No announcement yet.

BBSHD - which size for 100mm BB on a Motobecane Boris X9?

  • Filter
  • Time
  • Show
Clear All
new posts

    BBSHD - which size for 100mm BB on a Motobecane Boris X9?

    Lunacycle offers 3 sizes for BBSHD:
    * 68-73mm (Standard)
    * 73-100mm (Fat)
    * 100-120mm (Extra Fat)

    I will be installing on a Motobecane Boris X9 with 100mm BB.
    it seems the sizes for BBSHD have changed, and there aren't as many sizes available now.
    I have seen installs that use the 100mm BBSHD (exact match). I'm not sure whether to get the "Fat" or "Extra fat" version.

    Am i correct in assuming that the "Fat" version is 100mm with spacers, and the "Extra fat" version is 120mm with spacers?
    If yes, I would lean toward getting the "Fat" version.
    Is this this right assumption?
    Thanks in advance.

    I in the middle of converting a brand new Boris X7 and I went with the 100-120 mm HD unit...I needed multiple spacers...if I was in your position pre-purchase I would order two extra sets from Luna just in case...I found this out the hard way and had to order them...just got them today so I could continue conversion. They will send you all types of spacers...big ones (which I needed for bottom bracket and smaller ones which I did not think I needed but ended up using on my wife's Electra Townie that I am also converting.


      Make sure to order extra XT90 pig tails if you are doing your own battery leads...if you have not already purchased your Boris and think you might like a RockShox Bluto fork then go ahead and order the bikes fat bike with the Bluto...again, I decided later to add the Bluto and that was costly and a waste of time...I am paying for my newbieness. Mr. 4x4's on YouTube did a great Luna/Bafang HD install video...the guy knows his stuff...he also purchased the Bluto equipped fat bike...can't remember the name...just trying to save a fellow e-biker some pain and suffering.


        There is no advantage to installing with 20mm of spacers. If 100mm is what you need order the 100mm kit not 120mm. Take a few minutes to search the frame and read what other successful builders have done. All of my builds have been done with the best fit kit, not adapting a too large kit with spacers.

        I've been meaning to write up a post-build log of the e-bikes I've done so far, but I'm going to start with the second one since that is more fresh. I found out

        There's a bunch of builds using that frame. Spend some time reading about them.

        The motors come with Anderson connectors and pigtails. Eric and I prefer direct solder and shortening the wires. Crimping also works with the frame packs. If you decide on a triangle pack do order XT 90S pigtails.

        Learning to solder and owning a budget solder kit is the best single skill a kit builder can learn. $18 Amazon Prime. I hate those wire bundles builders end up with without shortening the wiring. Sans connector also means one less point of potential future failure. The boss hates them but I do have bikes with several year old Anerson connections that I just shorten tended the kit wires on and used the included connectors and shortened and soldered. My newest dolphin builds are without connectors.


          RBF, I probably will order extra spacers. This looks like a lot of fun and may be my first of several installs for other family members. Depending on how this goes I'm already thinking about BBS02 on smaller bikes. Here's the Mr 4x4 video you're talking about: It's on a Boris the Evil Brut.

          I had originally thought i'd start with a $400 Gravity and add an IGH, then crept up to the Boris X9 after looking at how much work and $$ it would take to add everything to the Gravity. I hadn't considered going up to 1K for the Bluto version of X9 - but now i'm reading about it and having buyers remorse. Should have spent the extra 200 for the Bluto version. My Bluto-less X9 is en route, due to be delivered Monday, so I may call BD tomorrow and see what it would cost to swap it. It might help my case if i don't even open the box.

          Louis, thanks for the links. I have searched for everything I could find about Boris installs, here is another that i will be studying closely:
 Motobecane Boris the Evil Brut Bafang BBSHD installation bottom bracket spacers chain ring spacers EMPowered Cycles

          This guy recommends the Lekkie Bling Ring to achieve the best chain line on this frame. So I'll probably go that route.

          I will plan to get the 100mm BBSHD (73-100mm).

          I have a soldering iron from college days but the tip is really small and i believe it's lower wattage for electronics. Thanks for the Amazon link, looks like $18 well spent. I definitely want to have a clean/stealth install, so will be cutting and soldering to achieve that.

          For battery, i'm planning to start with a mighty mini cube, in a saddle bag as suggested here:
          It seems like an inexpensive way to get my feet wet and might be the long term solution if I wind up adopting a strategy of swapping batteries on longer rides.

          Curious about other tools needed. I believe I should get a "4 notch M33 socket"
          Quote from the above link:
          • The most crucial part of the installation is getting the 4 notch M33 lock ring tightened properly with the motor positioned upwards against the frame of the tube. When the motor spins forward it relies on the frame to push against to counter the torque. The fixing plate needs to be tightened up flush against the shell face by tightening the lock ring properly and this hold the motor up in the correct position. You really need to snug down the M33 lock ring well and I recommend loctite as well. The best thing for this job is the M33 sockets made exactly for this. Many installations have issues with the motor moving around because they failed to tighten properly with channel locks or pliers.

          Is this the right tool:

          Thanks very much for the helpful replies so far!


