Nitron Race R1 Shocks and Fitting Guide

With a big blat weekend on the very near horizon (this weekend in actual fact) and the warm track day season approaching rapidly, I decided to treat myself (or the R500 should I say!) to a set of Nitron Race R1 one way adjustable shocks.

 

I checked out the price of shocks from various suppliers, and it seemed that buying from Nitron directly was the most cost effective method of acquisition. So I called Nitron, spoke to a chap there called Alex and discussed my requirements with him.  Alex spoke to the technicians and came back to me to advise that for my usage (fast road and occasional track day use) the springs to use would be 7" 225lb for the front and 9" 150lb rear.  I was also happy to go with the one way adjustable shocks, as there's just one dial at the bottom of the shock which adjusts (in 24 increments) the rebound and compression in a single click - perfect for me, as it's only one thing I can mess up!  Joking aside, it should just be a case of turning the dial four or five clicks for track use to stiffen the shocks and then turn the dial back down for road use

 

My only other final concern was that of the spring colour.  I thought that although the Nitron shocks look cool with their standard blue springs, this may clash with the blue of my car... I asked Alex if they would be able to supply my springs powder coated in RAL 2004 to match the orange stripe on my car, which was initially refused, but after some arm twisting (and a small additional fee) they agreed - which was great news.

 

So I took their advice about the springs, done a little of my own research, and placed the order.  Below is a picture of my suspension components on the parts allocation line, prior to assembly - I bet you can't guess which ones are mine?!? 

My Nitron Race R1 Shocks on the parts allocation line ready for assembly

For those interested in how the shocks are made, (and to save me going into a whole load of typing) I've embedded Nitron's promotional shock build video.  Although it's a video of their motorbike R3 shock, it's still a good insight into the assembly process.

Around two weeks after placing the order, the shocks arrived and I think they look awesome.  The orange springs look great, and are a perfect match for the stripe on my car.  I also noticed they used a silver spring collar, rather than their standard gold coloured variant for better aesthetics which was a nice touch by them.

Nitron Race R1 shocks ready for fitting to my Caterham R500 Duratec

Onto the Fitting Guide

Firstly - the disclaimer... This is my shock replacement guide for my De-dion Caterham R500 Duratec.  I'm not suggesting this is the only way to change your shocks, and this is by no means the best way, but the method that worked for me.  I'd recommend reading the full guide before you begin as there may be variances between my car and yours (if only slight).

I started at the front of the car, as the shocks are more accessible and it just felt like the right end to start at.  Firstly with the handbrake engaged loosen all the wheel nuts, both front and rear.  Next jack the front of the car up (I use the central point behind the horns where the chassis tubes form a cross).  I have a pretty decent jack, so didn't feel the need to use axle stands, but it would be worth lowering the car onto axle stands if you don't trust your jack.

Remove the wheels (and the nosecone if you feel this gives better access) and you should be looking at something like the picture below


Bilstein shocks on my Caterham R500 Duratec ready for removal

Using a 6mm hex adapter in a ratchet or a 6mm hex/allen key remove the lower suspension bolt pictured below.  



Use a 6mm Hex / Allen Key to remove the lower suspension bolt

The upper suspension bolt is a more fiddly to do, or should I say 'brave'... You need to push in the body skin somewhat with a fair bit of force to get reasonable access to the upper bolt.  Once you've pushed the body skin inwards, use a long arm hex / allen key, ideally with a rounded end (I found this set from Maplin to be perfect) and remove the bolt as per the picture below.

Removing top front suspension mount bolt using 6mm long arm hex key

Now both suspension bolts are removed, the shock will either slide out, or may need a little wiggle.  If you pull the shock down through the wishbone this seems to work best. 

Repeat the above steps on the other side of the vehicle and both from shocks will be removed.

With the shocks removed it was onto the 'How much lightness have I added test'...  The original R500 Bilstein shock weighed in at 2.178kg

Caterham R500 front Bilstein shock weighed in at 2.178kg

Now onto the Nitron Race R1 shock... Which weighed in at 1.986kg - nearly a 200g saving per shock, which is a combined 384g saving on the front shocks.  Doesn't sound like much, but combined with the saving of the rear shocks it all adds up.



