Front wishbone - another weak point?

glypo · #1 31-10-2008

Well I have broken 3 wishbones on my SX so far. One of them was full speed into a post, and wishbone completely snapped, can't blame anyone but me for that.

However 2 of the breakages have been really frustrating. It is the point where ball stud from the shock mounts into the wishbone. It's so frustrating to have to replace the whole wishbone and to have a race ended when the wishbone fails in this way. The image below shows my problems:

I apologise for the photo quality, I was using a flash. The second wishbone initially failed exactly the same as the first, it looks more damaged in the photo due to my testing.

Has anyone else had this happen to them? If so is it an issue Schumacher are aware of and correcting?

Thanks.

Garry Driffill · #2 31-10-2008

Is there anyway were the Ball is on the arm on the snapped ones to re-drill and put a Titanium one inplace into the arm? - Just an idea...

glypo · #3 31-10-2008

I'm not really sure I follow what you mean.

What I would like is 1/8th scale style wishbones, where the shock is braced both sides, distributes the load much better. Somehow I doubt Schumacher will do that though.

Just some wishbones that don't break would be nice

Mike Hudson · #4 31-10-2008

Quote:

Originally Posted by glypo

Just some wishbones that don't break would be nice

I'm sure everyone would like that for their cars

sime46 · #5 31-10-2008

I've seen Cats take some REAL hammer and keep going without damage. If you hit stuff it'll break. I think its unfair to say it is in anyway weak. If the wishbones were stronger then you'd probably rip the mountings off the bulkheads or worse. Its easier to change wishbones than the mountings ect. Its a fantastic car unlike any other I've owned so you should consider the crashes before you condemn the design and manufacturer.

showtime · #6 31-10-2008

which way up were they when they broke Jason?

if the holes were at the bottom it would be a case of the shock stopping due to being limited (to protect the porcelain outdrives

) but the force of the wishbone still being pushed up being enough to leave the bottom shock mounting behind?

were you landing on one front wheel when this happened or flat or on both?
most 8th cars have some reserve uptravel to take care of these landings but a car with limited shock travel landing on any of its corners would be severely stressing that part of the wishbone!

and like they say "somethings gotta give"!

Chrislong · #7 31-10-2008

Quote:

Originally Posted by showtime

if the holes were at the bottom it would be a case of the shock stopping due to being limited (to protect the porcelain outdrives

) but the force of the wishbone still being pushed up being enough to leave the bottom shock mounting behind?

Exactly what I was thinking too. I am convinced the wishbones are strong, there has got to be a reason for this.

Sorry to hear about the breakages, I have broken none despite some major crashes - infact all I have done is 1 outdrive and nothing else!!

I have seen wishbones break, but never without good reason, and never in this way.

Perhaps, email Schumacher.

ryan · #8 31-10-2008

I had a wishbone go exaclty like glypo's, also at newbury indoor. I will check the up travel of the front shocks, it sounds it could be that, it was a (very) big jump

bigred5765 · #9 31-10-2008

looks to me as though the shock has taken an impact, which has tore the ball stud out of the wishbone, have a look make sure the top of the shocker is free moving at the shock tower side,just imho

peetbee · #10 31-10-2008

They should have brought back the crashback system

sorry, couldn't resist

DCM · #11 31-10-2008

by the look of it, it appears to me ripping the ball out on landing. This may either be a point where the wishbone needs a little beefing up, or the material not flowing correctly in the mould and cooling with a 'weak spot'. You expect a certain amount of breakages, but if they are coming from normal running, thats not a good thing.

Try some Tamiya front wishbones, might need a little adapting, but they may fit... if you are concerned.

glypo · #12 31-10-2008

Sime46 - maybe take time to read my initial post before saying I am being unfair. I clearly say one of my breakages it my fault. The other two I feel are not.

Adam/Chris - Yes you are exactly right, I should have explained in my post. This happens after jumps, and it will be due to limited uptravel (although not because of spacers - I didn't have any in the front - it is limited enough under standard setup).

bigred - The shock is/was free moving on the shock tower, thanks for the idea though.

ryan - Glad I am not the only one

dcm - Good thinking about another wishbone. What makes you suggest Tamiya? Is it strength/impact resistance? Something I think I might look into.

I think the rest of the wishbone is indeed very strong. When this breaks, like in my photo, the rest of wishbone is fine, it is just the shock mounting that comes off. This hasn't been crash damage, I have crashed my cat sx plenty and can ensure everyone it is strong enough hitting stuff and I have only broken one wishbone in a crash.

jimmy · #13 31-10-2008

501X carbon front wishbones - doesn't get stronger than those, so maybe worth a try.

DCM · #14 31-10-2008

I think the Tamiya Wishbones are made from stuff planets are made from, I have been trying to break the ones on my DB-01 since I got the car, landing it on it's nose, hitting the track markers with them etc.... and not broke one.

Worth a look innit!!

Chrislong · #15 31-10-2008

Innit!

(DCM, you developing a Manchester accent?

)

SidewaysLS4 · #16 31-10-2008

Quote:

Originally Posted by DCM

I think the Tamiya Wishbones are made from stuff planets are made from, I have been trying to break the ones on my DB-01 since I got the car, landing it on it's nose, hitting the track markers with them etc.... and not broke one.

Worth a look innit!!

You need a faster motor

josh_smaxx · #17 31-10-2008

So is the shock bottom pushing through the bottom of the wishbone because its hitting its uptravel limit when landing?

I have to admit iv never seen a wishbone break in such a way (and i tended to clean out my LHS for B4 wishbones).

DCM · #18 31-10-2008

Chris, aye lad.... LS4, lets just say, speed isn't an issue haha

rcracer · #19 31-10-2008

Quote:

Originally Posted by jimmy

501X carbon front wishbones - doesn't get stronger than those, so maybe worth a try.

as anybody tried matching them up ? garry has some here i might have a look.

glypo · #20 31-10-2008

I totally forgot about the new more flexible option wishbones, Robin Schumacher suggested I try them. I will give these a go when they come out, I am sure they will sort my problems out.

Certainly a wise idea for a track with big air like Newbury

(and a driver with skills like mine

).