dynohub repack?
Nate Nagel
first of all I need some smaller brake pads so I can clean them without
removing them or pulling the front wheel (don't want my wheels to wear
out any sooner than they have to)
but the real question is, how hard is it to repack the bearings in a
Shimano DH3 series dynohub (I think mine is the N72) and is there an
exploded diagram of it anywhere? I should probably do that every now
and then if I'm going to keep riding in less than perfect weather, but I
don't know if there's any Special Instructions to cracking one open.
Didn't ride today because I spent the afternoon cleaning bike and
installing my new rear wheel (took a little longer than you'd think
because I had to fiddle with brakes; all my other wheels are narrower) I
finally have appropriate, matching wheels! I think that I can call this
bike "done" just as soon as I get a better headlight. (and do whatever
I'm going to do with the brakes.) Cool!
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
Peter S.
> first of all I need some smaller brake pads so I can clean them without
> removing them or pulling the front wheel (don't want my wheels to wear
> out any sooner than they have to)
I have really good experience with Kool Stop salmon colored brake
pads; not only does they brake very well, but they are really gentle
to the rim because they don't pick up alu pieces etc. With KS pads I
no longer need to clean the brake pads, nor do I bother with cleaning
the rims for other reasons that the rims look good when clean. Still,
I can hardly detect any wear on my rims. The downside is that KS seems
like a slightly odd company with a iffy distribution, so sometimes
there are veritable droughts of KS brake pads, at least here in
Europe.
> but the real question is, how hard is it to repack the bearings in a
> Shimano DH3 series dynohub (I think mine is the N72)
>and is there an
> exploded diagram of it anywhere? I should probably do that every now
> and then if I'm going to keep riding in less than perfect weather, but I
> don't know if there's any Special Instructions to cracking one open.
It is doable, but don't do it unless there is a specific cause like
rough bearings. The reason is, that one side of the bearings are so
problematic to maintain that Shimano has deemed it non-serviceable. So
when looking at the exploded Shimano diagrams, notice how only only
one side is serviceable. The problem is that the wire from inside the
rotor that generates the current, runs along in a trench in the axle.
It is very, very easy to break that wire when disassembling the rotor
part to get to the bearings.
On the upside, many people have reported +15000 km without any need
for repacking the bearings, and from what I have seen from my Shimano
generator hubs, the sealing is excellent and just riding in the rain
certainly isn't a reason to repack them.
There used to be a blog where some guy documented how to take the
rotor apart, but the site has disappeared. But here some hints;
Get a good feeling for how the wheel rotate when the cup and cones are
adjusted correct before taking it apart. The magnets makes normal cup-
and-cone feeling of preload difficult.
Measure dish on the wheel first, make sure it is centered. Take
accurate measurements of the distance between the end of the axle and
lock nuts. This is to avoid any unnecessary fiddling with the rotor
side lock nut and cone when assembling the rotor part again, since
this risks breaking the rotorwire. Place the lock nut and cone right
the first time when assembling the rotor.
Document exactly how you take the rotor apart with a digital camera.
Again the reason is that the wire seems only to be able to take that
many bendings before it brakes, so avoid too much fiddling, but
reassemble it correctly the first time.
You don't need any special tools, but a lancet and a pick will be
handy.
You take the cone off on the rotor side by screwing it off the axle,
but since the rotorwire runs along a trench /slot in the axle, the
cone may grab hold of the rotorwire and rip it apart when the taking
the cone off. So be careful that the rotorwire doesn't protrude above
the slot. Perhaps use a lancet to clean off the gum that Shimano seems
to use to glue the wire to the trench with, but avoid cutting in the
wire insulation.
There seems to be good reason to assume that the "hidden" cone inside
the rotor is identical with the other "visible" cone, so in case off
pitted cones, just order to two "visible" cones.
Be prepared that it may take longer than you thought it would, so
don't do it if you need the wheel later in the day, or early next
morning.
AFAIK, the rotor doesn't loose its magnetic power when out of the hub
shell like some old SA generator hubs did.
--
Regards
landotter
Drive side bearings serviceable. 11 loose bearings. Top up with some
thick grease and forget about it for a year.
Nate Nagel
> On 18 Okt., 22:26, Nate Nagel <njna...@roosters.net> wrote:
>
>> first of all I need some smaller brake pads so I can clean them without
>> removing them or pulling the front wheel (don't want my wheels to wear
>> out any sooner than they have to)
>
> I have really good experience with Kool Stop salmon colored brake
> pads; not only does they brake very well, but they are really gentle
> to the rim because they don't pick up alu pieces etc. With KS pads I
> no longer need to clean the brake pads, nor do I bother with cleaning
> the rims for other reasons that the rims look good when clean. Still,
> I can hardly detect any wear on my rims. The downside is that KS seems
> like a slightly odd company with a iffy distribution, so sometimes
> there are veritable droughts of KS brake pads, at least here in
> Europe.
