Bicycle Mechanics - Shimano nexus inter 7 and roller brake question?

First about the roller brake. I have notice it is getting VERY noisy. To the point it sounds like metal on metal scraping if I squeeze the brake enough. Is this just a sign that it needs oiling or of an impending failure? It is a used bicycle and I do not know it's history. I have put around 1200km on it in just under 3 months and have done no maintenance yet.

On the hub itself. I plan on replacing it as it clearly has a problem. Every other gear feels like it's grinding sand and there is a noticeable squeak. The others feel and work just fine. It was having shifting problems but I have it adjusted and that took care of that. I prefer to ask here as non of the local shops have experience with these internally geared hubs (one store said they could read up on them and work that way :eek: ).

If someone knows a place online to buy these things cheap or anything else I may need to fix/maintain things please post! I am on a tight budget.

First about the roller brake. I have notice it is getting VERY noisy. To the point it sounds like metal on metal scraping if I squeeze the brake enough. Is this just a sign that it needs oiling or of an impending failure? It is a used bicycle and I do not know it's history. I have put around 1200km on it in just under 3 months and have done no maintenance yet.

These are grease filled. There is a small plastic tab on the outside - fill with Shimano brake grease. You can remove the brake and run the hub without the roller brake (you'd want a rim brake such as a V brake fitted). This will reduce the width by about 4mm, so washers or a narrower frame may be required.


On the hub itself. I plan on replacing it as it clearly has a problem. Every other gear feels like it's grinding sand and there is a noticeable squeak. The others feel and work just fine. It was having shifting problems but I have it adjusted and that took care of that. I prefer to ask here as non of the local shops have experience with these internally geared hubs (one store said they could read up on them and work that way :eek: ).

If someone knows a place online to buy these things cheap or anything else I may need to fix/maintain things please post! I am on a tight budget.They're not particularly hard to work on as long as you do not dismantle the axle unit (lots of small parts). Open the whole thing up (instructions here (http://bike.shimano.com/publish/content/global_cycle/en/us/index/tech_support/tech_tips.download.-Par50lparsys-0022-downloadFile.html/16%29%20Inter%207%20ohaul.pdf)). Clean out well and see what is worn. Sounds like the bearings may be shot. I have had repeated trouble with the drive side cone, the seal keeps letting water in and rusting the cone :(.

More information at Sheldon Brown (http://www.sheldonbrown.com/nexus-mech.html)
PDF of parts etc (http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/SG/EV-SG-7R46-2128E_v1_m56577569830702947.pdf)

Good luck.

As far as a new one, just keep checking prices. I found mine through Amazon ~6 months ago for ~$85 complete. That was a great deal, but those kind of deals are out there if you can afford to wait. I could. I watched prices for months beforehand.

These are grease filled. There is a small plastic tab on the outside - fill with Shimano brake grease. You can remove the brake and run the hub without the roller brake (you'd want a rim brake such as a V brake fitted). This will reduce the width by about 4mm, so washers or a narrower frame may be required.

They're not particularly hard to work on as long as you do not dismantle the axle unit (lots of small parts). Open the whole thing up (instructions here (http://bike.shimano.com/publish/content/global_cycle/en/us/index/tech_support/tech_tips.download.-Par50lparsys-0022-downloadFile.html/16%29%20Inter%207%20ohaul.pdf)). Clean out well and see what is worn. Sounds like the bearings may be shot. I have had repeated trouble with the drive side cone, the seal keeps letting water in and rusting the cone :(.

More information at Sheldon Brown (http://www.sheldonbrown.com/nexus-mech.html)
PDF of parts etc (http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/SG/EV-SG-7R46-2128E_v1_m56577569830702947.pdf)

Good luck.

Thanks for the suggestion. I thought the hub was likely just suffering for a bad bearing. It feels and sounds quite simmilar to when my GT had bad bearings in the bottom bracket (but that would not go away simply by shifting gears like it is with the nexus). Also Other than the occasional shifting glitch the hub works fine.

Is there an alternative to the Shimano roller brake lube? I've got some leftover synthetic high temp brake snot for caliper glide pins.

harshbarj, I'd clean and then dip the internals in ATF, it might extend the life. If the internals are dead, you might buy a donor hub, use the internals and keep your existing wheel.