Hi, I need to tighten this screw on the fame of my coswheel m20. I know for sure one side fits a 8mm or 5/16 allen key and the other side takes something larger than 10mm or 3/8 allen key which I don't have. The side that fits my allen key is way too hard to tighten as well i'm not sure if i'm turing it in the right direction. what I need to know is what tools do i used to tighten this properly?
Coswheel m20 loose nut or bolt on frame
- Thread starter zrpt
- Start date
It probably is the swing arm pivot. And I don't know if it's the bushings that are worn. If you notice the seat shouldn't be that close to the wheel. that screw was keeping the bike raised. I ran over a speed bump and then it suddenly broke.
I bought this in April of this year.
I bought this in April of this year.
wturber
1 MW
Yeah- I don't think you need to tighten things. I think you need to loosen and remove the upper and/or lower shock/spring mount pivots, take things apart, and see if anything is broken with that shock/spring. Also, there's an adjusting "nut" at the top of the spring that may have come so loose that it became unthreaded. Tightening that increases the preload on the spring. That alone may be all you need to do. But it wouldn't hurt to disassemble that just to be sure that there isn't something broken in there.
If you can get the right sized allen key to get those mounts loose, you could also re-position the top mount (note the optional top mount locations) to tune up the swing arm geometry and get that wheel further from the seat.
If you can get the right sized allen key to get those mounts loose, you could also re-position the top mount (note the optional top mount locations) to tune up the swing arm geometry and get that wheel further from the seat.
wturber
1 MW
Hard to tell if that's right or a perspective thing. But it is certainly consistent with what the OP has described. So maybe that's it.
Mongo
1 kW
Hard to be sure, but it looks like the only thing holding the bike up is the chain tension (OP's second picture).
Here's a close-up of the top shock mount, stock:
And what the swingarm position should be when unloaded:
Here's a close-up of the top shock mount, stock:
And what the swingarm position should be when unloaded:
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wturber
1 MW
That "close-up" looks like a CAD rendering. But assuming it's accurate, I think @E-HP 's hypothesis is looking stronger. Also, I think you are right about the chain holding the bike up. The chain isn't even on one of the larger gears and the derailleur tensioner is being pulled to an extreme position.
Luckily it's an ebike and not a pedal bike. Pivot position was a huge deal when full suspension bike first came out. Ideally the chain would remain neutral relative to swingarm travel to eliminate bobbing when on the pedals. Its pretty obvious the frame would fail that test.
AGS
1 kW
LewTwo
1 MW
Or as an alternative you could upgrade to an air shock while you are at it.
Be advised all of the above ship from China (about 2 weeks). You would also need to determine the length that is appropriate for your bike and verify that the mounting bushings are the appropriate diameter and length. You would need a 'high pressure' air pump for the shock as well.
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Be advised all of the above ship from China (about 2 weeks). You would also need to determine the length that is appropriate for your bike and verify that the mounting bushings are the appropriate diameter and length. You would need a 'high pressure' air pump for the shock as well.
Pure air shock is not always an upgrade from coil spring. Depends the use scenario and rider requirements.
wturber
1 MW
I don't understand this sentence. I would think that the bike should take a more normal stance once that adjusting nut is tightened down as shown in your picture. You could re-install it and see. You could also re-install it using one of the lower mounting holes. The threads don't look in bad shape to me in the photo. From what I see, would think that spring and assembly should still work fine. But maybe I'm missing something. Was the top mounting bolt broken, or was it still in OK shape?
Agreed. I’ve owned about 4 (maybe 5) forks using air and was happy with them. I’m currently using a plain old fox vanilla coil fork, and it feels way better than any of the air forks when it comes to a smooth progressive feel. I don’t think I’ll ever go back since weight isn’t an issue on my ebike. For the feel and control, the coil suspension feels a lot more like a motorcycle fork.
