Up the creek!

[Scooterman]

Its why over here I say that we all need decent tools...
https://www.wheelchairdriver.com/board/ ... 63#p213580

Because the alternative means that you get to wait. To never know. To rely on "experts". To be trapped by the system. And in the end get stranded miles from home or pay out many £££$$$ for what may be something trivial.

I had a worrying experience on Saturday. I have two of the same power chairs but one has 4 x 6mm bolts and the other 3 x 8mm bolts. The previous day I had had the wheel off the 3 bolt one and re-tightened it nipping up the bolts (I don't like to be too aggressive tightened bolts/nuts). Anyhow trundling along a country footpath I started hearing a knocking from one of the rear wheels. I looked down and could see it wobbling slightly and one of the 8mm bolts was slight proud. I just thought I must have missed nipping up that one when putting back the wheel but the other two would be suffice. Anyhow a few more hundred yards and the noise was getting louder and I looked down and the wheel was really wobbling, so I stopped and looked down at it and two of the three bolts were missing and the third was only just hanging on! I looked behind me and there were the other two bolts laying on the footpath a few yards behind. I was relieved I hadn't lost them back up the footpath somewhere. A lady jogger picked up the bolts for me. I can't walk but fortunately can mobilise enough to get myself out the chair and sat on a low wooden rail next to the footpath. But I thought what the hell am I going to do, I've not got any tools on me and if the chair drops off the one remaining bolt that probably only had 1 thread holding it on, I'm screwed. But luckily I was knew there was a toolstation about 1/4 mile away. So I did a click and collect or for some metric Allen keys, scribbled down the collection code on a scrap bit of paper, and an older guy with a couple dogs when and picked up the Allen keys for me and we got the wheel bolted back properly. That's the first time I've been really worried about being stranded somewhere. And will be more careful in future. Powered mobility is wonderful, until it goes wrong and leaves you stranded! But this incident was my fault, not the chair's

But I wonder whether the 3 x 8mm bolts is a poorer engineering solution than 4 x 6mm. As with the latter you have an extra bolt and more threads per inch

[shirley_hkg]

I prefer hex head bolts, that won't get stripped when tightening them hard.

Add tiny bit of medium strength thread lock for your own sake.

[Scooterman]

I prefer hex head bolts, that won't get stripped when tightening them hard.

Add tiny bit of medium strength thread lock for your own sake.

I did wonder that on hindsight Shirley. I normally put a dab of grease on the threads, but maybe I’d do better cleaning that off and putting medium strength thread locker on the threads as you say.

[Burgerman]

Never had one come loose. Greased. You must have forgot to tighten them.

[Scooterman]

Never had one come loose. Greased. You must have forgot to tighten them.

Well I could! I do seem to have a lot memory lapses. I think in critical industries they mark the bolts/nuts once torqued to correct tiightness

[LROBBINS]

Or, the wheel wasn't fully seated on the shaft before inserting the bolts and when you tightened them they grabbed only part of one thread and felt tight, but were primed to shake loose.

[Raro]

A little threadlocker wouldn't hurt, besides the screws. Did you recover the conical washers? I think those rims have them.

[Scooterman]

A little threadlocker wouldn't hurt, besides the screws. Did you recover the conical washers? I think those rims have them.

Yes I did! I was so fortunate they were still on the bolts. I was so lucky the bolts were lying close by. This is the first chair I’ve had with conical washers on wheel bolts. So have to to make they’re round the right way.

[Burgerman]

Theres a lot of cars and trailers on the road. Some use conical washers. Some use conical nuts. Some are at 30 degrees. Some 45. Non use thread locker. Copper grease is advised. And they dont fall off...

Some cars/ trailers and big trucks use no taper at all. Some have 3 wheel nuts, some 4 and some 5 or 6. Trucks use plain old flat nuts and can have 8, 10 etc. Unless someone forgets to tighten them, or in the past has had wheels repainted and the paint prevented them seating properly until after some use! New wheels, first service check all wheelnuts.

Wheelnuts are no more likely to come undone than a bolt or nut in any other item. If like lenny says, is correctly installed. A slow tyre fitter will fit a full set of tyres easily in 30 mins. Thats 8 tyres per hour. 8 hours per day. So 64 wheels per day. Call it 50... He had a break.

So thats mon to friday, 250 wheels fitted. How many of them fell off? After 52 weeks that is 13,000 wheels! Did any fall off? Only if he forgot to tighten them! Logic.

[Raro]

Yes, if you are careful and install it correctly with the proper tightening torque, there shouldn't be a problem. It's just an extra precaution; some wheelchairs, like the Permobil, use it as standard.

[Burgerman]

As long as you dont use strong stuff. Blue ones should be OK. But really not needed. Might just make it really hard to swap a wheel one day. Thats why I always grease threads on everything except plastic. Or stuff that really needs loctite! Say, the Jesus nut on a helicopter...