Always be sure all of your stem bolts are properly tightened before riding anywhere a loose bolt in the stem can cause your handlebars to loosen, potentially causing a crash. If you're raising your fork, be sure that your brake and shifter cables are long enough to compensate for the increase in distance. Keep both wheels planted on the ground during handlebar adjustments to prevent the fork from sliding during height adjustments. Once you have them aligned, use the torque wrench to carefully tighten the stem clamp bolts evenly to the manufacturer's recommended torque, usually between 5 to 8 nm. Straddling the bike can make it easier to judge how the handlebars and front wheel line up. Tighten it until it is just barely snug.Īlign the handlebars with the front wheel. Not tight enough, and you'll feel rattling and vibration in your headset. Flip your bike upside down and the serial number is under the bottom bracket. The photo below has arrows that are pointing to each potential serial number location.
Trek 420 bicycle serial number chart serial numbers#
Too tight, and you'll have trouble steering. The majority of bike serial numbers can be found in the following locations on your bike. Once you have the desired number of spacers between the stem and the headset, place spacers on the remaining steering tube until the top spacer extends 3 mm to 5 mm above the top of the steering tube.
Rearrange the stem and the spacers until the desired height is reached. Once you remove the bolt and cap, you'll see the star nut inside the steering tube. Use a 5 mm Allen wrench to loosen the top cap at the top of the stem.
Bontrager stems usually use 5 mm Allen wrenches, but can sometimes use 4 mm or 6 mm Allen wrenches. Since around 1920 they used a production stamp, with which they can be dated: 36, therefore stands for example for the production date in 1936 later, there were also some 1-digit numbers: 5 or 55, built in 1955. Loosen the clamp bolts where the stem meets the steerer tube. The best bet on post-1957 machines is to check the Torpedo rear wheel hubs. Tighten each bolt to the manufacturer's recommended torque, usually between 4 and 8 nm, making sure to keep the faceplate even. Using the torque wrench, tighten each bolt a little bit at a time, keeping the thin space between the stem faceplate and the stem as even as possible.