# Pro-Set Stem adjustment



## ptf (Jul 19, 2008)

I have a '08 Roubaix with the adjustable Pro-Set stem. When I got the bike, the stem was set to the most upright position. I would like to play with it and experiment with a less upright position or perhaps in a horizontal position but I can't seem to find clear instructions as to how to do the adjustments and what impact it might have to my overall fit on the bike. Also, how do the different shims fit into the equation. What if I want the stem horizontal - do I toss the shims altogether? Can anyone point me in the right direction as to a good guide on adjusting the stem? I've read the instructions on the Specialized website, but they aren't the best. I've read prior posts here on this forum and it seems to be a mystery.


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## PJ352 (Dec 5, 2007)

ptf said:


> I have a '08 Roubaix with the adjustable Pro-Set stem. When I got the bike, the stem was set to the most upright position. I would like to play with it and experiment with a less upright position or perhaps in a horizontal position but I can't seem to find clear instructions as to how to do the adjustments and what impact it might have to my overall fit on the bike. Also, how do the different shims fit into the equation. What if I want the stem horizontal - do I toss the shims altogether? Can anyone point me in the right direction as to a good guide on adjusting the stem? I've read the instructions on the Specialized website, but they aren't the best. I've read prior posts here on this forum and it seems to be a mystery.


Just a fyi... with a 73 degree HT angle, you'd need a -17 degree stem to have it run parallel to the ground. But to adjust fit I wouldn't recommend setting a goal based on a stem position. Rather, get a baseline first by measuring your saddle to bar drop now, then adjusting from there. Roughly speaking, for every two degrees of angle change you'll change the drop by about 5 mm's.

If you look at your stem, you should see a small arrow < on the left side. The number that points to is your current stem position. So if, for example, you wanted to change it from +16 to -8, you'd just flip the stem. If you want to change to -10, you'd remove the stem and +16/ -8 shim and install the +14 /-10 shim so that -10 displays on the right side, then install the stem 'flipped down'.

IMO changes to fit should be done slowly and in small increments, giving your body time to adapt, so keep that in mind. 

Hope this helps. If not repost and we'll go from there.


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## ptf (Jul 19, 2008)

thanks for the response - one thing that always confused me is flipping the stem. what specifically does that mean? To flip the stem, I guess I would have to remove the handlebar from the stem?


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## PJ352 (Dec 5, 2007)

ptf said:


> thanks for the response - one thing that always confused me is flipping the stem. what specifically does that mean? To flip the stem, I guess I would have to remove the handlebar from the stem?


Yes. You would remove the bar, loosen and remove the top cap, then the stem, then flip it and reinstall. Remember that the shims position on the steerer tube shouldn't change unless you're replacing it. When you do that the arrow will be on the opposite side indicating your new stem angle. 

Just be aware that if you do this, when you reinstall the stem and top cap you need to readjust (preload) the headset bearings. It's not difficult, but if you're unfamiliar it can be tricky.


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## DNM (Feb 27, 2008)

*Flip the Stem*

Yes, to flip the stem, remove the Handlebar. Also when you flip the stem, you must reverse the shim in the stem. In other words, the flange of whichever shim you are using goes down, next to the headset (or spaces as used).

The Pro-Set stem does not work properly with spacers on top of the stem / shim package.

The previous post assumes you have the 12 deg stem, not the 17 deg version. If you have the 17 deg, then then numbers change.

So, flange side of shim down. Then by rotating the shim 180 deg, you either increase or decrease the rise angle (assuming you are not using the 12 deg / 12 deg neutral shim). The angle marked on the shim that is next to the arrow is the net resulting rise or drop.

Then look at the top cap... the hole is not in the middle. Hence the "+" and "-". You turn it so that the screw goes into the threads without binding. If you are using the neutral shim, the direction does not matter.


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## PJ352 (Dec 5, 2007)

DNM said:


> The previous post assumes you have the 12 deg stem, not the 17 deg version. If you have the 17 deg, then then numbers change.


 I didn't assume the OP had anything, I merely cited examples. Besides, there is no 17 degree position offered with this system.


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## DNM (Feb 27, 2008)

*Ok*



PJ352 said:


> I didn't assume the OP had anything, I merely cited examples. Besides, there is no 17 degree position offered with this system.


Sorry.


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## ptf (Jul 19, 2008)

eesh - is this adjustment best done by a LBS?


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## PJ352 (Dec 5, 2007)

ptf said:


> eesh - is this adjustment best done by a LBS?


It all depends on whether or not you want to learn about bikes. There are many positive aspects if you do, but for those that are mechanically challenged then yes, it's best left to a LBS.

Besides this forum, there are lots of good resources that'll basically walk you through the process. Google* bicycle headset adjustment* and you'll get lots of hits. The Park tool website is also a good resource.


