Author Topic: First Time Rohloff Owner  (Read 9267 times)

geocycle

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Re: First Time Rohloff Owner
« Reply #75 on: November 07, 2021, 06:48:19 PM »
Another question from ye olde first time Rohloff owner... is it common to feel anything notchy or unsmooth when standing while pedaling uphill in a lower gear? I can't tell if what I'm feeling is result of brief crank pause at 12 o'clock, or an internal bump. It's very definitely tied to crank position.
It's not a Rohloff characteristic that I recognise (the test is to see if the problem is consistent in different lower gears) and I suspect that it's elsewhere in the drivetrain. Have you checked that the chain tension is consistent through a whole rotation of the cranks?

Sounds like a chain to me as well. Sometimes if they are too slack they can fall off the teeth of the chainring at low speed.
 

AndrewJ

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Re: First Time Rohloff Owner
« Reply #76 on: November 08, 2021, 05:08:55 AM »
Another question from ye olde first time Rohloff owner... is it common to feel anything notchy or unsmooth when standing while pedaling uphill in a lower gear? I can't tell if what I'm feeling is result of brief crank pause at 12 o'clock, or an internal bump. It's very definitely tied to crank position.
It's not a Rohloff characteristic that I recognise (the test is to see if the problem is consistent in different lower gears) and I suspect that it's elsewhere in the drivetrain. Have you checked that the chain tension is consistent through a whole rotation of the cranks?
Thanks, the (front) chain ring is centered on the BB, and the rear cog is, well, affixed as best as a Rohloff 17T cog can be affixed to a snap-ring 2nd generation carrier.
Steel & brass, with lugs. Berkeley California US

JohnR

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Re: First Time Rohloff Owner
« Reply #77 on: November 08, 2021, 11:08:40 PM »
Thanks, the (front) chain ring is centered on the BB, and the rear cog is, well, affixed as best as a Rohloff 17T cog can be affixed to a snap-ring 2nd generation carrier.
However, is the chainring round and how is it adjusted? Thorn recommend a fairly slack chain when using a Rohloff hub as illustrated on page 12 of the Thorn Owners Guide. How does your chain adjustment compare with this recommendation?

AndrewJ

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Re: First Time Rohloff Owner
« Reply #78 on: November 11, 2021, 06:04:18 PM »
Thanks, the (front) chain ring is centered on the BB, and the rear cog is, well, affixed as best as a Rohloff 17T cog can be affixed to a snap-ring 2nd generation carrier.
However, is the chainring round and how is it adjusted? Thorn recommend a fairly slack chain when using a Rohloff hub as illustrated on page 12 of the Thorn Owners Guide. How does your chain adjustment compare with this recommendation?
Ring is round, yes, and centered on the spider last I checked. I'll go check again, perhaps it's shifted. I have an upward-pressing single cog tensioner, and perhaps it could be relaxed, certainly easy to test. It's also in good alignment with chainring and cog.



This could all be an artifact of uneven pedaling cadence, too, where crank rotation slows as pedals reach 12 and 6 o'clock positions.
Steel & brass, with lugs. Berkeley California US

mickeg

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Re: First Time Rohloff Owner
« Reply #79 on: November 11, 2021, 07:26:29 PM »
If something was not quite right, I would expect it to be felt mostly when at the highest torque, thus at 3 or 9 oclock.  If it is not smooth at 12 oclock position, that does not make much sense.

If you are applying a lot of power to the pedals, could you have enough frame flex to mess up the alignment?  I ask because I had a frame with a bad welding job at the bottom bracket shell, it had a lot of flex because the welder got their heat settings all wrong.  Thus, I am familiar with frame flex.

Is your chainline spot on?  (I did not go back and read this whole thread, if you said that, sorry.)  If your chainline is off, your chainring teeth might not yet have worn into the chain yet.

Is that tensioner spring loaded?  If it is spring loaded, that should not be the problem.  If it is fixed in position and has too much tension, that could be the problem.

JohnR

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Re: First Time Rohloff Owner
« Reply #80 on: November 11, 2021, 07:41:05 PM »
That's a remarkably clean chain. Would it benefit from a bit more lube?

