Nexus 3 hub with Shimano roller brake

GloveMakingMan

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I have lost almost all rear braking on my Woosh Zephyr CDN with Nexus 3 Shimano Roller Brake hub. Does anyone know if there is any adjustment possible? It appears to be a sealed unit. Also, does the nut that holds it on the shaft have to be put on only finger tight to allow the unit to move and be secured to the frame? Thanks
 

trex

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GloveMakingMan

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do you have trouble adjusting the innercable? you can loosen the pinch bolt on the arm (bottom of the picture) and adjust the innercable in the usal way.
The unit can be opened but there is no need to open the brake unit unless you accidentally drip oil into it.

The Shimano service manual for the Nexus-3 is here:
http://bike.shimano.com/publish/content/global_cycle/en/sg/index/products/city___comfort_bike/nexus_inter-3.html

post a picture if you need more help.
Thanks Trex. I will have a look at this link in a minute. It's not a cable problem, it's something to do with the actual brake, no matter how hard i brake it doesn't work. Only when i get off and try it does it actually do a little but bike can be pushed against the braking. The only thing i can see on it is a hole marked 'grease', i presume you have to pack the unit with grease!?
 

trex

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Don't grease the roller brakes.
You don't need to do anything to these brakes, not even adjusting the cable. They last for 5 years without doing anything. The usual cause for malfunction is water or grease getting inside. Dry the brakes with a hair dryer may help.
 
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GloveMakingMan

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Don't grease the roller brakes.
You don't need to do anything to these brakes, not even adjusting the cable. They last for 5 years without doing anything. The usual cause for malfunction is water or grease getting inside. Dry the brakes with a hair dryer may help.
Says 'Grease' with arrow pointing to rubber plug???? I have not done so but it's already full of grease, see photo.
 
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trex

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are the pads dry to touch? and the inner side of the outer shell also dry? no rust particles? like this one?

 
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GloveMakingMan

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are the pads dry to touch? and the inner side of the outer shell also dry? no rust particles?
Can't see any pads, all i see is what is shown in photo 3 and that's all covered in grease. Trex, your link to Shimano manual doesn't include this model roller brake. Model no. Is shown on front in photo 2.
 

tillson

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Don't grease the roller brakes.
You don't need to do anything to these brakes, not even adjusting the cable. They last for 5 years without doing anything. The usual cause for malfunction is water or grease getting inside. Dry the brakes with a hair dryer may help.
I think these brakes do require greasing. At least the Nexus Inter hub brake that I had on an Agattu did. There is a special Shimano grease for the job which comes at a special price.

I like these hub brakes for the back wheel, but wouldn't want one on the front. They are very low maintenance and suit the hub gear & electric bike configuration very well.
 
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flecc

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These hub gears do have to be greased to operate properly. Below are the Shimano grease packings with the part order numbers. 10 grams is sufficient for personal use:

Shimano Roller brake grease

10 gms Y-041 40020

100 gms Y-041 20400
.
 
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mountainsport

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I think these brakes do require greasing. At least the Nexus Inter hub brake that I had on an Agattu did. There is a special Shimano grease for the job which comes at a special price.

I like these hub brakes for the back wheel, but wouldn't want one on the front. They are very low maintenance and suit the hub gear & electric bike configuration very well.
I think I know of the grease that you are talking about, correct me if I am wrong tillson, is the grease white in colour ?

MS.
 

trex

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100g - that would be enough grease for 300 services. As flecc said, you don't need to grease it - I would suggest give it a clean and refit. If it does not work, email Andy@wooshbikes.co.uk
 
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flecc

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As flecc said, you don't need to grease it
No, I didn't say that, I said the opposite. That's why Shimano pack them with grease from ne and sell the top-up grease as I posted above.

That said, it doesn't appear to need any more at present.
.
 
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Geebee

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I have lost almost all rear braking on my Woosh Zephyr CDN with Nexus 3 Shimano Roller Brake hub. Does anyone know if there is any adjustment possible? It appears to be a sealed unit. Also, does the nut that holds it on the shaft have to be put on only finger tight to allow the unit to move and be secured to the frame? Thanks
Did your brake happen to appear more abrupt or stronger before failing?
Going off Sheldon Browns site, if the grease is washed out by rain the brake will lock up easily and then fail shortly there after, if so it will be a chuck away job.
 
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trex

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if grease gets onto the contact area of the 3 pads, efficiency may be lost.
Someone reported 'if you ride with them on down a long hill they get very hot, fade, the grease leaks or boils and they will then be very noisy.'
http://forum.ctc.org.uk/viewtopic.php?f=5&t=34273
 
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GloveMakingMan

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Did your brake happen to appear more abrupt or stronger before failing?
Going of Sheldon Browns site, if the grease is washed out by rain the brake will lock up easily and then fail shortly there after, if so it will be a chuck away job.
It's never been that good but i suppose a back brake doesn't need to be. It's so bad now that i would not be able to stop if front brake failed. It may have been caused by the amount of hills around here, i am on the back brake all the time trying to keep my speed down, but i would have expected it to last more than the 250 miles i've done!!!! The 10g Shimano Roller Brake grease is the more suitable quantity and a lot less money at £6 per tube. I will get it all back together and see how it is.
 

GloveMakingMan

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if grease gets onto the contact area of the 3 pads, efficiency may be lost.
Someone reported 'if you ride with them on down a long hill they get very hot, fade, the grease leaks or boils and they will then be very noisy.'
http://forum.ctc.org.uk/viewtopic.php?f=5&t=34273
See my previous comment, i reckon it's something to do with heavy use on our hills but i would have expected more than 250 miles use!!!
 

tillson

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I have limited experience of these brakes, but I thought that a lack of grease can initially make them lock the wheel with very little brake lever pressure and then fail shortly afterwards unless grease is applied. Once they have failed, there is little that can be done to repair them.

The brake internals in the photograph look a bit dry to me ( it may be my eyes). It could be worth cleaning out the old stuff the best you can and then re-greasing.
 
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trex

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I believe the best brakes for hilly terrain are hydraulic brakes. Bikes with torque sensor don't need brake sensors but the rest does. It's a shame that only a few brands make a version with sensor like Tektro and Zoom. It seems the most economical compromise for home builts to be front hydraulic without sensor and rear mechanical disc with sensor. If it were my bike, I'd put something like this to the front:
http://www.ebay.co.uk/itm/Shimano-M395-Hydraulic-MTB-Disc-Brake-FRONT-BLACK-/291217529004