Author Topic: newbie introduction and Shifter cable advice- does this suggestion make sense?  (Read 6565 times)

steve216c

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Long time lurker, short time Rohloff owner after 2nd hand purchase few weeks ago.

I've coveted bikes with Rohloff hubs for years. However until recently and with two good working bikes to choose from, never been able to justify the purchase to myself. My work-life balance had left me choosing to invest in the former at the cost of the latter. The two bikes I own once averaged 6-10,000 km/year between them for around 10 years while in my 30s, but had seen little use since I turned 40 with less than 200km a year being ridden. I could not justify the purchase of a Rohloff bike at a time I was not using the two other bikes I had available.

At just 49 I suffered  a DVT & stroke. That was March 2019. Looking death in the eye gave me the kick up the backside needed to make several lifestyle changes desperately needed to keep me from an early grave. Rehab helped me rediscover the joys of cycling once more as healthy eating and regular exercise have become a necessary part of my post DVT/stroke recovery.

Celebrating losing around 25kg since my stroke in March, reaching 1000 miles (1600km) since I took up cycling again in July this year, and with an upcoming 50th birthday in December, I decided to spoil myself. I bought a Rohloff hubbed 10 year/8000km old 28” trekking bike being sold locally for around 1/3 of its original price. Still on original sprocket and with rather worn chain I spontaneously purchased the bike hoping I could make it my daily commuter bike (vice petrol power) requiring less long term maintenance than my other two Shimano derailleur powered steeds.

A new chain, a sprocket reversal and an oil change brought new life back to this 2nd hand purchase. Gone was the chain skip and the hub rolled noticeably quieter and smoother than on purchase.
I've since ridden around 500 miles since that DIY servicing, and now I'm putting a to-do list together of other preventative DIY maintenance I'd like to schedule given that the previous owner had admitted that to his knowledge all cabling was original as when he took delivery. The only maintenance he’d had done were 2 oil changes and a replacement set of tyres during the first 3 years of ownership.

Here's the shifter advice I'm looking for. My plan is to use standard 1.1mm non-Rohloff shifter cables as I have a small stockpile of these for the other bikes in my household. I've seen threads about what alternative cables fit. But this thread is about possible improvement to process of servicing/replacing those cables.

1) Are both inner cables cut to exactly the same length as each other?

2) Given that we know that the fitted cable needs to protrude by 200mm, if answer to 1) is YES, then couldn’t the outer be cut to such a length so that the 1800mm 1.1mm shifter cable inner could be fitted without the need to trim to length? Presumably this would mean outer would need to be a little shorter than 1600mm to factor in cable inside shifter grip, and the small space taken up by the end pieces of the cable outers- right?

For me, this solution seems like a Rohloff users holy grail for simple servicing. No trimming of cable would be needed and on the road fixes need one less tool to carry if this were the case. Also, no trimming means cable is less likely to fray at cutting point.

Has anyone tried this or something similar? 

Any advice, warnings or suggestions to my idea would be great before I order up new outer cable. Constructive criticism is appreciated especially if there is something fundamental I’ve overlooked…

cheers

Steve
If only my bike shed were bigger on the inside...

geocycle

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Welcome Steve!

I think the answer to your first Q is unfortunately no, they are different lengths.  This is because of the slight difference in running lines and also the way it wraps around the shifter differs.  The length of the outers depends on the frame and whether you are using the internal or ex-box? Non Rohloff cables can work in some cases depending on the shape and size of the end barrel - I recall SRAM were mentioned as OK but not sure about other brands.  It's to do with how they lock into the shifter groove and whether they allow it to rotate smoothly.

The SJS and Rohloff youtube videos are useful.
 

mickeg

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1  It is best to cut each cable to Rohloff instructions instead of assuming both the same length.

