# how to tune xt thumbies to use for 8 speed



## chapel00 (Jan 23, 2004)

I brought my old steel kona, that I set up with the xt thumb shifters, to my local bike shop and the owner/mech swears that they will not work with my 8 speed xtr cassette and 8 speed xt deraileur. 
I even told him that my 93 explosif is set up this way from the factory and shifts great but proceeds to talk down to me and states that the shifters only are set to move a certain distance and there is no "hidden" extra shift.
So can someone step by step-like a child-give me directions on how to adjust the deraileur to work with the thumbies.
Are the directions the same for any rear deraileur adjustment. Is there a comprehensive site to teach me to do this?
Thanks


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## Guest (Dec 14, 2007)

chapel00 said:


> I brought my old steel kona, that I set up with the xt thumb shifters, to my local bike shop and the owner/mech swears that they will not work with my 8 speed xtr cassette and 8 speed xt deraileur.
> I even told him that my 93 explosif is set up this way from the factory and shifts great but proceeds to talk down to me and states that the shifters only are set to move a certain distance and there is no "hidden" extra shift.
> So can someone step by step-like a child-give me directions on how to adjust the deraileur to work with the thumbies.
> Are the directions the same for any rear deraileur adjustment. Is there a comprehensive site to teach me to do this?
> Thanks


if those are the m732 7speed thumbies no adjustment or tuning is needed, they will work with the 8 speed cassette and derailleur right away. you can push the lever beyond the 7th click. there's no further click but it will shift to the large cog. just adjust the hi and low adjusters properly to not drop the chain off the large and small cog.

Carsten


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## Rumpfy (Dec 21, 2003)

Also....find another shop. There are too many good bike shops out there where the owner/mechanics won't talk down to you.


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## DeeEight (Jan 13, 2004)

Carsten said:


> if those are the m732 7speed thumbies no adjustment or tuning is needed, they will work with the 8 speed cassette and derailleur right away. you can push the lever beyond the 7th click. there's no further click but it will shift to the large cog. just adjust the hi and low adjusters properly to not drop the chain off the large and small cog.
> 
> Carsten


Carsten, re-read what you wrote and then think about how index shifters work as far as the 'click' goes for the number of speeds.


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## DeeEight (Jan 13, 2004)

The bit about the hi-low limits is correct for how to do the setup. In reality (and I know what sheldon brown has on his page for the cogset thickness and spacings, he's wrong..., shimano published the numbers in their own instructions back in the day) and 7 speed shimano (except for the IG50/60 ones that were part of the STX group) used the same cog thickness as 8 speed shimano, but the spacers between the cogs was different. On 7speed its 2 3.3mm spacers (between the three smallest, one of which is a black plastic one, the other is metal and part of the smallest cog) and the other four are 3.1mm brown spacers. On 8speed cassettes the spacers are all 3.0mm thick. The cogs are all 1.9mm thick. This puts the cog-center to cog-center distance for the shifts at 4.9mm for 8spd and 5.0mm to 5.2mm for 7spd (depending on position, the smaller cogs got a bigger gap for mud/dirt clearance reasons). Close enough that over the full range of shifts with a DX/XT 7spd thumbshifter, you're only picking up 1.1mm of over-throw which is within the side-to-side play of the floating top pulley on shimano derailleurs.


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## MendonCycleSmith (Feb 10, 2005)

Sounds like a shop owner that got into the business in his fourties, as an "investment oppotunity". The singularly worst kind of shop and owner. Figures that he knows everything, since he went to a two week UBI clinic, and has changed flat tires on kids bikes for three summers.... 

Agreed, find a different shop, before they try to sell you a new Trek 4300:skep:

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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## Caffeine Powered (Mar 31, 2005)

But don't tell your asinine LBS how you did it, tell him you're running 7 speed and the extra cog is actually a martial arts throwing star.


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## richieb (Oct 21, 2004)

Shimano 7-speed thumb shifters have had a "secret" 8th speed click forever. Everyone knows this who read MBA in the early 90's.

I actually had a set apart way back to see what it was about...it appears that, in the shifting mechanism for a set of thumb shifters, there are 2 spring-loaded ball bearings that roll over a series of detents at opposite sides of the shifting discs within the shifter, so the shifter essentially has 2 sets of detents at all times, which is what makes the shifters feel so positive and snappy. 

