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Mid drive cassettte zip tie mod.

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    #31
    No news isn't always good news. To sum it up the BBSHD broke the first 15t idler bracket. So I added the massive battery hanger clamp and the 1 1/4x3/8" 6061 bracket. Passed all tests including wheels up launches. The during fairly light loading the BBSHD quit providing power. It turns out mine is the older version and the motor shaft snapped where the gear meets the rotor. This is uncommon but not unheard of. So the winner is the failsafe breakaway zip tie! It didn't break! Of course I wish that was the problem.

    Comment


    • Retrorockit
      Retrorockit commented
      Editing a comment
      I waited to post here until I knew it had nothing to do with it. But the chain management battle of the parts continues. 1 for the BBSHD, and one for the T-Cycle battery bracket. The zip tie is surviving all of this mechanical mayhem.
      I think the shaft is probably bigger all the way through, not just at the bearing, (It would be hard to press the rotors laminations on an 8mm shaft with 2 larger ends on it) and getting the keyway away form the change in section, plus a free area to absorb some torque will make big difference. If the shaft is full 9mm that's 26% more cross section right there. Keeping 2 stress risers away from each other is a big plus. TSDZ2 has shit like that and they never fix it. At least Bafang did something about it.
      Last edited by Retrorockit; 03-12-2023, 02:57 PM.

    #32
    I'm going to move away from the zip ties. I think they're the right way to do R&D on this. But when you get to the point they don't break any more there is another way to do this.
    I'm going to put 1 or 2 (concentric for 2) 3/16" O rings behind the cassette. I'll put some silicone grease on them so they don't get stuck and they will provide a friction type clutch instead of a breakaway solution. It will mostly be stationary since I'm no longer breaking zip ties. This may allow me to run the chain at normal length. Instead of breaking a zip tie it will just slip as needed.
    This is what I've found actually riding this setup.
    When leaned over in turns and can't pedal you can upshift and downshift as desired. ( I've spit the chain form shifting w/o pedaling like this)
    When accelerating in the higher power settings any shift when pedaling will be a power shift and can bend/break parts. Now you can pause pedaling to shift w/o damage at high power levels.
    Pedaling while braking is stupid. With this mod you can dump multiple gears while slowing down in real time w/o pedaling. This does require a manual gripshifter, not some single shot trigger shifter.

    Comment


      #33
      On the Shimano FFS freewheel, is that what they did? Ever taken one apart?

      I've never seen one.
      Last edited by ncmired; 06-17-2023, 05:22 AM.

      Comment


      • Retrorockit
        Retrorockit commented
        Editing a comment
        "The system had many detractors including Sheldon Brown. Most thought it was unnecessarily complex and heavy. I do think it is heavier than a standard freewheel however, it is also quite handy especially if you are an urban commuter who has to do a lot of start and stop biking. By not having to pedal in order to shift, you can shift into and easier gear while you are coasting to a stop so that you’ll be in the appropriate gear when you’re starting off again. You can also shift into a gear while you’re at a stop and as soon as the rear wheel starts moving the chain will fall into the gear that you’ve preselected."
        IDK how to respond to this. Do I have to weigh my zip ties and O rings?
        Last edited by Retrorockit; 06-19-2023, 05:40 AM.

      • Retrorockit
        Retrorockit commented
        Editing a comment
        I've ordered a pile of parts. I'm probably overthinking this, But I've ordered some 3/16"x 1 3/8 ID rings, and some Square section 3/16x1 1/2 ", and I have some 1 3/4" ID rings to go around the smaller ones. I suspect any of them will probably work just fine. The small ring should sit inside the holes in the back of the cassette and the hub flange and give a smooth surface. The square ring will bridge the holes better if I need more grip.I couldn't really find what I needed locally.
        Be aware that a lot of bikes have a spacer of some kind behind the cassette, so the 3/16" dimension may not always apply.
        Last edited by Retrorockit; 06-20-2023, 05:20 AM.

      • Retrorockit
        Retrorockit commented
        Editing a comment
        I'm guessing that Shimano did each cog separately because the math said each cog would have different force on the chain. Probably a different resistance for each one.

