Seems like NZ Post or China Post is much more worried than USPS about mythical CO2 cartridge expolosions.

Oh man china post won't carry batteries

not even cr2032 watch cells

there are 14 countries to which they will send batteries, but NZ isn't one of them.

stupid airlines

AND DX is overapplying the rules... the airline restrictions are all about lithium of various flavours, not other chemistries.

no I could get them cheap. $19/each for a 7 AH 12 V battery was astonishingly good, so $75 for 36Volts. The equivalent Lithium one would have been $600+ and I would have still needed a charger and a new BMS.

SLA is pretty idiotproof when it comes to charging.

I made a three-way harness to charge all three batteries at 12V with a car charger. Did that about 4 times a year. Normal charges were at 36V with no wiring changes needed.

@RoboKaren - I think they were shipped through UPS not USPS.

@Criggie Yeah, but Peukert sucks. Hate the man, hate the law. Means you only get about half of the capacity you pay for. :-(

well, paper is done. now just have to hope it gets accepted

@Batman yay!

now i have to finish the assignments for my class this week. :x

@RoboKaren Peukert ? something to do with SLA batteries being fully-discharged at 10.5V ?

So - I managed to pull the rear wheel out of the folder three times on the way home tonight

Even cinching the QR down super tight it still pulls forward on the right side, jambing against the left brake and chainstay and bending the rear mudguard stay on the right.

What to I do?

I've removed the trailer towball which was a metal plate on the left side, no difference

I'm sure its due to excessive leverage and power in the chain

cos it always happens on a hard take off modest

Do I need a chain tug to hold the axle in place? Do I need to rebuild the axle on a solid one with nuts, not a hollow QR one?

Is it because the 8 speed wheel's axle is wider so the drop-outs aren't completely parallel ?

is your QR steel?

I think so - BRB

Yes - QR stick is steel, and the QR lever is alloy. Frame is steel btw.

Want photos ?

On inspection, I'm sure the rear dropouts aren't parallel.

are the teeth steel or alloy?

on the skewer + nut

@RoboKaren en.wikipedia.org/wiki/Peukert's_law Yes - hating on that guy.

@Batman Photo coming... They are steel but quite smooth. I have a brand new spare front QR with alloy nuts, with sharp ridges. Better to swap ? Or do I need steel ones with sharp ridges? Could file some better surface into the ones I already have.

Alloy nuts should never be used with horizontal dropouts.If they're smooth, that is a good indication of why they're slipping out.

they were steel, but smooth. OK So refinishing the steel nuts with a file sounds like a plan, and making sure the dropouts are paralle in the frame. It used to be 6 speed and I've put it up to 8 speed. There was a lot of slop with a 6 speed freehub, and its just a little tight at 8 speed.

OK putting the alloy nuts away again.

in the photo the new alloy ones are on the left, and the original steel ones are on the right.

Do you think there's any advantage in putting the QR lever on the cassette side ?

I don't think so. Why not just pickup a new QR? the steel ones are easy to find if you look for a QR designed for a trainer

Found a couple of donors in the garage, but they're shorter front skewers. Going to find the beefiest one and file it to have pointy teeth. If that doesn't hold it. I'll go back to a solid axle.

All done - filed ridges into each side using a small triangular rats tail file.

took a while because it was hardened steel

but I can't make the wheel pop out now.

@Batman I suspect a chain tug would have cured the problem too, but nowhere to put them under a QR, so that would depend on a longer solid axle too.

@Criggie - thats good. But I'd have just chucked the skewer and got a new one. They're cheap enough that I don't normally do anything with them if they're worn.

And the paper deadline got extended. :-|

so i have to continue working on it to see if there are any improvements

Hah! Some skewers cost more than the whole bike did

yeah, but all you need is one of the ones that are marked for trainers. They're all steel.

as for a chain tug, I don't think it would have worked, anyway. the chaintug is secondary to the QR.

well there's a hole in the chain tug sized for an axle, but mine doesn't poke out enough so the tug would be under the QR only.

you want something like the thing that comes with the surly tuggnut

Hmmm - I found a couple of split-ring washers that fit inside the trailer hitch mount hole perfectly, so that will help. I had considered adding a bolt to the trailer hitch to stop it rotating.

ahh it makes more sense when you see it from that side

So yeah - its built for track bike horizontal dropouts

These look better.

wiggle.co.nz/dmr-chain-tugs-chain-tensioner

because they hook over the rear of the dropout

But no QR option so have to return to a solid axle, Which is not the end of the world.

I find that those work ok with a QR, you ideally want a 5mm hole but you can just use the edge of a bigger one.

Or if you're really fussy, get a bit of 10mm rod and drill a 5mm hole in the middle. I suspect that work better, but it would also be a effort and hassle every time you fiddled with the wheel.

Given the probs - I'm quite happy to go solid axle

well at least it seems the problem has been isolated -- you've been ha ving that slipping axle for a while i think

yup - I thought it was the weight of the trailer, or the raw power of my takeoff push.

bicycles.stackexchange.com/review/suggested-edits/24252

I'm torn on that one