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Discussion Starter #1
Recently I took my car in for the Air Conditioning to be recharged as it was almost nonexistent for cabin and battery cooling.
Whilst in they mentioned (again) that my rear pads and discs were getting low... I've done 50,000 miles on them and have already upgraded my fronts for better performance rather than because they had a lot of wear on them.
Around that time I was getting 12v battery warnings as well and after unlocking the car, the doors would take ages (5-10 seconds) to actually unlock and be allowed to open.
As I am out of the warranty period now and not keen on paying the £145 per hour for labour, I looked into doing it myself.
Despite my job, this would be the first time I have ever replaced parts on my own car!
I went to a local battery specialist to get a 12v Battery, they said the type i needed was for a bike... I'd just take in the old battery and get something similarly sized.
With the discs and pads, I ordered them from Seriously Lotus. Dave Garthwaite is a very helpful guy and now knows the exact specs needed for Roadster discs as I have done some trial and error for him.

Now when it came to the actual work it was pretty straight forward assuming you have a few of the necessary automotive tools. For the 12v battery you just have to take the front right wheel off, then undo all the bolts that hold the front plastic mud guard in place. Its very roughly 30cmx30cm. Then you can see the battery and its just a case of undoing the holder and replacing it. Note, the car does work without a 12v battery as I had to pause midway and go for dinner and reversed it back on my drive without any battery and it all functioned perfectly well.
Then replace everything back in the opposite order to put it back together!


For the discs and pads I found it a little more taxing but if you know what you are doing its a quick job. I didn't though and so with a bit of time and research as I was going through it I was able to do it over a few hours.
Make sure Hand brake is not on! Wheel off, extract the pin in the calliper that holds the pads in, knock the outer pad out, undo the locating bolt on the disc that is in between two of the bolt holes for the wheels, try to slide the disc out while wiggling the floating calliper, knock out the other pad, use long nosed pliers in the two small holes on the outside facing side of the calliper piston and turn clockwise to screw the piston back in (this is auto adjusting as the pads wear down so needs to be put back), then put the far pad back in, disc, other pad etc. until it is all done up!

If the first pad does not knock out easily then you have to take the calliper off which is a bit more work but equally doable. If anyone ever needs help on this then please let me know and I'd be happy to assist.
I strongly recommend using non original discs and pads to replace the Tesla ones with as the deceleration is hugely improved and actually becomes safe to drive! The disc looks bizarre from the outside once worn in because only the outside half of the disc is actually used but this is only because the surface area is greater than the Tesla one so looks more. Plus if you look at the Tesla original discs there is around 1cm of unused disc anyway...

When examining the original pads and discs I noticed that around 1/3rd of one of the pads was completely missing and had clearly failed a while ago as it was not clean at all. I certainly attribute some of the poor deceleration to this but equally it has never been good. When I repaved the fronts the improvement was very noticeable as well.

2014-08-04 20.47.15 copy.jpg
2014-08-04 20.48.10 copy.jpg
 
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Strange why the rear brakes have ended up like that.

What's the regen like in the Roadster? Is it not that strong so you end up using the brakes regularly ?

Do you generally drive it hard, I suppose you do considering it's a performance car and considering your day job ha :)

BTW loved that spa video of yours. Eau rouge flat out... I wouldn't even have the balls to do that on Project CARS :)
 

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Discussion Starter #3
Strange why the rear brakes have ended up like that.

What's the regen like in the Roadster? Is it not that strong so you end up using the brakes regularly ?

Do you generally drive it hard, I suppose you do considering it's a performance car and considering your day job ha :)

BTW loved that spa video of yours. Eau rouge flat out... I wouldn't even have the balls to do that on Project CARS :)
Well the calliper was designed like that, guess it's just easier to use a standard lotus disc and not use all of the surface than to design a specific disc with a smaller wear surface for 2,500 roadsters...
The regen is pretty strong, not quite as much as the i3 though. It goes up to 40kW depending on your speed when you lift off. Higher the speed, more regen... Above ~70 mph it gets the full 40kW.
I don't actually drive it hard, most of my miles are on the motorways cursing at 60-70mph. I rarely brake hard, normally relying entirely on regen. However brakes need to perform well when you do need them in an emergency and the standard Tesla brakes are simply pathetic. So much pedal pressure is needed and they work horribly at low temperatures (which is what they spend most of their time at when on roads!)
These new discs and pads work so much better from cold that it is work the £300 to upgrade them even if the current factory fitted set are not worn out.
 

