Chimaera 1994 Rear brakes

[l10tus]

After taking the car out for its first post- lockdown run, the passenger's side rear wheel is rubbing on the lip of the wheel arch, over every small bump and pothole in the road. As too is the driver's side but less so.

My set up is bog-standard, 225/50-16 Toyo's, standard wheels and basic, height adjustable rear shocks (not Bilstein's). There appears to be no damage apparent to chassis, wishbones, etc. I assume any slight tolerance in bushes or suspension joints, (none apparent), shouldn't be able to cause rubbing in this manner

However, on closer inspection, there appears to be 12mm wide, hub "spacer's" fitted?

Question mark here because, the "spacer" is exactly the same colour and metal (cast iron) as the brake disk, albeit slightly smaller in overall diameter as the boss on the disc.

Is it really a spacer ?

I've removed the wheel and tried to remove the "spacer", but wasn't able to remove the caliper (time wise).so didn't actually give it enough of a blow to see if the hub was made up of two separate parts

Couple of questions please:

1) can anyone help identify if it is a spacer or just a feature of the brake disc casting,by posting a picture of the rear brake disc / hub, seen through their own car's, rear wheel spokes.?

2) Were/are these sort of spacers available, presumably also needing longer wheel studs? (Who on earth would fit these! - if they destroy the tyre!!!)

3) I only have "2 finger's" clearance above the rear wheels tyre to the wheel arch lip (40mm?) - is this the standard sort of gap I should have?

4) Have my old looking springs and shocks finally gone Fubar, and the car is "bottoming out" over bumps? - if that is the case was the wheel designed to be an interference fit in the wheel arch?

5) Should'nt the rear wheels be able to pass by the inner lip of the body wheel arch, as it were, and travel into the larger general void of the wheel arch?

6) Could the rear negative camber facility accomodate this generally?

7) Any other possible causes for wheel rubbing?

P.S. I intend to replace the discs - can these be easily upgraded?

Pictures and any thoughts greatly appreciated!

[TarquinMX5]

I can't be absolutely sure because mine has the later brakes but that doesn't look right.

The attached link shows a picture of the earlier rear disc and it doesn't have the extra 'spacer/ridge'

https://partsfortvrs.com/tvr-parts/part-details/tv...

[Italian450]

Here is a picture of mine 1998 with vented discs.



Looks like you might have an extra spacer but difficult to tell from the photo.
Discs are relatively easy to change it can be difficult to get access to the allen head bolts to remove the calliper - I cut down my allen key for this.

[TarquinMX5]

Of course, if it's not the original disc, it might not necessarily be a separate spacer and might just be the wrong size disc. Ideally, it would be helpful to ascertain the 'height' of the original early disc and I don't have that.

Italian450's is an 'uprated' non/ standard disc and post '96 Chimaeras all had the larger Griff500 discs. 93/94/95 Chimaeras appear to have used three different sizes.

[l10tus]

Great replies, thanks Gents.

Must admit the racing green picture 0of the early disc, does look awfully like mine, but without the "spacer".

However when you look at the other picture of the later post '96 ventilated disc, its a dead copy of mine.!
But, mine's not ventilated!.

My unventilated, solid disc is 253mm wide. - which makes it an early version,methinks.

I will check the track width at 1460mm tomorrow, to see if that shows up any annomolies.

After that it's getting dirt hands time! (Friday)!

[l10tus]

Any thoughts on actual rear suspension travel distance (max)? and how much clearance between top of tyre and lip of wheel arch?

And does the tyre normally pass by the lip to retract further up into the wheel arch when on full travel upwards?

Or is it just the springs not doing their job?

How much travel should there be on the rear ? (50mm /2" or 100m/4") or what?

[Belle427]

Someone may have done it in the past to fit different wheels or for aesthetic reasons.
Certainly looks like a spacer to me, maybe it has been drilled with a grub screw to secure to disc.

[TarquinMX5]

I'm into non-scientific measurements now: I've had a look at mine (std suspension, 225/50/16, but later/bigger rear discs). Parked on level in garage approx 45mm between top of tyre and lower edge of wheelarch but I wouldn't profess to be 100% on the accuracy . I can get two fingers in, but not three but 'how big is a finger'

No point in me photographing wheel/hub mounting as mine are the later ones, so different sizes.

Re rear disc sizes, according to the bible, earlier Chimaera rear discs were quoted as:
1993 - 9.8" (248mm)
1993 - 9.9" (251mm) TVR quoted two different sizes in 1993, originally in imperial measurements, brackets are a conversion figure
1995 - 250mm

As far as I'm aware, those were all solid, ie non-vented.

The later 1996 onwards were 273mm vented.

Racetech also show a solid rear disc, also without the 'step' on the mating face of the disc

https://www.racetechdirect.co.uk/car-parts/brakes/...

I have seen a photo of an early chassis (silver) in the factory, which I think is a Chimaera, and that rear disc is solid and it appears, as best I can see because if has tape on it, to not have any steps in the mating part of the disc.

No idea on suspension travel.

[l10tus]

Just carried out a quick steel tape measure of the "Track" front and rear (centre to centre of wheels/ tyres) - showing 1500mm.

Bible says it should be 1460mm for both - so hopefully that seems to suggest it's been extended 20mm each side (spacers)?

I'll come back with results once I've removed the rear discs.

Thanks for all the replies Gents, much appreciated.

[TarquinMX5]

Just to support the 1460mm track figure you've quoted, I've looked at an Autocar test of an M-regd Chimaera, which also states 1460mm (presumably figures obtained from TVR). Another early source stated 57.5", which is also 1460mm.

Originally, rear tyres were 225/55 profile, which would just make your problem even worse.