>
That's what I keep hearing. I'm going back and forth between just
getting what I have, but in salmon (I think they're called Eagle Claw II
or something, and cheap) or what I put on my other bike, which are
called "Cross Pads" (e.g. cyclocross) but really appear to be a Dura-Ace
pad holder with a cantilever mount on it rather than the usual road
brake mount. The latter are way more expensive but I've been happy with
them on the other bike, and it appears that if I got those, the pads are
short enough that I could remove the straddle wire and then just flip
the brakes open and scrub the pad surfaces with a toothbrush and some
soapy water after a particularly abusive ride.
>> but the real question is, how hard is it to repack the bearings in a
>> Shimano DH3 series dynohub (I think mine is the N72)
>> and is there an
>> exploded diagram of it anywhere? I should probably do that every now
>> and then if I'm going to keep riding in less than perfect weather, but I
>> don't know if there's any Special Instructions to cracking one open.
(excellent post snipped, but copied and saved to my hard drive for
reference)
Wow- Thanks!
One question - where did you find any kind of diagram at all? Poking
about the interwebs all I can seem to find is the installation sheet, no
parts list or anything like that (like I've been easily able to find for
conventional hubs, which for the most part I didn't really need them,
because those are simple enough to be self explanatory...)
Nate Nagel
Thanks. Where the heck did you find that? I still can't figure out
what kind of sequence of clicks to use to get that from Shimano's web
site, but there it is.
landotter
> landotter wrote:
> > On Oct 18, 3:26 pm, Nate Nagel <njna...@roosters.net> wrote:
> >> Got to thinking today as I was cleaning yesterday's muck off my bike...
>
> >> first of all I need some smaller brake pads so I can clean them without
> >> removing them or pulling the front wheel (don't want my wheels to wear
> >> out any sooner than they have to)
>
> >> but the real question is, how hard is it to repack the bearings in a
> >> Shimano DH3 series dynohub (I think mine is the N72) and is there an
> >> exploded diagram of it anywhere? I should probably do that every now
> >> and then if I'm going to keep riding in less than perfect weather, but I
> >> don't know if there's any Special Instructions to cracking one open.
>
> >> Didn't ride today because I spent the afternoon cleaning bike and
> >> installing my new rear wheel (took a little longer than you'd think
> >> because I had to fiddle with brakes; all my other wheels are narrower) I
> >> finally have appropriate, matching wheels! I think that I can call this
> >> bike "done" just as soon as I get a better headlight. (and do whatever
> >> I'm going to do with the brakes.) Cool!
>
>
> > Drive side bearings serviceable. 11 loose bearings. Top up with some
> > thick grease and forget about it for a year.
>
> Thanks. Where the heck did you find that? I still can't figure out
> what kind of sequence of clicks to use to get that from Shimano's web
> site, but there it is.
I just entered via the northern European gate and went to the techdoc
link.
Tosspot
> landotter wrote:
<snip>
>> http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/DH/EV-DH-3N70_2N70-2290A_v1_m56577569830608789.pdf
>>
>>
>> Drive side bearings serviceable. 11 loose bearings. Top up with some
>> thick grease and forget about it for a year.
>
> Thanks. Where the heck did you find that? I still can't figure out
> what kind of sequence of clicks to use to get that from Shimano's web
> site, but there it is.
It's simple, dawn each morning, sacrifice 2 chickens, and paint the
walls with caterpillar shit before dealing with the Shimano Gods,
works every time!
Hank
The US Shimano site is just useless, only listing the top few groups
of each range. There's loads of Shimano stuff that QBP sells that
_does not exist_ according to the Shimano USA site.
If you want any good info at all, always go to the European site.
john dean
I am a newby, but if the Shimano dynohubs cost 90$ and last for >15km
how does one justify paying 200$ for the Smitt? hub?
Frank Krygowski
>
>
> I am a newby, but if the Shimano dynohubs cost 90$ and last for >15km
> how does one justify paying 200$ for the Smitt? hub?
You can ask that question about almost any bicycle component on the
market. You can get a Shimano crankset for less than $100, or you can
get a Shimano crankset for about $700. The second will not make you
measurably faster than the first.
Schmidt hubs have the reputation for lowest drag, highest efficiency
and most reliability. Apparently, people that are fond of riding in
competitive, all-day-all-night self-supported randonneuring events are
very happy to spend money for a hub and headlight that gives all the
light they need for as long as they need it, with minimum drag on the
bike.