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## goneskiian (Jan 13, 2005)

I'm not really sold on these Specialized Pro-Set stems. A regular stem is much more simple without all these shims.

I've got spacers on top of my stem. No, it's not ideal but it works.

A couple simple instruction videos....

http://www.youtube.com/watch?v=DgAiElcaVjs

http://www.youtube.com/watch?v=4Jfc-PEhep8&feature=related

Cheers!


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## PJ352 (Dec 5, 2007)

goneskiian said:


> I'm not really sold on these Specialized Pro-Set stems. A regular stem is much more simple without all these shims.
> 
> *I've got spacers on top of my stem.* No, it's not ideal but it works.
> 
> Cheers!


Do you mean _below_ the stem??  

I agree that the Spec stems add some complexity, but they (obviously) also allow for the option of changing angles (to a point). Whether or not that payback is worth it has to be weighed. And speaking of which, there is a slight weight penalty because the system requires the shim, so not many WW's are going to consider them.


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## DNM (Feb 27, 2008)

*Lengthy Answer*



ptf said:


> eesh - is this adjustment best done by a LBS?


I think you can do this. If you look at the YouTube on basic headset adjustment, then the only new info is how to use the shims.

Assuming this is the 12 deg model, you should have three shims. one is marked +12 -12, +12 -12. If you look down on it, you will notice that it is only a shim. The inside diameter and the outside diameter are concentric. This shim is not likely what is now on the bike, as you stated that it is fully up. If you look at the 14 / 10 shim, you will notice that the inside is slanted versus the outside. That is how the angle adjusts.

That means the shim you have on the bike, if you are looking forward, has a +16 on the left side and a small arrow on the stem pointing at it. I uploaded a picture of one of mine that has a +14 in that position.

From your starting point, if you wanted to lower your bars a little bit, you would take off the stem, remove the +16, and put in the +14. From there, if you wanted the next step, you would take out the +14 and put in the +12. From there, the next step would be to put in the +10. Note that it is the same shim as the +14, only turned around. Next is +8.

From there, the step is a big one. You would take the handlebars off. Let them dangle by the cables or whatever. When I pull the stem off my steerer, the shim comes with it. Either way what you will want is to turn the stem over, then put the 8 16 shim into it the opposite way, so that the flange is now on the other face of the stem hole. When you put the stem back on the steerer tube, again the flange of the shim is down. Now the little arrow of the stem is on the right side, not the left, and it is pointing to a minus number. If that minus number is a -8, then you have that next step. If it is -16, then you need to rotate the shim so that the -8 is showing.

The next 3 steps are small again. From -8, you can go to -10, then -12, then -14, then -16. Each time you would remove the stem and shim, exchange the shim for the next one in order, then put the stem and shim back on the steerer tube.

That is what the instruction picture is trying to say.

Top cap. The other picture is of the same bike that uses +14. The top cap is put on with the "+" to the back. If I were using a minus orientation of the stem, then I would turn the top cap around. Notice how the strips line up either way.

So, when the stem is turned for "+", the arrow is on the left and points to + numbers on the shims. When the stem is turned for "-", the arrow is on the right and points to - numbers on the shims.

Hope that helps.


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## ptf (Jul 19, 2008)

thanks - the pics, videos and the explanations have helped a lot. the next issue is that I only have the one shim that is on the bike. It is a 12 degree stem set at +16. So with only the one shim, the only option I have is to flip the stem to a -8, is that correct?


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## DNM (Feb 27, 2008)

*3 other positions*

You are at +16. You can go to +8 by rotating the shim. Then -8 by flipping the stem (and rotating the shim back to original position, then to -16 by leaving the stem flipped and rotating the shim. So, you have an 8 deg step, a 16 deg step, and another 8 deg step. The -16 position will be nearly horizontal (like old quill stems were.... for that classic look).

Remember, flange of shim always goes down.

Realize, also, that the handlebars will move slightly forward with each of these steps.

I never purchased a bike with one of these stems, only the stems. When the stem is purchased, it comes with all 3 shims. I would have thought a complete bike (if purchased new) would also.


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## PJ352 (Dec 5, 2007)

DNM said:


> You are at +16. You can go to +8 by rotating the shim. Then -8 by flipping the stem (and rotating the shim back to original position, then to -16 by leaving the stem flipped and rotating the shim. So, you have an 8 deg step, a 16 deg step, and another 8 deg step. The -16 position will be nearly horizontal (like old quill stems were.... for that classic look).
> 
> Remember, flange of shim always goes down.
> 
> ...


Not IME. My complete bike came with the 8/ 16, like the OP. Like you, when I purchased another separately, I got all three.

LBS's may be able to order them, or may have some available.


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## ptf (Jul 19, 2008)

Thanks everyone - you have all cleared it up for me completely and its no longer a mystery. I will try the +8, see how that feels and go from there. Thanks again - great forum!


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