      #34
      I got my assorted O-rings to try. Played around with a few setups, and settled on a 3/16" square profile ring behind the cassette. I felt that it wouldn't take a set and lose tension like a round one might. I greased it with some thick silicone Teflon grease that's used for urethane suspension bushings, it won't wash out, but it's designed to prevent sticking between rubber and metal.. Checked the cassette with a torque wrench. About 1 ft/lb to break loose and peak load when spinning it about 3 ft#. The reason to do testing with the zip ties is the bike returns to normal when they break. But once you have a setup that's working this will avoid the hassle of changing a zip tie every now and then. IDK why Shimano went to all that drama and expense making those complicated freewheel sets.

      Comment


      • Retrorockit
        Retrorockit commented
        Editing a comment
        I haven't ridden it under power yet. I'm finishing up a lot of small changes I made while the motor was broken.

      • Retrorockit
        Retrorockit commented
        Editing a comment
        I rode it around under power. The square section rubber ring instead of the the zip tie is working just fine. It's back to shifting like an IGH.
        I had tried putting the motor back together before and coulbn't get it to go in, left and did some other things for awhile. I tried putting the rotor in by itself, and that was the problem. It seems the first try I had knocked some grease down into the blind hole the small end of the shaft goes into. It was hydraulic locked and couldn't go in. Once I Q tipped the grease out it went in OK. I put some thermal paste between the stator and housing while it was apart. The new rotor, and old motor with the California Ebike conversion bearing(and shim) seems to be working.
        Last edited by Retrorockit; 07-02-2023, 05:08 AM.

      #35
      Here are my recommendations if you want to try this mod.
      1- Have a well lubed front freewheel in your Mid drive. This usually means very light grease or oil on the pawls, not heavy grease.
      2- A gripshift installed. The whole point of this is to be able to shift to any gear any time. The myth that Ebikes can only shift one gear at a time is nonsense. SRAM made gripshifts for both their own "1:1" system, and Shimano's "2:1" Rumor has it that SRAM 11 speed NX (1:1.2) works with Shimano XT (1:1.1) 11 speed stuff.
      3- Good chain management with no friction added to the system. Good chainline with Wide/Narrow chain ring and a modern clutch derailer will probably work. Bit I don't have any of those things and I made it work anyway.
      4- A 2 leg center stand is nice to have. You can spin up the rear wheel with the motor and test shift up and down. This allows you to see how your chain management is working (or not). It also allows you to show off how the bikes shifts. Just be sure the back wheel doesn't touch the ground while twisting the gripshift backwards.
      5- Start with a single small zip tie. It's all that's needed for this to work, and if you get to the point where it no longer breaks then go to the friction drive setup.
      6- An extra link in the chain to allow for some slack to come and go in the top run of chain is helpful, but maybe not needed with the friction drive setup.

      Comment


      • Retrorockit
        Retrorockit commented
        Editing a comment
        But I run Rapid Rise low normal deralleurs. they would all be upshifts for me.
        Tell the truth now. You actually run trigger shifters because you have a RH twist throttle so you can play make believe motorcycle.

      • AZguy
        AZguy commented
        Editing a comment
        Haha, if that were the case a grip shift would be better since they can be mounted on either side more readily than trigger!! ;-}

        And a right side trigger is fully compatibility with twist throttle


        I just prefer triggers - had one bike with grip shift (early 90's) and even after a few years of riding it they just didn't gel with me...

      • Retrorockit
        Retrorockit commented
        Editing a comment
        In urban traffic I don't like to have to ask twice for what I need.

      #36
      I finally did a zip tie on my off road bike. I really did like it. Partly because I did my street bike last year and was starting to get used to it but I did find it really handy for single track technical. I'm a little rusty from not getting out as often so there were a few times I found myself having to do a climb in the wrong gear so it was great while I was coasting around the corner (not able to pedal because of rocks) and able to downshift so as soon as I got past the rocks I could start to climb.

      It was going pretty great till about 2/3 the way through my 3rd lap and I did have a chain drop. Oddly it didn't break the zip tie. Chain fell between the chain ring and BBS case and at least with my setup of a Lekkie 42 and 10 speed chain there is enough room for the chain to just drag over the case. Took some paint off but really didn't drag much. Up till I did this mod I don't ever recall having a drop on this bike except in the snow which was likely a snow and or ice issue.