And some people just like having what they believe is the world's
best, whether it's hub generators, guitars, hunting knives, art work,
whatever. Personally, I tend to go toward the "good enough for me"
category.
- Frank Krygowski
thirty-six
I was almost tempted into a dynamo hub fifteen years ago, but could
not justify the cost when the risk of bike theft is acoounted into the
equation. Simply using a battery system with a spare battery set
worked well if not ideal. The availability of cheap battery supplies
as well as rechargeables influenced my descision. The self contained
LED units of today when matched up with long life lithiums must surely
be the best choice even for the night riding randonneur.
Andre Jute
> but the real question is, how hard is it to repack the bearings in a
> Shimano DH3 series dynohub (I think mine is the N72)
It can only be serviced on one side. But that isn't what is relevant
with the Shimano dynohubs. What is relevant is that you can buy a new
one for around forty bucks. For that it isn't worth servicing the
thing after the 15-40K miles you will get out of it. Just buy a new
one and bin the old one. Bless Shimano, they've made the hub dynamo a
consumable.
Andre Jute
"Cycling wisdom" is an oxymoron
Nate Nagel
My understanding is that the Schmidt has cartridge bearings (although I
guess you have to send them back for service, as a special tool is
required to disassemble) and also they supposedly roll freer and are
more efficient.
That said, I couldn't make that case either... VO's front wheel with
the Shimano was something like $180 all in with shipping, where that
would just get you a Schmidt hub to start with, and my bike just isn't
worth that much. Maybe if I were honestly commuting every day I could
make that case.
thirty-six
Tried the reflective tape around the hub shell yet?
Michael Press
<70ecbe77-f56d-4d81...@j19g2000vbp.googlegroups.com>,
Frank Krygowski <frkr...@gmail.com> wrote:
Good enough says little. I was informed a while back
that we were getting a set of flatware here. I began
remembering what I found unpleasant, useful,
aesthetically pleasing, et cetera about flatware. I
made a list of must have features. I started looking
and had trouble finding flatware that met all my
requirements. Eventually we went to a shop that had a
good selection, found a stainless steel set, and bought
it. It is exactly what I wanted. A bonus is that the
polish on each implement is so fine that it makes my
hand feel good simply holding it. Another bonus is the
dinner knife has a non-serrated carbon steel blade in a
SS handle that is sharp enough to retire the steak
knives. In my case good enough is pricy, but necessary
because less would be a waste of money.
--
Michael Press
Tim McNamara
<7f635afe-62c5-446f...@o21g2000vbl.googlegroups.com>,
john dean <john...@gmail.com> wrote:
> I am a newby, but if the Shimano dynohubs cost 90$ and last for >15km
> how does one justify paying 200$ for the Smitt? hub?
The Schmidt is a better made hub. Others have commented on it having
less drag, but Shimano has made great improvements with this and is very
close in this area. Unfortunately , based on the experience of friends
with Shimano dynamo hubs, they may not last 15,000 km. I have seen
several failures, mainly of bearings, of Shimano dyno hubs but none of
the Schmidts. The seals used by Shimano just don't seem to be as good
and permit water infiltration into the hub. Since I used to do a lot of
brevets, I've seen more Schmidts than Shimano hubs.
But the cost of the Schmidt hub is formidable, no doubt about it. You
could buy at least two if not three Shimano hubs for the price of the
Schmidt. I justified my Schmidt hub because of the brevet thing but if
I had been buying a hub for a commuting bike I would have bought the
Shimano.
I also expect Shimano to continue to narrow the gap between their
products and the Schmidt. Shimano is a competitive company with a lot
of resources to put into these things.
landotter
[snipt]
> I also expect Shimano to continue to narrow the gap between their
> products and the Schmidt. Shimano is a competitive company with a lot
> of resources to put into these things.
Seeing as they've become super commoditized the last few years, being
standard on a vast majority of Dutch, German, and Scandanavian bikes--
just like Nexus shifty bits--I also bet the quality will improve,
while the price should stay down.
It does strike me as strange that they use free bearings on the drive
side, and what I'm assuming are buried non-user-serviceable cartridge?
bearings in the generator lump.
Peter S.
> It does strike me as strange that they use free bearings on the drive
> side, and what I'm assuming are buried non-user-serviceable cartridge?
> bearings in the generator lump.
Shimano only use cup and cone bearings on both side of all their
generator hubs. The bearings inside the rotor are serviceable, but
taking the rotor apart has a genuine risk of tearing the generator
wire apart, so it isn't advisable to service the bearing unless they
give trouble.
--
Regards
N8N
not yet, no, just got rear wheel on Sunday. Next time I get home from
work when it's still light out and it's not pouring down rain I will
try it though. I also liked the idea of a few strips around the
inside edge of the rim, but like I said, I just finally got the rear
wheel.
nate
thirty-six
I was thinking of the front.
