forresto2

I just received a gently used bike with a Nexus internal 7 hub.
the bike has not been used for sometime.
I have not had more than 5 minutes on it.

Is it OK to shift under load? How much load?
Is there anything I should do for maintenance or are these truly maintenance free until something goes wrong?

thanks.

JanMM

You should consider reposting this in the Bicycle Mechanics forum even though I'm sure someone will respond here with some useful info.
Closest I've been to one of those hubs was when I almost bought one in 2000. They've been around for a while.

Gresp15C

My only IGH's are old 3-speed Sturmey Archer AW's, but I wouldn't shift any IGH under load, except maybe the Nuvinci. In the case of the AW hub, it won't downshift at all under load -- it just stays in whatever gear it's in until you release torque on the pedals. If I were to try and upshift it under load, I'd feel enough resistance from the hub that it would stop me from doing it.

The only maintenance I would suggest for now is to familiarize yourself with the procedures for adjusting the shift cable, and for removing and replacing the wheel in case you have to change a tire.

CliffordK

Get out and ride the bike. You'll figure out how it shifts.

However, one of the hard things on the internal gear hubs in general is to get a gear partly released or partly engaged, so the internal parts meshing aren't fully meshed. So, I'd ease back on the power quite a bit.

GamblerGORD53

+100
Especially for Rohloff. Shimano IGHs have a lot of finicky little shift parts. They need to move.

Mark Stone

Shimano Nexus 7? Oddly enough my tablet is a Google Nexus 7.

Dan Burkhart 

Shifting under load is not advisable, even when the hub seems to respond to this action without complaining.
The Nexus hubs have rising pawls on the axle which engage the sun gears. Shifting when torque is applied creates friction between these parts as they engage and dis engage.
Breaking torque to shift will greatly improve the longevity of these parts.

JonathanGennick 

I have the 8-speed version. Shimano's instructions say to avoid shifting under load. You can often "get away" with shifting under a light load, but you might also hear various pings of pain from the hub as a result. Best is to pause your pedaling ever so briefly whilst you are twisting the shifter knob.

It's perfectly fine to shift while stopped though. That's a nice thing to be able to do at intersections.

The one thing I can think of is to eyeball your hub alignment from time to time. Scroll down to the bottom image in the following blog post, and notice the two yellow marks that I've zoomed in on:

Shifting Priorities ? Jonathan Gennick Living in the 906

It's super easy to eyeball these marks and adjust their alignment. There's a range of tolerance, but too far out of line can lead to trouble in shifting. Once adjusted, they aren't likely to go out of line.

Otherwise, I just ride mine.

wschruba

Dan knows what he is talking about, I would suspect.

Attempting to shift an IGH under load can damage the pawls inside--especially the shift pawls/clutch (depending on the design). Even if you don't damage anything, the hub will often not shift until pressure is released from the pedals, or will slam into (or partially into) gear. Incidentally, partially engaged gears that cause slipping are not a minor nuisance, as they are with a derailleur drivetrain; they can quickly lead to damage of the shifting pawls/transmission gears. Anything other than the most occasional slip needs to be investigated.

Slash5

Also, usually they won't shift under load. I've found until you let up, they just stay in the same gear. I usually try to give a slight backpedal when I shift.

jeanettebcrivel

Thanks for the advice.

corrado33

No, not at all. You should not shift under load. Like most internal gear hubs you either have to stop pedaling or significantly reduce pedaling pressure to shift.

When I shift under load the hub can get "stuck" in gear until you let off, usually accompanied by a large "bang". So I avoid doing that.

Maintenance wise, take it apart once a year or every other year (just a lockring on the side then the whole thing comes out) and soak it in ATF or whatever lubricant you want, then put it back together. Takes no more than an hour or two.

CrankyOne

Some good advice above on shifting. When riding just let up on pedaling a slight bit while you shift. Keep turning your cranks but just not with pressure. It becomes second nature quite quickly.

