The assembly of the O.Symetric chain rings is very easy to handle. However it should be done by an authorised bicycle dealer only.

  1. Screw the chain guide nut on the external face of the large chain ring. The chain guide must come towards the right crank arm.

  2. Assemble the chain rings as usual on the right crank arm. The position mark must be under the crank arm (see right fig.). For crank sets with the 5th screw under the crank arm (f. e. SRAM Red) ‐ with exception of Campagnolo crank sets, for which we offer special chain rings ‐ the position mark must be on the opposite side of the crank arm (see left fig.).

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  3. Only valid for the 42 teeth chain ring in PCD 130 mm. In some cases – depending on the type of the crank set ‐ it can happen that you have to take away about 2 mm from the crank arm spider for a proper fitting

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  4. Adjust the front derailleur as usual ‐ about 1mm to 2 mm above the highest teeth with the crank arm in horizontal position.

  5. In order to avoid the chain from falling between the inner chain ring and the frame, please assemble the O.Symetric chain catcher (5). Please follow the Chain Catcher assembly instructions.

  6. Mainly on Time Trial frames – it can happen that you have to move back (2) the front derailleur, if it is positioned too much onward the chain ring. The right position is shown on below picture.

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  7. Following sketch shows the correct assembly of the chain catcher (5) and (in case of need) the alloy extension (2).

    2Alloy extension1
    3Screw CHC2
    4Frame + Derailleur fastener0
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  8. Finally make sure that all screws are well tightened and enjoy your ride with the O.Symetric chain rings.