Shimano Nexus 8 IGH and Winter Shifting Issues
 

Today was cool here in WI and got me thinking about what's coming. I'm a year round commuter in Wisconsin and got a new bike with a Shimano Nexus 8 IGH in March. I've put 2000 miles on it and have been very happy with it. However, when I first got it, temps were in the teens and I experienced some days when I could not shift gears. I attributed it to moisture condensing in the cable housing. Took it in to the LBS and they adjusted so the yellow dots lined up in 4th and I was good to go.

I would be very interested to hear from folks in the Midwest or other cold climates that are commuting with the Nexus 8 in winter. Please share your experience and what you found that works. I have read a number of posts and see conflicting information, but not too many with actual experience at cold temps (from 15 Deg F down to -20 Deg F).

I am considering buying the Gore RideOn Sealed Low Friction System - it is pricey, but if it works, its worth it. But if there is a fundamental issue with the Nexus 8 at low temps, that would be very good to know.

Thanks

I am considering a new bike with this internally geared hub. I haven't thought about how the winter affects the hub. I, too, am interested in anyone's experience.

My son has commuted with his Alfine IH through 2 Minnesota winters with no adverse effects.

Several members of the Yahoo Geared Hub Bikes group live in the midwest, New England and Canada so they might be able to answer your questions. There is a link to the group in my signature block below. Join up and ask away!

tatfiend,

Thanks, I just joined the Yahoo Geared Hub Bikes group and will review this. Just what I was looking for.

I've got a Nexus 7-speed hub and find it works great in the winter. No issues because of the cold.

I've had it for 4.5 years and ~6,500 miles and live in Cleveland. I put on studded tires in the winter and ride through the winter months. I don't ride below ~5 degree F (glasses fog too much), but the shifting works fine down to that point.

The best part of the IGH, for me, is that the chain has a proper chainguard and snow and ice don't accumulate.

Tons of info here on living with IGHs: http://hubstripping.wordpress.com/

I ran mine to -18*F last winter here in Chicago, it always shifted. Same thing for my Alfine. im9 only made it to 20*F, I've switched it to ATF and greased the gearbox so it shoyuld be better this year. On another forum our Canadian brothers took their Alfines to -40*C (which is also -40*F).

Can you tell us about this? I'm personally interested as a year-round cyclist and I9 owner that hasn't had the I9 during a winter yet....

That's the result of condensation freezing in the cables. The fix I found was to tell the bike shop to swap out the cable and housing every two years. As the cable and housing rub together, the gap groes and it becomes easier for moisture to get in. WD-40 is useful for displacing water.

Paul

I'm running one of my Alfines and my im9 on ATF. The Alfine (same guts as my high end Nexus) shifts even better, I'm sure it will have better cold weather performance, last winter when it hit -18*F here my Alfine had the factory grease still. Shifted fine, a little slow. The Alfine/Nexus is easy to service, just pull the guts and soak. im9 has disposable dust cap on drive side, need a new one to pull the guts, nobody sells the dust cap yet...for that hub I removed the non-drive side con and poured a couple tablespoons of ATF into it.

Nexus IGH in colorado winters = fine.
 

As requested, My winter rides in Colorado on my IGH have proven no different than summer rides.
I don't notice any more drag, yet my 12.5 mile commute always takes longer in the cold so maybe it is the hub. (I rather doubt it.)

I park my bike indoors on both ends of my commute so perhaps it has a chance to dry out before freezing up?

I find I have far fewer winter commute issues with the IGH hub than I did with conventional 3x6 (older bikes) drivetrains.

Scandinavian version Shimano cassette joint units CJ-8S40 has rubber boot/bellows to prevent icing. http://bike.shimano.com/publish/cont...nt%20Units.pdf
And +2 ATF if you ride -20 degC ( I use cheap motox ATF 3G oil )

I have a Jamis Commuter 3 with a plain non-red band nexus 8 - it is my winter commuter with
snow tires. Local temp at the start of this morning's commute was +36 F. Have ridden it to about -20, no shifting problems. However I do keep it at an outside ambient temp all the time- taking it in and out of a warm spot causes condensation that does not help either brake or shifting cables.

Did you check the adjustment again? I suggest doing it yourself because IME the idiots that work at LBSes couldn't adjust an IGH if their lives depended on it.

Around here cold is usually accompanied by wind. Also the rolling resistance of tires increases significantly as they get colder.

It's probably the wind and the tires.

That's a rather broad statement. You need to find a new LBS.


I believe cold weather merely decreases the PSI of tires by about 2 pounds per 10 degrees. Where did you find this information?

Per info I have read in "Bicycling Science" and in the IHPVA journal the poster is correct. Rubber tires do give higher rolling resistance in cold weather. I suspect that it is a matter of changing the flexibility and durometer of the rubber.

Another Jamis Commuter 3.0 rider. I haven't had the pleasure of riding in -20 temps, but I do ride frequently in the single digits for 2+ years with no problems. I would also attribute your issue to a faulty cable, not the IGH.

I've given up because, IME, their all the same. Besides, I'm not much interested in finding the needle in the haystack because my main attraction to cycling is that it allows me to be more self sufficient.

