# Help with IGH Nexus 7 speed (SG-7R40)



## David C (May 25, 2011)

Hi, I got a Nexus Inter 7 IGH from a friend and I want to use it on a year-long commuter bike.

I read a bit on Sheldon Brown website and a few other sites, but I really need you guys to walk me trough this. I don't know how much it been used, what maintenance has been done (if any) and what the current condition is (internally).

Before dropping money on the other parts for the conversion, I want to be sure this IGH is viable and won't be a money pit.

Here's the infos I got so far :

Shimano Nexus Inter 7 (model SG-7R40)
Shimano Roller brake Inter M
Shimano Nexus 7 speed shifter (ST-7S60)

The spacing look to be 130mm and my frame is 135mm, but using a old Shimano RapidRise rd sandwich between the locknut and drop-out I get it right on. I'd like to get it 135mm however if possible to help with the chainline (currently at 42.5mm).

The gears are shifting fine and silent, but the roller brake feels like a weak disc brake (like before you get bed it in). I don't know yet if this is an easy fix or means the brake itself is done, I hope to learn it fast.

Many sites says to lube the internals and do a over-haul once a year to prevent wear, even more if riding wet weather (which I will be doing a lot in North East). Now Sheldon Brown's website say to only use the Nexus grease, bla bla bla... Another site say they use Phil Wood oil and heavy duty blue marine grease. I'm not a fan of "special" greases and oils and I don't believe Nexus grease is really "unique". What's your opinion ?

Now what I'd really like is to get instructions/directions on how to check the hub and brake to make sure they are still going strong and how to proceed to service everything and what to look for. For the rest, I'm pretty good at fixing stuff.

Thanks very much for your help


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## Wombat (Jan 25, 2004)

The shimano tech tip site has lots of good information on servicing and repairing the IGH hubs:

Tech Tips

Tim


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## David C (May 25, 2011)

Thanks for the link. Found a few answers there.

Anything wrong to just take it apart, solvent clean everything, rinse and solvent clean again, then dry up, sink into oil bath, let drip out and put back together ? The internals doesn't seems bad at all, but I guess I should fill it up with new grease and check/clean the seals to make sure it will stand up to future use ?

And I did not find info yet on the roller brake maintenance/troubleshooting.

Thanks


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## David C (May 25, 2011)

I just realized... I don't have *all* the tools I need to make this happen.... Which is likely to be an issue when I'll have to put it back together.... I'm at the beach for the next 3 months and while I can just bring it to a lbs, I'd rather do it myself, my way.

Let's put the internals service back for a while then.

To anyone who have experience with those IGH, if the hub is shifting fine and seems to be working well, even if it could easily have been used in bad weather for a while and for an unknow period of time, should I really check it out anyways or ride it for the summer (dry weather, at the beach) and hope nothing happen? And what for the roller brake lack of power ?

Another thing to mention is the wheel can be rock'd back and forth about 5° when the brake is fully applied, but the cog doesn't move, a bit like the internals had play inside. Is this normal or a bad sign ? Could it just be some loose axle bearings or a broken down part ?

Thanks  !


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## David C (May 25, 2011)

Bump.

Any advices please ?


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## pursuiter (May 28, 2008)

Pull the internals, dip them in some ATF and re-install. Never pull the internals apart, just lube as a unit. If the internals are dirty, use solvent to clean before dipping in ATF. Only tools needed for that are standard cone wrenches.

No need for special lube. OTOH, for the brake, I do have the Shimano lube. The container has a special tip that fits the brake's lube port perfect, I can't figure out how to replicate, $15, cheap.


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## David C (May 25, 2011)

Thanks for your reply. Do I should also clean and re-grease the bearings and right-side seals ?


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## pursuiter (May 28, 2008)

I clean the bearings and inside hub shell then use some synthetic grease on the bearings and seals.


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## David C (May 25, 2011)

Good. I guess I'll just open and see what needs to be done. Worst case I can always get a bike shop to tighten the locknuts if I can't get it right with my basic tools here.

Another problem is the non-turn washers. I have one that fit the old frame, but my current frame needs a vertical style one, which are about $7.50 each. I'll check around as they have plenty of old bikes and 3 speeds IGH. Might get lucky.


