vaarticus
New Member
This was for my 2022 Turbo Levo (8mmx500mm rod) but the idea probably translates across brands.
There shouldn't be threads on the inside and the pressure on the drive unit would be far less that what would be achieved in normal riding.Its a good idea, but i will point out you are putting pressure on the threads of the main drive unit, so even turning the pedals could be damaging. It is steel on steel. Nice concept all the same.
So how are the cranks attached then ?. Far as im aware its a hollow axle, threaded on the inside. Am i wrong here ?. You'd need to remove the crank bolts.There shouldn't be threads on the inside and the pressure on the drive unit would be far less that what would be achieved in normal riding.
Maybe this helps. Definitely there are no threads where the rod goes through… and just to be clear, it’s not like you are actually pedaling the bike on the stand. But the ability to rotate the pedals helps a ton for things like chain lubrication.So how are the cranks attached then ?. Far as im aware its a hollow axle, threaded on the inside. Am i wrong here ?. You'd need to remove the crank bolts.
As vaarticus said the rod would rest on of the internal bore of the retaining bolt and not touch any of the threads.So how are the cranks attached then ?. Far as im aware its a hollow axle, threaded on the inside. Am i wrong here ?. You'd need to remove the crank bolts.
It’s not a problem at all actually, but to your point, the rod is 8mm and the hole is also 8mm.Next best engineering solution if you are worried about pressure on the inside of the bolt would be to have a rod that is very close in diameter to the internal diameter of the bolt.
But honestly I very much doubt this is a problem.
As I have already said, not all bikes have a hollow crank bolt to allow a rod to be inserted but an 8mm steel bar would be plenty strong enough. If the bar sits on the hollow bolt it will be held off the threads for the tiny distance past the end of the bolt. The threads do not go all the way through the crank shaft, so even if it did bend it will still not touch the threads.If the retaining bolt is hollow, and not every one is. Mine is solid, so to slide a rod through you'd need to take the bolt out completely, so im my case, and I expect other manufacturers it wouldn't work.
The rod would also have to be hardened, and of significant diameter not to bend, and im quite sure a rod going through supported on the ends only, will bend internally unless it is the exact size of the internal bore and place pressure on those threads. Given most bikes weigh 50+lbs
I said it was a good concept, im not knocking it entirely, but theres a lot more to engineering something than just sliding a bar through.
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