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Making a Sturmey-Archer axle torque plate from a $5 Home Depot gate latch

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  • Making a Sturmey-Archer axle torque plate from a $5 Home Depot gate latch

    Decided to make a pair of torque plates for my Sturmey-Archer (S-A) IGH axle. The powerful electric assist keeps loosening the axle nuts and I have cracked serrated lock nuts and torque washers, so I'm looking for a better way to keep the 13/32" axle with ~8mm flat sides fixed in place inside 10mm sliding dropouts. Currently the S-A single tab torque washers aren't cutting it for me. Some of the problems I've experienced are outlined here:

    https://electricbike.com/forum/forum...and-spins-free

    First I will say that the best solution would be to have sliding dropouts that simply have a ~8mm slot, but I can't find any. Another solution that many work well is to simply have a machine shop continue the axle slot up, but only at a depth needed to use a dual tab torque washer like indicated in the photos.

    That alone might be enough to resolve most axle twisting problems, but I decided to go with a fixed mounted torque plate that won't allow the axle to twist or slide out of the dropout if the axle nuts loosen.
    Last edited by Rider; 1 week ago.

  • #2
    After wondering the hardware stores looking for any brackets that could be adapted, I found a gate latch that already had 1/4" square holes in it for those bolts with the square on the shaft to hold the head in place while you tighten the nut. This is very close to the right size for a S-A 13/32" axle with ~8mm flat side to side thickness. My thought was I can use a round file to oblong both ends and file to fit the axle snugly.

    First I cut the round latch in half and removed it. Then cut the bracket piece I didn't need off, filed the hole oblong with a proper size round file and cut the tabs on both ends off leaving a 90* tab. Finally I cut the bracket in half to make two "L" shaped pieces and notched the tabs on each side leaving a piece just the right size to fit the dropout 10mm slot.

    The plan is to drill a hole in the upper half and drill and tap a matching hole in the dropout itself while the axle is in position resting all the way up into the dropout, so the weight of the bike is on the axle when it is tightened down

    Didn't get to drilling and tapping today. Hopefully later this week these will be completed.
    Last edited by Rider; 1 week ago.

    Comment


    • #3
      I think you just need a couple of these made by SA for CS-RK3.

      Comment


      • Rider
        Rider commented
        Editing a comment
        Lol... Read the thread referenced above in the first post and look at what happened using those. The reality is you need something that fits the axle tighter and doesn't let it move at all. If the bolts loosen just a bit the axle torques back and forth within the dropout and things go pop, bang and clunk! It even affects shifting.

        If those had dual tabs like the ones for horizontal dropouts or slide-ins from the front, I think things would be much better.
        Last edited by Rider; 4 days ago.

    • #4
      Finished off the FIXED torque plate for the long-slot Paragon 10mm dropout. The upper locking 5M x 0.8 bolt is threaded through the tapped dropout and will eventually get a locknut that will be used as a jam-nut against the backside of the drop. That way it will not come loose. This torque plate with upper bolt also prevents the axle from ever falling out of the dropout if the axle nuts do come loose (nice plus). Going to paint it up, then permanently mount it.

      ADDED photo from Sheldon Brown's anti-rotation washer page. This can happen when enough torque is applied, although I haven't "broken" any HMW534 anti-rotation washers myself; just had them work loose...
      Attached Files
      Last edited by Rider; 2 days ago.

      Comment


      • #5
        All buttoned up and ready to go. The Sturmey-Archer 5spd IGH that I have on my eCruiser didn't come with the HMW534 anti-rotation washers, so I added one of those to the chain side for extra strength.

        It is worth noting that following up axle bolt tightness on a new build with new washers and alloy dropouts is a must! IMHO the teeth on the anti-rotation washers need to bite into the alloy. This may take a few rides with retightening to get the bite holes worked into the alloy. Once the holes are in place with flat surface of the washer makes contact with the dropoutyou should be set for most applications.
        Last edited by Rider; 3 days ago.

        Comment


        • calfee20
          calfee20 commented
          Editing a comment
          Again very nice work. My S-A 3spd hybrid has given me no problems twisting around so I wonder why you are having problems. We must have very different riding styles.

        • Rider
          Rider commented
          Editing a comment
          I really put my CS-RK3 3spd belt drive through the ringer (the one I cracked parts on). I've ridden it hard in the dirt and hard level 9 starts in the left turn lanes to stay in front of the cars through the turn. When I hit the street, I have a tendency to push it as hard as it will go, because I hate riding next to cars and just want to cover ground fast. Many 1100W bursts with pedaling and full throttle stresses bicycle parts to their limit. I've backed off on how hard I ride Soma B-Side now.

          The RX-RK5 hasn't had any issues yet, other than the initial axle nut tightening did require a couple additional tightenings, but no broken parts to date there. The torque plates give me extra confidence that I won't ruin my 5spd IGH from running it while having axle twist; I shouldn't get any axle twist with this fixed plate. Only put one on the disc brake side. The thick 6mm HMW534 anti-rotation washers do catch more of the slot on that side then the HMW518 anti-rotation washers that came with the 5spd (the CS-RK3 washers FatMarty posted are much better).

          I've had what appears to be cable stretch on the 5spd shifter cable. On yesterdays ride I checked the yellow mark alignment in 2nd gear, because I kept getting those pesky auto-upshifts; it was way off. After resetting it for the ride home, the auto-upshifts were minimal.

          Have to keep an eye on all the adjustments with use...
          Last edited by Rider; 3 days ago.

        • calfee20
          calfee20 commented
          Editing a comment
          That is it. I am in PAS 3 or 4 and rarely go past 5.

      • #6
        Todays 21 mile test ride was uneventful. All worked well and I think the axle is locked in place for good. Great piece of mind.

