Building - Cutting carbon fibre wheel fairings

Cutting carbon fibre wheel fairings

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Topic: Cutting carbon fibre wheel fairings

Posted By: LWaB
Subject: Cutting carbon fibre wheel fairings
Date Posted: 14 June 2024 at 3:16pm

I have a set of CF wheel fairings to fit to HK’s ICE Micro with some Sikaflex. The CF is very thin - single layer woven except at valve holes, which are double layer. What is the best way to trim the wheel covers/ cut valve holes?

Any traps for the unwary player?

Replies:

Posted By: russellbridge
Date Posted: 14 June 2024 at 6:13pm

Dremel with a cutting disc. Go slow. Watch for it ‘grabbing’. Wear a mask! It’s hard to see any line drawn on carbon so mask it and draw the line on that.

Posted By: LWaB
Date Posted: 15 June 2024 at 1:29pm

Thanks for that

Posted By: LWaB
Date Posted: 05 May 2025 at 12:38pm

I got some scissors specifically designed for cutting carbon fibre to trim the outside edge of the cover to match the rim diameter after bonding it in place. They work well leaving very little excess to be cleaned up by the dremel.

Sikaflex EBT+ polyurethane seems to be doing a decent job of bonding the wheel cover to the rim.

I have found a problem with one half of the rear wheel cover not matching the actual spoke angle. The LH hub flange sticks out further from the wheel centreline than the wheel cover maker thought, so the it keeps buckling/ lifting at the rim despite bulldog clips for the entire circumference.

I suspect I will have to cut through the Sikaflex and rebond it but with a radial cut and slight overlap to form the cover into a steeper cone. I guess the best place for this overlap would be at the valve hole cutout. Do I need to bond on another layer of carbon just over the overlap or the entire wheel cover half?

Posted By: LWaB
Date Posted: 07 May 2025 at 3:49pm

I think I need to modify this wheel cover. Any suggestion for sourcing a piece of prepeg carbon fibre and a suitable epoxy and hardener for somebody in NW London.

Posted By: Martin Kiszel
Date Posted: 07 May 2025 at 4:41pm

Easy composite delivery very quickly, next day for me, usually.

https://www.easycomposites.co.uk/" rel="nofollow - Materials, equipment and training for advanced composites with next-day shipping and expert technical advice. - Easy Composites

Check local suppliers, but they'd only sell off-the-shelf components.

Posted By: garryb59
Date Posted: 07 May 2025 at 7:52pm

I was going to suggest some [quite probably] sacrificial scissors.
I was also going to ask you - have you bought these dedicated wheel fairings already convexed in shape, or are you dealing with a flat sheet of carbon fibre and shaping as you go? And you don't need to cover the entire disc, just the overlap. I would super glue the overlap to get the shape, then when you're happy you have the right convex, put a strip of carbon over the join with some compression to keep it flat.

As regards sourcing some materials......if you're using prepreg then you won't need epoxy [at least that is my understanding?] but prepreg is a bit overkill for this [and only serious fabricators use prepreg - puts me right out of the frame]. I have loads of old [10yrs to be precise!!] epoxy that I'm still using for various bits and messing about bobs, and odd bits of carbon fabric kicking about, you're more than welcome to have some, but that would involve you coming out this way. But if you're only doing a one off repair job, something like this would be fine.

https://www.ebay.co.uk/itm/335603474056?_skw=carbon+fibre+repair+kits&itmmeta=01JTP168X2DP2DQNFMVZ2STXEF&hash=item4e23869e88:g:oD4AAOSwZAtm~42R&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0w3yXCmi1f%2BhbOsLRz1S6IuandFGdUHfXGpJ8ufrmABaKZEnxaKW6mAML6XgPPw8S8VBVkVyeS2D6gCezR6v8hbHj%2BHdrIjkFOSI%2BQkdCqktweeb3kQwMR1zxWm9XEg%2F9Xg%2FjMb0irMS8t3ShhLKrEzVMC1GpKp7sdz1LfKiKg974RZpDf1%2Bj%2BksNguPInOJ6tX6%2Bhs9A3eMydxiO%2FxO4LoHTQCLVBBfPiVgNE6604PmKr6l3OSMHawDahxm7D1yFdNfwRtRV30ZYREtgULFIUnYAPj1snU8hxTNh%2BrniI%2F3UTqdftRLA%3D%3D%7Ctkp%3ABFBM2o6ZwdVl" rel="nofollow - https://www.ebay.co.uk/itm/335603474056?_skw=carbon+fibre+repair+kits&itmmeta=01JTP168X2DP2DQNFMVZ2STXEF&hash=item4e23869e88:g:oD4AAOSwZAtm~42R&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0w3yXCmi1f%2BhbOsLRz1S6IuandFGdUHfXGpJ8ufrmABaKZEnxaKW6mAML6XgPPw8S8VBVkVyeS2D6gCezR6v8hbHj%2BHdrIjkFOSI%2BQkdCqktweeb3kQwMR1zxWm9XEg%2F9Xg%2FjMb0irMS8t3ShhLKrEzVMC1GpKp7sdz1LfKiKg974RZpDf1%2Bj%2BksNguPInOJ6tX6%2Bhs9A3eMydxiO%2FxO4LoHTQCLVBBfPiVgNE6604PmKr6l3OSMHawDahxm7D1yFdNfwRtRV30ZYREtgULFIUnYAPj1snU8hxTNh%2BrniI%2F3UTqdftRLA%3D%3D%7Ctkp%3ABFBM2o6ZwdVl

Posted By: LWaB
Date Posted: 08 May 2025 at 6:41am

These covers are preformed, ostensibly for 349 wheels.