Double spacers for larger Q factor

Former Member
Former Member
Are there any limitations or restrictions to adding two spacers between the Vector 3 pedal and the crank?

I currently have one spacer, and my cycling dynamics data always shows a positive PCO (Pedal Center Offset), with values between +5 to +10. This is a clear indicator that when I push the pedals I always press on the outside of the pedal center. As well I developed pain on the external edge of the foot.

Moving the shoe closer to the crank (to align with the pedal center) is not possible, as doing that correction generates knee pain. Today I went for a sports medical consult and we concluded that, based on my anatomy, I need to move my shoe further out from the bike, and therefore to increase the Q factor of the pedals.

Due to the factors above, I would like to move the pedals further away from the cranks. Are there any limitations to adding an extra spacer (total of 2 on each side)? Should I pay attention to something in particular?
  • As per the manual you should only add one washer per side.
  • Doing this reduces the available thread engagement into the cranks and consequently it compromises the load and impact handling capability of the spindle. It is not recommended to use more than one spacer. If you did want to do something like this it may be worthwhile to look at cranks with a wider Q-factor (such as MTB cranks).

    I will point out that for me, positive PCO correlates significantly with outboard knee tracking. If I ride with my knees close to the top tube then PCOs are pretty neutral; if I ride wide-legged then PCO goes significantly positive.
  • We have seen several Vector 3 sets destroyed by people trying to thread them into spacers like these. Typically the female spacer threads are not deep enough to accommodate the full length of the Vector 3 spindle threads. Even if that were not a problem, you will not get good radio performance once you encase the inboard end of the spindle in solid metal.
  • Former Member
    0 Former Member over 2 years ago
    Thank you all for your replies! I thought of the pedal spacers, but then I realised that at the end of the Vectors there are some blinky lights, which I would not want to mess up with.

    I will take another look at the cleats to see if there is anything that can be done to bring them outside.

    t_smit will there be any long-term issues if I keep my PCO always on the positive side?
  • t_smit will there be any long-term issues if I keep my PCO always on the positive side?


    Not for the pedals.

    And, if you are not experiencing any pain or discomfort, then don't change cleat position just to try to make the numbers look a certain way. The PCO and power phase numbers can be of interest if you see them changing as a result of fatigue, pedaling load, or injury. In that case it might be worthwhile to discuss these changes with a bike fitter or a physiotherapist that is familiar with bicycle kinematics.

    You might try doing a trainer session where you wear street shoes or runners rather than your cleated cycling shoes. If the PCO is substantially different, then this can come about because you are inadvertently twisting your feet (pronating) in the shoes. Again, this is something where the assistance of a bike fitter or physiotherapist may help - they may be able to fit your shoes with wedges or suggest some other exercise to reduce this tendency (again, only if that ends up causing some other collateral effect).
  • We have seen several Vector 3 sets destroyed by people trying to thread them into spacers like these. Typically the female spacer threads are not deep enough to accommodate the full length of the Vector 3 spindle threads. Even if that were not a problem, you will not get good radio performance once you encase the inboard end of the spindle in solid metal.


    Oh man, I hadn't even thought of that! I have used them before, but it must have been before I got my power pedals. Once you said that, and I started thinking about it, I can definitely see where that would be a problem with both the longer threaded body and the lights not being visible anymore. Sorry for the bad idea!

    I also have a ~10mm outboard PCO on both sides even with my cleats adjusted as much as possible and the spacer installed. I feel like it is putting an extra amount of tension and stress on the outside of my ankles, but I think it is primarily a shoe issue because I don't have this problem with my old pair of shoes. The wedge idea or a different crank with a higher Q factor are probably the only viable solution TBH.
  • Former Member
    0 Former Member over 2 years ago
    I also have a ~10mm outboard PCO on both sides even with my cleats adjusted as much as possible and the spacer installed. I feel like it is putting an extra amount of tension and stress on the outside of my ankles, but I think it is primarily a shoe issue because I don't have this problem with my old pair of shoes. The wedge idea or a different crank with a higher Q factor are probably the only viable solution TBH.


    I started on this route as I have pain on the outside of my left foot, at the bottom of my smallest finger. I train for triathlons and I have no problem during the runs. But after cycling I always get this issue and I had to stop training now as the pain only gets worse. At this stage I cannot blame it on the pedals, as I got new shoes and insoles at the same time as the Vectors. Will try to adjust my position of the cleats and see if that corrects it.