Nigel B

That’s an interesting observation Graham & I’m glad it’s not just me who prefers the feel of the car with the rear ARB! Years ago, I had a couple of weeks off work. The first week, I visited my Dad, driving down from Scotland to the Midlands in the Caterham. The following week, we had a week away in the Highlands. We took my every day car, which was a Clio 172 at the time. On the drive north I was bemused by how ‘baggy’ the Clio felt, assuming my perception of it was down to the contrast with a week spent driving the Caterham. However, as the drive progressed, I started to feel there was a problem. When we arrived at our accommodation in the Cairngorms, I had a peek under the back of the Clio & discovered drops of oil, leaking from the rear near side damper. It felt very much as you describe. The problem was most noticeable on subtle dips or rises on the dual carriageway, where the car would momentarily feel ‘floaty’ & unsettled. I bit the bullet & replaced all the springs & dampers (with new, standard spec ones) & wow, what a difference that made! The car no longer felt under damped & as you describe, it would deal with & recover from lumps & bumps far more quickly.

Removing the rear ARB is such a common recommendation, but it’s one that I find puzzling. For the last few years, I’ve been playing around with the ARBs on my car, trying to hone the balance of grip, front to rear. I’ve tried most combinations, from fully stiff, to fully soft at both ends, including removing both bars (though I haven’t tried removing both bars at the same time). I’ve had a lot of fun trying the various combinations & I’ve learned a lot about how different settings affect the handling balance. I drive the car for a fair few miles after each change to try to really understand the pros & cons, not just for one blat. I feel that the increased sensitivity to the handling that I’ve developed as a result of trying different set ups has actually improved my driving. It’s something I’d recommend, although I do think you need to have a good basic set up (corner weights etc) before you start experimenting with the ARBs. On Blatchat, Pistonheads & the various Caterham Facebook groups, I’ve seen owners claim that removing the rear bar has ‘transformed the handling’. But when I tried removing my rear bar I really didn’t like the feel of the car at all. The increased roll at the back made it feel lethargic & considerably less agile. It was particularly noticeable when you wanted to change direction quickly, when negotiating a tight combination of left & right bends, for example. There was a pronounced sense of ‘waiting for the car to settle’ with the rear bar removed. I also felt the car’s tendency to ‘lift off oversteer’ was exacerbated to quite a degree. With a moderately stiff rear bar the ‘lift off oversteer’ tendency is pretty much eliminated. Although the ride quality was improved, I didn’t feel it was as ‘night & day’ as people claim & it certainly wasn’t a sufficient improvement to make up for the disadvantages. Perhaps different people focus on different aspects of a car’s handling? For me, a nice balance of grip between the front & the rear of the car is a key factor in how enjoyable it feels to drive. I wouldn’t want to adversely affect that in the pursuit of improved ride quality, particularly in a Caterham. Perhaps the answer is to seek out better surfaced roads?

The Goldfinger references mean I can’t resist posting up these!

Thank you all for your replies! I thought that might be the case, but I’m never sure about these things. I think I have a few bottles of distilled water lurking in the garage somewhere. And don’t worry Jonathan, I’ll avoid swigging it back!

This is probably something of a numpty question, but reading the information on the side of coolant bottles makes my brain glaze over! I’ve been using the coolant in the above photo since I bought the car, but Caterham & Opie Oils are out of stock (& have been for a while). I’m wondering if the stuff in the photo below would be a compatible alternative? I notice you have to dilute it, so that might be the only difference? Any clarification would be greatly appreciated! https://www.opieoils.co.uk/p-60206-motul-auto-cool-optimal-ultra-car-antifreeze-coolant-concentrate.aspx

I got a new one from Luke Stevens. It might be worth giving him a call.

To my eye, Sevens don’t look quite right without an air filter cut out. But then I did grow up in the 80s, lusting after BDRs & 1700 Super sprints!

I had a set of second hand roller barrel throttle bodies fitted by Luke Stevens, followed by a mapping session by Luke & Steve Greenald. I was delighted with the result. The car runs better than ever, pulls smoothly & strongly & sounds fantastic! https://www.lukestevensdevelopments.co.uk/

I had a carbon plate Titan in my 2017 420R that failed in less than 5000 miles. I replaced it with a Tracsport in 2020 and after almost 19000 miles, the Tracsport is still going strong. I’ve been extremely pleased with it, it performs very well & is near silent. I fitted my previous (live axle) Seven with a Quaife ATB. The Quaife was a definite improvement over the open diff the car was supplied with, with noticeably improved traction, particularly in wet or damp conditions. It was as quiet as the open diff & it didn’t give me any trouble in the five years I had it. Personally, I don’t feel the Quaife performs as well as a plate-type LSD though. I still remember how revelatory the (at the time, fully functional!) Titan felt when I first got the 420. That delicious sense that the clutch plates were locked up & any further pressure on the throttle pedal would gently rotate the car. The Quaife felt a bit vague by comparison & it never really gave me that sense of positive connection between throttle & steering. I think there are pros & cons to all these things & what diff suits you best depends on where your priorities lie. I hope that helps & good luck with your search!

