Suntour XC-Pro drivetrain

[Joseph Bauder (NC)]

My situation is this: I've got a Suntour XC-Pro shifter, new,
mated to a Suntour XC-Pro mid-cage derailleur, max tooth 28, Suntour
XC-Pro GG rear hub, cassette, new, and a Suntour
cassette cluster, new, 8 spd. Everything should work perfectly. My
problem is that after setting it up:

a) Shifting effort is monstrously difficult
b) Indexing is very poor - I can't get it so it won't skip cogs, make
noise, etc.

I've played with the b-tension adj. on the rear derailleur.
Nada. I'm hoping, basically, to leave it on friction for a while until
the spring eases up on the derailleur, then see.
If any of y'all have any suggestions on what might be wrong, I'd
gladly appreciate.

Thanks,
joe

[Steve Mattingly]

Check your chain length, it might be too short. Also check
the total capacity of your drivetrain. Add the front
difference (46-24=22) and your rear cassette (30-12=18) to
get your total capacity. You might unfortunately find you
need to go to a long cage derailleur to get the capacity
you need...I did and had to go with a Shimano XT long cage.

[William Kellagher]

Sorry Joe,

I had similar problems with Suntour XC-Comp and Suntour Superbe Pro drivetrains.
I never found a satisfactory solution. You may also have noticed by now that
there is no true friction mode with Suntour thumb shifters. There are still
faint detents, so the derailleur will always slip back into the mal-adjusted
indexed position.

Now you know why Suntour went out of business.

Bill Kellagher
Boulder CO

[James M. Reed (AA)]

On Mon, 6 Nov 1995, Joseph Bauder (NC) wrote:

>
> My situation is this: I've got a Suntour XC-Pro shifter, new,
> mated to a Suntour XC-Pro mid-cage derailleur, max tooth 28, Suntour
> XC-Pro GG rear hub, cassette, new, and a Suntour
> cassette cluster, new, 8 spd. Everything should work perfectly. My
> problem is that after setting it up:
>
> a) Shifting effort is monstrously difficult
> b) Indexing is very poor - I can't get it so it won't skip cogs, make
> noise, etc.
>
> I've played with the b-tension adj. on the rear derailleur.
> Nada. I'm hoping, basically, to leave it on friction for a while until
> the spring eases up on the derailleur, then see.
> If any of y'all have any suggestions on what might be wrong, I'd

> gladly appreciate.
>
> Thanks,
> joe
>
>
>
>
Ah yes, Suntour woes. Beware the wise cracks and insults that
will surely come your way. Still as a Suntour freak (and Deore DX) I think
your parts picks are great! The best way to smooth out the shifting is
to toss those awful Suntour cable housings in the trash and use something
with a little more flex! The last loop of housing before the derailleur
should also be a little longer than usual, say add two inches. If your
frame has top mount cables try running full housing from the last cable
stop on the top tube to the rear der. Keeps the gunk out of the housing
better. Finally, Use as narrow a chain as possible (Daido supers and
Suntour Superbes are great) and keep an eye on chainline. A fat Sedis
chain and 2mm bad on the chainline can mean index doom for a Suntour
drivetrain.
Once you get it set up this drivetrain will last forever, setting it
up will drive you nuts! Stick with it and be patient, you will be rewarded.

Good Luck,
James
Sandhill Bicycle Wheels

[Joseph Bauder (NC)]

> Ah yes, Suntour woes. Beware the wise cracks and insults that
> will surely come your way. Still as a Suntour freak (and Deore DX) I think
> your parts picks are great! The best way to smooth out the shifting is

The Kona I'm working with came with DX, last year it was spec'd
too - I just jumped on the closeout suntour stuff, the DX is fine and
I've loved it.

> to toss those awful Suntour cable housings in the trash and use something

...still using the housing and cable that came with the bike.
That's the thing that gets replaced tomorrow - I work in a shop here at
school.

> better. Finally, Use as narrow a chain as possible (Daido supers and
> Suntour Superbes are great) and keep an eye on chainline. A fat Sedis
> chain and 2mm bad on the chainline can mean index doom for a Suntour
> drivetrain.

Hmm...you might have hit the nail on the head. It's an
SC-M50/55. I've yet to check the chainline.

> Once you get it set up this drivetrain will last forever, setting it
> up will drive you nuts! Stick with it and be patient, you will be rewarded.

One thing I've contemplated is replacing the top guide pulley
with a floating Shimano pulley and leaving the lower tension one
Suntour. The Suntour sealed bearing pulleys have no float, and I could
swap with my old LX derailleur.
I've been getting advice from all corners - I'll keep you posted.

Thanks,
joe

[VeloBat]

Had this stuff on my MB-ZIP (Bridgestone) when I bought it. It didn't
shift well .. and needed lots of attention. Finally swapped it out for
Shimano XT stuff .. never been happier.