2  I did cut some outer housing to the exact length for replacement cables so that my inner cables did not need to be cut.  But it took some serious calculations and the old theory of measure twice so you only have to cut once (double check your math and measurements) to get it right.  But in my case I then learned that my cables that were a standard length were no longer available in that length, so next time I need cables, still need to cut them to fit.

The good news is that the cables can last a long time.

If this bike was neglected for years, you might want to do another oil change after a few hundred km to make sure that if any rust formed on the moving parts or if any particulates were not flushed out, that the insides of the hub gets a good flushing.

Danneaux

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Hi Steve!

I've found recabling my EX box to be an easy and straightforward task even on the road provided I...
a) Follow Rohloff's recommendations and use my little brass tube to exactly calculate cable length.
b) Use my ancient, razor-sharp SunTour v-jawed cable cutters to make a clean cut
c) Put a drop of beta-cyanoacrylate (super glue) on the cut cable ends and allow it to dry so they do not fray in storage or during installation.

Measuring the cables and gluing the ends goes a long way toward making the task easier than it would otherwise be.

What I do at recabling time is to cut two sets of cables. One gets installed right away, the other pre-cut and pre-glued set goes in my touring kit, as I know it is pre-sized to match the housing length for both runs (and by cutting replacement housing to the same length as the old, new housing can work with the pre-cut cables). I use a marker to mark the leaded end as to "T" for an upper run or "B" for the lower run into the EX shift-box so I won't get them mixed up. This approach accomplishes the same end goal as fitting housing of a length that matches the pre-cut cables with pre-tinned ends you are proposing. As an added benefit, it ensures the cable housing runs are the appropriate length for a given frame and are not too long (which gets in the way) or to short (which can bind) and takes into account the slightly different path each cable takes to the hub. I tend to be risk-averse so I also carry a spare pair of uncut cables and my cutters and brass tube for extended journeys in truly remote areas "just in case" the pre-cut set gets damaged during installation (hasn't happened yet but could).

I've also found it helpful to fill my EX shift-box with Phil Waterproof grease as this works best for me to prevent galling of the cables and fixing grub screws to the aluminum pulley wheel over time.

Best (...and welcome! Glad you are feeling and doing much better after that Very Scary health event),

Dan.

steve216c

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@ geocycle- I have internal mech version for the hub.

@ mickeg - I'd considered another oil change, but was pleasantly as surprised how clean the old oil and flushing oil were when removed. With the Rohloff oil prices as they are I am considering getting some Mobil SHC 626 and running the hub with more frequent but cheaper oil changes. I don't have a guarantee to worry about and I'm not too emotionally attached to the bike in the unlikely event the Mobil turns hub into a 32 spoke paperweight.
I may just cut cables to length as suggested each change. It is not such a chore.

I purchased the 0.9mm kit to replace the internal mech cable. I was able to source some 0.8mm cable and might try that as alternative just for fun.

If only my bike shed were bigger on the inside...

martinf

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With the Rohloff oil prices as they are I am considering getting some Mobil SHC 626 and running the hub with more frequent but cheaper oil changes. I don't have a guarantee to worry about and I'm not too emotionally attached to the bike in the unlikely event the Mobil turns hub into a 32 spoke paperweight.

I decided it wasn't worth skimping on the oil for an expensive (new) Rohloff hub that has a guarantee. So I bought bulk sizes of Rohloff cleaning and lubricating oils.

That said, I have used Mobil SHC 626 in Shimano Nexus 8 Premium hubs for a few years now, no problems so far with the plastic parts inside and I believe these hubs run better with oil than with the factory grease.

mickeg

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... With the Rohloff oil prices as they are I am considering getting some Mobil SHC 626 and running the hub with more frequent but cheaper oil changes. ...

I would advise against alternatives, I think there are some plastic parts that can absorb something and swell if improper lube is used. 

I bought the 250ml bottles of oil, but not sure if those bottles are still sold.

Andre Jute

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Welcome, Steve.

