Nexus 8 conversion advice needed
#1
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Nexus 8 conversion advice needed
Hello.
I can get a second hand ( but new/unused ) nexus inter 8 hub for a bargain price.
But it is a di2, roller brake hub. I don`t want electronic shifting & I want a disc brake.
I had a good look at the hub & all the info i could find on the net.
I am fairly certain I can make a custom manual shifter&shifting mechanisam for this hub... possibly a dual pull/cable style... since as I understand di2 hub doesn`t have a return spring. Are there any other differences I should be aware of ?
I am also fairly certain I can fit a 6 bolt disc brake rotor to the hub with the use of a custom adapter that would fit the roller brake interface on the hub.
Suppose i can do that... could there be any other issues with using a disc brake on a roller brake hub?
Is the interface geometry the only difference between a disc nexus 8 & roller brake nexus 8 hubs?
Or are there any other differences that would render such an adaptation not possible?
Any and all info is very welcome. Thanks.
ps.: before anyone asks, I understand such a conversion is not feasible for most folks..But I work in a machine shop so I can get stuff made.. for free, basically.
I can get a second hand ( but new/unused ) nexus inter 8 hub for a bargain price.
But it is a di2, roller brake hub. I don`t want electronic shifting & I want a disc brake.
I had a good look at the hub & all the info i could find on the net.
I am fairly certain I can make a custom manual shifter&shifting mechanisam for this hub... possibly a dual pull/cable style... since as I understand di2 hub doesn`t have a return spring. Are there any other differences I should be aware of ?
I am also fairly certain I can fit a 6 bolt disc brake rotor to the hub with the use of a custom adapter that would fit the roller brake interface on the hub.
Suppose i can do that... could there be any other issues with using a disc brake on a roller brake hub?
Is the interface geometry the only difference between a disc nexus 8 & roller brake nexus 8 hubs?
Or are there any other differences that would render such an adaptation not possible?
Any and all info is very welcome. Thanks.
ps.: before anyone asks, I understand such a conversion is not feasible for most folks..But I work in a machine shop so I can get stuff made.. for free, basically.
Last edited by roza; 05-09-24 at 12:50 PM.
#2
Senior member
The Di2 has a different axle assembly with no spring return so it can’t be retrofitted with a mechanical shifter. The stepper motor does the work both ways on the Di2 .
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#3
Clark W. Griswold
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Also I don't recall Nexus doing Di2 that would be Alfine but unfortunately as Dan Burkhart said it is not convertible. However roller brakes work well and di2 is awesome so would be a cool bike or if nothing else sell the Di2 stuff and get a new wheel and shifter and assuming your bike has disc brake mounts a disc brake and bingo-bango you have what you want and probably won't cost you much and potentially the sale of the Di2 stuff will more than cover it.
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Maybe the smart play is to shop for the exact hub you want, and sell this one to help pay for it.
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An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
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#5
Also I don't recall Nexus doing Di2 that would be Alfine but unfortunately as Dan Burkhart said it is not convertible. However roller brakes work well and di2 is awesome so would be a cool bike or if nothing else sell the Di2 stuff and get a new wheel and shifter and assuming your bike has disc brake mounts a disc brake and bingo-bango you have what you want and probably won't cost you much and potentially the sale of the Di2 stuff will more than cover it.
#6
Senior member
SG-C6061-8R appears to be a Di2 Nexus for roller brake, exactly as the OP stated. He wrote "I can get" not "I have purchased". There's nothing about a Di2 hub that prevents you from making a mechanical shifter for it, it just has to be able to push and pull, rather than only pulling and relying on a return spring.
Note I did not say impossible.
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#7
I was thinking you could do it with a 3D printer; all you need is a helical ramp with detents, mounted concentric with the axle, a sprung follower and two cables pulling in opposite directions going to a throttle-cable-like shifter. So the indexing would be nearly in the hub.
#10
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From my files:
"Cesur rollerbrake to disc adapter"
Now you know as much as I do.
"Cesur rollerbrake to disc adapter"
Now you know as much as I do.