[Kristan Roberge]

"Joseph Bauder (NC)" <bau...@virtu.sar.usf.edu> wrote:
>replacing the top guide pulley
> with a floating Shimano pulley and leaving the lower tension one
> Suntour. The Suntour sealed bearing pulleys have no float, and I could
> swap with my old LX derailleur.

No you can't. Suntour uses larger size pulley bolt than shimano so shimano
pulleys won't fit.

ANy of the aftermarket aluminum/Ti pulleys that have JUST the cartridge
bearings (and no cutesy spacers for float) will also work. I recommend
TNT since they are packaged individually.

YOU DON"T NEED Floating pulleys with suntour (or shimano for that
matter). The whole floating pulley business got started because shimano's
tolerances of the derailleurs left much to be desired. By having a derailleur
pulley that moves laterally half a millimeter, some of this slop can
be avoided.

I mix suntour and shimano parts on a couple of my bikes. My Rocky
Mountain Team Comp uses an ALL XC-Comp drivetrain but runs control tech
pulleys in the derailleur (works fine).

My Trek9000 mixes a custom 7 speed cassette (made up from an HG90 12T
cog, and XTR 14T, and the 16-28T cogs from an XT-8Speed cassette),
giving me a 7speed stack with 8speed spacing. Wait, gets weirder...
XTR rear shifter, and an XC-Comp middlecage rear derailleur with TNT
pulleys... YOU DON'T NEED A FLOATING PULLEY! I've got proof in this
bike (which shifts great).

[Kristan Roberge]

kell...@sweng.stortek.com (William Kellagher) wrote:

> I had similar problems with Suntour XC-Comp and Suntour Superbe Pro drivetrains.
> I never found a satisfactory solution. You may also have noticed by now that
> there is no true friction mode with Suntour thumb shifters. There are still
> faint detents, so the derailleur will always slip back into the mal-adjusted
> indexed position.

WRONG! The light-action mode of the suntour xc-pro thumbshifters doesn't
have detents. The clicking noise comes from a spring inside the shifter.

Suntour XC-Pro shifters have had this clicking noise since about 1980.
Suntour invented index shifting in case you weren't aware. They just
didn't market it very well.

[Matt Wenham]

Kristan Roberge (krob...@magi.com) wrote:

: I mix suntour and shimano parts on a couple of my bikes. My Rocky

: Mountain Team Comp uses an ALL XC-Comp drivetrain but runs control tech
: pulleys in the derailleur (works fine).

I use Control Tech pulleys in my XC-Comp rear mech too, and they improve
the shifting beyond measure. Those and Gore-Tex cables. Stock Suntour
pulleys are naff. Avoid 'em.

Matt Wenham.

[William Kellagher]

WRONG YOURSELF! I'm not talking about the light clicking of the
SunTour power shifters. Actually, the power shifters went back to
the early '70s (In case you weren't aware.)
When you switch SunTour indexed shifters to friction mode, there are
faint detents in the same postiions where the indexing detents used to be.
This causes the lever to fall into the same places where the indexing
forces the lever to be. This happened to me in a race once when I
had to go to non-index mode and found that my Suntour Superbe Pro
levers actually didn't have a non-indexed mode. Very frustrating.
Upon inspection I found that the thumb shifters on my XC-Comp mountain
bike had the same detents in friction mode. Go check your bike and
see for yourself. (Might be a good idea to check the facts before
you go flaming.)

SunTour may have made great hubs, or cranks, or whatever, but their
derailleur indexing never worked right. Alot of people really
wanted SunTour to succeed (including me) as an alternative to Shimano,
but the indexing just never worked well. Sorry.

Bill Kellagher
Boulder, CO

[JOHN K HARRISON]

> > When you switch SunTour indexed shifters to friction mode, there are
> > faint detents in the same postiions where the indexing detents used to be.
> > This causes the lever to fall into the same places where the indexing
> > forces the lever to be.
>

> If the lever falls into ANY place, its because you don't have the
> bolt tightened enough after switching from index to friction mode.

>
> > Upon inspection I found that the thumb shifters on my XC-Comp mountain
> > bike had the same detents in friction mode. Go check your bike and
> > see for yourself. (Might be a good idea to check the facts before
> > you go flaming.)
>

> The detents are there to be an indication of which gear your in (they
> click faintly while your shifting) and do not prevent you from using
> the shifters in friction mode. This is explained in the Suntour manual,
> which you'd know had you bothered to read it.
>
this also brings to case the (probable) main reason that suntour went out of
buisness - their production tolerances went to shit in the last few years. i
have had three sets of xc pro shifters from the same year, each rear shifter
having a very different level of "ghost" click in the friction mode. in one
the click was faint enough to not matter. in the other two true friction was
not possible.