Just gauging opinion. I'd had a wing stay go on my Locost last August. It seemed to be the original one made by the original builder 16 years
previously out of bits of Boots the Chemist stock cage so can't grumble at how long that one lasted. I bought a pair of new MK Sierra upright
stays late last August and fitted them over winter, first use this March. I've done 3 track days and no road miles since and one has broken. The
tab that bolts to the mushroom pinch bolt has broken just past the weld to the horizontal bar near the base. To me it looks like poor quality steel,
probably rolled at too low a temperature, possibly embrittled further by the weld.
I contacted MK and they say its fatigue and as I've done track days its my problem. That seems a bit unreasonable to me but is that me being over
sensitive?
[Edited on 12/8/22 by Sanzomat]
Id agree, you cant blame a trackday use on a car that is specifically designed for trackdays. Fair enough if you were racing, but a track day should
be no more rough than fast road use.
I'd be expecting/pushing a good discount on a replacement at a minimum, or ask them to recommend a product that's fit for purpose, as I
would assume if they expect the road versions to fail after 3 trackdays, they must(?) make a uprated version for track/race - or the poor old
racers would be loosing wings without contact every other race.
[Edited on 12-8-22 by loggyboy]
Did you lose a cycle wing with the broken stay and have to watch it fly over your head and crash in the road? Did it dig into the tyre and shear the
brake line off the caliper?
If not, you've probably done better than most of us (the brake line wasn't mine, but was one of the first other people I met driving an
Indy, broken down waiting a transporter).
If you're keeping them, when you're welding it up, linish the weld back and weld a generous diamond shaped gusset across the joint at the
end of each vertical tube where it goes into flat too. If it hasn't cracked there yet....it will.
I think it's poor that MK (Sportscars) wouldn't just send you another out. There must only be a fiver of material in it. Martin would
have....
I'm not condoning retaliatory spam, but you have the opportunity to leave an honest review on the MK website
here
If you're getting no joy in terms of remedial customer service, it seems only fair to alert others to the potential issues. Perhaps add some
photos to your OP and add a link to your review so people can make an informed choice.
A common problem at one time, do a search on here for broken wing stays . Got fed up with repairing mine and made my own heavy duty items, been fine for best part of 15 years
This was my take on this problem - created after suffering broken stays 2 or 3 times:
LINK
It's a bit geeky, and needs a lathe + other machine tools, but it lasted many years, up to the time I sold the car. It was also fun to show it
to other 7-style car owners and watch them try to work out how it worked! 
They're strong enough to sit on when the car is parked...
quote:
Originally posted by David Jenkins
This was my take on this problem - created after suffering broken stays 2 or 3 times:
LINK
It's a bit geeky, and needs a lathe + other machine tools, but it lasted many years, up to the time I sold the car. It was also fun to show it to other 7-style car owners and watch them try to work out how it worked!
They're strong enough to sit on when the car is parked...
quote:
Originally posted by Sanzomat
How are your cycle wings fitted to the stays?
Can you see them visibly wobbling/vibrating when you are driving?
quote:
Originally posted by CosKev3
How are your cycle wings fitted to the stays?
Can you see them visibly wobbling/vibrating when you are driving?
quote:
Originally posted by Sanzomat
quote:
Originally posted by CosKev3
How are your cycle wings fitted to the stays?
Can you see them visibly wobbling/vibrating when you are driving?
Wings fitted to stays with sikaflex plus M5 s/s domed cap heads with washers. No obvious wobbles/vibrations. Certainly nothing that gets into any kind of resonance. Watching back my gopro footage there is a bit of movement. At high speeds (90mph+) the air resistance appears to pull the front in and rear out maybe 10mm max and this relaxes back as you slow down but no higher frequency movements. A wobble of similar range when you go over a bump or track kerb but quickly damps itself out with no resonance or vibration. In my mind that's normal movement and might lead to fatigue after a few years but not three trackdays (actually 2.5 trackdays as it broke midday)
Saw this thread this morning and then this afternoon saw this cycle wing mount. Maybe we're doing it wrong.
tractor cycle wing bracket
Although I suspect this doesn't see 90mph very often I bet it goes over a lot more bumps!
quote:
Originally posted by MikeR
Saw this thread this morning and then this afternoon saw this cycle wing mount. Maybe we're doing it wrong.
tractor cycle wing bracket
Although I suspect this doesn't see 90mph very often I bet it goes over a lot more bumps!
I used MK supplied wing stays on my MK Indy. Did 3k miles of road use and didn't suffer any issues. The guy I sold car to had it a couple of
years with no issues before he sold it on.
I'd say you're being reasonable to expect a discounted replacement at a minimum.