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The Giant Anthem Project

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    The Giant Anthem Project

    I thought I'd share my experiences assembling the new love of my life, a Giant Anthem 29er. First a little back ground. I stumbled on the whole e bike thing by accident about three years ago. I had noticed a new shop selling E bikes. I'd driven past a few times and one day my curiosity coinciding with a vacant car park directly out the front. Well, a trial ride later and I was the proud owner of a BH Neo Cross. My 50klm round trip work commute suddenly became do-able and over the next 18 months I put 6500klm on the thing. Out here in Australia we have adopted the same E bike power restrictions as Europe so 350watt torque assist was all I knew. My second purchase was a second hand Neo Hard Tail 29er. At $1.3K I thought I had a bargain until I discovered voltage sag in my battery. The replacement set me back another 1k but 18 months and another 6500k later, I couldn't be happier with my old 29er. As a bike path commuter it's been great. The 29 inch wheels roll beautifully across most urban surfaces and the wide tyres offer great grip and smooth ride. The only issue is when you take it out of the urban environment and onto unpaved tracks. The hub drive is just unbalanced, ungainly and doesn't seem to handle anything other than a minor bump before throwing up an error code and cutting out power in protest. Then a few months ago I bumped into an old mate that had fitted a 500w/36V Bafang to a Specialized Rockhopper 29er. It was a fairly rudimentary fit out but I could certainly see the potential and after a few laps of the block, was convinced the build yourself system might have merit. I was looking for something to replace my old dirt bike as my motor cross days are most definitely behind me, but still enjoy hitting the trails. Another mate and I decided on building up a couple of second hand mountain bikes using a Bafang kit. I scanned ourl ebay bikes and located a Rockhopper 29er for him. Now obviously I needed something better than his mount for myself (it's just the natural order of things) so a second hand full suspension, Giant Anthem 29er caught my eye. At this point I should have done some research but I noticed there were other Anthem conversions around so just assumed it would all be a bolt together job like the Rockhopper. Wrong.

    I ended up parting with $900 for a 2014 Anthem 29er in an unloved condition. Getting home and a clean up later I realized I was in for a couple of engineering challenges. First up, the only kit I could purchase locally that was wide enough to fit the bottom bracket on the Anthem, is the BBSHD 48V. I certainly never intended to get a unit this powerful but that was my only option. Secondly, the 48 volt/14ah down tube battery was not going to bolt directly onto the drink bottle holder and I didn't like the other battery options on offer. Rule one compliance is mandatory, It has to look good. I also didn't like the idea of bolting an essentially flat plastic battery mount to a curved aluminum down tube. Also, there are hydraulic brake lines on the Anthem running down the top side of the down tube and even if I re routed the lines, the locating lugs wouldn't allow battery to tube mounting unless I ground them off. (and I didn't want to do that) I posted in the Trouble Shooting section here for guidance and direction (thanks for everyone's contributions) but ended up persevering with my adapter plate concept.


    Basically I purchased a piece of 40 x 5 aluminum flat section. By picking up the two 5mm drink bottle holder holes I was able to screw the plate to the bike frame with 2 counter sunk 5mm screws. as depicted in the pics I then simply spaced the adapter plate off the frame with 8mm spacers. (initially I just used two oversized nuts but later turned up some 25mm dia nylon spacers) Because I had access to a Nutsert tool I drilled out and fitted a third 5mm mounting bolt further up the down tube. Finally I had to use a round file and notch out where one of the molded frame brackets contacted my adapter plate. Next I drilled and tapped the three 5mm battery mounting points to my adapter plate. End result, the battery is very secure. I have since placed a rubber strap around the whole tube and battery assembly which eliminates any battery rattle. In hindsight the 3rd nutsert fixing point on the frame probably wouldn't have been necessary with the rubber strap in use, but still 3 fixing bolts are better than 2.

    Challenge Number 2 was replacing the original crank bearings with aluminum bushes to accommodate the Bafang BBSHD. In the U.S.A you have a couple of off the shelf options offered by Luna and others that would certainly do the trick. In a rush of enthusiasm, I choose to spend a day reacquainting myself with a lathe and turned up my own. (next time I'll probably just buy off the shelf and save my effort)

    At the end of the day, I'm very happy with the result. The advantages of fitting out a quality full suspension bike such as this, is it's a pleasure to ride, beautifully balanced and that Bafang BBSHD just puts a smile on your face. (I know it's not quite legal but anything this much fun couldn't be, could it) The bike owes me $3k Aust and I believe it's every bit as good, if not better than the full suspension factory made models currently on offer for around the $6.5K mark. . I'll also not be held hostage to whatever price the big brand manufacturers wish to charge for a replacement battery in the future.

    One other little quirk, and apologies if this is old news. I didn't like the glue on magnet brake cut out switches provided by Bafang. Because the BBSHD really puts down some power I consider a cut out switch as necessary in the event of full throttle fault scenario. My solution was to fit the cable brake lever provided in the kit so the lever is under the Left hand rear hydraulic brake lever. This second lever is only for the cut out switch and would be easily thumb activated to cut power if necessary. Seems to work fine.

