Author Topic: Working with Correx  (Read 3053 times)

Working with Correx
« on: 24 June, 2022, 01:19:52 pm »
My DIY skills extend to and end at IKEA furniture and painting walls, so I want to keep my ambitions very minimal.  At the same time the summer allows me a little time to work on projects and I am considering working on wheel covers and some sort of rear tailbox for my catrike.
As I am a simple person with the use of tools that encompass "stuff I find lying about" (a go-to tool in our house is a steak knife) so I am thinking of using correx and zip ties.  I'd like to not reinvent the wheel, so would appreciate any experience anyone else has had (even lack of success is a useful learning tool).
simplicity, truth, equality, peace

Kim

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Re: Working with Correx
« Reply #1 on: 24 June, 2022, 01:40:52 pm »
The best way to stick correx together is with a polypropylene-friendly hot melt glue like Tecbond 261.  It sticks admirably well, but supposedly won't stand up to prolonged exposure to wet.  Fine for a racing season or two.

When anchoring correx with cable-ties, it helps to double layer with the corrugations at right-angles, so it doesn't pull through.

I molished wheel covers for the Baron using 1mm ABS.  Easy to cut a perfect circle by drilling a central hole, and bolting a Mk 1 bit of wood in place with a scalpel blade attached at the right radius.  Probably viable with correx too.  The problem I found was that you have to split the circle to get the dish right, then anchor it in place on the wheel.  I tried to be clever by gaffer-taping it in place then removing it from the wheel and solvent-welding a strip of ABS across the seam, but this just made for a lump of stiffer material that stuck out.  Attaching to the spokes with cable ties seems like a good idea, but unless done very loosely tends to result in warping.  I found that insulating tape to the rim's braking surface gave the best results.  But not as good as some sort of heat-shrink plastic (think model aircraft wings) that other riders have used.

Disc brake calipers and derailleurs need more clearance than you think they will.  I had to swap the BB7 on the front back to a nasty Shimano caliper to gain a bit more clearance for the disc, and bottom gear at the back (which you don't need for racing) makes godawful rubbing noises.


Re: Working with Correx
« Reply #2 on: 24 June, 2022, 02:03:15 pm »
I understood ... some of that.
Naïve consideration, the idea of wheel covers is just to flatten the surface of the wheel, no?  So covering it and no gaps is the main point, yes?   I have a simpler job on the back wheel as I have no brake.
simplicity, truth, equality, peace

Kim

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Re: Working with Correx
« Reply #3 on: 24 June, 2022, 02:05:48 pm »
Yep.  The problem is that the surface of a wheel is effectively a very shallow cone, and molishing smooth cones with very specific angles using a semi-rigid material isn't as easy as it might appear.

At least on the outer surface of a trike wheel you don't need to accommodate the hub[1], which probably simplifies things.


[1] Having cut my perfect circle using the bit-of-wood compass technique, I enlarged the central hole with a holesaw.

LittleWheelsandBig

  • Whimsy Rider
Re: Working with Correx
« Reply #4 on: 24 June, 2022, 02:08:00 pm »
The surface of a rear wheel is two different shallow cones and clearances are very, very tight on the chain side.

There are how-to guides for various types of cover materials. Have a look through those to find some traps for the unwary player.
Wheel meet again, don't know where, don't know when...

Kim

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Re: Working with Correx
« Reply #5 on: 24 June, 2022, 02:09:50 pm »
I'm suspicious that stretchy fabric may be a better approach, but I haven't attempted it (yet).

LittleWheelsandBig

  • Whimsy Rider
Re: Working with Correx
« Reply #6 on: 24 June, 2022, 02:12:46 pm »
HK's recently acquired Trice has removeable fabric covers that are tricky to set up cleanly (e.g. access to valves) but they do stay clear of the cassette and disc brakes.

Correx and zip-ties is much easier for a tailbox or suchlike. Expect to keep the third attempt for a significant duration but you might get lucky with an earlier version.
Wheel meet again, don't know where, don't know when...

Re: Working with Correx
« Reply #7 on: 24 June, 2022, 05:14:14 pm »
I'm suspicious that stretchy fabric may be a better approach, but I haven't attempted it (yet).
I did think this too.  Possibly stretch fabric + some sort of hardener.
simplicity, truth, equality, peace

Re: Working with Correx
« Reply #8 on: 24 June, 2022, 05:43:08 pm »
Answering my own thread
http://recumbents.com/wisil/wheeldisk/wheeldisk.htm
http://www.bentrideronline.com/messageboard/showthread.php?t=144202

I especially like the second link as it suggest you just tape cloth to your tyre and go.