      On my street bike I have probably 1000 miles on now since I put the zip tie on with no issues or drops at all. On the offroad bike I do really want to keep the feature but I am now concerned about drops. It was getting real hot out and I'm way out of practice so I was just on the green trails and not really pushing that hard. This makes me think if I was to push hard or hit the blues the drops could be a real problem. I think I do have a front derailleur in my junk box for this bike. I don't think it would really hurt anything to try putting that back on. I was also wondering if it would be worth getting a clutch derailleur? What I am running now is a Deore XT that must have been from just before they started with the clutch thing. Quick look a new 10 speed deore with the clutch looks like its around $50 and in stock multiple places so not that bad if it fixes the problem.

      Comment


      • Retrorockit
        Retrorockit commented
        Editing a comment
        I wouldn't do the front derailer trick for this mod. Any friction there just makes it worse. The same for the grooved block type.The clutch type derailleur should help. This mod can push slack into the top run of the chain if the derailer spring isn't strong enough to pull it back out. Unfortunately if that slack hits a stationary object like a front derailer cage it gets much worse. I posted photos of what I ended up doing. But a modern derailleur may be all that's needed..

      • Retrorockit
        Retrorockit commented
        Editing a comment
        Intend, the builders of Magick Cranks, which are the pedal bike version of the zip tie mod state right up front that a chain guide is required for this. They don't say what kind. I tried a bunch of them, and Terra Cycle's toothed idler, on their heavy duty battery bracket is what worked for me.It needs a really solid bracket because the BBSHD will be trying to push it out of the way. On mt crosschained street bike it was mandatory. The clutch derailer with the stiffest spring I've seen is the Sunrace M9. IDK if it plays well with 10s stuff.

      #37
      Originally posted by 73Eldo View Post
      ....I was also wondering if it would be worth getting a clutch derailleur? What I am running now is a Deore XT that must have been from just before they started with the clutch thing. Quick look a new 10 speed deore with the clutch looks like its around $50 and in stock multiple places so not that bad if it fixes the problem.
      I'm running an 11sp Deore XT with the clutch and don't think I've ever dropped a chain with a narrow-wide ring with or without zip tie. They do a really good job of keeping the chain tensioned.

      Comment


        #38
        My street bike is what appears to be an older shorter range XT with no clutch and I have not had any drops on that but that is the street bike so generally much smoother surfaces and a lot less on and off the power. I think what dropped it off road was just the right combo of a big bump and coming off the power at the same time or maybe a combination of several bumps and on and off the power so just increasing the likelihood of the combo of slack and gravity clashing. Gonna have do do some reading on the differences are since there seems to be at least 6 different deore derailleurs not counting the big class differences like XT vs XTR or the range/cages. Maybe I can also find one that will make it so I can remove the rear wheel without first removing the derailleur with my horizontal drop frame. Guess I should start by figuring what I have on that bike now.

        Comment


        • Retrorockit
          Retrorockit commented
          Editing a comment
          On my street bike I have a gripshift,2 leg center stand a Rapid Rise derailer. I can throw ridiculous speeds, silly numbers of up and downshifts at once, and watch what happens to the chain. Wide/Narrow handles side to side misalignments OK, but does nothing for vertical play which can happen under overrun with this setup. Add some bumps and you need some kind of chain control. If the derailer can pull the slack out of the top run of chain in real time you should be good. But I'm so relentlessly Retro that I went with the chain guide modeled after the rear derailer jockey wheel catching the chain in mid air. I tried the toothed idler with a retention peg to keep the chain in the groove and had the chain hanging down between the tire and chain stay the minute they touched. So freewheeling toothed idler with sidewalls won out for me
          Thanks for doing the mod and reporting back that it actually does something useful for you. Some BC riders like it for the reasons you do, but they probably already have chain guides anyway.

        • Retrorockit
          Retrorockit commented
          Editing a comment
          On page 2 there is a photo of my prototype Idler bracket. I ended up making a nicer one by using a wider piece of stock and drilling the mounting holes at an angle to match the seat tube angle for a level bracket.It was strong enough to break my Series A BBSHD during testing.