    I've fitted the 42T Bling Ring. Happy enough but would like to try a 48T just for comparison. And last of all, I routed the cable loom up via the seat tube and across the top bar to the head stem. It all seemed t fit perfectly this way with no unsightly excess cable loops.

    Writing this I realized I haven't really got any decent pics on my phone here to share, but if anybody is interested, I'd be happy to provide better details and pics as required.

    Hi hardtail nice bike!
    I recently purchased the same year/model anthem and then last week got a bbshd motor.
    im wondering how you went with lining up your drive chain ring with your rear sprockets. I got the stock 46T and when mocked up install of the motor the chain lines up best on the smaller sprocket (I don't think this is ideal).
    Im thinking itd be best lined up either central to the rear sprockets or closer to the highest gear (or largest sprocket).
    so I wonder how your bike drives being you have a smaller chainring...if you use most of your gears etc? and if you have any tips on the cups you turned up for the BB.
    It looks like I'm going to have to re-face the drive side of the BB and remove about 5mm or more...or something...



      Hi OzVolt. You've got a great project bike there. I'm loving mine and actually looking for a higher specked Anthem project to make another.
      Re the spacers/ alignment, after removing the original bearings, I made up the internal bushes so that the right hand bush was flush with the outer face of the RH side of the bottom bracket. The LH side bush spacer protrudes about 12 mm. Now I used a 42 t Bling Ring and I think they throw back in a few mm more than the standard sprocket. Just looking at my chain line, it looks good for around the centre of the rear 10 speed cluster. If you're not handy with a lathe you can always purchase the bush spacers from Luna Cycles or a couple of other crowds in the U.S and the alignment should be right.
      On the first couple of rides I had some chain slip issues with the high gear / smallerrear sprockets but after a short time they all bedded in nicely. I ride mostly urban trails and bike paths commuting so I'm hardly ever in the lower gears. If that's the
      kind of riding you intend to do, the 46T should work well. I'm getting used to the
      42t now so will stick with it. I cruise along at 35klm on power setting 3 of 9 no problems and that's fast enough for me.
      I wouldn't go refacing the bottom bracket. You shouldn't need to. If you really have chain alignment issues I'd spend $100 on a Bling Ring before cutting the frame. Others have used the standard BBSHD sprocket though so we can assume it works.

      What at type of battery do you intend to run. I found mounting that a little tricky but think I've found a workable solution described above.
      Just had a look for my old shop drawing/ sketches of my spacers and can't locate at present. I'll persevere if you need them though.


        thanks for your detailed input!
        i was thinking the wrong way somehow confused myself with the gearing......
        i was going to get a local fitter to turn me some cups.
        thanks again.


          I'm most likely going to mount a large shark pack. I've seen it done on another anthem in Fremantle.
          I was thinking of perhaps having a lip of a few mm or so on the right side bb cup/bush/spacer but you went completely flush to the face of bn.. did you bevel the inner edge of your cup? I was thinking to follow the shape of the bearing case..
          And yes now I can see the stock chainring will be fine.
          Im using this bike for urban commuting.
          Havnt had the chance to work on it lately but now I can go ahead with the cups. I wasn't that keen on having to shave the bb face.


            Hi Ozvolt. Sounds like you've got it sorted. Im riding my bike virtually every day and really clocking up the k's. No real issues and I intend to make a second one when I can access at second hand Anthem1 29er for the right money. The 42t Bling ring is perfect in my opinion. If you've got a mate or local business to turn up the aluminium bushes, that's great, otherwise just as easy to buy off the shelf from the states. I wouldn't leave a lip on the right side. Any lip here will be throwing the chain alignment out. Keep all the spacing on the left side.
            The next big challenge is the battery mount. I'm going to blow my own trumpet here, but I personally don't like the way most people fix the battery directly to the drink bottle holder mounts. You're asking a lot of 2x5mm bolts. I reckon my solution using the adapter plate is best and most secure. It also lifts the battery assembly up off the frame using spacers that clears the cables on the upper face of the Anthem down tube.
            The only small niggle I found was riding over corrugations at highter speeds, I'd get a resonance that would shake the battery connections and cause a momentary loss of power. I had a rubber strap around the frame/battery so I replaced this with a webbing strap and that sorted the issue. Took me a month or two to figure it out though.

            All the best with the project.


              Hahaha I just picked up my're right, the offset is too much, so I'll have to make a jig and grind down that flange then put one of those spacers I got with the kit onto the LHS......I can't find the 'off the shelf' ones you speak of... but for anyone else that reads this you might want to purchase these....mine were done locally I got 2 pairs done it took 3 days.

              I intended fitting a 48v tiger shark pack (shorter in length extra height) perfect for the Anthem frame with 17.5ah but I can't find them in WA for a decent price with charger anymore and online it seems they may not be making these any more......I've found one local but they ask a bit.....I think.....

              i decided to follow your lead on the aluminium baseplate except I plan to 'notch' out the brake line and rear derailleur segments so I can lower the height of the baseplate.....this means I've unclipped the rear brake line (x3) from the down tube and will move the line over the edge and perhaps hold in place with cable ties, fed through the existing clip holders....I'll document...
              and im going to try mock fit a Panasonic 48v 17.5ah shark pack....I think I can shave some of the pack cover as this style offered by lunar is very tight......this might actually add to a nice secure jam-tight fit holding that cell pack in there tightly....I am commuting within the city but when I see a little curb or garden section, step gap.....anything with a bit of air time on the other side I'm going to hit that thing......
              anyhow thanks for staying in touch. I'll keep you posted.