AndrewJ

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Re: First Time Rohloff Owner
« Reply #81 on: November 12, 2021, 03:27:59 AM »
That's a remarkably clean chain. Would it benefit from a bit more lube?
Plenty of lube, good spray-on Boeshield: https://www.rivbike.com/products/boeshield-t9-multi-purpose-spray-4oz

But surprise surprise surprise... the tensioner is moving up and down as the crank is spun. Between the chainring and the cog, there's one or more eccentricities. I will investigate, remediate, and report back.
Steel & brass, with lugs. Berkeley California US

mickeg

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Re: First Time Rohloff Owner
« Reply #82 on: November 12, 2021, 10:50:45 AM »
...
But surprise surprise surprise... the tensioner is moving up and down as the crank is spun. Between the chainring and the cog, there's one or more eccentricities. I will investigate, remediate, and report back.

When I change chainrings, there is a lot of slop in the holes in the crank spider arms and the chainrings.  Thus, if I just put a ring on and tighten the bolts, the chainring will not be concentric with bottom bracket spindle.  I have to semi-tighten up the bolts so that the chainring and crank arms can be shifted in position with a little pressure on them, and then it is an iterative process of trying to get the chainring in exactly the right spot where the chain slack has minimal change when I spin the crank backwards before I tighten up the chainring bolts.

I use different chainring sizes for touring versus riding around near home (36T for touring, 44T for riding around near home).  Thus, chainrings get changed on a regular basis, so I am accustomed to doing this.  And when I change chain rings, add or subtract four chain links.

I do not have a tensioner like you have, thus I need a small amount of slack in my chain, see photo.  It is an old photo, I was using the 44T chainring as a bash guard, but now have a real bashguard sized for the 36T chainring.  The chain looks tight in the photo, but if you hold a straight edge on your computer screen, you can see some slack in the chain.

That said, I would not expect an off-concentric chainring to have any noticeable feel when pedaling with a sprung tensioner.  But perhaps your tensioner movement for part of the time causes something else to rub?


AndrewJ

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Re: First Time Rohloff Owner
« Reply #83 on: December 20, 2021, 02:42:31 AM »
A brief update from California... the bespoke frame & Rohloff hub continue to impress. I'm just about ready to head off on a long winter tour (240 miles, four days, Northern California coastal region). The IGH remains slightly mysterious, with its noises and occasional skipped ratio, but is in every way that matters a true delight. An enormous bag from WaxWingBagCo now straddles the front rack, and my brakes lines are just about done. Bar tape is all that remains. Thank you to all here who have helped me along this path.

Pictures from today's ride, I succumbed to an overpowering need to quench my thirst!



Steel & brass, with lugs. Berkeley California US

Andre Jute

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Re: First Time Rohloff Owner
« Reply #84 on: December 20, 2021, 04:11:52 AM »
That's a seriously good-looking and (apparently) functional bag, Andrew. Suits your bike to a T.

mickeg

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Re: First Time Rohloff Owner
« Reply #85 on: December 20, 2021, 01:47:50 PM »
... The IGH remains slightly mysterious, with its noises and occasional skipped ratio, ...

Not sure what you mean by skipped ratio.  Did the hub skip instead of engage correctly after a shift?

If so, perhaps:
https://www.rohloff-au.com/faq-gear-loss-slipping

Or, another alternative:
On a tour a couple years ago my hub seemed to skip a couple times.  There was an "adjustment" that I had read about but could not remember what that adjustment was used for, so I tried it anyway even though it might be the right solution to a different problem.  Pull the wheel off the bike, and give a good whack to the axle on (I think it is the) right side (but is it the left side?) with a rubber mallet.  And of course I do not tour with a rubber mallet, but I do have a pair of shoes with a rubber sole, so the rubber heel became a mallet head.  You do NOT kick the wheel, you take your shoe off your foot and use the shoe like a mallet.  In my case, it appeared to fix everything, did not skip any more. 

Maybe others will explain more on the rubber mallet solution to whatever the problem was.

« Last Edit: December 20, 2021, 02:14:31 PM by mickeg »

PH

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Re: First Time Rohloff Owner
« Reply #86 on: December 20, 2021, 03:12:49 PM »
... The IGH remains slightly mysterious, with its noises and occasional skipped ratio, ...

