Custom Plastic Parts for Vintage Bike Restorations - Anyone Had Success?

[bayko]

Hey everyone! Hope you're all staying busy in the garage this season. I've been working on my '78 XS650 restoration project and ran into an interesting challenge that got me thinking about the broader community here.


I'm sure many of you have faced the frustration of needing specific plastic components during restorations - whether it's reproduction side covers, custom instrument housings, or even unique brackets and fairings for those custom builds. The original parts are getting harder to find, and when you do locate them, they're either cracked, faded beyond saving, or priced like they're made of gold.


Recently I've been researching the world of custom plastic manufacturing and injection molding services, and it's pretty fascinating how accessible this technology has become for smaller projects. Companies like the ones offering injection molding services can now work with individual builders and small groups to create custom plastic parts that would have been impossible to source just a few years ago. The quality and durability of modern plastics like ABS and polycarbonate can actually exceed what was available when our bikes were originally manufactured.


What really caught my attention is how cost-effective it can be when you're working on multiple bikes or coordinating with other builders who need similar parts. The setup costs for injection molding make more sense when you're producing 50-100 pieces rather than just one or two, which got me wondering if there's interest in our community for group purchases of commonly needed reproduction parts.


I'm curious about everyone's experiences with custom plastic work - have any of you worked with injection molding companies for your projects? What about 3D printing versus injection molding for durability? I know some members here have incredible fabrication skills and might have insights into the best approaches for different applications.


Also wondering if anyone has tackled projects like custom airbox covers, reproduction electrical housings, or even modernized versions of classic fairings using these newer manufacturing methods. The possibilities seem pretty endless once you start thinking about it.


Would love to hear your thoughts and experiences. Always learning something new from this community!

 

[jetmechmarty]

It’s tough to make a go of it. Years ago there were custom side covers available for cafe racers. Someone made a run of them, then they went away. Periodically someone comes on here looking for a Heritage lower left side cover. I doubt there’s enough interest to recover the cost. Revival Parts Group offers us very low quality rubber bits that are otherwise NLA. That’s the state of it.

 

[bosco659]

I used to work in the injection molding industry and know molds are extremely expensive. 3D printing has come a long way and the products that come from that process are quite good now. I think 3D is the way to go from a cost perspective.

 

[AUTOMAN]

bosco659 has the only alternative.
Calling a "shop" to make a mold is for 80000 shots at a time.
At $80000 for a mold for 80k shots is a buck a piece.
Then trim, prep. would cost 50 bucks a piece.

and i am lowballing cost

paint is on customer

this is for a .020" piece of polypropylene that will not hold shape or age well

might as well vacuum shrink some suitable plastic

 

[gunk]

May be slightly off topic. But For vintage dirtbikes there's a real good company I've dealt with in the USA. Had all plastics foir a 77 IT250 and several XT and TT500's I resto'd. A friend has a 3d printer and mocked up several compone nts for another friends H.D nitro bike. they then did the CADCAM thing to machine from metals. Not quite the same but an option if yoiu know anyone with a 3D plastic printer I suppose. Also a place named Clauss Studios that make hard to find rubber M.C. parts footpeg rubbers to airbox snorkels and some quite rare tank badges for a lot of old bikes and Brands.
https://www.dcvmx.com/
https://www.claussstudios.com/index.html

 

[festerandolini]

This idea will only grow from here. The prototype phase of making one-off or replacement production parts is growing here on the forum every week.

I am looking at the same processes and methods you are and i am finding a lot of good results, and resources for the home restoration obsessed.

For 3d FLM and resin printing the materials, equipment and information are all at the point of development to allow a small home shop to make enough parts for 1 to 10 projects, with about a 1 month lead in of set-up, learning and practice.

The real boon lately has been the simplicity and availability of 3D drafting software and tools. From 3d scanners to cloud based CAD applications. Free online software, open source software and premium or "freemium" solutions in mesh, design, slicer and drafting software.

The use of online tutorials, podcasts and documentation really elevates this space and allows absolute beginner level engineers to capitalise on this advancement.

China has the application now for beginners to order cheap and effective batching of any application of injection moulding, machining or extrusion.

As this space extends and continues, many of us will see at home tooling replace the need for outsourcing, but that's a future shock, waiting to happen.

Honestly, this is the most exciting factor in motorcycling for me currently.

 

[Signal]

Late last year I was able to buy a set of reproduction mirrors for a Suzuki GS 1000s (unavailable and expensive as well) . They were made by an individual person. The process was 3D scan original items then resin print. The mirrors came as a kitset that required sanding painting and assembly.
I like the idea of being able to use TPU to 3D print hard to get rubber items like odd shaped grommets for example.

 

[arcticXS]

There is a guy named Steve Burgess in the UK who 3D scans and prints various parts for Yamaha RD models. Stuff like plastic side cover, various trim pieces etc. He posted his services in "Yamaha Aircooled RD owners club" FB Page.
I had him make a LH side cover for a RD350, to replace the steel Autolube tank that doubles as a side cover. Just to save some weight and room while maintaining a stock-ish look. I run that bike on premix.
To do that, he just had to mirror the 3D model for the stock RH side cover. The finished product appears just as
good as a stock RH cover.
There is also a US member on a 2 stroke forum I am on. He just 3D printed an air intake "Y-boot" for RD250/350 that allows VM32/ VM34 carbs, instead of the stock VM28.