                Hi Ozvolt. Apologies for. The delayed reply. Only just noticed the post. Considering how you ride, I’d personally consider the smaller 14ah battery. I get 60 plus klm out of mine. I think the extra weight and size of the jumbo pack might be an issue on such a fine machine , and It doesn’t look as neat. Either way, look forward to viewing some pics.


                  Hard Tail:

                  How is your soft tail frame holding up? I'm getting flex in my rear triangle that is kind of jarring when I hit the power too fast. Have you had to do a rebuild of the pivot bearings. Otherwise, I love my 52V BBSHD Anthem. I just thought I'd reach out to you to compare notes. I have a 2014 Anthem 3 that I converted last year. I have a 13.5MaH 52V battery (tight fit) and a BBSHD that serves me well on a 40 mt RT to work with 1800 ft of vertical. I get about 36 miles with my battery, but I'm hammering all the way to and from work given the distance. I also find that I have to raise my PAS to match my bikes speed, or the motor tends to drag as I try to ride faster.

                  I've noticed that the rear frame jumps a bit when I hit the throttle too hard, and I'm working on isolating the flex. It's odd, but I don't see links to Giant frame pivot replacement parts. I'll be hitting my LBS to see what they can do to order for me.


                  Vienna, VA USA

                  PS, I'm running a 52T Bling Ring as I'm moving pretty fast on road bike lanes 30-35 MPH a lot of the time, though I have stops and turns that kill my average speed, plus the hill climbing.
                  Last edited by marcva; 03-01-2020, 06:35 PM. Reason: more details...


                    Hi Marcva. Interesting to hear about your Athem flex issues. Bottom line, no I haven’t experienced any issues with flex but I think we’re using considerably lower power settings and cruising speeds. I also don’t have a throttle and only use PAS. I’ve converted 3 Anthems now, one for my mate, the one above for my wife and I’m on the carbon framed one for my everyday ride and commute bike. I actually checked all the bearings on my wife’s bike recently but they were like new so just repacked and re fitted. I’ve noticed full bearing replacement kits on eBay so should probably get one on standby.
                    Out of interest, how are your chains and sprockets wearing. I’d imagine those speeds and power settings would be placing a big demand on them.


                      hi Hard tail,
                      im after i little advise!

                      i am looking at purchasing a second hand Giant Anthem X3 2013 29r bike and putting a 750 w midrive Bafang motor on it. I currently have this motor set up on a Gaint Hybrid bike but the bike is copping a pounding and i need something a little sturdier! i use it solely for transport to work but i travel on a very rough fire trail. very steep hills.

                      my Q. is , what size bottom bracket does the Giant Anthem X3 2013 29 r have? i know i need a 68-73 mm bottom bracket for the motor to fit!

                      Thanks heaps!
                      p.s im impresded with your battery mount solution !!


                      • Hard Tail
                        Hard Tail commented
                        Editing a comment
                        Hi Mick. As much as I like Giant Anthems for commuter bikes,and cant recommend them enough, I don't think you'll be able to get a Bafang750 watt mid drive unit to fit because the Anthem bottom brackets are too wide. This is why I had to us 100mm wide, BBSHD units on all the Anthem conversions. Reckon this would be the only viable mounting solution.
                        All the best with the project.

                      California Ebike sells a 100mm bbs02 motor, and they sell a conversion kit that allows you to put a longer driveshaft on an existing bbs02, the the somewhere us that it's too pricey and you are better off selling your motor and buying a bbshd. That is what I had to do.

                      Some of the very old anthems had smaller bbs, but I think it was back in 04? Sirens some time on the giant site going through catalogs of old years to check specs. They're all there.

                      Also realize that a small frame will restrict the battery options. You need a medium for a 13.5 shark type battery.


                        Also since this is an anthem thread, I found and bought a pivot bearing tool if anyone needs it. I tried using washers and bolts, but that didn't work very well.

                        I'll ship it to rent if someone needs it, but want to hold onto it since they're hard to find.


                          Thanks all for your comments and suggestions, VERY helpfull!
                          CHEERS , Mick


                            Thanks a lot for your documentation and work Hard Tail , doing my own bbshd conversion on an anthem X 29 from 2013. Followed all the advice from your build and other threads, re-greasing the new motor now as well as changing the steel gear.

                            I have a solution for the tight fit of the batteries. So grin bikes over here in Mapleland has a triple bob adaptor that uses shrink tube and hose clamps to mount the battery on the downtube (think Luna makes something similar). It can take upto three hose clamps. ( For my conversion, I didn't want to mess with the suspension just yet so this is what I'm thinking.

                            Mount the tripe bob to the battery frame. Close the battery frame. Fit within triangle and ask a friend to hold it there while I tighten the hose clamps on the downtube.