Tiagra FC-4603 triple owners replacing lost, seized or damaged inner chainring bolts.
These are genuine Shimano inner gear fixing bolts (part Y1MJ98010) for the Tiagra FC-4603 triple road crankset. The pack holds five sets, enough to fix the inner (small) chainring all the way round.
Inner ring bolts are a different length to the ones that hold the outer and middle rings together, so it pays to use the right part. At M8 x 9.6 mm, these match Shimano's spec for the FC-4603 inner ring.
Genuine Shimano
Original part Y1MJ98010.
Made for FC-4603
Holds the inner ring on the Tiagra triple.
M8 x 9.6 mm
Correct length for the inner ring.
Five sets
Enough for the whole ring.
Bolts
Compatibility
Great for
Maybe not for
Inner gear fixing bolts for the Shimano Tiagra FC-4603 triple. M8 thread, 9.6 mm length, 5 sets. For other cranks, compare with your old bolt before fitting.
Fitting chainring bolts
Clean the threads and add a small dab of grease, then tighten the bolts gradually in a star pattern so the ring pulls in evenly. Finish to Shimano's torque with a torque wrench, as over-tightening can strip small bolts.
Check the others
If one inner bolt has worked loose, the rest often aren't far behind. Check them all, and the outer ring bolts too, while you have the tools out.
The world's biggest maker of bike components.
Shimano was founded in Sakai, Japan in 1921 and is now the world's largest maker of bicycle drivetrain and brake components, from entry-level groupsets through to Dura-Ace.