Caterham front Nitron Race R1 shock weighed in at 1.986kg

I thought it a good idea to take a picture of both Nitron and Bilsten front shocks, so you can see the difference in size, but the angle of the picture seems to make the Nitrons seem even shorter than they actually are.  They are around 1cm shorter than the Bilsteins and this is due to the higher spring rate meaning that the shock has no sag, in turn the shock doesn't need to be as long.

R500 Bilstein vs Nitron Race R1 front shock comparison

Nitron also supply a metal bush fixing kit, which makes the shock swap even more hassle free.  The metal bushes come with an o-ring and require a little grease then are slotted onto the top and bottom eyes of the suspension tube ends

Metal bush shock fixing kit with o-rings

I just put a little bit of grease on the metal bush and on the o-ring, then you push two of these metal bushes together around the suspension tube end (see picture third below)

Metal bush, greased with o-ring fitted

You will need to remove the metal sleeves from both rubber bushed ends of the front Bilsten shocks - this should be easy, so long as they were copper slipped before they were fitted.

Remove both metal sleeves from rubber bushed ends

Then with two of the metal bushes greased (with O-rings in place) place them together over the suspension tube mounting eye.  I thought it was worth re-applying some copper slip to the metal sleeve prior to inserting - see picture below.

Metal bushes and metal sleeve being fitted to top mount of Nitron Race R1 shock

Repeat the metal bush fitting process to all four front suspension mounting points, and ensure the metal sleeve is fitted into each mount too.

With the shock complete and ready for fitting it's time to fit the shock.  It's just the reserve of removal and pretty straight forward.  Carefully push the shock into place (note these are spring at the bottom, not at the top like the Bilsteins).  Secure the top of the shock first, by lining up the mounting eyes and then pushing in the bolt.  Use the long arm hex key to gently tighten.  Due to the shorter shock body I found the lower suspension mount requires you to gently lift the wishbone to line up the mount with the bolt hole, but when lined up simply insert the bolt and tighten gently - torqueing the bolts will come a bit later.


Nitron Race R1 shock with RAL 2004 springs fitted to the front of my Caterham R500

With the first shock fitted, complete the process on the other side, refit the wheels (and nosecone if removed) then lower the car.  With the car lowered torque both suspension bolts to 20nm and then that's the front shocks replaced - oh yeah and don't forget to torque your wheel nuts too!

Now onto the rear shocks... This is similarly straight forward as per the front shocks, but I've detailed the process below, skipping some points as I've detailed those stages above.

First loosen the rear wheel nuts, then jack the car up.  Again use axle stands if necessary, but this is the lighter end of the car, so most jacks shouldn't be under too much load. 

You'll need to start by using a 19mm socket to loosen and remove the lower suspension mounting bolt as pictured below.


Use a 19mm socket to remove the lower suspension mounting bolt

Then using an 8mm hex adapter in a ratchet or a long arm hex / allen key loosen and remove the top suspension bolt through the hole which is located behind the seats (pictured below).


Loosen top suspension mount using an 8mm hex / allen key

With both upper and lower suspension mounting bolts removed the shock should just with a touch of force pull out of it's upper mounts.  The shock should now be removed, and at this stage I decided to weigh the rear shocks.  The original R500 Bilstein shock weighed in at 3.768kg

Caterham R500 Bilstein rear shock weighed in at 3.768kg

Onto a more surprising result than the front Nitron shock, the rear Nitron shock weighed in at 2.168kg which is a saving per shock of 1.6kg. This gives a combined saving of all the shocks of a pretty impressive 3.584kg

Rear Nitron Race R1 shock for Caterham weighed in at 2.168kg

Again I took a comparison picture of the Nitron vs Bilstein shock so you can see the difference.  On the rears the length difference is probably around 1.5cm - 2cm shorter, and again the reason for this is the lack of 'sag' on the Nitrons.



Rear R500 Bilstein shock vs Nitron Race R1 shock

With the rear shocks removed, remove both metal sleeves from the upper rubber bush (there is only one on each rear shock).

Remove the metal sleeve from the upper rubber bush

Repeat the process of greasing the Nitron supplied metal bushes, fitting the o-ring and pushing them together on each end of the suspension tube eyes (which I detailed above).  Also re-apply some copper slip to the outside of the metal sleeve, and insert the metal sleeve into the top metal bushes, then align the upper suspension mount first.  It's a little tricky to line up properly, but once it's lined up push the bolt through and gently tighten this should hold the shock in place whilst you fit the lower shock mount.