To be fair, wheel covers were an afterthought in my OP, I was more focussed on the tailbox.
simplicity, truth, equality, peace

Auntie Helen

  • 6 Wheels in Germany
Re: Working with Correx
« Reply #9 on: 26 June, 2022, 02:52:40 pm »
Velomobiles here have stretchy wheel covers which are a metal circle with the cover over it. They fit onto widgets on the spoke nipples. I think they cost about 15€ for a set of two 20” but you need a single-sided axle of course.
My blog on cycling in Germany and eating German cake – http://www.auntiehelen.co.uk


Re: Working with Correx
« Reply #10 on: 26 June, 2022, 03:01:46 pm »
Nice price, esp compared with googling stuff for 5x the price. 

I would need to fabricate as I have 18” wheels
simplicity, truth, equality, peace

LittleWheelsandBig

  • Whimsy Rider
Re: Working with Correx
« Reply #11 on: 26 June, 2022, 05:50:00 pm »
HK’s Micro also has 355 tyres.
Wheel meet again, don't know where, don't know when...

Re: Working with Correx
« Reply #12 on: 26 June, 2022, 07:01:08 pm »
^ With effective wheelcovers?

Back to correx, I'm sure it was a cheap and cheerful material, but all the sellers seem to have sheets at £100 per pack, am I using the wrong key words?
simplicity, truth, equality, peace

Kim

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Re: Working with Correx
« Reply #13 on: 26 June, 2022, 08:12:31 pm »
Given that you're at the prototype stage, go for a ride and see if you can find a couple of windfall mistake agents' signs...

Problem with sheets of correx is the cost of shipping big sheets of anything.  I managed to get a load as packaging for some more expensive sheet material at one point (acoustic foam?  polycarbonate?  something like that).

2mm correx seems to be used in bulk for protecting floors from builders, so might be obtainable from a builers' merchant, but it's a bit too flexible for a tailbox.  Might work for wheel covers.

Re: Working with Correx
« Reply #14 on: 26 June, 2022, 08:21:50 pm »
https://visionplastics.co.uk/4mm-white-correx-sheets

From £1.92 per sheet, minimum 10 sheets, £12 delivery.

Kim

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Re: Working with Correx
« Reply #15 on: 26 June, 2022, 08:23:53 pm »
They also have red ones, which go faster.

Re: Working with Correx
« Reply #16 on: 26 June, 2022, 08:37:11 pm »
Given that you're at the prototype stage, go for a ride and see if you can find a couple of windfall mistake agents' signs...

Problem with sheets of correx is the cost of shipping big sheets of anything.  I managed to get a load as packaging for some more expensive sheet material at one point (acoustic foam?  polycarbonate?  something like that).

2mm correx seems to be used in bulk for protecting floors from builders, so might be obtainable from a builers' merchant, but it's a bit too flexible for a tailbox.  Might work for wheel covers.

You can buy the 2mm by the sheet from Wickes, etc, which would be more ecconomic for low quantities. In my experience, builders buy in bulk chuck unused sheets. https://www.wickes.co.uk/Proplex-Black-Surface-Protection-Sheet-2400-x-1200-x-2mm/p/118670?fix&gclid=CjwKCAjwh-CVBhB8EiwAjFEPGR9dKfX__-sTTkmnfPIMKl5uo0S2Ghlxks-3Zg9Nf_lVn2NdXZwkRhoCFY8QAvD_BwE&gclsrc=aw.ds

Could 2mm sheets be laminted together to help smooth  joins in wheel covers and other structures?
If it ain't broke, fix it 'til it is...

LittleWheelsandBig

  • Whimsy Rider
Re: Working with Correx
« Reply #17 on: 30 June, 2022, 06:11:25 pm »
^ With effective wheelcovers?

Yes, they are a proprietary item that look a lot like https://www.velocityvelos.com/products/flevo-wheel-covers but with different retention hooks.
There are aluminium hoops sized to just fit within the rim and fabric/ plastic wheel covers that stretch over the hoops with a circumferential tie to tension the fabric over the hoops. The hoops are retained by little metal hooks glued onto the inside of the rim at several locations. A cover must be partially dismounted to access the valve to inflate a tyre.
Wheel meet again, don't know where, don't know when...

Mr Larrington

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Re: Working with Correx
« Reply #18 on: 30 June, 2022, 06:23:55 pm »
See also: How to Make Wheel Disks courtesy of the splendid chaps at WISIL.
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

Kim

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Re: Working with Correx
« Reply #19 on: 30 June, 2022, 06:26:39 pm »
BZZZT! Repetition!

Mr Larrington

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Re: Working with Correx
« Reply #20 on: 30 June, 2022, 06:41:26 pm »
 :facepalm:
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime