applying heat shrink tubing to fork legs without damaging paint

[E-wan]

Hi

 i'm currently building up a Thorn Audax and plan to cover the fork legs in heat shrink tubeing to prevent abrasion before zip tieing a thin carbon fibre rod running from the outside of the fork leg to the underside of a Thorn accessory bar (to  act as a cable guide for the front light and dynamo usb charger)

 my heat shrink tubing is meant to activate between 70 and 110°C

I had hoped that the tubing would shrink by holding it in front of the grill of a blow heater but no luck

any other suggestions? I am understandably wary of using a paint stripper style heet gun.

Thanks

 Will post photos when finished

Ewan

[jags]

Ewan why not use clear frame saver (tough clear plastic) it sticks on  i think SJS sells it .
man don't use heatshrink it will look awful 

jags.

[Danneaux]

Hi Ewan!

It is possible to reactivate (melt) powdercoat if a heat gun gets too close. I have a couple and the one with two heat levels tops out at about 1,600°F/871°C, which is *hot*. Fortunately, your tubing's 70 and 110°C  is well below that, but I would take care when applying heat.

You can sometimes get by with much less heat if you choose the tubing's shrink ratio carefully:
2:1 - Becomes half of its original size once heat is applied. The original heat shrinkable tubing is twice as large as its shrunken form.
3:1 - Becomes one third of its original size once heat is applied. The original heat shrinkable tubing is three times larger than its shrunken form.
4:1 - Becomes one quarter of its original size once heat is applied. The original heat shrinkable tubing is four times larger than its shrunken form.

Also, relatively narrow bands of HST shrink faster than wide ones. If you don't need a continuous channel, you may be able to cut strips that shrink easily to become bands. Though intermittent rather than continuous, the bands might still provide sufficient barrier protect your fork from the carbon wire channel.

You may wish to consider adhesive backed flat (strip) wire such as this: http://www.taperwire.com/ I've used it indoors and then painted it; works a treat for running speaker wires invisibly, but might or might not hold up well to outdoors conditions and I can'tg speak to how well it would grip on a rounded tube.

Hoping something in the above will help. Really looking forward to your photos. All best luck,

Dan.

[E-wan]

Thanks

this gun seems to have a lower 300°c setting

if waved to and fro from a distance is this likley to melt the fork paint?

Ewan

[mickeg]

I just zip tied wires to my fork leg and called that good enough.

[in4]

There is a product called shrink wrap that is primarily used to cover soldered wires. It shrinks to a firm grip at relatively low temps. If you can get it in the right size it might be worth considering.

[rualexander]

Might applying such sleeving to bike tubing lead to retention of moisture underneath the sleeving in contact with the paintwork and the possibility of encouraging corrosion to set in over time?

[John Saxby]

E-wan, what colour are your forks? 

Other things equal, I'd opt for the clear frame saver that Jags suggests.

Or: If your forks are matte black, then I'd suggest what I use -- good quality wide plastic electricians' tape, or (readily available in Canada, maybe not so much elsewhere) hockey tape.  I realize the latter may be lowering the tone, but desperate times call for sensible measures. More to the point, an onlooker can't tell the difference from more than 15" away.

[macspud]

I think I'd use clear helecopter tape instead, available in various sizes on ebay.

[StuntPilot]

I have done something similar to the front forks and rear chainstay of my Raven Tour. I used old inner tubes wrapped round, superglued and zip-tied.

The reason was to minimise paint chips caused by larger stones when cycling on rough stoney tracks.

I would be interested if anyones experience of wrapping the forks/chainstay has caused rust to take hold under the rubber (or heat shrink tubing/other material). If there is no break in the paint layer to begin with then rust will not take hold?

I would stay away from applying any heat to the frame.

[mickeg]

...
I would stay away from applying any heat to the frame.

I have used a hair dryer on low setting to warm up a bottom bracket shell while trying to get penetrating oil to soak into the threads so I could get the bottom bracket out.  No damage to paint or frame, but I should point out that I used a hair dryer on 110 volts at low setting.  I have no experience using a hair dryer in a country with higher voltage.

[Paul S]

i'm currently building up a Thorn Audax and plan to cover the fork legs in heat shrink tubeing to prevent abrasion before zip tieing a thin carbon fibre rod running from the outside of the fork leg to the underside of a Thorn accessory bar (to  act as a cable guide for the front light and dynamo usb charger

Why not just settle for a very good fork & one layer of zip ties, without the complications?

The RH side of my Thorn Fork looks like the rear end of a wasp when viewed from the side. From the saddle, it looks normal, well to me anyhow.
Paul.

[DAntrim]

I use heli-tape on all my bikes to protect the frame from chips / scratches and have found it to be very hard wearing, though it can be a bit fiddly to apply and best cut to shape prior to applying it.
I use the cable ties on the front fork to hold the dynamo wire in place and heat shrink in sections along the rear break cable running the wire inside to the rear light if your fitting one, keeps it neat and tidy

Carlos