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Converting a 27.5 Pitch Expert to an E-bike, requires your help!

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    Converting a 27.5 Pitch Expert to an E-bike, requires your help!

    Hi,

    I’m new to the world of E-bikes and I want to make my own with a mountain bike that I already have. I currently have a 27.5 Specialized Pitch Expert and I’m wondering where to start in terms of choosing the parts. I have a basic amount of knowledge such as you need a motor, controller, battery, etc., but I get confused on choosing the right parts in terms of compatibility which will be explained down below. Also, 27.5" motors seem to be hard to find? A lot of the ones I’m finding are 26"

    Here is a link to the specs of the bike I have: https://www.specialized.com/us/en/me...-27-5/p/129308

    Minimum specs I’m looking for:
    • 750w-1000w
    • 48v
    • 27.5 rims
    • Rear wheel motor
    • 7 or 9 gears (the bike I have has a 9-speed cassette. Will a 7-speed cassette/freewheel work as well? Compatibility issues if I use a 7-speed freewheel on a 9-speed bike, besides of course resetting the limiter screws on the rear derailer?)
    • Freewheel or free-hub (preferably the latter as I heard they're more durable?)
    • I’m in the USA, but totally okay with my bike going faster :)

    I’m looking for a “cheap” setup (all in <$650). The more inexpensive the better. So if you have any part recommendations and or links to parts please let me know. For the most part, I’m pretty handy and can figure things out and am reasonably knowledgable about bikes. Any help would be much appreciated. Been trying to get this project off the ground for a while, but it hasn’t gone really anywhere yet. I’ve looked on Alibaba and Ali-express for parts before as well as they seem to be pretty cheap, thoughthe quality is also important as well.

    Thank you for your help,
    Michael

    #2
    I'd suggest you consider the pros/cons of a mid-drive vs. rear hub motor

    If anything remotely steep is in your sights, the mid will far outperform

    If just the flats, there are still advantages to mid-drives and the disadvantages of a rear hub include much more difficult rear wheel/tire maintenance and very high weight

    Comment


      #3
      For the most part I don't think you can mount a mid-drive to a bike not meant for it? Which is why I was thinking more rear drive. Also going for more of a motorcycle like feel, which I don't think you can get from a normal mid-drive because there is no freewheel/hub aka you have to always be pedaling. Going for more of a commuter rather than a trail bike. Having a rear wheel drive will definitely be harder for climbs because of the weight on the back that could easily flip you over if you accelerate to fast, but I live in a mostly flat area so that shouldn't be too much of an issue...hopefully.

      I'm still learning, so any help or knowledge is helpful.

      Comment


        #4
        You have some misconceptions so before you go purchasing things I think you will want to get more information


        Mid-drives go great on conversions and there are likely hundreds of build on this board alone - mine is an off-the-shelf bike and the mid went on easily, much more so than a rear hub

        The mid I'm using and most others I've seen do have clutches to allow for pedals being stationary while power is applied - my BBSHD has two internal clutches, one that disengages the pedals when the motor is turning and the pedals not, another that disengages the motor when the pedals are turning an it isn't and you can also pedal and power at the same time

        I would suggest that a mid is more moto like since you have gears - with a hub you are stuck in one gear which really limits the range just like it would in a moto

        A hub won't flip you over - it just doesn't have the torque unless it's really big, OTOH my mid will pull wheelies readily

        The problem with the small hub (<1000W) is since you are "stuck" in one gear they have insufficient torque for anything steep or if they did you'd never be able to go much more than a few mph

        Another really big issue with the hub that I sort of pointed out is that it makes rear wheel maintenance a pain


        My first electric bike is a rear hub bike and I use it only to loan to others - I figured out within a week or two it would not fulfill my needs and I have no interest in going back

        Comment


          #5
          I agree with AZ guy mid drive all the way. I’m also a newbie with only one build under my belt. I used the BBSHD and 52v Wolfpack combo. Straight up I had a harder time putting the bicycle together than the motor battery kit. Once I got the kit took about 30 minutes to install and I was flying.

          I live on on the side of a volcano, so really hilly. Your either going up the hill or jamming down. My mid drive 7 speed gets me up a 1500 ft ascent in just under two miles no problem.

          Comment


            #6
            Thank you, I found what you were talking about. I didn't know that the pedals could be disengaged. I want to be able to use it as pedal assist, and or a "motorcycle" in some cases. Going with a mid-drive definitely seems like it is the easiest in terms of conversion as I don't have to worry about a lot of things with a hub motor. And i can keep the bike mostly stock.

            Do you guys have any recommendations on kits (looking at the BBSHD as it seems more reliable based on what I read) and or batteries for this? Or vendors with the best pricing?

            Based on my reading...and lack of knowledge this is what I've come up for a kit.
            - BBSHD kit 1000w
            - 42 T chainring (for commuting and trail climbing)
            - 52 V battery (18650 and Ah will vary based on the distance I want to go)

            For the BBSHD a lot of sellers list this as 48V, but from what I'm reading online it should be able to handle 60V correct?


