1.5 years ago I bought
8-speed Shimano Nexus hub, shortly after I bought new city/road bicycle for daily commuting.
I became concerned when read on
Sheldon Brown's website that these internal gear hubs are improperly lubricated for wet climate. I live in Ireland, and it's very damp here, it rains quite often. Another complication is that my bike is stored inside my house, in a heated space, so when I bring it outside every morning, the air inside the hub obviously contracts as the hub cools down and moisture together with sand and dirt can get pulled inside. This risk is very real since Nexus hubs aren't sealed well, compared to Alfine hubs, for example.
Therefore I followed
Sheldon Brown's advice and properly lubricated my hub, in order to prevent water and dirt contamination in future. I did it in January 2015 right after the hub was built into my bike's rear wheel by LBS. First, I removed manufacturer's grease using special spray, allowing hub's parts to dry after that. Then I applied
Phil Wood waterproof grease for the outer bearings, white lithium grease for the gears and
Phil Wood Tenacious Oil for the pawls and in the hub shell 'to slop around', just like you can see on this photo:
http://www.rideyourbike.com/images/i.../alfineoil.jpg
(picture taken from
here) (actually you can see marine grease applied too, where left side outer bearings will sit)
During all 1.5 months of riding (3-7 times per week, making 2 * 6 km trips) I continued having two issues.
First issue is a gear slips now and then (I get sudden 'idle' turning of my pedals for like half or their revolution). It can happen once during my 6-km trip, it can happen twice, or not happen at all. There's no difference which gear is on now. It's especially frustrating when it happens as I'm accelerating standing up on my pedals (and it's always accompanied by four letter words). I know that gear isn't there 100% and this is very discouraging. This makes me in-confident and I don't commit to my full power efforts while riding.
Is this normal? I read somewhere on Amazon, in comments, that a Shimano hub can 'skip' a gear now and then (suddenly go up or down one gear, as I understand), but this is supposedly normal "until the unit 'beds' in". Does this mean that slippage, which I'm having, will also go away when the unit 'beds' in? Did anyone have such experience?
Second issue is the sound I hear on 4th and 6th gears. It's like grinding or something, not too strong as sound, more as vibration I feel with my feet. I am also wondering if this is normal and if it will go away too.
Like I said, I've been riding my upgraded bike for 1.5 months, 5 times per week in average, making 12*5 = 60 km per week. So it's like 60*6.5 = 390 km (242 miles).
Can this slippage be because my rear wheel is a bit askew after hub's installation? Unfortunately, I couldn't manage to correct it, no matter how I tried, even though dropouts are vertical. I didn't have this issue when there was a regular Shimano Altus derailleur...