Is it acceptable to mount a pair of sprockets on a disc brake mount ?

[stormbird]

Hi all

As title ..

Looking at options for 2wd on a delta , one option would be to mount a pair of sprockets on the 6 x M4 bolts on a disc brake mount attached to a IGH hub and using the hub as a mid-drive.

Difficulty would be the sprockets may have to be spaced quite a way apart for the chains to be inline with 2 x BMX freewheels each mounted on a halfshaft driving the rear wheels ?

Paul

 

[Popshot]

Disc brake mounts are usually M5. They will take more punishment from braking than you are likely to dish out in acceleration. Using long M5 bolts will likely be a problem though. Long bolts will supply leverage to try to strip the threads out. If the female threads are deep and you use high tensile bolts it may do. I certainly wouldn't totally poo-poo it.

 

[stormbird]

Using long M5 bolts will likely be a problem though. Long bolts will supply leverage to try to strip the threads out. If the female threads are deep and you use high tensile bolts it may do. I certainly wouldn't totally poo-poo it.

Quantifying ' spaced quite a way apart ' actually looks like being 20mm ! so under 1" should do it.

Paul

 

[Popshot]

Then my best guess would be it'd do ok.

 

[DannyC]

If the intervening gap was taken up by a thick piece of solid aluminium with only the bolt holes drilled through it then I would expect the movement to be minimal indeed. Slap a disc rotor on top to use as a drilling guide?

 

[quixotic]

Stormbird, I've seen multiple instances of using an IGH paired with a differential on Greenspeed Anura on the Utah Trikes site. Top photo is with Alfine hub, bottom is Nuvinci

Utah Trikes also converts tadpoles into quads. Here's a picture of a Catrike conversion where they used a cassette to drive a differential.

 

[stormbird]

Stormbird, I've seen multiple instances of using an IGH paired with a differential on Greenspeed Anura on the Utah Trikes site. Top photo is with Alfine hub, bottom is Nuvinci

Yes however I am asking if I can mount 2 sprockets onto the disc brake mount , so 2 on 1 side ?

Like option B [ with straighter chain runs ]

Paul

 

[DannyC]

My only mildly negative observation on option "B" was that it places all of the resistance load on only one side of the N360 casing whereas an implementation in a wheel has the resistive load distributed from the tyre/rim to both case flanges equally. But I have no idea whether this would result in any failure. I am doubtful that it would, but it is not how it was designed to be operated. Although this has never stopped any of us in the past and indeed the implementation shown in the photos above suggest that it is not an issue, so I would say go ahead and try it.

 

[stormbird]

My only mildly negative observation on option "B" was that it places all of the resistance load on only one side of the N360 casing

Surely there is an even restive load as the pedals provide one and the rear wheels provide the other ?

Paul

 

[DannyC]

Surely there is an even restive load as the pedals provide one and the rear wheels provide the other ?

Paul

Not sure that is true.
The pedals turn the sprocket and the internal gubbins turns the whole casing while the axle stays stationary.
On a normal bike the pedaling force on the sprocket is the input source and the output is both halves of the casing (the two flanges) that are turned and BOTH are connected to the load via the spokes and share the load/resistance to turning.
In this case only one side of the casing is retarded by the load.
It probably doesn't matter as the Anura and the other implementation attest to.