Ducati fork tubes
An out of production part no longer available from Öhlins or Ducati
Managing Director, Martin Thrower has raced the PDQ Precision bike in the Ducati TriOptions Cup – a support race held at British Superbikes. This affinity with Ducati motorcycles led to the opportunity to reverse-engineer and manufacture a much needed out of stock part.
Reverse-engineering that classic look
Having raced in the Ducati Tri-Options Cup, the team at PDQ Precision have developed a good relationship with JHP/Ducati Coventry. We received a phone call from the Midlands-based Ducati specialist in late 2020. They were keen to enquire about the possibility of reverse-engineering a set of Ducati fork outers for a classic 1989 851 SP racer. Of course, were more than happy to help.
The forks were a pair of trick Öhlins original items that were fitted to the model when Ducati changed to 17″ wheels for the 2nd generation version. The forks continued to be fitted to the 1992 Ducati 888 SP54 and SPS.
Let’s get to work
A donor fork leg outer and lower cap were received and we began work. First, we precisely measured the cap, drew it up using CAD software and began production.
Having the original fork outer allowed us to use it as a thread gauge, ensuring the internal fine thread of new cap was going to be a sweet fit. We cut the knurls rather than form them – this way we could ensure the finish was extremely high-end, as any Ducati customer might expect.
Going for gold
Once we were happy with the fork cap, we moved on to the fork outers. The drawing was initially pretty straightforward until the borescope revealed there was a machined section halfway down inside, this was required for an internal Teflon bush.
Clearly, we couldn’t cut a perfectly good Öhlins original in half, but we needed to know accurately the size and position of this section. We used a non-shrink silicone, which is typically used for inspection, to take a cast of the internal features. When removed we were able to measure the silicone cast and add the feature to our drawing.
Machining the parts
With the drawing complete we were ready to begin machining the parts. It was essential to avoid any marks or blemishes that may be created during machining process. We knew that the final anodising process would only accentuate any inconsistencies even further.
Alongside the final parts, we also produced some miniature samples from the same material. These were supplied along with the original tube outer to our trusted local anodising partner.
Completed and delivered
JHP’s required the forks to look like new and to match as close as possible to the original gold colour. Our miniature samples were sent to JHP’s HQ for their inspection and approval. They were a perfect match and we received the go-ahead to anodise the final tubes.
Once complete, the freshly recreated Ducati fork tubes were carefully packaged and dispatched direct to JHP who were delighted with the result.