        Comment


        • #7
          Woah

          "I've had what appears to be cable stretch on the 5spd shifter cable. On yesterdays ride I checked the yellow mark alignment in 2nd gear, because I kept getting those pesky auto-upshifts; it was way off. After resetting it for the ride home, the auto-upshifts were minimal."

          What auto upshifts? This may have been the problem I was having.

          Comment


          • theronchaplin
            theronchaplin commented
            Editing a comment
            I'm curious on this as well. I tend to ride in 2nd and 3rd gear mostly and occasionally I'll get a situation where the hub seems to be trying to shift. I haven't noticed a pattern for when it happens or doesn't and my remedy is just to change gears (ie. if I'm in second, change to 3rd, then back to second) which fixes it.

        • #8
          Originally posted by calfee20 View Post
          Woah

          "I've had what appears to be cable stretch on the 5spd shifter cable. On yesterdays ride I checked the yellow mark alignment in 2nd gear, because I kept getting those pesky auto-upshifts; it was way off. After resetting it for the ride home, the auto-upshifts were minimal."

          What auto upshifts? This may have been the problem I was having.
          Originally posted by theronshaplin
          I'm curious on this as well. I tend to ride in 2nd and 3rd gear mostly and occasionally I'll get a situation where the hub seems to be trying to shift. I haven't noticed a pattern for when it happens or doesn't and my remedy is just to change gears (ie. if I'm in second, change to 3rd, then back to second) which fixes it.
          When the heavy-duty S-A 5spd two yellow lines aren't in prefect alignment in 2nd gear (and sometimes when they are), the hub sometimes upshifts to the next gear or two on its own. This happens in 3rd and 4th. Haven't had it happen in 1st or 2nd that I recall and once in 5th all is fine (used infrequently with current gearing). At first I thought it was only when I "flick" shifted the top-bar lever shifter, instead of a slow deliberate shift, but it does still happen infrequently when aligned right and deliberately shifted. Many times it is when I decide to put the human pedaling hammer down on a flat or climb. Other times it is when I up the power level. This is very annoying, because those are the times I need to stay in the gear I'm in.

          I don't know exactly what is causing this. I never tried the twist shifter, so I don't have that to compare to the top-bar shifter. Holding the shifter lever in position doesn't seem to help (you can feel it want to go and the only fix is to upshift, then down shift back to where you want to be; like theronchaplin stated). So if there is a way to tighten the lever, I doubt that will help either. It seems to do it when under load and low cadence most, a time when shifting up is clearly not wanted or needed.

          Unlike theronchplin, my "hub wants to take control and upshift on its own" when in 3rd and 4th, but I start in 2nd and normally shift to 3rd, then 4th for cruising. 4th gear is my favorite with a 42T X 20T on 29 X 2.5 tires setup. I don't ride in 1st or 2nd for any length of time, so that doesn't mean it won't happen in those gears if I was.

          I really want a trigger shifter and 24T rear cog! I'd prefer to keep the low gears for climbing once this wheel goes on something like a Soma Juice MTB. On the cruiser riding only flat ground I sometimes start in 2nd and double shift to 4th. That has been working well lately, and upshifts haven't been happening as often. I'd be happy with a 5th gear gearing at about 20mph. That is my favorite cruising speed, so gearing it down with a 24T rear cog would allow 3rd gear 1:1 starts and 5th gear cruising (so up shifts will be null). It never tries to downshift. A 24T in back will give me a 1.12 climbing ratio, instead of the current 1.34 (As a comparison, my S-A 3spd with 50T X 28T belt drive has a 1st gear ratio of 1.34).

          After over 300 miles on the S-A 5spd, I think I like the simple 33% gear spacing 3spd better for flat ground riding. The Shimano 36% gear spacing 3spd may be even better (?).
          Last edited by Rider; 1 day ago. Reason: Ratio correction

          Comment


          • theronchaplin
            theronchaplin commented
            Editing a comment
            Interesting. I really do like the gearing on the 5 speed too, works very well for my kind of "cruiser" riding. I've wondered about cable stretch but had written it off because the 2 yellow marks are ALWAYS lined up perfectly in 2nd gear. I've never had the hub actually make the shift on its own, just on occasion it feels like it's in between gears. And yeah the twist shift... ugh... I guess it's better than the original that came with the 7-speed bike, but it's terrible. I still wish I could somehow modify this one that I purchased a while ago

            https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

        • #9
          Originally posted by Rider View Post
          Finished off the FIXED torque plate for the long-slot Paragon 10mm dropout. The upper locking 5M x 0.8 bolt is threaded through the tapped dropout and will eventually get a locknut that will be used as a jam-nut against the backside of the drop. That way it will not come loose. This torque plate with upper bolt also prevents the axle from ever falling out of the dropout if the axle nuts do come loose (nice plus). Going to paint it up, then permanently mount it.

          ADDED photo from Sheldon Brown's anti-rotation washer page. This can happen when enough torque is applied, although I haven't "broken" any HMW534 anti-rotation washers myself; just had them work loose...
          I have to believe that if you are busting/twisting out those anti-rotation washers from regular use via torque that the hub isn't going to fare well no matter how tight you get it with extra plates.
          The SA hubs only have small cowl teeth (I think that's what they are called), that spring out inside to turn hub.
          I trashed one cs-rk3 by busting one of the two teeth off; I figure if/when the current hub goes I will just switch to a regular cassette.
          The hubs are fine for "cruising" - but they are not built for off-road with a motor.
          I've got almost 7000 miles on a BBSHD and have learned to not treat it like a dirt bike; there are simply too many components on a bicycle that are not made for what we do.

          Comment

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