Frame and Derailleur Hanger Alignment Tools

FRAME AND DERAILLEUR HANGER ALIGNMENT

Not having proper alignment for your bike frame and derailleur can have an adverse effect on your riding experience.

If your frame is not well aligned, you could have problems with handling and tracking. This is usually because the wheels are not aligned to the mid-line of the bike. You could have shifting and chainline problems because the rear cogsets would be badly aligned with the front chainrings. You could also experience difficulty when installing and removing wheels.

If your derailleur is not well aligned, you could experience poor shifting performance while riding.

If you don’t know how to correct this, then read on for step by step instructions.

Frame Alignment

Start by measuring the hub’s width over the locknuts. Your measurement should go from the face of locknut to locknut. Write down the number for future reference.

Compare the width of dropouts to the hub’s measurement. If you discover that the width is either too wide or narrow in comparison to the hub, you might experience difficulty while installing and removing the wheel. Ideally, the width of a hub should be from 1 to 2 mm.

You should also note the dropout thickness of the left and right. If any of the sides is different, record the difference and account for it while measuring the frame.

Place the straight and long portion of the frame alignment tool on the head tube’s left side. Ensure that the tool rests on the tubes. Slide the pointer when necessary to account for differences in chain stay length. Turn the knob until there is contact with the dropout face.

When you have referenced the bike’s left side, compare this to the right side. Now, set the tool to have contact with the same three points on the right. In the comparison, there would be two possible results.

The first is that the pointer would directly sit on the right dropout. It means that it is aligned well from left-to right. Even if the pointer and dropout have a small gap, it is still well aligned.

The second situation is that the frame alignment tool would be on the right dropout, with a gap between the seat tube and it. The dropouts would be on the mid-plane’s right. If the pointer gets contact with the seat tube, it would seat in the dropout and not its surface.

If this happens, you should reset the tool to reference contacts at the seat tube, head tube, and dropout on the right side. Move the tool to check the left side. You would now see a gap between the left dropout and the pointer.

It is best if you hold the bike securely by its bottom bracket in order to cold set it. An easy way is to install steel adjustable bottom bracket cups in place of the regular one.

It is best if you start with mild hand pressure as you bend the dropout and stays. Check your progress by crosschecking the width with a calliper. You should also increase the pressure if it is necessary.

When you are bending the frame, you should beyond just a stay at a time when it is necessary.

Derailleur Hanger Alignment

Begin by placing the bike on a repair stand and the wheels as level as they would be on the flat ground. Make sure you mount the rear wheel straight in the frame. Remove the rear derailleur and install the derailleur hanger alignment tool.

Rotate the tool’s arm towards the rim’s left side at 9 o’clock position. Also rotate the valve to this position. You would use this point as a reference point when working on the hanger.

Loosen the knob of the sliding gauger and make the sliding gauge secure the knob by contacting the rim.

Slide the gauge bracket in the direction of the hub before you rotate the arm. It helps to prevent you forcing the gauge on the rim.

Rotate the tool and the derailleur hanger alignment tool and the rim valve to 3 o’clock position.

There would be three possible outcomes:

First is the gauge would barely touch the rim, meaning that the hanger is horizontally aligned.

In the second instance, if the pointer is some distance from the rim, the hanger would be misaligned.

The third outcome is when the pointer strikes within the rim, meaning the hander is misaligned. In this instance, reset the tool to 9 o’clock and rotate to 3 o’clock.

When you bend the hanger, bend it a bit and recheck. Generally, it is ideal to have the tool close to the chainstay. This lets you use the stay as leverage while controlling the amount of bending. Repeat the bending until the gap is 4mm.

After horizontal alignment, check the 8:00 and 12:00 position. Set the gauge to 6:00 and check at 12:00. Note that you should only bend to half of the gap’s amount. Reset the pointer each time you bend the hanger. If the gap becomes less than 4 mm, retain the setting and check the 3:00 position.