Lining up the upper suspension mount can be a little tricky

With the upper suspension mount holding the shock in place, you need to align the lower bolt to the De-dion mounting boss.  You have to be very careful here as you don't want to thread the boss in the De-dion tube for obvious reasons!


Carefully line up the lower mounting bolt with the boss on the De-dion tube

With the lower mount lined up, securely tighten the bolt and then the shock is fitted.


Lower shock bolt secured in place

Repeat the process on the other side, and then both shocks are fitted.  It's a little difficult to get access to the lower suspension mount for torqueing purposes with the wheels fitted, so I torqued both upper and lower rear suspension mounts whilst the car was still on the jack with the wheels off.  The torque setting for both upper and lower mounts is 54nm.  Your shocks will now be fitted and ready for use, simply refit your wheels, torque the wheel nuts, lower the car off the jack and you're ready to go!


Rear Nitron Race R1 shock with RAL2004 coloured spring fitted to my Caterham R500 Duratec

 Just to give a good visual overview of the shocks I created a quick video which is embedded below...

 

And then I thought it was worth going for a quick blat to see what they felt like - again video embedded below...



 

So after my short blat, the initial first impressions are that the shocks are much more responsive, and the car turns in a fair bit quicker with less understeer.  I've not fiddled around with the one way adjustment yet, but they come factory preset at -10 out of 24 available settings, so I should be able to crank them up to -5 for the upcoming track day this weekend and report my full findings.

In terms of the quality of product, service and the general 'look and feel' of the shocks, I'm very happy indeed.  You can visit the Nitron website for further details and pricing information by clicking the following link:- http://www.nitron.co.uk



Third Brake Light Fitting Guide

Since upgrading to the clear rear light kit that was originally supplied with my kit, I was concerned by the lack of illumination when hitting the brake pedal.  A few friends were running a round third brake light, so followed suit and bought my own.

There is a bit of a debate on the lotus 7 club forum about fitting third brake lights, so though it would be a good idea to make a post of how I fitted mine, so others can follow (if necessary). Now for the disclaimer... This is just the way I thought was best for my requirements, and I'm not saying my way is the correct way, but the guide should help or give ideas to most third brake light installations.

 

There wasn't much to buy, but I've listed it below (with links):-

• FIA 51 LED Rain Light - £30 from Demon Tweeks
• High Level Brake Loom - £9 from Caterham Parts
• Some 2 core electrical cable
• Some various size and length heat shrink tubing
• Three packs of black Sugru

First part - installing the wiring loom

The first step is the remove the grommet on the inside of the offside rear wing.  Once the grommet is removed, gently pull through the connector block (there is just enough slack) and remove the indicator connector block from the main loom by lifting the black clip with a flathead screwdriver as pictured below.





Lift clip with a flathead screwdriver to remove indicator connector block from main loom

Now fit the two connector blocks from the high level loom provided by Caterham - there should only be only one way this fits together.  Then push the whole lot back through the hole in the body panel, and refit the rubber grommet. 



Connecting the high level brake light loom

I thought long and hard about how to neatly get the wiring loom up to the bottom of the roll bar, and the best solution I could find was to thread the cable up through a very small hole where the underside of the boot joins together.  I used a two core wire which I threaded up between the seam of the boot, as you can see in the picture below.


Two core wire threaded up through boot seam

As I've carpeted my boot, you'll see that the two core wire comes very neatly out behind the carpet and just at the start of the roll bar. 


Two core wire coming out behind the boot carpet

Then I cut the cable loom to length and ensured there was plenty of the two core wire pulled through the top to allow plenty of slack.  All the wires were soldered together protected with a couple of layers of heat shrink tubing.  I cable tied everything in place as you can see in the picture below.


Cable loom and two core wire joined, heat shrunk and cable tied into place

Whilst I was at it, I decided to cut down the excess of microphone wire that I had (as I have a stereo microphone mounted on the underside of one of the harness straps).  I threaded the microphone wire and two core cable through some 7.5mm heat shrink tubing, heated it (neatly) and tire wrapped it into place on the roll bar.