You need to buy two of the small Rohloff sets anyway to get two syringes with screw-thread tubes, one to use with clean oil, one to use with dirty oil. That should service your Rolloff-equipped bike twice at once a year. After that you can buy a bulk set of Rohloff oil, two canisters of 250ml, one of all-seasons oil, one of cleaning oil (also used in ultra-cold conditions as a winter running oil). That should last you about ten years.

Rohloff optimises available oils so that their official oil changes all the time, and is thus guaranteed to work with the Rohloff internals.

I was horrified to read that you contemplated putting oils with unknown chemicals into a Rohloff gearbox: you don't know the Mobil works with plastic gears and paper filters (by design, some of the oil will "mist out" past paper filters*), and if your gearbox ever has to go to the factory and they discover someone else's oil in it, they could easily refuse you service.

That Martin services Shimano gearboxes with the Mobil oil is not sufficient evidence for you to try it with a Rohloff. Basically, you should grasp that the Rohloff is a highly specific, almost orphan design because if it were designed like Sturmey-Archer or Shimano gearboxes, it would be too heavy for bicycle use. Sorry to sound like nanny, but sticking to Rohloff's service suggestions is the key to happiness with a hub gearbox that will be properly run in roundabout the time a Shimano gearbox lies itself down to die, and from there the Rohloff will go on, for practical purposes, indefinitely.

Yes, I know, if you read this forum passim, you will discover that I service my EXT click box only once in 5000km rather than every 500km as advised by Rohloff, but I've thought it through, and obtained a special quality of proven grease (Phil's) for the job, and if I'm wrong, it's an external part that can be replaced as easily as ordering another one from SJS and fitting it without tools because it is held on by a thumbscrew.

Enjoy your new bike.

* I'm a painter and so only too painfully aware that two papers which look and feel the same can technically be very different, and behave differently too when the paint is applied. For oil painting I have a couple of dozen oils that perform different, often mutually exclusive, functions but are all called "drying oils" -- that doesn't mean they are necessarily intermixable.

Thomas777

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Daň,
My wife has the Rohloff I just do the service work!
I like your idea of a spare set of cables for the touring kit. Do you use stainless steel cables?

Danneaux

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Quote
Do you use stainless steel cables?
Yep! :) I prefer double die-drawn stainless cables that are very smooth and slick and do not stretch (they are effectively pre-stretched by the double drawing process).

I have found it false economy to use galvanized cables. I have not found them to be as smooth and they tend to discolor and grow rougher over time when exposed to the alkai dust I often encounter on my desert tours.

Of course, I use lined cable housing as well to minimize friction.

Best,

Dan.

Thomas777

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Thanks!!

PH

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I use the Rohloff specific inner cables, I always have, others may work fine but at around £7 a pair it hardly breaks the bank and they get changed when i feel they need it, which is less often than on a derailleur bike, maybe every couple of years or 15,000 miles.  They have a slightly different hexagonal nipple than other gear cables, but having no experience of others i wouldn't know if this makes any difference.  I'm about half way through a 30m roll of Shimano grey outer gear cable, I think I paid half the current price, it's lasted a decade of three bikes (Not always the same three!) It's a 1.1mm inner in an outer designed for 1.6mm, it's not a critical fit and I can't see a liner making much difference.  I just oil the cable with a light oil and bung some marine grease in the ends to stop water getting in. I've never had a cable issue in 15 years, sometimes it might have been an advantage to change it earlier, it's been noticeably smoother when changed but the deterioration so gradual I hadn't noticed.  It's such an easy job i wouldn't compromise the outer length to save a snip of the inner. I'd have to be on a multi month tour before considering carrying a spare.
One issue I did have was with the bayonet fitting, I managed to break one refitting after a puncture.  I removed the bayonet altogether and joined the two cables with an electric choc box connector, it stayed in daily use for months! I consider these an essential part of any toolkit.
Enjoy your new hub, it doesn't take much looking after, but what little it does is worth doing well.
This outer
https://www.sjscycles.co.uk/cables/shimano-slr-5-mm-brake-cable-outer-grey-workshop-roll-of-30m/
« Last Edit: November 28, 2019, 08:35:49 pm by PH »

