Chain tension for internal hub?
anon a mouse
Rohloff Speedhub, with the OEM sliding dropouts. I'm still not sure
if I'm setting the tension right. (I'm not using a chain tensioner.)
The manual says there should be about 10mm play in the chain. Is this
with or without any pressure on the pedal? The weird thing is, it
seems like after just a couple rides, the chain becomes MUCH more
slack than it was after adjusting it. (I though there was LESS
maintenance with this thing?) Could that be from having too much
tension on it? Should there be any visible slack in the chain? A
friend recommended an Isumi track chain; could this be part of the
problem?
(PeteCresswell)
>Should there be any visible slack in the chain?
For better or for worse, I've been tensioning mine by feel too.
Been well over 5 years now and no problems.
I try to get it just tight enough that it doesn't drop.
--
PeteCresswell
Tom Ace
> I recently had a custom bike built, specifically designed for the
> Rohloff Speedhub, with the OEM sliding dropouts. I'm still not sure
> if I'm setting the tension right. (I'm not using a chain tensioner.)
> The manual says there should be about 10mm play in the chain. Is this
> with or without any pressure on the pedal? The weird thing is, it
> seems like after just a couple rides, the chain becomes MUCH more
> slack than it was after adjusting it.
That may have been a one-time thing,
my chain did that initially and then settled in.
The idea behind play in the chain is just like the
need for play in the cables on a Rohloff shifter.
You want enough play that it runs freely,
but there's no point in having more. It's
easy to gauge whether the chain is binding
by turning the crank backwards by hand.
See also Sheldon's tips on how to center a chainring at
http://sheldonbrown.com/fixed.html#tension
Tom Ace
Andre Jute
Are the axle holders, the ali pieces to which the axle fasteners hold
the axle, bolted up tightly enough in the slider slots? Mine require
16Nm, which is quite a bit to ask from the short handle common on
bicycle tools.
A bicycle chain should have a visible bow in it when the correct
amount of slack is dialled in. If the chain isn't falling off, *and
everything is bolted up correctly*, I wouldn't sweat it.
A good chain, proven by lab tests and experience to be dimensionally
stable and long-lasting, and for that reason preferred over even
Rohloff chains by the makers of my bike (seen partying with Herr
Rohloff in the link under my sig), is the KMC X8. Mine hasn't required
adjustment since new at the beginning of the year, 1800km ago. Mind
you, the cheap SRAM PC1 and the nicer Connex chains on my other hub
gear bikes didn't settle enough to require adjustment either.
Andre Jute
http://www.audio-talk.co.uk/fiultra/Andre%20Jute's%20Utopia%20Kranich.pdf
someone
> I recently had a custom bike built, specifically designed for the
> Rohloff Speedhub, with the OEM sliding dropouts. I'm still not sure
> if I'm setting the tension right. (I'm not using a chain tensioner.)
> The manual says there should be about 10mm play in the chain. Is this
> with or without any pressure on the pedal?
With the bike on the ground, backpedal and grab the top run of the
chain in the middle and pull it up and push it down. The distance
between the extremes is the 10mm the manual refers to.
> The weird thing is, it
> seems like after just a couple rides, the chain becomes MUCH more
> slack than it was after adjusting it. (I though there was LESS
> maintenance with this thing?) Could that be from having too much
> tension on it? Should there be any visible slack in the chain? A
> friend recommended an Isumi track chain; could this be part of the
> problem?
If its a new chain, the generated slack is the installed grease being
squeezed out of from the bearings of the chain. This is why a factory
fresh chain is generally ok when fitted tight to a single speed.
Subsequent refitting shhould be to prevent any binding with only a
little chain dip as seen on the lower chain run. The viscocity of the
lubricant will have an effect here. Running a tight chain prevent the
lubricant from refreshing the bearings. It will wear and the chain
will 'stretch'. Leaving a chain slack permits the wet lubricant to do
its work. A grease is best, but oil (of a viscocity which suits the
rider) is the preferred choice due to its ease of application.