Two core cable and microphone wire heat shrunk and tie wrapped into place

I thought at this stage it'd be a good idea to test the light!  So I just put a connector block into place, wired everything together and crossed my fingers.


Light connected with connector block

It worked - and is extremely bright too.  As these lights are LED the polarity will make a difference, so if you wire the light up and it doesn't work it may just be due to the polarity being wrong, simply re-wire and re-test and it 'should' work.

Rain light being tested - check out how bright it is

Now how to fit the light onto the roll bar
A number of other Caterhams I've seen have this third light fitted to the roll bar, by way of a suitably sized rubber lined P clip.  The P clip fits around the roll bar and is tightened with an M4 bolt which fits directly into the rear of the light.

As OCD as I always am, this wasn't quite elegant enough for my liking, so I looked into some other mounting solutions and the best idea I could come up with was to fit a u-bolt that was covered in rubber.

I contacted a number of U-bolt manufacturers, but none of them wanted to make a u-bolt in M3 size.  The u-bolt needed to be M3 in size, as this is the correct size for the thread of the bolt to fit through the mounting eyes on the light.

Lee (my business partner) has a lathe and other gear for making things like this, so I popped over to his, cracked open a beer and let him get to work. (well not entirely, but it sounds good!)


Tiger beer - whilst I was hard at work

 We used a piece of aluminium tube as a template to work out the bend and tube length required.


Aluminium tube offered up to roll bar as a template for bespoke u-bolt

The aluminium template was then flattened and measured.  We needed 130mm of material with approximately 15mm threads on both ends.  Brass was used as this is soft enough to bend into shape, but still provides enough rigidity too.

130mm brass tubing ready for machining.

The brass was a little too thick for the M3 size required, so 15mm of each end was machined to 2.8mm in diameter.

Brass rod being machined to 2.8mm diameter

Lee then used one of his M3 dies to cut a .5 pitched thread into both ends of the brass rod.  We then tested the thread with an M3 nut and it was perfect.

.5 pitched M3 thread cut into brass rod, ready for bending

Lee then carefully bent the brass rod around a 60mm piece of nylon he had lying around, and then slipped on a piece of black rubber tubing and the u-bolt was finished ready for fitting. 

60mm u-bolt with black rubber tubing and M3 threads

These round rain lights are supplied with a ten degree angle on the rear profile, and for the fitting system fabricated above, this angle fouls the roll bar and makes the light slanted.  The next dilemma was then to reduce this profile so that the light fits correctly.  The solution was Sugru - it's a mouldable plastic which sticks to pretty much anything and hardens into a tough rubberised silicone.

I trimmed a small amount of the profile off the rear of the light using a sharp scalpel to flatten it as much as possible before applying the sugru.

Third brake light and sugru in packaging

Opening the Sugru packaging reveals the gummy substance which is ready for moulding.  I used three packs of the black Sugru.

Sugru packet opened

Once moulded into shape on the rear of the light, I pressed the light up against the roll bar so the profile of the Sugru is indented with the roll bar shape for a good fit.  It's not an extremely elegant solution, but it works extremely well as the Sugru is rubbery it creates a really good fit against the roll bar.  The positive is that the Sugru is hidden when the light is fitted, so I've not real problem with the aesthetics of this solution.


Third brake light with Sugru roll bar profile applied to rear

We then fitted the u-bolt and the light. The u-bolt fits extremely well around the cross of the roll bar, the rubber tubing helps in creating a very secure mount, that will also not scratch the roll bar if removed.

Caterham R500 with third brake light fitted

In the picture below you can see how well the third brake light illuminates in comparison to the (extremely poor) illumination of the clear lights - you can hardly see they are on which is pretty scary indeed.

Caterham R500 with third brake light illuminated

Overall I'm extremely happy with the neat finish of the u-bolt mount we made, but for ease I'd recommend others the rubber p clip mounting method (detailed above).

Track Day Wheels and Tyres - Finished!

I'm very glad to finally be writing this post.  I thought the day would never come, but the track day wheels and tyres are finally finished and fitted!