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## pursuiter (May 28, 2008)

David C said:


> ...Another problem is the non-turn washers. I have one that fit the old frame, but my current frame needs a vertical style one....


You could also run the shift cable up the seatstay instead of the chainstay, that may allow you to use the existing washers.


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## David C (May 25, 2011)

Well I took it apart today, minus opening the hub itself since I couldn't deal with the locknuts and my lack of cone wrenches.

Just wiping off old grease and dirt and put back the brake unit on the hub. I managed to use the non-turn washer by having about 20° angled toward the bottom, but at least working. I also fixed the brake arm to the chainstay like recomended.

I measured my rear channel at 43mm. My stock crank and BB were supposed to be at 50mm using a 113mm spindle length and 47.5 with a 110mm spindle. The stock spindle was in fact 112.5mm on my ruler, so I guess the "113mm" is in fact 112.5mm to match the 50mm chainline.

I'll see tomorrow about the new BB spindle length. Thanks for your help


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## pursuiter (May 28, 2008)

David C said:


> ...I measured my rear channel at 43mm....


When you flip the cog's dish outward is ~47mm, very close to the middle ring's chainline for most triples.


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## David C (May 25, 2011)

The cog is already flipped outward. What really gets in my way is a big lockring that take about 5mm or more that I could really use. I'll post pictures.


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## David C (May 25, 2011)

Here's the cog and the locknut :


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## David C (May 25, 2011)

Must spread some more before getting back to ya for your help 

I'll order a 107mm BB and shim in my chainrings to match.

Next if everything turns out great, I'll buy spokes and rebuild it on a 26" rim to be able to run my custom studded tires for the winter :thumbsup:


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## David C (May 25, 2011)

Well I finally got around.

Fit is alright, roller brake needs grease (ordered some) and need new tire (also ordered one).

Shifting is great, geo is a bit funky, but what can I say 

I'll wait a bit before deciding on building it up to 26", see how it goes. So far the results are great, did about 30km already and love it.

I also found the complete user manual for this exact hub and brake. Except it's in German


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## fokof (Apr 24, 2006)

I had one on my commuter and it lasted 2 years.


( even if I opened/clean it twice a year )


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## David C (May 25, 2011)

fokof said:


> I had one on my commuter and it lasted 2 years.
> 
> ( even if I opened/clean it twice a year )


Which model ?


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## pursuiter (May 28, 2008)

Some people run Shimano hubs for years with no issues, some folks grind through hub after hub and never figure it out. IGHs are not for the naive or uninitiated.


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## fokof (Apr 24, 2006)

David C said:


> Which model ?


Same as yours


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## fokof (Apr 24, 2006)

pursuiter said:


> Some people run Shimano hubs for years with no issues, some folks grind through hub after hub and never figure it out. IGHs are not for the naive or uninitiated.


Some ride their bike , some don't .


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## David C (May 25, 2011)

fokof said:


> Same as yours


Interesting. Since we both live nearby, it will be easy to ride the same conditions and see if yours was only bad luck or bad design.

Cheers 

Oh, and btw I went ahead and took a look at some of your posts. You mind me asking which shop you work at ? It might even possibly met you at some point  and I too be riding this IGH on a commuter year long in da snow


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## fokof (Apr 24, 2006)

David C said:


> Interesting. Since we both live nearby, it will be easy to ride the same conditions and see if yours was only bad luck or bad design.
> 
> Cheers
> 
> Oh, and btw I went ahead and took a look at some of your posts. You mind me asking which shop you work at ? It might even possibly met you at some point  and I too be riding this IGH on a commuter year long in da snow


Yeah sure , come back to this thread in two years (two winters) and tell me if it still works fine.
BTW I think that two complete years (with the KM I'm putting in) is very good for a product of that price.

OTOH I have my rohloff for 8 years , transferring it to it's third frame.
No broken frame , just the GAS syndrome doin' it's thing


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## David C (May 25, 2011)

Well I've been known to last the **** out bike parts. I wouldn't be surprised to get a few years out of this one.

Also I don't think I'd log as much km as you do per winter since my college commute is only 5km round trip. And I mostly like to ride my MTBs if I don't have to lock them outside. But we'll see.

If I have an occasion, I'd like to meet up with you and go ride some snow


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