"Peter" <[email hidden]> wrote in message
news:[email hidden]...
Quoted message said:Andre Jute said:Peter said:landotter wrote:
> On May 13, 3:06 pm, "Peter" <[email hidden]> wrote:
> > Hi
> > I have an approx 7 year old bike (a Nishiki 407 hybrid) which
> > has an internal gear hub (called a "Nexus SG-7R46).
> > The gear hub has recently become very "sloppy" and now is
> > basically unusable. The local bicycle mechanic has told me it
> > would cost about 170 to 200 Euros to replace.
> > Before I accept this offer, I was just wondering if it is
> > possible (in general) to change a bike from using an internal
> > gear hub to using external gears?
> Possible? Yes. Practical? No. If you're in the part of the world
> where 700c 3/5/7/8 Nexus replacement wheels are common, then this
> is the best option--if the part needs to be replaced.
> Has the obvious been checked? Is there bearing play? Is the
> shifter worn? Is the cable adjusted properly? It could be a cheap
> fix--but seven years on a well used city bike could very well
> mean that it's time for a fresh hub.
Thanks for your comments. The bike mechanic said the hub was shot,
not that he opened it to look at what exactly was wrong. It would be
cheaper to replace the whole hub than to try to fix it.
The entire real wheel rocks about 1 to 2 cm from side to side, so I
guess something is pretty broken.
That might just mean the axle is loose in the track ends. Get the
fitting and maintenance instructions from the Paul Lange site and just
check for a start that everything is bolted up correctly, and then
follow the instructions for adjusting the gearbox -- it is a lot
easier than you might think, and you can do it without any tools.
Hi - thanks for the tip. Do you have the url to that website?
/Peter
Hi Peter,
Hold on there a bit. This is classic bearing failure. But so what - as
long as you can spin the wheel and you do not hear or feel metal
grinding on metal, the races are probably fine. In any case until
someone actually looks at the bearings, your "mekanics" are just blowing
air out their asses.
If you go here:
http://cycle.shimano-eu.com/publish/content/cycle/seh/nl/en/technical_service.html
click Technical Documents, you get
http://techdocs.shimano.com/techdocs/index.jsp
put the cursor over Comfort and find your hub, then download it. You will
get an exploded drawing. Here is the URL for one for example:
http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/SG/EV-SG-7R46-2128C_v1_m56577569830615762.pdf
When I looked at it I thought Sheesh how simple, I was taking apart and
fixing stuff like this when I was 15 years old.
If the bike mechanic you are using doesen't want to touch it (sounds like it
to me)
then find another one or take it apart yourself. Why not - if your
convinced that
the hub is shot and your going to replace it, then take the thing apart so
you can
see how it works - what are you going to do, break it? It's a learning
experience.
I doubt the race is shot, I suspect more likely that the ball retainer
inside the bearing
is damaged and 1 or more bearings have fallen out. That part can be tossed
and
new and more bearings added. Most of the time ball bearing retainers are
for pussies
anyway, all they do is make it easy for someone on an assembly line to slap
together
bearings a mile a minute.
A mechanic that makes a "replace it with a new part your part is shot"
diagnosis
without even taking it apart, simply is either a tremendous lazy-ass, or
incompetent,
or just has a lot of work already lined up that he can do in his sleep,
since he's
done it over and over and over again. None of which you want to reward by
tossing them money for taking a part out of a box and replacing it on your
bike.
These hubs are designed to be taken apart and rebuilt. Parts are available.
Just
because the locals you have talked to are too unimaginative to e-mail a
credit card number
to a foreign distributor and get a part mailed to them doesen't mean that
it's not
possible to do it. Print out the exploded diagram, go back to your
mechanic,
and tell him to get off his butt and show you the "shot" bearing race.
Ted