You will find these forks on low-cost bikes, but also on old bikes. Installing a 1 inch steerer fork is a bit more complicated than a 1 1/8 inch. Even so you will not need to make a considerable effort. In this article you will see, step by step, what you need to do.
Step 1: We presuppose you found out beforehand what type of fork your frame supports. Today the most popular fork standards are 1 inch, 1 1/8 inch, 1 1/8 – 1.5 inch (conical, narrow in its superior part and thick in the lower part) and 1.5 inch. Cheap suspension forks built for low cost bikes are not exactly the best option when you want to replace your fork. This is why it may be a good idea to search second hand shops for an older 1 inch fork made by a famous producer.
Step 2: For installing the fork you will need a rubber hammer and a special tool for introducing the headset on to the fork.
Step 3: Lubricate the place where the cup meets the fork’s steerer. Afterwards introduce the special tool on the cup.
Step 4: Hit the cup until it gets on to the fork. Fix it such that it has a uniform position (it should not be with one side on a different level to the other). While gently hitting it you can verify if the cup has been well fitted. After completely entering you will hear a metallic noise.
Step 5: The bearings should remain fixed on the headset after you have removed the fork. It is recommended you take them out, clean them and lubricate them. Introduce the fork back to its place.
Step 6: screw the cups. (TIP: if the thirst 3 thread lines screw in harder then you have not done it correctly). Tighten it with the hand till there is no play.
Step 7: Introduce the safety washer and, if it is the case, the support for the cantilever brakes or the lighting system.
Step 8: screw the last nut fully. Fix it firmly with a 24 sized wrench. If the steerer of the new fork is too long after fixing the upper cap of the headset then you should add another spacer. If this is not enough you might need to cut the steerer.
Step 9: Introduce the stem and you can now start to try on the new configuration: move the handlebar to the left and right, pull and push the bike. If the handlebar is not moving easy enough then the cup on the lower part is too tight. You should unthread it a bit (not more than half a round). Afterwards you should tighten the upper nut. If the fork has a play then the lower nut needs to be tightened a bit more. In order to do this you will need to loosen the upper nut again.
Because the components have threads you can finely tune everything. In the end you should obtain a system that moves freely but has no play. If you are also changing the headset you should verify the system after a few kilometers on the bike. TIP: as the lower cup cannot be tuned with a fixed wrench you should use a piece of cloth and a mox to hold the upper nut against the lower one so that you can ensure a better tuning of the cup.