The whole process from deciding what wheel colour / design to go with to the finished and fitted wheels took around three months!  The stages involved to get to where I was a couple of days ago were:-

1. Deciding on what colour choice to go with for the wheels
2. Ordering the wheels and tyres
3. Specifying the colour of the wheels and having them re-powder coated
4. Getting the rims painted in the correct orange and attempting to get the tyres fitted

With the tyre walls being so stiff on the ZZR's the tyre fitters were finding the tyres were peeling the painted rim off, so I waited until the weather warmed somewhat and took them back down to my local tyre fitters a couple of days ago.  They left the tyres in the sun for the day to warm up, and managed to fit them with only some light scuffing of the painted rim.  So there's a good and bad there,  good is that the ZZR's are fitted, bad is that the scuffing on the painted rim looks a little like kerb damage which is pretty irritating, but, and in hindsight, I should've had the wheel powder coated in the RAL 2004 orange, then had the spokes and wheel barrel painted black to avoid this (there's a tip there!).  Anyway, the tyres are fitted now so time to move on.

Caterham 8 spoke alloy wheels with orange rim fitted with AVON ZZR tyres

On a trip to Halfrauds a while ago I took the opportunity to pick up a couple of tyre wall paint pens. So with the tyres fitted to the wheels now was the time to start the tyre wall letter painting.

Tyre Wall Paint Pen

The instructions on the pack said to throughly clean the tyres with hot soapy water, along with the usual shaking of the pen for ages and pressing the nib in to activate.

AVON ZZR's washed prior to painting tyre lettering

The tyres had to be fully dry before painting began - I used a microfibre towel to dry the tyres off.  The next stage was to be brave and start painting!

No turning back now!

I started off with a light first coat, and just done the AVON wording on one side.  It didn't look right, so done the AVON on the opposite side of the tyre, that didn't look quite right either, so went the whole hog and also painted the ZZR lettering too.

Each coat took around 15 minutes per wheel, and each wheel required between three and four coats.  The painting was quite fiddly as care had to be taken not to paint over the edges of the lettering, but after the first couple of tyres were painted it became a little easier.  The instructions of the paint pen suggested to leave 10 minutes between coats, but the duration of painting each tyre was far longer, so I ended up leaving at least an hour between each coat.

AVON ZZR's with painted tyre wall lettering

The final touch was to fit the Caterham badge to the centre caps - a two minute job.  Peel the sticky badge off the backing paper, and stick to the centre caps - job done.

Caterham wheel centre caps with centre cap stickers ready for application

With the wheels and tyres ready to be fitted, I thought it would be a good idea to do a quick time lapse video of the fitting process.  So here it is below.

And then the long awaited track day wheels and tyres were fitted, and I think they look great!  Very sporty and kinda 'F1' - so perfect for track days!

New track day wheels and AVON ZZR tyres fitted to my Caterham R500 Duratec

Below is a video so you can see the detail that's gone into these wheels and what the car looks like from various angles with the wheels and tyres fitted.

It was then onto a blat to try out the ZZR tyres to see what effect they had on the ride, handling a general grip.  I thought it'd be cool to see what the tyres look like when they're motion, but it was pretty hard creating a solid mount for the GoPro.  I used the motorsport suction cup mounted to the front cycle wing, with a GoPole extension arm.  It gives a good view of what the tyres look like in motion, if somewhat shaky!

Overall my first impressions of the ZZR tyre are:-

• Better cornering grip
• Better accelerative grip (less wheelspin in 1st and 2nd gear)
• Less tyre wall flex meaning bumpier driving on B roads

As these will be predominantly track day wheels and tyres I'll have no problems in trading off the bumpier driving on B roads (on the way to track days) against the improved grip characteristics.  The AVON CR500's are more fun on the road but I thought that'd be the case anyway.

If I were to the coloured rims on a set of wheels again, the main thing I'd do differently would be to have the wheel powder coated in the colour I wanted the rim, then have the spokes and the inside barrel painted. This way when the tyres are fitted they will rub against baked on powder coat, not a painted rim which should stop the rim from becoming scuffed.

Easter Sunday Blat

What better to do on Easter Sunday, than to do for a blat with your nine year old nephew...?
Exactly... nothing...!

Here's the video of the fun bits - it looks like he's holding his ears, but the sunglasses were a little too big for him, so he was trying to stop them flying off! Enjoy...