It sounds promising. I’ll be interested to hear how you get on with the Drexler. Correct adjustment of the crown wheel & pinion is critical. Years ago I had a Quaife ATB fitted to my live axle Seven. The local garage fitted the Quaife into the diff casing & when I drove the car, immediately there was a whine from the CW&P that wasn’t there before. Over the course of a few hundred miles, the whine became more pronounced, so I took the diff out again & sent it to Road & Race for adjustment. When I refitted it, it immediately sounded quieter & it became quieter still with use. It was verging on silent when I sold the car!

Pipercross do a cleaning kit. It’s essentially a can of detergent that you spray on the filter before rinsing it out with water. You then leave the filter to dry & re-oil with the second can. I think other filter manufacturers have similar products. https://www.thepipercrossshop.co.uk/products/filter-servicing-products

I recall reading an interview with Graham Macdonald in Low Flying several years ago, where he explained Caterham had originally taken on the Gatwick facility because they were anticipating selling their version of the car that eventually became the Alpine A110. Obviously, the collaboration with Renault didn’t work out & they were left with a larger showroom than they needed. Graham said at the time that they wouldn’t renew the lease when it came to an end.

https://www.frost.co.uk/v-5-diy-reverse-brake-clutch-bleeder-phoenix-systems-2104-b/ I find this useful for brake and clutch bleeding. I think it works very well for the clutch. I suck the old fluid out of the reservoir using a syringe, then pump the fresh fluid in via the bleed nipple.

That’s terrible Rob, I really feel for you! What year is your car? There have been a few areas on my 2017 car that needed to be re-powder coated. Notably the pedal box, where the powder coating flaked off in large sheets. Thankfully the chassis itself seems to be okay. I had my previous (2002) Seven for seventeen years & the powder coating on that car still looked like new when I sold it.

I’ve fancied a Reilang oil can for a while & back in August, when my wife was at a loss for birthday present ideas, I sent her a link. It’s a lovely piece of kit, thoughtfully designed. It has a mechanism inside which means it will dispense oil when held at any angle & the trigger is very sensitive. A small squeeze will dispense the tiniest quantity of oil. It has the satisfying feel of a precision instrument. I’ve found it perfect for applying ACF50 at this time of year. The long nozzle means you can get it exactly where you want it.

My car has no knocks, clonks or whine, so I don't think you should accept such things as 'normal'. In my experience, whine from a diff tends to be caused by an incorrectly adjusted crown wheel & pinion. Chasing down such noises rather than simply accepting them is well worth it in the long run.

That sounds like a very good approach! The drilling aspect makes me nervous & is one the reasons why I haven't been brave enough to fit half doors! I've just had a look in the assembly guide, but I can't find any mention of half doors. Strange.

I don't have half doors, but I seem to recall a template is available from Caterham. The holes have to be drilled in very specific positions & I believe the poppers go through the side skin into the chassis tubes. Don't do any drilling until you're absolutely sure!

I spotted this on a driveway near Torridon in the Highlands. It was a real double take moment! Not in the best condition, but it looked like it was being used.

I simply added an additional rubber seal underneath the standard AP cap. I felt the cap was 'bottoming out' before the rubber seal was fully compressed, as there was little sense of 'squish' as the cap tightened up, it seemed to simply come to an abrupt halt at the bottom of the thread. With an additional seal underneath the cap, there was a definite sense of the rubber compressing as the cap tightened down. It did the trick. That was three & a half years ago & I've had no further leaks.

I'd agree that a poorly adjusted crown wheel & pinion can cause damage. I fitted a Quaife ATB to my previous Seven, a live axle car. I got the local garage who did my MOTs to fit the Quaife, but they didn't get the adjustment of the CW&P quite right & it developed a whine that got louder over a few hundred miles. Prior to getting the Quaife fitted, it was pretty quiet. I took the diff out again & sent it to Road & Race, who re-adjusted it. When I refitted it, it immediately sounded quieter, but over the next 500 miles or so it got progressively quieter still, until it had no discernible whine at all. I can well imagine that if I hadn't had the CW&P re-adjusted quite promptly, it could have caused permanent damage & a permanent whine.

#17 I had that issue with my old (live axle) Seven. In my case, it was caused by driveshaft splines that were a bit loose in the diff. My current car doesn't exhibit any clonking at all when you come off & on the throttle at low speeds, so I don't think it's a case of TADTS.

The compound is thick & waxy, so it tends to stay on the mop. Strands of cotton from the mops do fly about a bit, but I found them reasonably easy to tidy up!

I bought one of these kits, with electric drill mounted polishing mops & different grades of polishing compound. It was very effective & I managed to get a good finish reasonably quickly. I find you have to redo it periodically however, to maintain the shine. https://www.thepolishingshop.co.uk/polishing-kits/steel-stainless-steel-polishing-kits/steel-stainless-steel-kits-for-drills

Amazing! They're imposing looking beasts.