            Louis that is good advice if you can find some posts where people have converted the frame already - then it should be easy to see which will fit the best. When you can't find a previous build, sometimes, it's not so obvious when you have aggressive chainstays that may require a lot of spacers on the drive side. In those cases, it's better to have spacers than not enough space - you can always paint the spacers too, if shiny aluminium is not your thing. ;)


              Hopefully we will do a better job of logging fit and build. Believe me, BBS dominates the bikes here, in my personal home shop, with 5 builds. I get the reasons for oversized kits. I also like the clean installs of a perfect fit. I also have an over sized BBSHD to be able to move to another frame. unlike the poster who flipped on being 5mm off center on his 68mm kit, I don't find 5mm objectionable. But on some builds 20mm or more does constantly grab my attention. Maybe it's just old age. Its a detail that jumps out at me. But as you point out, kit building isn't about perfection, it's about making workable compromises. Some compromises are easier to swallow than others. I'm one that has to bite his tongue when some manufacturers budget frames are even considered. But in the end, creative builders are my favorite customers.

              Thanks for the feedback!


                Empowered recommends the Lekkie because that's all they have. The eclipse may or may not be a better fit. I wish I could advise. The Eclipse is the best fit on all of my BBSHD builds, 3. I used a Lekkie and when the Eclipse came I sold it for a fair recovery of costs. The Eclipse is art and utility


                • Biker-Ken
                  Biker-Ken commented
                  Editing a comment
                  I apologise if this is not the correct procedure to ask for advice. I have a Felt DD70 fat bike (2016 model) with 100mm threaded BB and I want to fit a BBSHD mid drive. Do you, or anyone else reading this, know if a BBSHD with 100mm BB would be suitable - I would prefer a perfect fit without a 120mm BBSHD and using spacers? I have read of a fat bike with a 100mm BB (not the DD70) and when a BBSHD with 100mm BB is used it can't be pushed far enough through the BB because the chain drive hits the frame of the bike. Thanks for any advice offered.

                This thread maybe worth a look.
                Last edited by Rodney64; 06-24-2016, 02:55 AM.


                  Originally posted by Louis Luna View Post
                  Empowered recommends the Lekkie because that's all they have. The eclipse may or may not be a better fit. I wish I could advise. The Eclipse is the best fit on all of my BBSHD builds, 3. I used a Lekkie and when the Eclipse came I sold it for a fair recovery of costs. The Eclipse is art and utility
                  If I'd used the Eclipse (instead of a Lekkie), I would have needed another spacer on the drive side to clear the chainstay as the offset/inset is greater on the Eclipse and the teeth are taller - as it is, I have just a few mm of clearance. My chain alignment is bang on now. Also, I've never had a chain drop with the Lekkie on my old BBS02 100mm conversion or on my current BBSHD so their narrow/wide tooth profile is flawless as far as I'm concerned. Horses for courses - I'm sure that the Eclipse will be a better option for other frames and it's great that we have more options these days.


                    Originally posted by Ade View Post

                    My chain alignment is bang on now. Also, I've never had a chain drop
                    That's encouraging. I bought the cheaper aluminum 42T ring, it probably cut the number of chain drops in half but still far too much, and the line is awful.


                      Originally posted by Rodney64 View Post
                      The most worrisome part of this article:

                      Unfortudently the X9 also ships with a 10 speed cassette and
                      derailleur. The X9 is the only bike I’ve had trouble with broken chains on (with the BBS02), and I expect if you make the mistake of shifting under load you’ll have a few snapped chains as well. I highly recommend carrying around SRAM PowerLinks around with you when you ride as they will save a lot of time fixing chains and only cost a few dollars each. Make sure your power links are the right size for your chains. My personal feeling is that 7-8 speeds are ideal for the BBS02 if the front chain-ring is sized correctly and the largest cog on the cassette is 32T or bigger. Some cassettes have cogs as big as 36T which I highly recommend.

                      I'm hoping this doesn't turn into a big issue. If it does, I will try to find a 7 spd setup for the rear.
                      BTW, It was comments like this that had me looking into an IGH in the first place. But an IGH seemed like too much to tack for a first build.
                      Last edited by fatboy; 06-24-2016, 04:24 AM.


                        On the Motobecane Sturgis Bullet (BBSHD) I couldn't use the Luna Eclipse without putting 7mm spacers on the motor shaft and 5mm spacers under the Luna Eclipse. This left practically no thread on the 33mm mounting nut. With the 100mm BBSHD/Sturgis combination the Lekkie would work better because it has less offset and give you more threads showing on the 33mm nut. With the 120BBSHD, you can use either the Lekkie or the Luna. With fat bike chainstay width you will probably have to use more spacers with the Luna than the Lekkie. The 120BBSHD has lots of thread for mounting the 33mm nut and keeper.


                          Originally posted by CraigAustin View Post

                          That's encouraging. I bought the cheaper aluminum 42T ring, it probably cut the number of chain drops in half but still far too much, and the line is awful.
                          Yeah, I have the Luna 42T too and while it may be a good and inexpensive option for some, I'm guessing the Lekkie and the Eclipse are going to be better for most fat installs.


                            I'm sorry that I was unclear. The Luna 42 that I was referring to was the Eclipse. If you are going to use the cheap luna 42 (with 130BCD), you shouldn't have any problems using the 100mm BBSHD. But the chainline will be a worse with the cheap Luna 130BCD than either the Lekkie or the Luna Eclipse.