I have managed to break both front wing stays on the GTS now. Both failed in the same place, at the weld joining the bent bar to the tubular frame (see pic).

Tomorrow I am going to attempt to solve the problem for good, but would like to see some of your solutions

I was thinking of welding a gusset either side of the bent bar which takes the bending loads off the weld. What do you think?




David

Hi Mate,
Congrats on getting your car done and dusted....sounds like you're starting to reap the joys of ownership already!
I welded a 5mm bar, instead of the 2.5mm that is there...only onto the forward most stay on each bracket.
Has lasted more than 1k miles. (touch wood it doesn't snap now)
Just got back from a weekend camping in the blue machine...dissappeared to anglesey - the first longish blast I have had for a long time!
If you're free next weekend, fancy organising some sort of road trip?

Tom

David,

The Luego stay is 5mm and is pressed into the tubular section to give some more support - Was a sod to bend over the wheel but shows no sighs of any fatigue (even after yesterday's fun and games).

Neil.

Welcome to the joys of cycle wings!

Previous discussions

I believe that a radical redesign is required - the one from locoR1 makes the most engineering sense, but not easy to implement (I'm still thinking about that one).

Clam shell wings are looking more and more attractive - I rarely drive fast enough to worry about aerodynamic lift!

One of the main issues seems to be the material spec that people are using. After on of mine flew off I use some 25x5 bright drawn bar. Seems to have done the trick for a couple of years.

Bright drawn bar is tougher than black mild steel - but much harder to bend into shape. It can crack on bending, if care isn't taken (been there, done that). You usually have to heat to at least red-hot to avoid cracks, but then you may lose the inherent toughness produced when the steel was rolled.

I still think the real solution is to stop the mudguard flapping in the first place - not easy, when the mounting points are on one side only!

[Edited on 29/7/07 by David Jenkins]

i welded gussets across the back of the joins on my MK brackets. they just weren't up to supporting relatively heavy dax cycle wings without it. they were fine after that.

tom

I had the same problem
I used 5mm bar as all ready suggested
still ok after 4000 miles

I'm not a fan of flat bar for cycle wings, unless you use really heavy stuff its bound
to fracture eventually.
Iv'e found brazing rather than welding is much better for longevity.
See pics below for my latest take on cycle wing brackets, made from 14mm x 1.2mm tube and fully brazed. My last brazed pair never let me down, sadly i killed one at Anglesey hence the new ones.

Al.


Description



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Deffo Not planning on a repeat performance! too expensive.
Hard to tell on here, but both front wheels are actually off the ground, must have been going faster than i thought.

Sorry for the hijack david





Originally posted by chris mason
thats a great picture that one Al, lets hope you don't do the same when we go back

Chris

great picture, looks like the wing mirror nearly twatted you!

thats one of the best pics i have ever seen. the cone, mirror and wing flying through the air

As above - look at the previous threads. My solution was no welds and used 2x flat bar (about 30mm x 5mm) bolted through the original triangular base plate.

I doubled up the flat bar between the tube top and wing by adding another bit of the same material 25x3mm and tapering the edge towards the wing so as to make an inverted U shape . I fully welded the edges and then heated all the welded joints on the stays to a medium red heat and let them cool naturally.
i have had the car on the road for 3 years now and no problems so far although the wings do flex a fair bit.
Paul.

Wadders, how is the stay connected to the wing?
Is there another frame inside the wing?

Al, did you get the whole sequence of pics?

With regard to wing brackets, our original MK brackets have now covered more than 10,000 miles, been thrown around a lamp-post in a front end collision and are still going strong

They'll now probably drop off tomorrow having said that..............

Phil

Try giving Chris or Marc at ring at MNR as there stays are fully tubular (not flat bar) and look more than good enough for the job.

Nitram38,
yes iv'e bonded flat bar underneath the
cycle wings which pick up on the stays with bolts.


Phil,
i've started a new thread in Clubs and events, so not to hijack this one any more than i have already. A full sequence in technicolour

quote:

---

Originally posted by Wadders
Nitram38,
yes iv'e bonded flat bar underneath the
cycle wings which pick up on the stays with bolts.

---

http://www.locostbuilders.co.uk/viewthread.php?tid=63669

told you so

Out of interest, can carbon fibre be made in such a way that it doesn't suffer from fatigue fracture? If nothing else, it could be moulded thicker in all the appropriate places.

It would be quite cool to have c/f mudguard stays...
(but damn expensive, I'm sure! )

Now there's a thought david, wonder if it would be possible to use the carbon fibre rod from a golf club or fishing pole etc with ally brackets bonded into the ends? slighly lower cost version of full cf.

Al.




Originally posted by David Jenkins
Out of interest, can carbon fibre be made in such a way that it doesn't suffer from fatigue fracture? If nothing else, it could be moulded thicker in all the appropriate places.

It would be quite cool to have c/f mudguard stays...
(but damn expensive, I'm sure! )

I'm using the mnr wing stays and i'd be extremely suprised if one of those has ever failed from fatigue.

Ned.

I have had an idea, inspired by something matt.c said when we were out the other night.

Another stay to the back edge of the wing would fully constrain it and stop it flapping. A bit of tube welded to the rear tubular part of the stay, with another bent bit of strip bolted to the wing should solve the problem I think. Time will tell.

I am currently making the bits to do it, and should have it sorted next week. I will tack it together and see if it stops the flapping. I could also do with another bit of bracing under the bend on the inside of the wing.

The current stiffening has got this far, and has made a huge difference already
Rescued attachment Wing stiffening 1.jpg

Looking at that picture i would say that the flat strip is far to long, it would be better to get the tube closer to the wing to reduce the length of it.
Paul.

quote:

---

Originally posted by flak monkey
The current stiffening has got this far, and has made a huge difference already

---

The trouble with bracing one bit is that you move the flexing point somewhere else, and get a fracture in a new place...

That's why I was wondering whether the flexing can be shared along the length of the stay.

Will take a photo of what I made for mine in the end.

I bought boggo locosty ones and they would clearly break before many miles, so I bought some MNR ones and they were no good for my cycle wings and clashed with the caliper (not MNR's fault I hasten to add! )

I eventually made my own using 17mm OD seamless tube, and bent in one piece (per leg) from the plate at the bottom all the way round to the outer edge of the tyre. The tube is cross drilled and tapped (its 1/8" wall) and the stays screwed straight into it with neoprene foam tape in between.

no welds at all north of the plate on the upright.