Step 1: Planning
Tools/materials needed:
- Blocks, jacks or supports to secure the bike when front end is removed.
- Hand tools to remove the existing front end.
- Basic measuring tools (steel ruler is sufficient for this task)
- Steel plate (I used 6mm mild steel)
- Sharpie
- Angle grinder with cutting and sanding discs
- Magnet for test fitting/tack welding
- Welding machine (I used TIG, however MIG would also do the job)
- Files/sanding discs on a Dremel
Design process:
In this case, the client’s bike was a Yamaha XV750 fitted with a Yamaha R6 front end. There were existing steering stops cast into the R6 lower triple clamp, but they didn’t make contact with the XV steering stop block welded to the lower neck.
On inspection, all I needed to do was make the existing neck block about 15mm (5/8″) longer.
Step 2: Prepare the existing steering stop
Using a Dremel with a sanding disc, I cleaned off the paint of the neck block. You could use files to do this. I’d avoid using an angle grinder and sanding disc in this instance as this could result in too much metal being removed. On such a small part, I’d consider this approach “overly aggressive”.
This is the lower neck block:
Here is a close up of the same location:
Step 3: Cut an “extension” piece from steel plate
Since the front end moves in an “arc” around the centreline of the steering stem, the actual shape of the extension piece should technically be a “segment”:
This was marked out roughly in a piece of scrap 6mm (1/4″) mild steel plate. Since the existing bike frame is steel (check if a magnet sticks to it), the extension piece doesn’t need to be any more exotic. At the top (and widest part) the piece is only about 25mm (1″) wide, and the sides of the segment are the desired 15mm (5/8″) length.
I cut this piece out with a cutting disc on an angle grinder, and roughly sanded to the Sharpie line with a sanding disc on the angle grinder.
Step 4: Test fit
Here I’m using a magnet under the extension piece to secure it to the existing stop block. In this photo you can see I have also ground both the existing stop block and the extension to create a “V” that I will fill with weld material.
Step 5: Weld and finish
For this job, I chose to use the TIG process because this is a very small part, and at low current I can use a small arc to accurately place the weld material into the “V” groove. A MIG weld (or an arc weld) would be possible but might result in extra clean up time. In addition, the lower bearing cone was still pressed into the neck and I aimed to avoid too much heat in this area (which could distort the neck or temper the bearing race and soften it).
The next photo shows the finished item with the welds sanded smooth in order to blend the shape of the old steering stop block into the extension. Files, and sanding discs on the Dremel were used for final finish.
Since this frame is yet to be painted, I simply hand painted a black enamel paint over the new steering stop to prevent rust. Spray painting would take under 5 seconds but the masking required to protect the rest of the bike would take much longer. The stop will be located under the headlight and the client can repaint the whole frame if they choose.
This was a relatively quick and simple job, taking under two hours (including removal and reinstallation of the front end).
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