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how to tune xt thumbies to use for 8 speed

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#21 ·
DeeEight said:
On a shimano Deore DX or Deore XT 7 speed Light Action SIS thumbshifter, as well as the rarer Deore LX and Exage LX 7 speed ones, there are 7 clicks of equal noise/feel, the 7th one being past the lines on the cover plate though. This is the fabled 8th speed click. On the XT in my hand right now, if you push past the point of that 8th gear (and the 7th click) then there is enough lever throw in the now "friction" zone of the shifter to move 2 more gears with 7 speed spacing (with the lever ending up pointed directly forwards).
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you clearly have the Canadian version. ;)

Ive never considered that 7th click really a click since it is not like the others in sound or feel.
 
#23 ·
DeeEight said:
Sigh you still didn't get it... in a actual 7 speed shifter...there are only 6 clicks. You start out in the highest gear. There is no click. You shift to the next gear...it clicks. This continues for 5 more shifts to the 7th gear with a total of six clicks. Repeat this procedure with one of these thumbshifters and when you push past the 7th gear you get...wait for it....wait......a SEVENTH click to tell you you've gone into the 8th gear. It would only be if you tried to shift to a 9th gear position would you not have another click after the 7th one.

I explained already that in my second post.
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***Sigh***

Please allow me to re-iterate

There is NO excuse for a shop guy to talk down to you...and, in my opinion, nor is there a reason for it on Forums, either.

Lighten up, man!

If you replace the technical term "click" with the more non-tecnical "detent" everything Carsten said was true.

Geez!
 
#24 ·
I tried this setup for a while, XT 7sp thumbie w/XT 8sp drivetrain, and was never quite happy with the way it engaged the lowest cog. Maybe my shifter was a little haggered but it just never seemed to be very smooth getting into that 8th cog. Being old and outta shape I kinda need access to that cog whenever possible. :D
 
#25 ·
Rumpfy said:
Wow...we're really splitting hairs here.
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more than just splitting hairs, I think they might be trying to slice atoms. And it's funny.

The mechanic mentioned in the first post must not have much experience. I've used XT and DX 7-speed thumbshifters on 8-speed cassettes for years, and I think they work great. I'm not saying anything new, just adding my confirmation to the collective.

But this thread does need a photo. I don't have a Potts, a Ritchey, a Yeti, a Bonty, a Fat, or anything close, but I do have a set of XT thumbies in the original package.
 
Discussion starter · #28 ·
uhm yeah...
got that same blister pack of nos shifters in my garage!!

another question...
I have been trying to get the shifting smooth but I may have been mistaken that my rear deraileur is 8 speed.
Can anyone verify, I have the original deraileur from a 94 or 95 kona kilauea it is a white frame. The deraileur is black with the xt lettering-7 speed or 8 speed? Does it matter since the total cassette width is the same?
 
#29 ·
chapel00 said:
uhm yeah...
got that same blister pack of nos shifters in my garage!!

another question...
I have been trying to get the shifting smooth but I may have been mistaken that my rear deraileur is 8 speed.
Can anyone verify, I have the original deraileur from a 94 or 95 kona kilauea it is a white frame. The deraileur is black with the xt lettering-7 speed or 8 speed? Does it matter since the total cassette width is the same?
Click to expand...
The derailleur doesnt matter as they all have the same mechanical pull except for some years of Dura Ace. If its a sloppy old derailleur though you may have problems. Also make sure your cable is attached correctly under the fixing bolt. If not it will throw things off.
 
#30 ·
I'm running XT thumbies with M900 XTR 8-speed drivetrain. Works great...no brainer.

I tried a set of 8 speed XC-Pro shifters. I could get the combo to shift alright in the stand, but once I hit the road, shifting became "crunchy" again in short order. :mad: Real bummer......XC-Pro shifters are damned sexy.

Regarding derailleurs, Fillet-brazed is spot on. In general, you can use a 9 speed derailleur for 9, 8, or 7 speeds. No problem. You may find that a seven speed derailleur way not have enough range to cover the entire 8 or 9 speed cluster...but that may not always be the case. I ran a short cage 7 speed XT derailleur on a 9 speed cyclocross bike with no problems. Opposite end of the spectrum, I installed a 9 speed M952 XTR rear derailleur on my fiance's bike, to replace a defunct 7 speed Deore derailleur. Shifts fine.
 
Discussion starter · #31 ·
thanks for the responses
it is a m735 deraileur-I read somewhere it is compat with 7 and 8 speed, but I am not sure if it is the long or medium cage
 
#32 ·
Trick with suntour thumbies is that you need to run the cable tension a bit loose and just shift the lever a titch past the click, then let it spring back to the detent. If you run it "tight" cable on the stand, its just not gonna work right when yer actually riding. Remember shimano has LONG used a floating top pulley, and if you run a tight tight cable, its the top-pulley that takes up the minor distance of an overshift on the lever. Suntour derailleurs ran fixed upper pulleys because they just knew people would tend to shift past the click a bit, and that cables tended to stretch. ALL my own personal bikes (the ones only I get to ride) have suntour thumbies.
 
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#33 ·
chapel00 said:
thanks for the responses
it is a m735 deraileur-I read somewhere it is compat with 7 and 8 speed, but I am not sure if it is the long or medium cage
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I've run M732 shifters with an M735 rear derailleur in both long and short cage with an 8spd cassette with no problems.
 
#34 ·
Cage length doesn't matter for the number of speeds though it can for the maximum cog size (Suntour's MicroDrive shortcage derailleurs for example are iffy on cogs over 28T).
 
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#35 ·
I'm running 7 speed XT thumbies and an 8 speed cluster on my police-bike now but I'm running friction. I'll try out indexing and let you know.
 
#36 ·
The trick with the Suntour shifters is to use them with a DuraAce deraileur of the same era. Even better is to use a DuraAce deraileur with an M900 cage on it. I have been using this combo for years. There are some lighter options out now but back in the early to Mid nineties you couldn't find anything that shifted as well and weighed as little.
 
#37 ·
Hmmmm, i think i'll test that theory. I have a DA of that era that came off my Rocky mountain Turbo.
 
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#38 ·
MendonCycleSmith said:
As to your question, despite all the numbers thrown at you, yes, I've had nothing but great luck doing this, no set up required of the shifter at all. Just set up the deraileur and shifter as normal and simply push it beyond "first" gears click (which currently has you in second gear), and you enter the fabled "mystery position". Have fun!
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That is exactly how my bike is set up right now with shimano SIS thumbies. It works fine although I seem to notice that clean shifting is a little more affected by a worn out derailleur. New derailleurs go on my SIS thumbies bike and then are hand-me-downed to my Suntour equipped thumbie bike when the shifting starts to get iffy.

Although this will no longer be a concern as I just scored a set of 8sp Suntour thumbies for my other bike. It'll feel good to ditch the Shimano thumbies.

paetersen
 
#40 ·
Jah-on said:
What I'm curious to know is if these old school Suntour power shifters (thumbies) will shift my 9 speed cassette?
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I have a set too... I should give it a try for giggles.
 
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