            Best,
            Michael

            Last edited by Jyang3153; 3 weeks ago.

            Comment


              #7
              I bought two BBSHD “hot rod” kits and 52v Wolfpack batteries from Luna Cycle. Couldn’t be happier. Pedal when you want / hot rod when you don’t. You may be able to find cheaper on foreign market but everything is a hassle and quality sucks.

              Luna is in El Segundo, CA. They have great products and customer support (and are pretty much the reason we have the wealth of knowledge this site provides). I much prefer to buy local and have real people to go bother if anything comes up. Something did come up (I didn’t have long enough controller cable) and I went over there and they were great. Even opened shop early to accommodate me.

              My experience with them was awesome and I’m not just saying all these nice things because I covet a Ludicrous controller...
              This is my first ebike build and since this forum has been invaluable providing ideas and assistance, I decided to share my experience too. The bike is an old Northrock cruiser I found at a bike rental place. Its aluminum and has 1 1/8” integrated head tube. I wanted to do a cafe racer / board tracker style build.

              Comment


                #8
                Oh and I went with the 32 t mini ring. Lost about 3 mph on the top end but much better torque and performance. Also more reliable in regular riding conditions. If you get the kit you can have both and try out different sizes.

                Comment


                  #9
                  The BBSHD is likely the most compatible, easy to install and reasonably reliable approach to a RYO mid-drive and it's very configurable (get a programming cable!)...

                  Comment


                    #10
                    These guys are telling you straight. I have a Luna BBSHD on my bike and a friend wanted to build one similar. He purchased his from a Chinese company for about $150 less than I paid. BUT, he has TONS of issues. The battery pack quality of cells are junk, his controller does not allow 52v (58.8 charged), only a max of 54v for some reason(higher than that and he gets an error code). Bafang also had a defect on an internal part, and mine broke. A Luna employee saw me asking on this site for recommendations on who to buy a replacement from, and he informed me of the defect and sent the part out THAT DAY FREE! So I would also say, 1 stick with Luna or at least a highly respected company. 2 Go mid drive unless you are thinking of a QS hub motor(10k watts+). 3 Read, Read, and read some more, then do what is best for YOU. Lastly, be a little more flexible with you prices. Depending on the range you require, a good battery pack can cost as much as you are stating for your entire build. My Pack was near $600 with tax and shipping. That is just the battery pack, the BBSHD kit was around $650. If you put some pics of the bike up, people will help out with recommendations and ideas to help along.

                    Comment


                      #11
                      yeah, I'm definitely going to have to increase the budget, but dang 600$ for the battery pack alone? Thank you guys for all your input!

                      Comment


                      • Defjr333
                        Defjr333 commented
                        Editing a comment
                        You dont HAVE to get one with as many ah/ watt hours. I wanted performance(+50 continuous) AND endurance (ah/ watt hours)

                      #12
                      It's an investment - my batteries were all less than $600 but some not by much... OTOH even my oldest cheapest ones have seen thousands of miles over the three years I've been in the electric scene so if I count on another couple of years and another few thousand miles the annual cost and per mile cost isn't bad at all

                      Paying even ~$100/yr for a box that holds a ton of electrons seems a good investment to me! =]

                      Paying less, you will get less - seen plenty of folks trying to cut big corners on batteries and it never seems to look like a practical or worthwhile effort to me

                      Click image for larger version  Name:	ricky.gif Views:	31 Size:	1.3 KB ID:	86421

                      Comment


                        #13
                        I was checking out Lunacycle do you think it makes a huge difference between the 52v Wolfpack versus the 52v Panasonic battery pack. Both look similar to me, a layperson. Any significant difference that would cause you to spend 100$ more.

                        Comment


                          #14
                          Since the wolf states if you need 50+ amps continuous often (throttle junkie-see me) choose the 30q model. That leads me to believe the Panasonic would be better for high amperage use. I chose it not only for the 50+ amp BMS but because it is installed inside a metal tank and easier to fit in there. NOTHING is free. So built into that wolf price is the housing case and mount. The Panasonic is just wrapped in thick heatshrink with plastic under. So 99.9% of the cost/ price are the batteries and BMS.
                          Last edited by Defjr333; 1 week ago.

                          Comment


                            #15
                            Originally posted by Defjr333 View Post
                            Since the wolf states if you need 50+ amps continuous often (throttle junkie-see me) choose the 30q model. That leads me to believe the Panasonic would be better for high amperage use. I chose it not only for the 50+ amp BMS but because it is installed inside a metal tank and easier to fit in there. NOTHING is free. So built into that wolf price is the housing case and mount. The Panasonic is just wrapped in thick heatshrink with plastic under. So 99.9% of the cost/ price are the batteries and BMS.

                            is the wolf battery lockable to the frame? I believe the Panasonic one is, but from what i understand the wolf one attaches via magnets?

                            Comment

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