Maintaining Shimano Friction (downtube) Shifters
HKEK
Exage components, 7-speed cogset). The friction shifters are not
holding their position. Can these shifters be easily disassembled to
clean (lube?) the friction mechanism? How is it done? Should the
friction mechanism be assembled "dry" or should it be coated with
"xyz?" compound to prevent slippage? — Thanks in advance.
landotter
Dry. "Lubrication" is provided by the nylon washers.
A Muzi
Unscrew end bolts 2-3 turns, drip oil in all spaces, tighten and ride.
If they are full of crud, open, clean, coat all surfaces with oil during
installation. It's the oil film which makes it work correctly; dry
shifters 'jump' and slip.
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
sergio
> Unscrew end bolts 2-3 turns, drip oil in all spaces, tighten and ride.
> If they are full of crud, open, clean, coat all surfaces with oil during
> installation. It's the oil film which makes it work correctly; dry
> shifters 'jump' and slip.
I might appear not to make sense to lubricate a friction mechanism,
but in full amazement that's what I also learned while watching an
expert mechanic, back then.
Sergio
Pisa
Qui si parla Campagnolo
What Andy Muzi said plus a little blue loctite onto the fixing bolts.
HKEK
destructively) for cleaning/restoration?
sergio
> But can these mechanisms be completely disassembled (non-
> destructively) for cleaning/restoration?
Why not?
Yes, we (all) can.
Sergio
Pisa
sergio
> What Andy Muzi said plus a little blue loctite onto the fixing bolts.
I have never done so, nor shall I.
After a while it is all too common to find the friction mechanism too
tight, mainly because of dirt having got inside. Then, whle you
riding, it is common practice to release a little bit and quickly
retighten it as needed.
That would be impossible if a bonding chemical is holding it in place.
Sergio
Pisa
jim beam
two things:
1. paradoxically, if you're worried about the thread getting grit in it
an jamming up, loctite prevents that from happening. and not only is
loctite very low strength so release is not usually a problem, it's
easily released by temperatures only slightly above boiling, so not very
hot.
2. using oil to lubricate a polymer washer like nylon is doing to cause
stickiness - the two interact. it should be left dry or an inert
lubricant like a silicone should be used. there are other more specific
non-reacting nylon lubes, but i forget what.
Qui si parla Campagnolo
If installed correctly, there is no need to use any 'common practice'
of releasing a little bit and quickly retightening it if 'needed'". I
have used only friction downtube shifters on all my bicycles for over
2 decades and have never had to do this 'common' practice and I have
cleaned, lubed then blue loctited the bolts for those same 2 decades.
I do not have shifters get loose or tight and they do not shift
themselves while climbing.
sergio
> If installed correctly, there is no need to use any 'common practice'
> of releasing a little bit and quickly retightening it if 'needed'". I
> have used only friction downtube shifters on all my bicycles for over
> 2 decades and have never had to do this 'common' practice and I have
> cleaned, lubed then blue loctited the bolts for those same 2 decades.
> I do not have shifters get loose or tight and they do not shift
> themselves while climbing.
That's been happening to me a few times during these 37 years of
cycling with downtube shifters.
I clean and lube once in a while, only perhaps too seldom.
Or, alas, do I ride too much?
Sergio
Pisa
HKEK
I can see the internals and how they are held together? I have had
them off the bike and they stayed in one piece. Thanks.
A Muzi
There's a product number on it, "SL-__ "
What number?
HKEK
A Muzi
> Thanks, Andrew — The front one is SL-A400 and the rear is SIS S7.
That series does not open easily (or at least in a non-destructive manner!)
http://www14.big.or.jp/~number-2/No.1_ShimanoSLA400.html
Tighten the side screw and otherwise leave it alone. Despite being 'non
serviceable' this entire series has proved extremely reliable over 20+
years.
If it's rusted or wrecked a similar replacement is dirt cheap.
HKEK
I have not used the index feature as it doesn't seem to work well.
Maybe I have not spent enough time trying to adjust it properly.
Would I be better off installing bar end shifters (don't like to take
my hands off the bars)? If so, can I get some kind of barrel adjuster/
cable stop to mount on the downtube where the shifters were mounted?
Or is there a cover that can be put over the old shifter mounts? I
would still need some new cable stops...
John Forrest Tomlinson
wrote:
>Those are the ones! To replace them, would/could I buy new old-stock?
>
>I have not used the index feature as it doesn't seem to work well.
>Maybe I have not spent enough time trying to adjust it properly.
And there are some non-obvious things that can improve shifting, such
as the alignment of the deraileur hanger and the quality of the the
cables and housing
JT
russell...@yahoo.com
> Those are the ones! To replace them, would/could I buy new old-stock?
>
> I have not used the index feature as it doesn't seem to work well.
> Maybe I have not spent enough time trying to adjust it properly.
>
> Would I be better off installing bar end shifters (don't like to take
> my hands off the bars)? If so, can I get some kind of barrel adjuster/
> cable stop to mount on the downtube where the shifters were mounted?
> Or is there a cover that can be put over the old shifter mounts? I
> would still need some new cable stops...
http://harriscyclery.net/page.cfm?PageID=49&action=details&sku=FS1095
This is what you would put over the brazed on downtube bosses.
>
> On Jan 26, 8:49 pm, A Muzi <a...@yellowjersey.org> wrote:
>
>
>
> > HKEK wrote:
> > > Thanks, Andrew — The front one is SL-A400 and the rear is SIS S7.
>
> > That series does not open easily (or at least in a non-destructive manner!)
>
> >http://www14.big.or.jp/~number-2/No.1_ShimanoSLA400.html
>
> > Tighten the side screw and otherwise leave it alone. Despite being 'non
> > serviceable' this entire series has proved extremely reliable over 20+
> > years.
>
> > If it's rusted or wrecked a similar replacement is dirt cheap.
> > --
> > Andrew Muzi
> > <www.yellowjersey.org/>
> > Open every day since 1 April, 1971- Hide quoted text -
>
> - Show quoted text -