Disk Brake Hub

[Tommy Griffin]

Ok so I have a 12 gauge coaster brake wheel that has the sprocket adapter attached to the hub . I have trouble with the hub adapter slipping and I really dont like coaster brakes at all . I was wondering instead of buying a whole new wheel for 70$ why not buy a hub and replace the coaster hub ? Could I use the same spokes and rim ? It could be too hard right ? I see disk brake freewheel hubs on eBay ranging from $10 to $75 . I wanna know how hard it would be and what hub can be trusted ? Im running a ZEDA PK80 and the motor is pretty strong so I dont wnat anything weak .

 

[crassius]

you're planning for both the adapter & sprocket and a disk brake all on same side of wheel???

that would be harder than most folks want to get into

 

[CrazyDan]

You could lace in the disk hub and drill out a 6 bolt pattern to mount the sprocket in the disc location then use spacers to mount the disc brake. Having the drive gear and a disc brake on left side of the rear wheel is very hard to do, tons of alignment issues with both parts. Odds are your rim is not made to use v or u brakes so those won't work too well, but is an option.

 

[FurryOnTheInside]

Surely the OP meant to use a top hat adapter for mounting the sprocket inboard of the disc rotor mount, the standard 35mm-ish from the centre line, rather than offset the whole motor & chain to the left.
I would love to do this too but the top hat adapter is only made in USA so it's ridiculously expensive in UK/Europe so I have a clamshell adapter and I'll just have to solve the slippage issue the best I can until I can save up for the SBP shift kit.
If the clamshell adapter simply will not stay in one place and slips around then I may have to bolt something to the rotor mount to brace the outside of the sprocket as a secondary mount but idk, I'll burn that bridge when I get to it.


To the OP. Idk yet, but I expect 12g is overkill once you have a reliable hub driven wheel with no interference with the spokes. If you want to drill out spoke holes then a hub with lots of excess material outside of and between the holes is going to be able to handle having some removed better than a more minimal one, I guess. I still expect the spokes will end up stronger than the hub flange. As the holes get bigger the space between gets smaller and then it's basically perforated like toilet paper which we all know usually rips along the perforated lines! Personally I think I would just invest in quality spokes, 14g or Alpine III if you can afford them, plus nipple washers if your rim needs them to take the 14g nipples.

 

[Tommy Griffin]

Surely the OP meant to use a top hat adapter for mounting the sprocket inboard of the disc rotor mount, the standard 35mm-ish from the centre line, rather than offset the whole motor & chain to the left.
I would love to do this too but the top hat adapter is only made in USA so it's ridiculously expensive in UK/Europe so I have a clamshell adapter and I'll just have to solve the slippage issue the best I can until I can save up for the SBP shift kit.
If the clamshell adapter simply will not stay in one place and slips around then I may have to bolt something to the rotor mount to brace the outside of the sprocket as a secondary mount but idk, I'll burn that bridge when I get to it.


To the OP. Idk yet, but I expect 12g is overkill once you have a reliable hub driven wheel with no interference with the spokes. If you want to drill out spoke holes then a hub with lots of excess material outside of and between the holes is going to be able to handle having some removed better than a more minimal one, I guess. I still expect the spokes will end up stronger than the hub flange. As the holes get bigger the space between gets smaller and then it's basically perforated like toilet paper which we all know usually rips along the perforated lines! Personally I think I would just invest in quality spokes, 14g or Alpine III if you can afford them, plus nipple washers if your rim needs them to take the 14g nipples.

You dont have to do that . There is a one peice sprocket on Ebay I seen today and its sold from the UK . So that should be rigt up your alley

 

[FurryOnTheInside]

You dont have to do that . There is a one peice sprocket on Ebay I seen today and its sold from the UK . So that should be rigt up your alley

Hi Tommy. What mount type are you looking at?
I have a disc rotor compatible hub (but no disc brake), and a clamshell adapter that's a bit oversized so it needs some shims making.
I have tried the 9 hole kit sprocket against the clamshell adapter and it's a "no go". Three new holes would have to be made. Adapter is about 94mm BCD and the sprocket about 75mm BCD.
I have tried the 9 hole kit sprocket against the disc hub, and it's also a "no go". The central hole would need to be cut out quite a lot bigger to be able to slip over/past the disc rotor mount.

There are some 6and9 hole sprockets, that is they have two circles of holes (outer set is kit 9 pattern, inner set is I.S. disc rotor pattern) and a small central hole, but I think it's very important to note (and the point I was making, badly) that the disc rotor mount on the hub is approximately 51mm from the centre line of the bike (on my 135mm O.L.D. multispeed hub), where as the motor's output sprocket is only about 36mm from the centre line.

I have not had a single speed disc hub to get the measurement for that but still,
I or the OP would have to be careful to make sure the motor sprocket is lined up correctly with the rear sprocket for reliable, quiet and efficient function of the chain.
That's why there's a top hat. I believe that it offsets the sprocket inwards towards the centre line just enough to line up correctly with the motor sprocket when it's used on 110mm O.L.D. single speed disc hubs. It must require a sprocket with a large central hole so that the sprocket fits past the rotor mount.

