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    Hello

    Hi all. Just finished my first week of riding my MTB with BBSHD. Honestly had no idea how powerful it was going to be.

    #2
    Got some build details coming? Lots of fun eh? Planning upgrades or your next build yet? Working on getting others hooked so you have someone to ride with?

    Looks like there is getting to be a decent number of twin cities ebikers, we should have a ride some time.

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      #3
      Great to read. Ride the tide ! Two wheels down

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        #4
        Here are build details. Would love to hear any and all suggestions/comments!

        Had a few bikes to choose from in my garage, but picked this one for general readiness and suitability, even though I knew the brakes would be highly questionable. I thought it would be the best platform for experimentation. I love the geometry and look of the 90s steel MTBs anyway, but I think I need to take this project in a different direction.

        My setup:

        BBSHD from Luna with "hot rod" programming and whatever the larger color display is called
        Shift sensor added
        Cro-mo framed 1995 Schwinn MTB (had it since new)
        Rear XT hub laced to 26" Salsa Gordo rim
        Front Shimano Alfine dynohub , 26" Salsa Gordo rim, headlight/tailight connected
        Schwalbe Marathon 50-559 tires
        9 speed 11-34 cassette, Deore shifter
        Bafang brake levers connected to the bike's stock Altus cantilever brakes (these are short pull levers, but not short pull enough, not sure what they were aiming for there, I have to squeeze really hard)

        Chainline was 51mm from center of seat tube with stock Bafang chainring. I was unable to make any real use of the 2 largest cogs with this combination. I also had a fair amount of trouble with downshifting to larger cogs in general. Didn't matter much since the BBSHD has so damn much power.

        I have just this morning (after a week and about 50 miles) installed the Luna 42 tooth chainring in an attempt to improved chainline. The bike has a 68mm BB and the stock 46 tooth Bafang chainring and motor both easily cleared the chainstays. However, I had to grab a large deep well socket today and beat a small dent in the drive side chainstay to accomodate the 42 tooth Luna ring. Chainline is better and downshifting has improved dramatically. I was surprised at the extent of the improvement. I had to use the 1.8mm Luna spacer as well as walloping the chainstay, so I think I gained about 4mm. Haven't remeasured yet, but that's what the documentation would suggest. I have become convinced that the optimal gear setup for this bike would be to use a 135mm 7 speed MTB hub with a 12-32 cassette and the Luna 42 chainring. This would eliminate another 4mm of the chain having to move inward to reach low gear, as well as reducing wheel dish. I also think that the BBS02 is more than plenty for riding in not too hilly Minneapolis.

        I have a completely bare, size medium Surly Troll frame, which is a touch small for me. I also have a Nuvinci N171 hub new in the box. I'm thinking that with an upsloping stem and slightly rising bars I can put together an altogether more appropriate and safer machine with that frame. I'll get some fat street tires like Maxxis Hookworms. I'm looking for a quick, safe, stout commuter bike for my 7 mile one way trip. Don't always want to get too sweaty before work.

        I imagine that I will again face a chainline dilemma with the Nuvinci, that hopefully wont be too hard to resolve. It seems as though I'll have limited options to adjust chainline at the rear, since the N171 accepts only single speed freewheels. I guess you can also thread on a track cog, since the Bafang itself freewheels and the Nuvinci can even run backwards. I also don't possess the double secret Nuvinci tool that you apparently need to remove the freewheel from that hub. I would have to resolve that before going forward.

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          #5
          Seems odd that you can't get a workable chain line on a 90's bike. Usually the bikes with the 3x's had decent lines just because they had to. I suppose maybe the issue is going to the 9? My antique with the BBSHD is still a 7. The Lekkies are about the same offset as the stock ring so can be a better fit for some frames. The Lekkie 40 can have the same offset as the Luna and being smaller plus not having as tall of teeth may also help in a case like this maybe? 50-559 is 26x1.95 so right in line with what the bike likely came with stock. so no new issues there.

          The Nuvinci build sounds interesting. I'm content with what I have now but keep thinking about those and what they would be like with a mid drive. Even cooler if you could also do a belt. My local shop had a $5k Trek with a Bosch drive in stock all winter and said I could test drive it any time I wanted because it would never sell. Apparently they had it all summer of 2020 and it was practically the only bike in stock and it never sold. Based on that I wasn't in a hurry and didn't want to bother them when they were busy or when the weather was bad since it was very unlikely I would buy it but when I was in for some parts a month or two ago it was gone so I never got to try it.

          When I was reading about those hubs I never ran into anything about a cog tool. I remember some special tool for making cables if you had custom lengths or maybe internal routing and there was some tool related to brakes but it looked to be it was some sort of drum option like rental bikes used, not regular discs so I didn't dig too much deeper into it.

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            #6
            Yup, it's the 9 speed wheel that did it. The extra two cogs result in the chain having to go inboard about 5mm more than 7 speed, despite the smaller intercog spacing. Along with this comes increased wheel dish creating a somewhat weaker wheel. Not to mention a bit flimsier chain. If I still had 7 speed, I'd likely not have needed the Luna chainring, or at least less so. I do like the tooth profile of the Luna ring, but that sucker is definitely noisier. Bike seems slightly slower at the top end with 42 teeth instead of 46. Probably a good thing with these brakes...

            7 speed is a better platform all the way around, I think. It's also likely that the cheaper, heavier 7 speed cassettes that are available these days can better take the beating administered by the BBSHD.

            I have the long discontinued N171 Nuvinci. You need a special Nuvinci tool in addition to the freewheel tool tool to remove a freewheel from it, which is very hard to find. Both the hub and the tool were discontinued 10 years ago.

            This is one workaround, but also seemingly unavailable:

            https://calfeedesign.com/product/freewheel-tool/

            That's the place where I bought the hub, by the way. They're quite cheap and still available there at present. Supposed the be the toughest IGH out there, along with the 3 speeds.

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              #7
              I take back the part about the Luna chainring being noisy. It seems that I was a bit too conservative with my whacking of the chainstay. A few more whacks and now it's quiet as can be. 2 mm clearance now. I thought I had clearance before, but apparently not quite. Just enough rubbing to make noise, but not enough to really hurt anything.

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                #8
                I have had bikes I wondered about denting the frame for clearance but it didn't seem like a good idea strength wise but maybe your frame is different than what I was looking at.

                I didn't really notice any difference when I went from the stock 46 to my Luna 42 speed wise but me an my rig are easily in the 300 pound range so we aint setting any speed records even down hill anyway. I would imagine things could be quite different if you were a light person on a light more road like bike with a lot less rolling and wind resistance.

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                  #9
                  Probably not the best idea, but it's not worth much at all. I notice that the Surly Troll frame has quite flat chainstays behind the bottom bracket already. O course, it also has a 73 mm bottom bracket, so chailine problems would be worsened a bit right out of the gate with a derailleur setup. Most likely the dent there won't hurt the old Schwinn. Frame geometry is not noticeably altered. I did it with the wheel clamped in lying on its side.

                  If it breaks, and I make it through the possible crash, then the Troll build is coming that much sooner :)

                  I notice the speed difference only on the screen with full throttle, without pedaling. About 1 mph or so, maybe 1.5. No correction for terrain or anything, I didn't keep any record of the speeds with the 46 tooth. It's way too fast for the brakes anyway.

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