Category: making things

 

 

 

 

I’ve had little luck finding products to protect bicycle frames against chain slap (on the chainstay) and cable rub on the frame itself. As illustrated here on the Bianchi D.I.S.S. cable rub can be quite ugly, and chain slap can lead to paint chips on the chainstay. After a bit of research I found McMaster-Carr part number 76445A764, a 5 yard long, 2″ wide roll of 0.0115″ thick Ultra High Molecular weight polyethylene (UHMW / Wikipedia article) tape with a self-adhesive backing. Selling for $17.85, this translucent material is commonly used to make slick abrasion-resistant surfaces, so I figured it would work well protecting bicycle surfaces from rub wear.

The roll of tape arrived today, so I devised some abrasion and impact tests which would replicate wear conditions found on bicycles along with testing removability of the tape and its acrylic adhesive.

These five tests, two impact and three abrasion, are as follows. All surfaces cleaned with 99% isopropyl alcohol prior to UHMW tape adhesion:

Impact Test #1

Scenario: Tape applied to curved edge of clear powder coated steel and hit with metal objects such as file handles, tweezer handles, and a chain whip.
Result: Tape dented, no damage to surface below. Tape shown to be deformed by impacts but did not pull away from surface.
Photos: Dented Tape · Undamaged Surface

Abrasion Test #1

Scenario: Tape applied to curved edge of clear powder coated steel and abraded with small and medium fine metal files.
Result: Tape abraded, no damage to surface below. Sharper cutting with the corner of a file may have pierced the tape and damaged the finish below.
Photos: Abraded Tape · Undamaged Surface

Impact Test #2

Scenario: Painted aluminum panel with tape applied to a portion of it. To each of the protected and control surfaces the handle end of large file is dropped 20 times in a space the size of a dime and a metal rod is set in place and hammered gently with a metal bar for 10 impacts.
Result: Small metal nub on metal rod pierced the tape and damaged the metal. No other visible damage.
Photos: Bare Metal Control Surface · Taped With Impact Marks · Surface Below Tape Showing No Damage

Abrasion Test #2

Scenario: Brush made from Jagwire cable housing is placed in an electric drill. Brush is run for 45 seconds against each of the protected and control surfaces on painted aluminum panel.
Result: Severe damage to control surface, much less damage to taped area, occurring only after brush wore through tape.
Photos: Jagwire Brush · Control and Taped Surfaces After Brushing · Control and Taped Surfaces with Tape Removed

Abrasion Test #3

Scenario: Painted aluminum panel is bent, tape is used to protect half of the bend. Wire wheel is run for 45 seconds over both the protected and unprotected areas, simultaneously.
Result: Severe damage to unprotected area resulting in removal of paint and erosion of aluminum. Taped area is undamaged.
Photos: Wire Wheel and Test Surface · Control and Taped Surfaces After Brushing · Control and Taped Surfaces with Tape Removed

This tape was also relatively easy to remove from both the powder coated steel and painted aluminum surfaces. It sticks solidly in place, but picking at one corner of the UHMW tape with a fingernail will lift it and allow it to be pulled off the surface. Some adhesive residue was occasionally left behind, but it was not difficult to clean up with an isopropyl alcohol-soaked paper towel.

With these tests complete I feel that this UHMW tape will work wonderfully as a product to protect against bicycle frame damage due to cable rub and chain slap. Lacking logos and being translucent white it should be fit nicely on most frames. The tape is easily cut with scissors or a sharp razor blade and conforms nicely to simple curved surfaces. More complex surfaces such as joints should be possible to cover with some smart trimming of the tape.

While protecting the frame it will not deaden the sound of chain slap much, so it may be desirable to use some manner of rubber chainstay protector if one wishes to cut down on both noise and wear. As done previously I’ll likely continue making chainstay protectors from old tubes, or perhaps with bits of old tire as Trail’s Edge Cyclery does.

If you would like to see all of the photos from this series, please look here in the UHMW Tape album.

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Here’s the start of a new project, building up a road / path / dirt road bike around a Vassago Fisticuff frame. While I haven’t decided on everything about it yet, I’m pretty certain that it’ll have disc brakes and be setup as a 1×9 with mountain bike parts, starting with a 44t chainring up front and an 11:34 cassette, shifted using an SRAM twist shifter on a HubBub drop bar extension for twist shifters. This should give plenty of range for going fast on smooth stuff and climbing the steepest roads in the area while still being easy to shift. Coloring will be mostly brown/black with silver bits as needed, with things such as brown powder coated Velocity Deep V rims, beige bar tape, Salsa Moto Ace Bell Lap bars, and a honey-colored Brooks B17.

There will be some odd niggles to sort out, such as fender and rack mounting, particularly with the close-proximity brake and fender mounts, the lack of rack mounts, and the slot dropouts, but it shouldn’t be much of a problem. Being a steel frame I’ll also need to seal the inside (with Frame Saver or a similar product) and promptly deal with chips (it arrived with a tiny one on a seat stay), but this shouldn’t be too difficult.

To see pictures of the Vassago Fisticuff as it currently exists (just a frame), please check out this album: Vassago Fisticuff.

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