I think having a top hat that positions the sprocket about 36mm off the centre line so that it nearly touches the spokes (just like a kit rag joint) would allow some room for a rear disc brake caliper, at worst it would need a little modification to the caliper mount, or the use of a very large rotor and a small sprocket.

 

[Tommy Griffin]

Hi Tommy. What mount type are you looking at?
I have a disc rotor compatible hub (but no disc brake), and a clamshell adapter that's a bit oversized so it needs some shims making.
I have tried the 9 hole kit sprocket against the clamshell adapter and it's a "no go". Three new holes would have to be made. Adapter is about 94mm BCD and the sprocket about 75mm BCD.
I have tried the 9 hole kit sprocket against the disc hub, and it's also a "no go". The central hole would need to be cut out quite a lot bigger to be able to slip over/past the disc rotor mount.

There are some 6and9 hole sprockets, that is they have two circles of holes (outer set is kit 9 pattern, inner set is I.S. disc rotor pattern) and a small central hole, but I think it's very important to note (and the point I was making, badly) that the disc rotor mount on the hub is approximately 50mm from the centre line of the bike (on my 135mm O.L.D. multispeed hub), where as the motor's output sprocket is only about 35mm from the centre line.

I have not had a single speed disc hub to get the measurement for that but still,
I or the OP would have to be careful to make sure the motor sprocket is lined up correctly with the rear sprocket for reliable, quiet and efficient function of the chain.
That's why there's a top hat. I believe that it offsets the sprocket inwards towards the centre line just enough to line up correctly with the motor sprocket when it's used on 110mm O.L.D. single speed disc hubs. It must require a sprocket with a large central hole so that the sprocket fits past the rotor mount.

I think having a top hat that positions the sprocket about 35mm off the centre line so that it nearly touches the spokes (just like a kit rag joint) would allow some room for a rear disc brake caliper, at worst it would need a little modification to the caliper mount, or the use of a very large rotor and a small sprocket.

http://www.ebay.com/itm/Motorized-B...ash=item2a6781ea1d:g:~3MAAOSwa-dWh719&vxp=mtr

 

[FurryOnTheInside]

http://www.ebay.com/itm/Motorized-B...ash=item2a6781ea1d:g:~3MAAOSwa-dWh719&vxp=mtr

Wow those are really cool sprockets. Nice find! Looks like they have the "top hat" offset built into the sprocket (and stainless steel too) which means the price is actually very good!
I think these would be great for the OP or anyone with a 110mm O.L.D. disc compatible hub, but they are not for me with a 135mm O.L.D. multi speed hub (where the difference between the motor sprocket distance from centre line (about 36mm centre of the teeth) and the rotor mount face distance from centre line (about 51mm) requires a very large "top hat" offset.)


Edit: some bad pictures


Idk why that came out sideways. Ugh. -_-



So I've asked the eBay seller if he can tell us the offset of his sprockets, and I'm expecting they'll be fine for 110mm width single speed hubs although I do not know what the measurement for those is.

 

[Tommy Griffin]

Wow those are really cool sprockets. Nice find! Looks like they have the "top hat" offset built into the sprocket (and stainless steel too) which means the price is actually very good!
I think these would be great for the OP or anyone with a 110mm O.L.D. disc compatible hub, but they are not for me with a 135mm O.L.D. multi speed hub (where the difference between the motor sprocket distance from centre line (about 36mm centre of the teeth) and the rotor mount face distance from centre line (about 51mm) requires a very large "top hat" offset.)


Edit: some bad pictures

View attachment 76453
Idk why that came out sideways. Ugh. -_-
View attachment 76454


So I've asked the eBay seller if he can tell us the offset of his sprockets, and I'm expecting they'll be fine for 110mm width single speed hubs although I do not know what the measurement for those is.

Furry I found the perfect solution . This stuff called aluma-steel . Its a welding rod that is made specifically for welding aluminum to steel . It would be 30 bucks to buy since I gotta buy a pound . I would just buy it , taske it to a welding shop and have them put about 5 or 6 tacks on each side of my hub where it touches the adapter . That would keep me from slipping . What you think of that ?

 

[FurryOnTheInside]

Furry I found the perfect solution . This stuff called aluma-steel . Its a welding rod that is made specifically for welding aluminum to steel . It would be 30 bucks to buy since I gotta buy a pound . I would just buy it , taske it to a welding shop and have them put about 5 or 6 tacks on each side of my hub where it touches the adapter . That would keep me from slipping . What you think of that ?

So you have a steel hub, I presume? I haven't seen one of those in a while. I have no idea how well that product works and I'm no welder, so I can't really comment.

I have an aluminium hub and a loose clamshell adapter. I have not got around to making shims yet but they will just be aluminum strips just bent over some tube and cut down to make semi circles. I am hoping to get away with just shims and a bit of red loctite (but no loctite between shims and hub, I think).
I have only been able to get a 36t rear sprocket so there'll be less torque (than I'd like) being applied through my adapter. I really don't think I can get the adapter welded to the hub since I would have to deconstruct a perfectly good and strong wheel.
I have the rotor mount that is not being used, so I will try just bodging up a secondary attachment on that if the adapter slips.