        #39
        Tom Petrie at Cantitoe Road (Wippermann Connex chain vendor) took the time to look at my posts here, and objected to my saying I have reservations about using "Connex" links on my overpowered, crosschained Ebike. When I say I don't run "Connex" links I'm referring to all tool less links of that type. I use the name Connex because they are regarded to be the best, so my problem isn't because of low level brands. He didn't understand that the default Ebike here is a 1500W BBSHD. He has forwarded my emails to him regarding this to Wippermann. Maybe a BBSHD rated chain solution will come out of it. They do have 31mph Pedelec bikes in EU. I'm sure Wippermann supplies chains for them..........

        Comment


        • ncmired
          ncmired commented
          Editing a comment
          I use Wipperman->Connex model 108 1/8 chains on the IGH builds and have had great service life and no pull-aparts or failures, even at 3KW. Maybe some of the tech can be migrated to new derailleur chain designs if they haven't been doing it already.

          They run VERY tight when new on, at least, the Lekkie 40T.

          I also use a Wipperman->Connex 7E8 on a Photon build and an 11SE on a BBS02 build.
          Last edited by ncmired; 07-15-2023, 09:21 AM.

        • Retrorockit
          Retrorockit commented
          Editing a comment
          I've been running the 8SE, and want to try the 11 speed. But the Connex link can fail on derailers under power when cross chained. I rivet the 8SE, but the Connex for the 11s is $25, and the newer Rohloff Revolver 3 rivet tool is $210. So this is pushing me towards Shimano where the rivet is an option, and costs less than with the tool less connector. Whether the pressed in rivet is as good as a peened one I will have to find out the hard way.
          I went to a lot of trouble and expense on a TSDZ2 IGH project to get the single speed chain lined up. Then realized I could avoid all of that by running the thinner cogs with a multispeed chain off line a bit. The 1/8 chains don't flex sideways so that tech doesn't apply to derailers.
          Last edited by Retrorockit; 07-16-2023, 07:39 AM.

        #40
        I've had the motor back together for a while now with the much improved B version of the rotor. I used the California Ebike conversion bearing so I didn't have to replace the stator and the cover also. it's working just fine. The friction drive version works the same as the zip tie mod. The cogged chain guide is smooth and quiet ( I can hear the chain rub in the 2 cross chained lowest gears, this lets me know when I've downshifted more than i need to). The Terra Cycle chain guide is rock solid now. it seems I like to hoist the front wheel in the first few gears every now and then. I don't think this will bother the newer shaft. I already have the PEEK gear in there so that should be pretty solid also.. So this mod is a permanent part of the bike now, and i think it's how I'm going to build from now on. I can't think of any reason to bother with an IGH hub when a derailleur can shift like this.
        Last edited by Retrorockit; 07-21-2023, 08:14 AM.

        Comment


        • Retrorockit
          Retrorockit commented
          Editing a comment
          The difference between the zip tie mod (fail safe) and the friction drive (fault tolerant) is that I can run my chain right at the limit of derailer travel and the friction drive will slip if the chain gets a little tight, the tiny zip tie would break and need to be replaced even though there was no derailment happening.
          With a vintage Rapid Rise XTR mid cage derailleur, and a modern 11-40t cassette on a stock hanger I'm right on the edge. So if you just want to give it a try the zip tie mod is cheap and easy. In the long run the friction drive is better and there is no real reason not to start off with it.
          Last edited by Retrorockit; 07-21-2023, 08:28 AM.

        #41
        On my last ride I didn't drop the chain but the zip tie broke at some point. I did stop by the bike shop today and ordered a new Deore clutch derailleur to see if that helps. With my membership card discount it was only $40 so a very reasonable fix if it solves my occasional drop issue.

        Comment


        • AZguy
          AZguy commented
          Editing a comment
          I really like my M8000 (deore xt)

        • Retrorockit
          Retrorockit commented
          Editing a comment
          I have a couple of the clutch type derailers sitting around. But I'm still rockin' the 8 speed Rapid Rise/ Revoshifter setup. My flat 50t chain ring probably does need the cogged roller chain guide I'm running anyway.So I'm not going to try the clutch derailer on this bike. So thanks for the feedback on this for offroad use
          . Intend sells an $800 FFS crankset for that purpose with a free zip tie included.
          Integrated ratchet mechanism Ratchet system with 47 engagement points Highly optimized construction for hardcore applications … Continued

          Expensive, noisy as hell. But intended for hard use. We already have everything but the zip tie. And ours is silent too.

        #42
        The zip tie mod is working without incident. Long rides, deep water, whatever. It's just there. It no longer has a zip tie to break. Just shift it like an IGH.
        I also lost the key to my Pinhead locking skewer, seatpost and headset. it was missing for over a week, then I found it. But the Tannus Armor, and the Stan's in the front tube are working flawlessly too. If I had a flat I would have been SOL without that key. The Shimano ICE rotors are quiet and smooth. I had registered my key# with Pinhead, but disappointed with no response from their tech support. I ordered another lock set for my XC bike (keyed the same) so I can ride it into town and have an extra key. This bike seems to be in a good place as far as being a reliable vehicle. The BBSHD was always that way. Getting the rest of the bike to catch up took some doing. The zip tie mod took some sorting out, and there is still some question about hard offroad use. But I think the potential is there for that too.

        Comment


          #43
          Here is my explanation for the broken zip ties w/o chain drop. In one place on my ride home I would take off in 2nd gear instead of 3rd. To get there under braking I would dump it all the way down to 1st and back up to 2nd gear. No need to count, and I can't see the shift indicator at night anyway. The down shift to first put the chain right at it's limit because i had sized the chain the usual way. When the downshift tried to push slack in the top of the chain the chain got tight and broke the zip tie. A 4t smaller cassette = 1 whole chain link. With the 36t I could downshift all the way to 1st, and take off from there. No broken zip tie. With the friction drive this isn't a problem any more, and I'm back to the 11-40t cassette
          I had a spare wheelset with an XT hub. So i could find out the O ring size off the bike. The labor to install the friction drive mod was the same as installing the new casssette. I liked the custom 11-36t cassette OK but it took, 3 cassettes to make one out of parts. When I found out the XTR derailleur could run 40t with a B screw mod in stead of an extended hanger that sealed the deal.
          Last edited by Retrorockit; 08-21-2023, 06:58 AM.

          Comment


          #44
          I finally got my new clutch derailleur installed and got one good ride in. So far so good, no chain drops. The drops started happening in one stretch of trail at my local MTB park after I did the zip tie mod. 3 years of riding before with no drops so it had to be the mod that made it happen. I have had zero issues with the mod on my street bike but it doesn't get banged around like this bike does going off road. Figured since clutch derailleurs seem to be 'the' thing for off road I would give it a shot since I really like having the mod. I rode pretty hard and fast a couple laps and no issues at all in that stretch or anywhere else on the trails.

          Comment


          • Retrorockit
            Retrorockit commented
            Editing a comment
            I developed this mod on a cross chained bike that would drop the chain any chance it got.Butt if the derailleur can pull the slack out of the chain all the way around it should work OK. If the zip tie breaks every now and then w/o a chain issue either a little longer chain, or a friction drive setup should cure that. After the chain drops were sorted out I haven't had to touch it with the friction drive. But it's so stealth there is no yellow zip tie to show it off any more.
            Last edited by Retrorockit; 08-29-2023, 09:23 AM.

          • 73Eldo
            73Eldo commented
            Editing a comment
            I have black zip ties. Black spokes. Black hub. Black rims. Black tires. I don't think anyone would notice my zip tie. Most people would just assume that is how a mid drive works.

          #45
          Does anyone know if any factory built mid drive E bikes work like the zip tie mod?

          Comment


          • Retrorockit
            Retrorockit commented
            Editing a comment
            TBH I never looked at them. I haven't heard anyone say that they do. I had this on Endless Sphere with 4K views, every negative comment you can imagine, but not that one.
            As a bicycle mod it's been around off and on for quite a while.

          • Retrorockit
            Retrorockit commented
            Editing a comment
            All the experts seem to agree that Ebikes can only shift one gear at a time. Shimano, Box, Electrifybike.com.
            So obviously I'm no expert.
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