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BBS02 STREET BUILD on a GT Avalanche 2.0 26er

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    BBS02 STREET BUILD on a GT Avalanche 2.0 26er

    Hey guys wanted to share with you my build which was designed around my 16 mile commute to work and intended primarily for street and paved trail riding. I live in the Chicagoland area where the world truly is flat so I went with the BBS02 for cost purposes and complete street legality since the extra power behind a BBSHD just really isn’t necessary. Most of my upgrades are centered around speed, efficiency and comfort. I love how the build turned out and have clocked over 1500 miles so far this year!

    My donor bike was a GT Avalanche 2.0 26er which I snagged off Craigslist for a nice price at $280. I wanted as much range as possible out of my ebike because the goal was to be able to make the 32 mile round trip on one charge. So naturally the 52v 13.5aH Shark Pack was the battery for me. Now, one might ask why even go with a mountain bike base if speed and distance are of primary concern. Well, unfortunately, my route through suburbia makes a few miles on 2-lane 40+ MPH roads in rush hour traffic unavoidable. So, I wanted something heavier and more stable with better shock absorption. I also needed a bike which I felt comfortable taking into a turn at higher speeds. A hard tail turned out to be a great solution, though sometimes I do daydream of 27.5s.

    Comfort was a factor for me before I even made the conversion to electric, and the geometry on the stock GT wasn’t doing me right. I wasn’t trying to go crazy on componentry for this build, but I had some credit at Performance Bike so I opted for the only piece of carbon fiber you’ll see in this post in the form of a Forte CR720 Handlebar with a 53mm rise. I capped it off with Ergon grips which I now feel are an absolute necessity. They only had the GP1s though and I was hoping for bar ends which I use mostly to kick back on when cruising. So, on a whim I thought to myself maybe I can slip some cheap ones on inside the grips in a make-shift triathlon set up and it came together really spectacularly. So comfy-cruisy for those easy winding forest preserve trails! I also switched to a soft tail seat for a little extra padding on my 200lb ass.

    Then came the Bafang. Installation was fairly straightforward once I popped for the Bafang lock-nut tools. If you’re building an ebike I would highly recommend just buying them. You’re gonna want that motor torqued down into place properly. I hit a hiccup when I attached the speedosensor to the drivetrain side of the rear wheel which left the magnet too far away from the sensor and resulted in the infamous Error 21. Yeeaah, It’s definitely gotta go on the other side. Then I had to deal with the fact that my GT came equipped with hydraulic brakes. At the time Luna didn’t offer the Shimano hydraulics for Bafang motors yet, so I ordered some Avid BB7 mechanical brakes to get the job done, which worked well with the stock Bafang brake levers. They’re super easy to adjust which I love, but tend to need adjustment fairly often. I’ll probably go with the Shimano hydraulics next time.

    As soon as my motor started running I knew I wanted more air volume in my tires. I debated back and forth over whether to retain some nubs for trail riding, but in the end decided to stick to a street-centric build and go for efficiency and speed. There was really only one tire for the job. Maxxis Hookworms are basically motorcycle tires and just look and feel so badass. The 2.5” width and big air volume cushion your ride and hug turns perfectly. I consider them one of the core components of my build and love the stability and quickness they provide when I need to bang a left across two lanes of oncoming traffic. I also swapped out my seat post for a Cane Creek Thudbuster ST which is much more comfortable but doesn’t have so much travel that it messes with my pedaling position.

    So everything was pretty much together and my ebike was running great, with one super annoying problem. The stock Bafang chain ring dropped my chain whenever I hit the slightest bump with the motor spinning. It was such a pain in the ass, and I knew I needed a narrow-wide chainring. The problem, though, was that I didn’t want to go down in teeth from 48. Actually, what I really wanted was to go up to 52 because I thought it would provide a better pedaling cadence in my mid gears and higher top speed. Now most “spider” adapters that are being made to fit Bafang specs are of the 4-arm 104 BCD variety. I couldn’t find any 48T+ chain rings that would work with those spiders. Then I found this guy.



    Wow. Pricey but EXACTLY what I was looking for. A 5-arm 130 BCD spider with multiple chain ring capabilities!? SOLD. I only planned to use one cog since I wanted narrow-wide teeth, but oh the possibilities. Light and well-made! This allowed me to hook up a Wolftooth 52T chain drop-stop chainring in place of the stock Bafang. What a difference! I haven’t dropped a chain since, my pedaling cadence is slower and more comfortable, and damn it’s FAST. Try to keep up!

    Hope you guys like my build! Lemme know what you think.

    Cheers,

    Dennis

    #2
    Hi there! Nice build. I am looking at doing a BBSHD installation on the same bike. Do you know if it will work? also, do you know the bottom bracket size for the bike?

    Cheers,

    Tim

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      #3
      Very nice indeed. I intend to use the same bike for my first ebike build. I am going back and forth considering a front wheel Magic Pie Vector or possible a MP5 rear wheel conversion. Like to have your thoughts about either of those solutions. I will be using it just to tool around some back roads and winding hills.

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        #4
        How is your speed, distance and battery usage working out?

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          #5
          Do you ride without saddlebags? Have you found a rear rack that works for the GT?

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            #6
            Some EBC metallic pads will fix the frequent adjustment on the BB7s. Be sure to sand the rotors to remove the old organic lining or you'll get yelled at (by your brakes). 200mm front rotor is worth doing also. Those 2 changes and you won't miss the hydraulics at all. Squeal under light braking means the inner pad need adjusting. One pad braking lets the rotor vibrate.

            Many of us add a suspension seatpost to the mix. Thudbusters are popular, but Suntour NCX can be found for 1/2 the price.
            Last edited by Retrorockit; 08-30-2021, 08:28 AM.

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              #7
              Nice write up. I really enjoyed reading about your build. It looks like the link no longer works for the 130 BCD adapter you were talking about. Do you have any more info on it? I'm interested in getting something like this eventually. Sorry to bump an old thread. Thanks!

              Comment


                #8
                Looks like this is a zombie thread coming back to life after 5 years! FlowRyder hasn't been active since 2016, so I wouldn't hold my breath on reply to any questions! But who knows, maybe he has just been enjoying the build and lurking on the forum a bit !

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