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Discussion Starter #4
Strange why the rear brakes have ended up like that.

What's the regen like in the Roadster? Is it not that strong so you end up using the brakes regularly ?

Do you generally drive it hard, I suppose you do considering it's a performance car and considering your day job ha :)

BTW loved that spa video of yours. Eau rouge flat out... I wouldn't even have the balls to do that on Project CARS :)
Oh and regarding Eau Rouge, it really is quite something to do it flat in a GT3 car!that was my first time ever and so was rather chuffed, in the end the car balance was so nice, along with it being new tyres/low fuel (2 lap qualifying run) that it was relatively straight forward!
In single seaters it is almost flat in the wet and really a non corner in the dry but in the heavier plus lower downforce GT cars it is an awesome challenge :)
 
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Definitely, £300 is well worth the money if it improves the braking performance. Especially as you say most of the time the brakes are fairly cold. Something you can forget driving an EV isn't it.

Well you certainly must have had the confidence in the car to do that! Watched some of it on Eurosport. Make sure to keep us updated on your next race. I'm sure us fellow SpeakEV members would like to keep an eye out for you.
 

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Looks very similar to the VX220 brake setup, it uses the same discs front and back and only the pad area touching the disc is different. I suppose it keeps down costs, the 220 uses Vectra front discs on both front and rear.
 

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Discussion Starter #7
Looks very similar to the VX220 brake setup, it uses the same discs front and back and only the pad area touching the disc is different. I suppose it keeps down costs, the 220 uses Vectra front discs on both front and rear.
Correct, the discs were vx220 fronts.
 

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Thanks for the write up @Alexander Sims :) Good job !!

I recently changed the brake pads - an essential job (agreed - the standard pads just dont inspire confidence).
all pretty much as described .. hardest aspect I found was jacking up - getting jacking points and axle stands positioned right. Once up with 4 wheels off it is easy to work on - I jet washed and waxoyled the steel suspension bits.

Good to know the 12v battery job is easy when needed (thanks for sharing symptoms of it going down .. always good to know these).

I've recently been adjusting the adjustable suspension (to balance out a bit of front understeer as per TMC) .. eg softened the front anti-rollbar, and shock (1 notch each):
So rears are middle anti-roll bar hole, No.4 on shock
front outside anti rollbar hole No. 3 on shock
These settings aimed at rough dorset roads, rather than smooth tracks -

As a race driver, I'd love to hear your thoughts on optimising roadster handling and balance: it seems to be more 'understeery' cf Elise's I guess for lift-off safety, with all that extra battery weight ?. eg as the spring mounts are adjustable would it be worthwhile adjusting corner weights ? or even ride height (with corresponding steering rack height adjust to avoid bumpsteer) ???
 

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Discussion Starter #9
Have you tried the larger front tyre width? I had horrible understeer for a long time and then found out that the 'sport' tyre is actually just wider whilst sitting on the same rim. I'll get the tyre size confirmed but I think the standards are 55/175s and the sports are 50/195s...
That sorted my understeer and now makes the front almost a bit too strong! way more fun than understeer though :)
 

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VERY Good point !
My fronts are AD07 Yoko's 175/55 R16 'LTS' (as used on Elise!, 111R, and standard Roadster, apparently)
but should be (as its a sport):
195/50 R16 84WADVAN A048 LTS
(as used on Elise Mk2)
This would probably give THE biggest improvement. thanks for some light :) now where is that track day thread :)
(or test circles).
 

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Discussion Starter #11
The beauty of the larger front tyre is that, like the rears, you are then not restricted to the Tesla prices!
I used DUNLOP Sport BluResponse fronts, I got them through eTyres and am quite pleased with their performance at the moment...
 
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