PH

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I bought the 250ml bottles of oil, but not sure if those bottles are still sold.
They are, cleverly priced to make splitting the big bottles not quite worth the effort...

mickeg

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Ph made the comment that using a brake outer housing for larger diameter cable works fine, which is accurate.  That reminded me that I forgot to advise you what I advise to all new Rohloff owners, the cables are supposed to be somewhat slack.  My cables might be more slack than necessary, but to give an example if I am in gear 10, my shifter when I am not touching it may be anywhere between 9.5 and 10.5 on the shifter scale.  My cables are loose enough that I have that much play in the shifter.  If your shifter cables are too tight, you might accidently shift into a position between two gears.

Having loose shifter cables can seem wrong to a derailleur bike rider that is used to only using one cable that is always under tension to shift, but the Rohloff system of using one cable to upshift and the other to downshift does not need the tight cables that derailleur users are used to.

Agree with Dan, get stainless cables.

Also, I have occasionally heard of problems on the EX box of the two Torx screws getting stuck due to dissimilar metal corrosion, best to unscrew those screws once a year and apply some lube.

The oil filler screw, be careful not to over-tighten it.  If re-using the old screw (which I always do), I apply some thread locker to the screw to keep it from also having a dissimilar metal corrosion problem.  Dave (formerly of SJS) suggested a specific thread locker for that screw, but I always use the generic blue removable variety instead.

I loosen up the thread-on sprocket every couple years, clean it, and apply new grease.  Large tools make removal easy, wrenches that are too short make this a more difficult task.  See photo.

On a bike tour, I do not carry a precut shifter cable, instead I carry one that will need to be cut.  And I carry two 100mm long plastic drinking straws that taped together gives me the 200mm length I need to cut the cable.  I also carry the sprocket removal tool in case my Rohloff had a serious problem, but my thinking is that any bike shop would have a chain whip but it unlikely to have the Rohloff tool.

Touring, the attached photo shows my tool bag from my last tour.  To pack the bike in an S&S case, I have to disassemble most of the bike and remove the crank arms, thus more tools than the average for bike touring.
« Last Edit: November 29, 2019, 01:33:00 am by mickeg »

steve216c

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Update to my old thread. I bought Jagwire outer cables and replaced the Rohloff cables. Then I fitted standard size derailleur shifter cables through the Jagwire outers. Took Teflon Coated cables just for fun, although I actually have a small stock of stainless steel cables for running repairs on the other bikes. I was surprised that the derailleur cable actually fitted without problems through the original shifter outers as they are fractionally thicker than the Rohloff cable inners. I would wager I probably could have fitted the shimano cables to the old outers without buying new outers.

My old cables had begun to deteriorate and replacing not just the main cable but the gear mech cable too has improved feel and accuracy of gear change which had occasionally jumped- possibly due to fraying cables catching while switching.

As for measuring cable length before cutting I took the drinking straw tip, and used a slightly heavier duty plastic tube from a McDonald’s kids balloon stick as it is a bit sturdier. It worked a treat.

In Germany getting Mobil 626 or Shell Omaha in less than 20 Liter volume was proving more trouble than it was worth. I was lucky to pick up original Rohloff hub oil 1000ml bottle for just Eur 44-. Following the oil analysis from crazyguyonabike I made a 1:10 mix hub oil:white spirit for flushing. I realise this may be sacrilege for some of you, but after talking through with engineer friend he said the risk was minimal given the mix. Even if mix were too aggressive, the length of time before draining and refilling ought to reduce potential risk further.

Thanks to those who shared tips and ideas to my original post.
If only my bike shed were bigger on the inside...