The "hidden" 8th speed click is a result of a tiny rivett hole that is drilled beyond the far end of one of the series of detents. That "hidden" click makes for a slightly less positive click which allows you that last shift. It's only on one side, so click is less positive and may wear out sooner.

As for the "by the numbers" concept, it's true. The spacers are different, and that a "by the book" shop or mechanic will say it doesn't work.

A "good" mechanic (not just a parts swapper) will tell you that the shifting will work pretty well, but never quite perfect...but this is mountain biking....it works pretty well. If you're willing to accept 95% perfect, then do it!

I say adjust your derailleur so that you have the swiftest shifting at the middle two cogs (4 and 5) and the g-pulley should take up most of the slop at the extreme ends of the stack.

Just my 2 cents.

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.


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## Guest (Dec 14, 2007)

DeeEight said:


> Carsten, re-read what you wrote and then think about how index shifters work as far as the 'click' goes for the number of speeds.


yeah, it clicks for the seventh time when you overshift out of the 7th raster but there's no defined raster for the 8th gear. wanted to express something like that. my brain is old and slow late at night...

the reason why shifting is still pretty good althoug spacing is not perfect is indeed the float in the upper pulley.

carsten


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## Shayne (Jan 14, 2004)

Good Answer :thumbsup:


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## DeeEight (Jan 13, 2004)

Carsten said:


> yeah, it clicks for the seventh time when you overshift out of the 7th raster but there's no defined raster for the 8th gear. wanted to express something like that. my brain is old and slow late at night...


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.



> the reason why shifting is still pretty good althoug spacing is not perfect is indeed the float in the upper pulley.


I explained already that in my second post.


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## hollister (Sep 16, 2005)

DeeEight said:


> I explained already that in my second post.


yoda talk like much?


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## Guest (Dec 14, 2007)

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.


i think that's exactly what i wrote. maybe in proper canadian english rather than in german english...

the INDEED in my floating pulley statement refered to your original statement, just wanted to confirm how great your knowledge is 

carsten


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## Fillet-brazed (Jan 13, 2004)

Carsten said:


> i think that's exactly what i wrote. maybe in proper canadian english rather than in german english...
> 
> the INDEED in my floating pulley statement refered to your original statement, just wanted to confirm how great your knowledge is
> 
> carsten


Carsten you did just fine. There may not be 7 clicks but we all know what you meant. There are 7 detents and you can push past the last one. There.

Is that ok, D8?

Another "not meant to be" set up that even works better is Suntour's 8 speed XC Pro shifters combined with Shimano derailleurs and cassette. Perfect... and perhaps the best feeling thumbshifter set up I have ever felt.


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## hollister (Sep 16, 2005)

Fillet-brazed said:


> Carsten you did just fine. There may not be 7 clicks but we all know what you meant. There are 7 detents and you can push past the last one. There.
> 
> Is that ok, D8?


oh you're so gonna get it for that!


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## Guest (Dec 14, 2007)

Fillet-brazed said:


> There may not be 7 clicks but we all know what you meant. There are 7 detents and you can push past the last one.


so is there a click when you shift out of the 7th detend or not? i haven't used the bike i have set-up with XT thumbies and 8speed gear in a while but i thought there is a 7th click... and D8 too if i got it right...

better don't start an argument with both of us 

Carsten


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## Fillet-brazed (Jan 13, 2004)

Carsten said:


> so is there a click when you shift out of the 7th detend or not? i haven't used the bike i have set-up with XT thumbies and 8speed gear in a while but i thought there is a 7th click... and D8 too if i got it right...
> 
> better don't start an argument with both of us
> 
> Carsten


no, there are only 6 clicks on a 7 speed shifter. There is not a click when pushing beyond the 7th detent. Basically you push it up against the "L" limit screw on the derailleur and friction holds it there.


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## Guest (Dec 14, 2007)

Fillet-brazed said:


> no, there are only 6 clicks on a 7 speed shifter. There is not a click when pushing beyond the 7th detent. Basically you push it up against the "L" limit screw on the derailleur and friction holds it there.


got it. what i meant as 7th click is when you push out of the 7th detend.

thansk, Carsten


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## DeeEight (Jan 13, 2004)

Fillet-brazed said:


> no, there are only 6 clicks on a 7 speed shifter. There is not a click when pushing beyond the 7th detent. Basically you push it up against the "L" limit screw on the derailleur and friction holds it there.


