Replace Shimano Nexus M roller brake (front) or move to another rim

[scottinwales]

Hi folks

Hoping someone might be able to help me.

My bike has a Shimano Nexus M brake system on the front.
It's not something I've ever seen before.

I need to change the rim on my front wheel, so would like to know - can this brake system be moved to any rim or is it reliant on a specific hub in the wheel ? (I suspect it may be the latter since the hub also says Shimano)

Failing this, do you know if its possible to replace this type of brake with cantilever or disc ?

I've recently moved to Wales and want to keep the bike I've got, so have bought a front wheel electric kit - only to now discover this may be a non starter thanks to the brake system.

Never seen any of this stuff before so apologies for my cluelesness at this point!!

Grateful for any advice.

ta

[mjr]

My bike has a Shimano Nexus M brake system on the front.
It's not something I've ever seen before.

Oh they're lovely. I slightly prefer the Sturmey-Archer hub brakes, but Shimano roller brakes are also good.

I need to change the rim on my front wheel, so would like to know - can this brake system be moved to any rim or is it reliant on a specific hub in the wheel ? (I suspect it may be the latter since the hub also says Shimano)

I believe it needs a roller-braked hub. Why do you need to change the rim? The lack of brake pads rubbing on it should mean it lasts for a very long time.

Failing this, do you know if its possible to replace this type of brake with cantilever or disc ?

I think that will depend on the front fork. Has it got brake mounting points? It's unlikely to have disc brake points if it was supplied with the Shimano brake originally, but I've seen some with cantilever or V brake bosses as a backup plan.

Maybe you can replace the fork. I hope others will know what you need to know to choose a fork: I've never had to.

I've recently moved to Wales and want to keep the bike I've got, so have bought a front wheel electric kit - only to now discover this may be a non starter thanks to the brake system.

You have my sympathy. I've had a few problems with wheel compatibility over the years. You think a wheel is just a wheel and then you buy a replacement...

What brake system(s) is the kit compatible with? Actually, what's the kit?

[scottinwales]

Hiya

Thanks for the reply.

It's a Swytch electric conversion kit. Basically it replaces the front wheel with an electric one.
When I sent them pictures of the bike they said it would fit, obviously they didn't spot the roller brake.

It's a shame, you're right the brakes work nicely, but if I change the front wheel to the electric one it means either no front brake, or sending the kit back and starting again.

Looks like I need to see if I can find some replacement forks then!

[backnotes]

Can you post a photo of the fork crown area? If there’s a drilling for a mudguard bolt that goes from front to back there may be options for mounting a suitable calliper brake on the existing forks.

[scottinwales]

It looks like I can get some forks off eBay relatively cheaply which seem to have the same measurements so might not be TOO bad (granted they're only basic)
But might do as a proof off concept at least.

Existing ones in attached pic.

[rjb]

Some Shimano roller brakes use a standard disc mount to hold the reaction arm. If so then all that would be needed would be a disc hub in the switch hub kit and a disc plus a cable disc brake. Assuming the original brake lever could be reused.
If changing the forks be aware them come in different standards, 1",1,1/8" threaded or thread less and different lengths to suit wheel size plus brake mounting systems. It's a can of worms if you don't know exactly what you need.

Roller brake for a disc fork mount. https://store.pedalrevolution.co.uk/dpt ... ount__3530

[scottinwales]

I've taken the forks out and they're straight, threaded, 1 and 1/8th 28" forks as far as i can tell.

The swytch wheel definitely accepts a disc.

Any ideas what I'm looking for on the fork to know if it's using a disc mount?

Thanks for the reply though, that would be an ideal result.

[rjb]

Post a side view of your forks from the left side and it may have the mount already.

[scottinwales]

Alas nothing on the side.

[scottinwales]

Pic got lost then.

[531colin]

I don’t think there’s a disc mount there.
To match the fork, you need to know
Fork offset (AKA rake)
Axle to crown race seat measurement
….and headset type 11/8 threaded
and disc calliper mount (type)
and mudguard eyes at dropouts

I think that’s all….offset and axle to crown race length govern steering characteristics

Or use a side pull rim brake, it looks like the rim has brake block tracks. Hell, no, you are changing the wheel!
I don’t know what cable pull roller brakes use; there are 2 common cable pulls, and you need to match up if you want to keep the existing lever. Or replace the lever…..

Actually I would swap to thread less headset, that frees you from the task of getting the right length of thread for your frame….
…..complicated isn’t it?

[scottinwales]

Yeh complicated.

For the money I'm gonna take a whirl at the forks I've found. Try em. And see how I go.

[f.angular732]

Hey, I'm going under the EXACT problem (that's how I found this forum). Have you solved it?

My kit will arrive only on summer, and meanwhile I'm checking for solutions around the brake issue. So far I found these adapters to make the fork compatible with disc (would discard the roller system), seems the least intrusive solution so far:

https://www.amazon.co.uk/Yosoo-Health-G ... 54&sr=8-15