Not sure what you mean by skipped ratio.  Did the hub skip instead of engage correctly after a shift?
If so, perhaps:
https://www.rohloff-au.com/faq-gear-loss-slipping
I thought the same, skipping gears isn't something I've experienced and it would concern me.
Along with Rohloff's suggested causes, I've also heard over tight cables can stop the gear immediately engaging, but again I have no experience.
Quote
Maybe others will explain more on the rubber mallet solution to whatever the problem was.
That's a cure for a different problem, if your pedals turn with the wheel when you're pushing the bike.
One of mine does that, I've never bothered to cure it as I don't see it as a problem.

mickeg

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Re: First Time Rohloff Owner
« Reply #87 on: December 20, 2021, 03:24:32 PM »
Shifter cables too tight can cause poor shifting, but I do not think skipping is part of that problem.  I have about half a shift slop in the cables in either direction, in other words if I am in gear 10, my shifter may indicate anywhere from 9.5 to 10.5.  If the cables are too tight, when you shift the hub might not complete the shift exactly into an indexed gear position.

It is common to hear people complain about the pedals turning when you are off the bike and pushing it.  I find that happens less now after a lot of use, the seals or whatever was causing the friction has loosened up but it also depends on what gear I am in.


AndrewJ

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Re: First Time Rohloff Owner
« Reply #88 on: January 01, 2022, 03:34:26 AM »
I'm just home from a 250 mile, 12,000 foot ascent four-day ride through bitter cold and wet, truly the first good shake-out ride for the frame and IGH. I found the stem-mounted shifter (co-axial to fork axis) to be irksome in touring practice. It's simply too disruptive to move my hand (left or right) from handlebars to the stem-mounted shifter, and I feel I lose too much momentum while pedaling uphill. Maybe I could gain coordination and achieve lightning-quick shifts, but... I'm going to fabricate a Hubbub-style mount for the Rohloff shifter on the right bar end of my drop bars. That's a more natural place for my hand, and lets me maintain steering control. Like here: http://thorncyclesforum.co.uk/index.php?topic=11720.0

I also found, after patching two rear wheel flats, when my Surley Singelator decided it didn't want to press "up" any longer, that I can ride just fine without a chain tensioner. The chain is slack, but has good chainline and will not rise up off the chainring under stress. Pictures to follow.

Here's me about to drop 1,600 feet down the Meyers Grade to Highway 1, to Russian Gulch, just north of Jenner, California. The first dry day we had on the tour, and this descent was a highlight of the route.

Steel & brass, with lugs. Berkeley California US

mickeg

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Re: First Time Rohloff Owner
« Reply #89 on: January 01, 2022, 01:57:19 PM »
I'm just home from a 250 mile, 12,000 foot ascent four-day ride through bitter cold and wet, truly the first good shake-out ride for the frame and IGH. I found the stem-mounted shifter (co-axial to fork axis) to be irksome in touring practice. It's simply too disruptive to move my hand (left or right) from handlebars to the stem-mounted shifter, and I feel I lose too much momentum while pedaling uphill. Maybe I could gain coordination and achieve lightning-quick shifts, but... I'm going to fabricate a Hubbub-style mount for the Rohloff shifter on the right bar end of my drop bars. That's a more natural place for my hand, and lets me maintain steering control. Like here: http://thorncyclesforum.co.uk/index.php?topic=11720.0
...

The last post at that thread was my comment that I decided to switch to the Hubbub adapter.  I did that and have been very happy with it.

When I am riding slow in difficult terrain, such as a steep uphill on a cobble strewn road I can keep both hands on the handlebars out where I can get leverage for steering and one of those hands can be on the shifter allowing me to shift.  The Hubbub adapter allows that.  But if I am riding in such difficult terrain, I might find myself putting some force on the adapter.  I had read somewhere that someone had trouble with theirs coming loose, so I put mine on REALLY tight, tight enough that if I try to remove it I might break the bolt.  I wanted to make sure it does not come loose.

That thread you linked to shows the cables in a place that I wanted to avoid so I used a couple V brake noodles to route my cables forward for better knee clearance.  Also, when I pack up my bike for transport and have my handlebars off of the frame, that routing gave me a bit more cable length that helps packing it.  Initially my noodles were silver color, later I removed them and sprayed them black, a big aesthetic improvement.

Cut your outer housing so that both cables are the same length.  I later chose to cut a third inner cable of the correct length to carry as a spare on tours.

First photo, noodles painted black, second and third photos before I did that.  Last photo from my most recent bike tour, Canadian Maritimes in summer 2019.

« Last Edit: January 01, 2022, 02:02:53 PM by mickeg »