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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## DeeEight (Jan 13, 2004)

Carsten said:


> i think that's exactly what i wrote. maybe in proper canadian english rather than in german english...
> 
> the INDEED in my floating pulley statement refered to your original statement, just wanted to confirm how great your knowledge is
> 
> carsten


The question was to run thumbshifters on an 8 speed cogset, the way you wrote it... pushing past the 7th click would be shifting a 9 speed cogset.


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## Fillet-brazed (Jan 13, 2004)

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).


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.


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## Rumpfy (Dec 21, 2003)

Wow...we're really splitting hairs here.


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## richieb (Oct 21, 2004)

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.


***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!


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## jack lantern (Jun 23, 2006)

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.


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## djmuff (Sep 8, 2004)

Rumpfy said:


> Wow...we're really splitting hairs here.


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.


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## MendonCycleSmith (Feb 10, 2005)

djmuff said:


> but I do have a set of XT thumbies in the original package.
> 
> View attachment 318744


Close enough to porn for most who lurk here...


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## holden (Jul 27, 2004)

funny how threads like this get started and take on a dialogue of their own without the original poster


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## chapel00 (Jan 23, 2004)

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?


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## Fillet-brazed (Jan 13, 2004)

chapel00 said:


> uhm yeah...
> got that same blister pack of nos shifters in my garage!!
> 
> another question...
> ...


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.


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## mojo_matic (Jul 15, 2007)

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.  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.


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## chapel00 (Jan 23, 2004)

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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## DeeEight (Jan 13, 2004)

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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## Rumpfy (Dec 21, 2003)

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


I've run M732 shifters with an M735 rear derailleur in both long and short cage with an 8spd cassette with no problems.


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## DeeEight (Jan 13, 2004)

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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## vintagemtbr (Jun 6, 2004)

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.


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## AKamp (Jan 26, 2004)

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.


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## DeeEight (Jan 13, 2004)

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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## paetersen (Jul 28, 2007)

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!


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


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## Jah-on (Oct 2, 2008)

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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## Caffeine Powered (Mar 31, 2005)

Jah-on said:


> What I'm curious to know is if these old school Suntour power shifters (thumbies) will shift my 9 speed cassette?


I have a set too... I should give it a try for giggles.


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## MendonCycleSmith (Feb 10, 2005)

Jah-on said:


> What I'm curious to know is if these old school Suntour power shifters (thumbies) will shift my 9 speed cassette?


Yes, but (obviously), non-indexed only. They certainly have sufficient range to throw the derailleur from end to end though


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## Jah-on (Oct 2, 2008)

great then I,ll slap them on tonight, It has a sticky under bar shifter now and I've always run XT thumb-shifters on my bikes, (I think I'm getting old). I figure why get a new expensive bike when the old expensive bike wont die?


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## haaki (Sep 15, 2008)

*yup*

you can also go barcons with Paul Thumbies
not quite as cool, but gets the job done
Having a friction F-D makes for good chainline trimming

8 is great

just like choc'late cake


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## CabezaShok (Oct 15, 2007)

Anyone know if XT thumbies will work with a new 8 speed MegaDrive cassette? And with a new XT "shadow" rear derailer ? 

I thought id dust off this old thread, thumbies rule!


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## MendonCycleSmith (Feb 10, 2005)

CabezaShok said:


> Anyone know if XT thumbies will work with a new 8 speed MegaDrive cassette? And with a new XT "shadow" rear derailer ?


8 and 9 speed derailleurs work fine on either 8 or 9.

As for cassettes, 8 is 8 is 8. Mega or what have you, has no bearing on the spacing between cogs.... :thumbsup:


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## mechagouki (Nov 30, 2007)

MendonCycleSmith said:


> 8 and 9 speed derailleurs work fine on either 8 or 9.
> 
> As for cassettes, 8 is 8 is 8. Mega or what have you, has no bearing on the spacing between cogs.... :thumbsup:


But make sure your chain is the correct length...