If the bike has been sitting for few years the hub may need a bit of internal cleaning. As well, new tyres and cables might be a good idea. OTOH, I've seen a number of IGH bikes get pulled out of a garage or basement after sitting for several years and be perfectly OK.

Overkill and not at all necessary. Most IGH's perform well for decades and often while stored outside all year without any service whatsoever which is one of the benefits. If you love doing this kind of stuff then go for it, you'll not hurt anything, but there's little to no benefit in doing it. Maybe you can go 14.02 MPH for 100 watts effort instead of 14.00 mph.

forresto2

Thank you for the great replies.
I have had and still have Sturmey-Archer 3-speed hubs from the 70s and will keep the same style but slightly more aggressive.

corrado33

While I mostly agree with you. Shimano DOES recommend a 1 year or 1000 mile initial service for their internal hubs, IIRC.

Dan Burkhart 

Yeah, well here's an internal assembly I pulled out of a nexus 7 speed.The owner said the bike was stored indoors, but ridden in all kinds of weather.
An IGH that sees only casual riding in fair weather can safely be ignored for years, but not one exposed to the elements.

CrankyOne

There was something else going on with that hub. Defective cap? These normally last for years or decades being stored outside all of the time in all weather and ridden daily in all weather - throughout The Netherlands, Sweden, Denmark, and elsewhere. We've a 3-speed that's still going strong after 20 years.

The 7's do seem to have had more problems than the 3's, 8's, and perhaps others but even with a 7 I'd expect the majority to go 20 or 30 years with no problems.

hueyhoolihan

oh my!

maybe he meant "in doors". as in, "in amongst old doors on the bottom of Lake Nipissing" or something similar.

sweeks

Here are service (lubrication) recommendations for Nexus-7, Nexus-8 and Alfine-11 copied from specific user manuals ("UM") and service instructions ("SI") from the Shimano web site (Manuals & Tech doc) The Nexus hubs are lubricated with special grease at the factory; the Alfine-11 is lubricated with an internal oil bath. Note that 5,000 km is about 3,000 miles.

UM-37G0A-004-00 (Nexus 7)
In order to maintain proper performance, it is recommended that you contact the place of purchase or your nearest Pro shop to carry out maintenance such as greasing the internal hub about once every two years starting from the first time of use (or once about every 5,000 km if the bicycle is used very frequently). Furthermore, it is recommended that you use the Shimano internal hub grease or lubrication kit when carrying out maintenance. If the special grease or lubrication kit is not used, problems may occur such as the gear shifting not working correctly.

UM-38G0A-001-00 (Nexus 8)
In order to maintain proper performance of the product, it is recommended that you contact the place of purchase or a bicycle dealer to carry out maintenance such as greasing the internal parts about once every two years from the first time of use (once about every 5,000 km if the bicycle is used very frequently).

SI-37R0A-002-00 (Alfine 11)
To maintain the performance of the unit, it is recommended that maintenance such as internal oil change be performed at the shop from which you purchased it or at a professional shop after riding a total of 1,000 km after start of use and every 2 years after that (every 5,000km if riding frequently). In addition, the SG-S700 Oil and TL-S703 maintenance kit must be used for maintenance.



I have two Nexus-7 hubs, one of which was damaged by water incursion (though still useable), two Nexus-8 hubs (one "standard" and one "Red Band") and one Alfine-11. The Nexus hubs are opened once a year and the internals dipped in gear oil. I use the Nexus grease (a molybdenum disulfide paste)on the bearings. The Nexus-8 hubs have 12,000 miles between them and appear virtually unworn on inspection. One of these is used on my "winter" bike on Chicago's salty,slushy streets.
The Alfine hub has not needed to be opened as it is lubricated by an oil bath. Maintenance is a breeze! I've been doing the oil change about every 1,000 miles... somewhat more frequently than recommended, but it's easy and because I use a less-expensive synthetic gear oil, it's cheap insurance.

Here is a place I would consider sending my hub(s) if I did not feel comfortable maintaining them myself:
Aaron's Bicycle Repair (Internal Gear Hub Service)
Steve