, (4) waterproof those connections if they may be exposed to water, (5) always be mindful of corrosion (e.g. powder coat steel parts), (6) use Grade 8 (USA) or Grade 12.9 (metric) fasteners (including washers and nuts!), (7) try to plan in Tannus tires (you will never get a flat!). Tannus tires only come in so many sizes, but, seriously, no flat tires is huge. Also, (8) use 203mm hydraulic brakes front and rear, (9) be a safety nerd (lights, reflective vest, gloves, boots, take no risks), and (10) strongly consider using quality parts (if you buy junk, you get junk).

    Generally speaking, I overbuild the ebike in order to enhance reliability. I call this "sending a man to do a boy's job". I have had good success with setting no limit on time, cost or difficulty. Of course, this has made for expensive, difficult projects that take a long time. For example, I have two frames and forks that have been at the powder coater for over 3 months, and that powder coater is terribly expensive. But they do beautiful work! I am serious about preventing rust!

    My builds have taken me between 4 months and a year. I hesitate to say what I have spent, but the parts always cost over $7,000. (Financially) painful and disgusting, but the bikes meet my standard. My only problem is that I get a flat tire about every 1,000 miles and it takes me 2 hours to fix a flat tire in the rear. The green tube slime is an hour of that, however. The tube slime is effective but messy.

    There is a lot more that I can say, including recommending precrimped connectors, recommending a mid drive if you have hills on your ride, stressing again the use of quality parts, evangelizing about how you can and should be as involved as possible in your build and maintenance. When you have a troubleshooting issue, you want to be as informed as possible.

    Finally, I just want to remind you that changing a flat tire in the rear of a rear hub motor ebike takes longer than changing a flat tire in the rear of a mid drive ebike. If you have Tannus tires, this is a moot point. Also, hub motors do really well for high speed rides on flat terrain, but a hub motor will heat up and disappoint with the lower RPMs of climbing, even if you build a (mechanically) low geared ebike. I built two ebikes with 20T chain rings and 23T freewheels (30.5" outer diameter tires) and it is okay on hills, but not great. On this mechanically low geared ebike with a hub motor with a standard winding, very long and/or steep hills will require relying on pedal only or getting off and walking the bike. For really steep hills, you want a mid drive in a low mechanical gear.

    Also, I hate front derailleurs and rim brakes. I wanted to get that jab in there!

    Last point: I recommend always being willing to redo something if it does not meet high standards. I have had to redo things 2 or 3 times. Annoying and expensive, but satisfying."
    Last edited by commuter ebikes; 09-02-2018, 07:47 PM.

    #2
    I see that I left out a lot, including current draw, BMS info, cell capacity and choosing a system voltage appropriate for the desired max speed.

    I also wished that I had stressed "using common electrical components" more.

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      #3
      Great stuff but why the ding on aluminum?

      Comment


        #4
        Just my personal taste due to the facts that aluminum repairs require heat treatment and aluminum is more brittle than steel or titanium.

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