Sacrificial cycle and rear wing fixings - sikaflex / bigheads / zip ties etc

[anthonym]

Over the years we have had many threads about fixings for rear (fewer) and cycle wings (many - mostly sikaflex these days)

I wish I had given more attention to the few threads that mention the use of sacrificial fixings, but because they have always been track use related I didn't listen so hard.

Over the years I have pranged both cycle and rear wings to differing degrees.

The most recent was putting the car in the trailer and caught rear of a cycle wing on the side. This slightly cracked (really "tore" as it is carbon fibre) said cycle wing, and here's the thing, ripped the cycle wing off it's bighead/cable tie mounting.

The bigheads (many other threads about those) are sikaflexed in place and did not budge; now been there for some years. However, the double small cable ties broke. 

If these had not broken the damage would have been much worse than a slight tear in the side of the cycle wing.

I took one look and wished I had used only one small cable tie per big head instead of two. In fact that reminds me to cut one each of all the other pairs.

As long as they aren't cheap poor quality cable ties (the brittle type that break) the cycle wings (I speak of carbon here, don't know about GRP etc) won't blow off in the wind (that's a laugh, I once fixed a cycle wing with one cable tie 1,400 miles from home in the pouring rain, it stayed fixed for the rest of the tour of many weeks)

Cable ties are tough and yet have the advantage of breaking at some point.

The point which I do hope someone finds helpful one day, is that I have found that one cable tie per big head will be sufficient, and they don't need to be thick ones, just the type that one tidies electic wiring with.

I have seen others suggesting no big heads at all and just use sika flex. I wonder whether that is sacrificial or not; in the above story the cable ties broke but the sikaflex join did not.

Maybe someone with a "sikaflex only join" can comment.

I crunched a rear wing last year, reversed in to an invisible (of course it was!) post and the wing rolled into itself and bounced out to shape as I move away (carbon advantage, I suspect GRP woud have been a different story. However, again it took me to thinking about sacrificial rear wing fixings as an upgrade - and they need to be accessible so it can be an "on tour" repair.

So there you are, sacrificial fixings to save our wings.

Anthony

This post is intended to share experience and to be helpful to those who follow; I do hope it will not be viewed as spamming the forum; if it is please can I be informed without being abused.

[DJ.]

I've fitted plastic bolts to hold on my rear wings. I think even if they don't save a wing in an accident, they might save so much damage to the side skin and shouldn't corrode into the rivnuts either

Duncan

[nickh7]

I had the stuck on cycle wings , the powder coating let go and the wing made a break for it

[SM25T]

You do have to be sure the powder coating is sound ... the Sikaflex will stick to the coating, but if that is not secure ..... byebye ! This happened to me ... sanded down the coating and painted with black Smoothrite before rebonding wings. Wrapping the Sikaflex round the stays will help too.

[Jonathan Kay]

What SM25T says about application; get down to metal and make a sausage roll of the stuff. I have lost two before doing it that way and none since.

I think that some people use methods other than Sikaflex (or similar) alone in order to ease removal.

I prefer nylon bolts for the rear wing, and I'd put in any list of build tips.

Jonathan