> Next time I get home from
> work when it's still light out and it's not pouring down rain I will
> try it though. I also liked the idea of a few strips around the
> inside edge of the rim, but like I said, I just finally got the rear
> wheel.
If you do the rim decoration you need a three or four patches at least
as long as between adjacent spokes, double this length on the three
patch application. I'm not particularly fond of it and prefer
uncoloured polished rims.
The suggestion to patch the hubs was because of it being neater and
giving a wider block which I think is more noticeable when directly in
line with the bike from afar. There are some who are passionate about
their rim relectors and will have none of it that they can be
bettered. 'Better' usually means more and brighter tape. I dont
agree.
Flat plate retroreflectors to the front and rear fitted low give the
best conspicuity when riding in the normal manner. With a rear
mudguard you can fit a plate to the end of this usually using the
mudguard stays as support. A front reflector is best mounted with a
bracket under the axle nut or QR nut. Both these positions are
susceptible to damage on a commuter or grocery bike. A leisure only
bike will also suffer damage to these reflectors when taken off road.
Riding in groups, these reflectors will also be a hindrance. The
wheel hub is a place where no item may encroach while you are riding.
Reflective tape is inferior but the advantage of it being placed where
it can never be displaced or damaged is high. I think it is important
to have large steady bright reflectors. Flashing effect is useful of
the day, not so much at night, it becomes a distraction in my eyes.
Andrew Price
<tim...@bitstream.net> wrote:
>The Schmidt is a better made hub. Others have commented on it having
>less drag, but Shimano has made great improvements with this and is very
>close in this area. Unfortunately , based on the experience of friends
>with Shimano dynamo hubs, they may not last 15,000 km. I have seen
>several failures, mainly of bearings, of Shimano dyno hubs but none of
>the Schmidts. The seals used by Shimano just don't seem to be as good
>and permit water infiltration into the hub.
Maybe I was unlucky, but I can certainly confirm that. The bearings
in my DH-71 had to be replaced after 4,000 km.
Andre Jute
>
> I am a newby, but if the Shimano dynohubs cost 90$ and last for >15km
> how does one justify paying 200$ for the Smitt? hub?
You can't. SON might have been superior once, many years ago, but
right now Shimano hubs are as good for most things and better for
some. If you commute 10,000 miles a year, perhaps you'll recover the
cost of a SON in six or seven years. Gee.
Only Shimano offers you the option of roller brakes which, believe me,
are quite as good as disc brakes and a huge, huge deal less
maintenance and cost for consumables. (I have disc, roller and
hydraulic rim brakes on various bikes. Shimano's 70/75 seriesroller
brakes are superb and the best all-round brakes, period, no contest:
they just leave every alternative for dead.)
For the record, I have SON as well as Shimano hub dynamos.
Andre Jute
The rest is magic hidden in the hub.
For rare hub gear bikes, visit Jute on Bicycles at
http://www.audio-talk.co.uk/fiultra/BICYCLE%20%26%20CYCLING.html
Peter S.
> I also expect Shimano to continue to narrow the gap between their
> products and the Schmidt. Shimano is a competitive company with a lot
> of resources to put into these things.
The point is that while Shimano generator hubs have become slightly
better and lighter, so have SON's. The SON 20R is at least 100 gram
lighter than the lightest Shimano DH3N80 hub. The SON 20R also only
have 0.5 watt drag with the lights off at 20 km/h compared to 1.5 watt
for the Shimano DH3N72 (1 watt vs 2-2½ watt at 30 km/h), or 5.5 watt
drag with the lights on versus 7.5 watt for the Shimano at 30 km/h.
Off course, a 2 watt drag is nothing for most cyclist, but for long
distance cycling this will be a measurable difference everything else
being equal. For the weight weenies, being able to shave off 100 gram
for perhaps $2 per gram isn't that much, others like the no fuzz
bearings, or that SON makes generator hubs suited for small wheels, or
makes 28 hole versions etc. Some people are willing to pay that extra
for what they desire.
SON, B&M, Rohloff are all small family owned German business that
specializes in high quality parts that are the best in their category
and that requires as little maintenance or fiddling as possible. Such
companies just have to stay nimble and innovative to survive in their
niche. Shimano's hub generator line grow every year, with perhaps 4-5
new models this year alone, something that indicates that this is a
fast growing segment, and while the new DH-3N80 hub may steal some
sales from SON, Shimano's huge influence also generate consumer
interest in this very special niche, that may lead to more sales even
at SON.
All in all, I think companies like SON will be able to stay ahead of
Shimano for a foreseable future.
--
Regards