ISO Hubs / Bolt on cogs

I've been running a bolt on velo-orange cog on a Shimano Deore front disc brake hub I built up years ago without a single issue. Solid.

Anyone got a spare 16t?

https://m.ebay.co.uk/itm/Hope-6-Bolt-BMX-Sprocket-Driver-Ex-Demo-Ex-Display-From-Evans-Cycles/122855882817?hash=item1c9ac80041:g:YNMAAOSwyP5aLt49

Not too expensive.

Thanks, will give that a punt if @c00ps can't find his

I have a 17t, they are pretty roughly finished for a Hope product but at that price...

Oh and ignore what the ad says, they are steel.

Sorry dude. (Hangs head in shame)

I've decided to have my local machinist make up one of these axle inserts for an upcoming wheelbuild.

I was wondering:

Do you mind if I borrow the design?

Did you do it in stainless steel or in aluminium alloy (and if the latter, what grade did you opt for)?

Did you find the 119.5mm length allowed for adequate tolerance when tightening the screws? I'm assuming elastic extension of the axle under tension is negligible; I'll do the calc but can't recall a good rule of thumb to relate tightening torque to axial force just now (and haven't chosen my material, see above)

It looks like you've used off the shelf button screws with regular washers - is this the case? I was considering using countersunk machine screws with corresponding countersunk washers, but if -say- you found that serrated washers were needed to avoid slip, I would rethink.

Thanks in advance.

Do you mind if I borrow the design?

I'd rather you stole it

Did you do it in stainless steel or in aluminium alloy (and if the latter, what grade did you opt for)?

The tandem one is 316 stainless, the 464 one is 7075T6 aluminium. This design for a solo should be plenty strong enough in cheap 6082T6

Did you find the 119.5mm length allowed for adequate tolerance when tightening the screws?

Yes, as long as your spacers are sized accurately. The hub should be very close to 100mm, if it isn't then send it back.

I'm assuming elastic extension of the axle under tension is negligible; I'll do the calc but can't recall a good rule of thumb to relate tightening torque to axial force just now (and haven't chosen my material, see above)

If your bolts aren't on the point of breaking, you haven't got enough tension in the axle to get anywhere near closing up that 0.5mm gap.

It looks like you've used off the shelf button screws with regular washers - is this the case?

Yes

I was considering using countersunk machine screws with corresponding countersunk washers

If you use M6 screws as I do on solo bikes, you need chain tugs, and then you need to change the axle design to give the tugs something to hang on to. Anything bigger doesn't need the countersunk screw/washer combo to create a large enough bearing surface, the head on an M10 button is already plenty big enough.

On the tandem, all the interfaces are smooth and the M10 bolts hold without any assistance (although there's no harm in using tugs if you have some which fit), and I didn't even gronk on them, they're only done up to 20Nm.

Anyone got a source other than Velosolo for iso cogs?

I need a 17t and they are out.

Might just try and drill a threaded cog.

Here.
http://www.only-highend.biz/epages/63221174.sf/de_DE/?ObjectPath=/Shops/63221174/Products/OH-000093

Cheers.

aliexpress: 3/32"

I've bought a cheapo threaded one off ebay to dry and drill, should be fun.

If the velosolo one aint gonna be too long I can maybe just spin about on a 19t for just now!

post a photo if you make it yourself

Will do.

My dad has just bought a lathe/mill so I figure if I can mark it up accurately I should be able to drill it accurately and then turn the centre bore to the correct diameter and remove the shoulder.

turn the centre bore to the correct diameter

For a cheaper and simpler conversion, start with a flat HG sprocket like Shimano DX, the ID on the splines needs somewhere between nothing and a bit of light filing to fit the disc rotor register on the hub (assuming it has one, not all do) and you have no shoulder to take off.

I wonder if anyone's done this with a dynamo hub? Do dynamo hubs work if you run them backwards?

There doesn't seem to be any particularly good reason to do it (except if you really need a double-dynamo fixed gear setup for max. Instagram cred), just curious really.

Biggest problem with using a dynamo hub would be changing the axle.

Some of the Shimano ones might work?

I don’t think your meant to be able to remove the axle from any dynamo. Something about alignments if certain elements...?

I’m sure I’ve read about people successfully stripping and rebuilding Shimano and Sturmey hubs though.

If it’s something you really want to do, I’d be looking for posts about servicing bearings on dynamo hubs to find out which hubs people have successfully stripped and rebuilt and going from there.

Do Shimano do a 6 bolt dynohub? My Alfine one is centrelock.

problem with using a dynamo hub would be changing the axle

You don't have to change the axle if you get a through-axle dynamo hub, just make a suitable through axle and spacers as described above.

Oh yeah, good point.

@spotter How thick is the hub body on the FIXIE Inc. - ShuRi hub?

I looking for a hub to convert to 10mm thru axle so there needs to be room for a ~18mm Ø sleeve/spacer inside.

The novatec/aliexpress version looks to be too narrow:

Ah I've sold mine long ago, but ask the shop who sells them maybe they can help?

Good idea, thanks