Yup, I also saw a set of amateur measurements posted somewhere online; PSI was kept constant, but rolling resistance went up, which I'm inclined to believe because the casing of my tires feel stiffer as they are chilled and they generally just impress me as being more like cheap high RR tires.

Besides, is it so surprising that rubber gets more supple as it is warmed, thus, reducing RR?

Could you tell us a bit more, or should we start a new thread? I'm interested in oil conversions because I love my sturmey archer oiler.
You simply opened the NDS of the hub and poured Automatic Transmission Fluid from an automobile in? You didn't strip the factory grease first?
Didn't that cause grease to be displaced?
How do the seals hold up?
Displacing grease and then having the oil leak out of the seals sounds like a good way to end up running the hub dry...
This lubricates both the bearings and the planetary gears?
How did this change the behavior of the hub?
Why do it this way instead of removing the internals and drilling & tapping a proper oil port in the hub shell for easy topping off?
How often do you repeat your process?
Why not light-weight ND motor oil?
thank you, Mr. IGH. Very interested in all you know about the I9 and in oil conversions.

Shimano now offers an oiling kit for their hubs. Per their write-up on oiling the hubs you remove the innards from he shell and dip them in the oil for some time, then lift out and let it drain off the excess and reinstall into the shell. Nothing about degreasing first in their recommendations. Here is a link to their oiling instructions.

http://www.shimano.com/publish/conte...ance%20Oil.pdf

When I asked about it to SRAM Tech Support I was told that their hubs can have oil added too if shifting is sticky. Their email indicated that it is suggested for improved cold weather shifting. I would not be surprized that it could improve all shifting and operation regardless of temperature.

As generally speaking IGH hubs are pretty similar in design and internal material used in manufacturing I would expect that about any greased hub could be converted to oil lubrication.

Grease lubrication for IGH units was most likely introduced to take care of the IGH owners who ignore normal maintenance as factory greasing will last longer than oiling but is not really as good a lubricant IMO. An idiot proofing measure.

The Rohloff and I believe the NuVinci CVT both use oil bath lubrication. They have seals designed for a true oil bath lube system though so it all stays inside.

If/when I get another Shimano IGH I will add an oiler to it before building it into a wheel.

yes, just poured in a few capfuls, quite frankly, I was so fed up with the im9, nothing could have made it worse.

Had a slight amount of seepage/weepage for the first 100 miles, now it's fine. The hub is holding oil so if the grease is displaced, the oil bath has replaced it.

If this hub dies, so be it. I wasn't going to tolerate its bad performance anymore so I added ATF as a final attempt to love this hunk of junk.

yes, it's running in an oilbath. I might add another fact, my GM 4 speed automatic trans runs without any grease in an oil bath...500lbs*ft of torque....

Shifts much better. I've since put a couple thousand miles on the hub, it's starting to grow on me.

Not interested in a "proper oil port", I prefer to pull the guts and soak them in cleaner, then oil bath. Right now there's no source for the disposable dust cap on the drive side of the hub. Can't pull the guts until SRAM makes those available....

I had this hub running on oil for a ~3 months, as soon as I can source a disposable dustcap I'll pull the guts and decide on a time period for maintanince. I had several quarts of synthetic ATF left over from my hod rodding days, I decided to use some up. I do like synthetic lubes, much better cold weather performance.

thank you for the info - you seem pretty knowledgeable about this hub and its shortcomings.
can you tell me more about the problems you had with it that caused you to dislike it, and to what extent the oil treatment improved them? It sounds like you had shifting problems - do you mean that the hub was slow to engage your new gear after making a shift?
Have you had any problems other than that?
Was that problem partially solved by the oil treatment?
When you soak a hub's internals in "cleaner" before an oil soak, you use some sort of degreaser? Can you tell us more about that?

thank you again.

I started with the hub on one of my mountain bikes, the cones wouldn't stay adjusted because the torque washers don't fit in the dropout snug enough to prevent the axle from rotating. So the hub was always coming loose. I concluded the im9 isn't up to MTB'ing (unlike the Alfine), I moved it to my commuter and started piling miles on it. I like the even steps, esp on the road, I still hated the shifting, was always catching and making engagement noises. I added to oil as a last attempt to have this hubs performance meet my standards. Right away I noticed the shifts were much better, no sticking, no disturbing engagement noises. I've since put a couple thousand miles on it, it's coasting much smoother. I suspect this hub needs to be broken it before judgement is passed, the oil bath is worth the effort IMHO. Between the two (miles and oil) I'm starting to like this hub. It will be interesting to see if it can take a Chicago winter, we use LOTS of salt here.

I haven't had to clean the guts of my Nexus/Alfine or my im9. When I do, my plan is to soak in mineral spirits (paint thinner) to remove dirt and grease/oil, dry then soak in ATF. I pulled my Alfine guts after a week long MTB vacation with lots of rain and stream fording, I suspected there would be water intrusion, there wasn't any. So I just soaked the guts in ATF and re-installed.

Yahoo groups? What is this, 2009?