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## CabezaShok (Oct 15, 2007)

MendonCycleSmith said:


> 8 and 9 speed derailleurs work fine on either 8 or 9.
> 
> As for cassettes, 8 is 8 is 8. Mega or what have you, has no bearing on the spacing between cogs.... :thumbsup:


thanks a lot Craig, i was worried about the huge jump in cog size from the high to lowest gear on the "Mega", and possibly that my DR couldnt handle this jump.

Now i wish Shimano would make thumbies for my 9 speed cassettes!


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## girlonbike (Apr 24, 2008)

you can use Shimano's 9 speed bar end shifters.


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## colker1 (Jan 6, 2004)

girlonbike said:


> you can use Shimano's 9 speed bar end shifters.


And Paul adapters.


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## CabezaShok (Oct 15, 2007)

colker1 said:


> And Paul adapters.


Do you have the exact model number 9 speed Shimano bar end shifters that work well with those Paul's? It sounds like an expensive combo, getting close to the cost of IRD 9 speed thumbies ($138) I might stick with 7 speed XT thumbies...they can be found on Ebay for $30-45 range (used)


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## girlonbike (Apr 24, 2008)

If you google shimano 9 speed bar end shifters, the model numbers come up. The Pauls have either Shimano 25.4 or 26.0 or SRAM compatible models. That's it. Pretty simple. It's not cheap but it's cheaper than brifters. We were just giving you 9 speed options since you asked. good luck!


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## colker1 (Jan 6, 2004)

ird sells something taht goes along thelines of Paul and barcons


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## girlonbike (Apr 24, 2008)

Yeah, the stage one shifter perches. It's nice because it has a hinge.


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## DeeEight (Jan 13, 2004)

Got a notification from this thread so I thought I'd add some info not present 11 years ago... Microshift offers thumbshifters for shimano and SRAM drivetrains as well as 
road bar-end and dual-control levers compatible to shimano DynaSys mountain derailleurs (so you can build your gravel bike without using the Shimano GRX stuff).

For Shimano they offer stuff compatible to the 2:1 ratio geometry derailleurs (mtn up to 9sp, road up to 10sp other than that weird Tiagra 4700 crap and the 7/8 speed DA).

For Shimano DynaSys Mtn they offer 10, 11 and 12 speed thumbshifter (or bar end shifter) sets... so you can have thumbies AND clutched derailleurs. You can buy the rear shifters as singles for all three speed levels and as pairs for 10 or 11 speed rear ends. 

They also have 8sp thumbies for Shimano Nexus & Alfine internal gear hubs.

They're drop bar levers for shimano 10 & 11 speed DynaSys derailleurs come as a 1x10 or 1x11 setup with the left lever being for braking only.

For SRAM they offer 1x11 and 1x12 speed models. 

Currently I have 2x10, 1x10 and 1x11 Microshift thumbies running shimano XT and XTR DynaSys derailleurs on my mountain bikes.and a 1x11 gravel bike with drop bars and a Deore XT Shadow+ rear derailleur.


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## colker1 (Jan 6, 2004)

There are new 7sp cassettes in town and the old ones are fine as well. I can´t recall so please... are the old 7sp rear hubs 130 or 135mm?


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## DeeEight (Jan 13, 2004)

Pretty much all 7 speed shimano and suntour mountain lineup hubs were 135mm from around 1988 onwards. Obviously there were some exceptions with many brands being slow to update the lower end frames, also hybrids and touring bikes were slower to make the switch to 135mm and road bikes didn't do it until recent years due to the rise of disc brakes. 130mm hasn't been used as a rear hub standard in mountain or hybrid bikes for decades now though so any modern hub production is likely to be 135mm.

There IS the issue that older 7 speed Shimano HG splined freehub bodies, pre-1994 don't play well with 11T cogs. One of the changes made going from a 12T smallest position cog to 11T in 1994 was machining away the end of the splines creating a roughly 1mm wide shelf at the end of the freehub. To put say a 11-28 7sp cassette on a 1991 Deore XT freehub body you need to run a 1mm spacer behind the cogs, and hopefully own a lockring with a deeper threaded section.


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## colker1 (Jan 6, 2004)

DeeEight said:


> To put say a 11-28 7sp cassette on a 1991 Deore XT freehub body you need to run a 1mm spacer behind the cogs, and hopefully own a lockring with a deeper threaded section.


1991 deore xt was alrady an 8sp group? Or were those spacers mandatory then?


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