Handwheels

Now I've removed my leaky rad I've had a closer looked at the mounting brackets - and I'm now thinking of ditching the silly Z brackets and welding a small tab on the bottom of the chassis-radiator bracket. This would be aligned with the mounting points on the radiator and set back enough to allow the use of significantly longer & slightly narrower bobbins. It would be possible to fit in 25mm dia. x 30mm bobbins instead of the existing 30mm dia. x 15mm ones. Unfortunately, I can't see a way of using longer bobbins at the bottom of the radiator, but I think it's a case of 'every little helps'! I wouldn't make any other modifications to the chassis-radiator bracket, so in theory I could remove the new tab and return to the factory set up if required. I'm also planning to follow the lead of others, and cut back the rigid top hose and use a straight connector to fit a section of silicone hose. I bought a silicone 620 top hose, as recommended, but at first glance it doesn't seem to align with the angled top hose connector on the radiator - so I'm looking at other silicone hose options. Also, once I've finally got a new radiator fitted I will never use the towing eye as a jacking point again!! The attached pics show the existing set-up and my bobbin bracket proposal. I'd welcome any comments on my plans 😁 Thanks for all the comments & advice I've already received Cheers, Richard

@raw I noticed your alternative to bobbins in an older post. Have you had to replace them since you first installed them, or have they lasted well? Sure they must be more effective at damping vibration than the 'token' ones Caterham supply Also, what silicone hoses did you use for the top and bottom hoses? Cheers, Richard

Thanks for all the comments. For clarification it's a 2021 (not 2001!!) self-build, & I've always used the Caterham spec Motul OAT coolant. I am aware of the discussions about what is best coolant for the rad, but (as others have previously said) I've been concerned about it for the engine first. I also used washer on rads 2 & 3 to eliminate any twisting of the rad, & I've found the fixing holes on the brackets line up perfectly with the mounting holes in the rad so not sure if I would benefit from enlarging the bracket holes. I've not noticed a need to adjust the brackets to ensure they are parallel to the rad, but I'll double-double check that next time. When I built it I was aware of the issues some have had with the mounting bracket touching the top hose, but I've got a 2.5mm gap. I've been concerned about the top hose being so rigid and also not being in perfect alignment of the rad coupling - so the idea of a 620R silicone hose sounds good. I've looked on Caterham Parts - is this the one (currently out of stock of course) people have used? Thanks

I hadn't spotted those discussions, so I'll do some homework :). Thanks

My 2001 420R has got through three radiators in just over 13,000 miles - they have all leaked in the same area near the upper hose connection on the left hand side. The first one failed after 4400 miles and was replaced under warranty. This second one lasted 4480 miles (at least they failed at consistent mileages!). I then decided to try a non-Caterham rad in the hope that the cause of repeated failure was the (poor) quality of the Caterham supplied rads, so my third one was supplied by Radtec - they sell rad without the oil cooler (which I've not had a problem with) so Radtec were considerably cheaper which was a bonus. However.. this rad failed started leaking after 4120 miles. Radtec repaired it but over the winter I've noticed it has leaked coolant while the Seven has been laid up. I am convinced that the issue with post-2018 420s unrelated to the quality of the rads, but the negligible amount of isolation from engine/chassis vibration - although Caterham beg to differ! The mounting bobbins are so small that there can only be a few mm of rubber between the end of the stud that fixes to the chassis brackets and the threaded female sleeve that the radiator is bolted to. The rad is also rigidly held in place by the inflexible upper coolant hose and the oil hoses - the oil cooler is fixed directly to the bottom of the rad. Pre -2018 420s had a separate oil cooler and much bigger bobbins because there was space to mount the rad slightly further forward because the fan was fitted to the back of the rad. From speaking to owners it appears that these earlier 420s don't have the same issues. Caterham has accepted that they have had a lot of warranty claims on 420 rads, and as a consequence have recently changed supplier - I don't know who they have switched to. I'm not convinced that will solve the issues . Is there anyone out there who has modified their set up and managed to get a rad to last more than 4480 miles, or have any suggestions? Cheers, Richard

Unfortunately, I've had to abandon plans for Blyton Trackday tomorrow (Fri 22/09/23). On the off chance anyone wants a free twin room at the Black Horse tonight then let me know. Cheers, Richard

My main piece of advice would be go in convoy with a support vehicle with a boot full of tools, a spare pair of hands AND arrive early enough to deal with the issues you discover on it's first ever journey. On my drive to Gillingham I discovered the speedo stopped working at about 65mph - bear in mind it had never been faster than 10mph before! Fortunately, I had enough time to jack up the car in the nearby Screwfix carpark, get out my feeler gauges and adjust the speed sensor by a fraction of a millimetre. When they put it on the rollers at 70mph I discovered I'd correctly adjusted it :) Good luck - it's a stressful but fantastic experience. Richard

I took my 420r to Gillingham in 2021. It was a bit stressful but also hugely satisfying - getting the certificate at the end was much more enjoyable than any academic award I've ever achieved! I wouldn't have wanted to miss the best bit of the build process. The guys there were very friendly and helpful- giving me time to adjust the Speedo tyre size setting and headlight alignment (both of which had been incorrectly set by Caterham!). Don't forget the added bonus of going to the IVA yourself is that you get the chance to drive it on the road. While heading down the A12 I discovered that the Speedo cut out at 70mph - but I had enough time in the Gillingham Screwfix car park to jack up the car and adjust the sensor, before going to the test centre. Going across the Dartford crossing for free (because didn't have registration plates) was the icing on the cake.

We've got the JAL set up; Bluetooth for driver and non-Bluetooth for passenger with a cable connecting the two. And another cable if I'm using the radio. You can change the settings so that you can speak to each other without needing to press the talk button - which is handy at times. This setting uses up the battery quicker (although battery life is normally good) and you get a little bit of background noise from the microphones (which I don't really find much of an issue as I keep the volume a bit lower and can still hear the passenger's words of wisdom). Richard

Yes, but I declined to pay for it!!

When I took my Seven to Gatwick for its Post Build Check they told me that the steering wheel was incorrectly aligned - which made me chuckle because they had just done the steering alignment

Hi - if the tool tube and dry bag are still available I'd take them Richard

Andrew that's the second time you spotted me in BS - until you get your Seven back on the road I think you need to put a flag on your Fiesta so I know to wave to you. I pass through BS quite a lot as son lives in Stansted Mountfitchet and it's a nice wiggly drive from Chelmsford. However today having a great drive in the sun up to Derbyshire

1 night in Ilam near Ashbourne & second night near Buxton. Thinking of heading home via the Motor Museum at Gaydon

I've just booked a couple of nights in the Peak District at the end of this week. Wondered if anyone has suggestions for a Seven-friendly route up from Essex, & any 'must-do' roads I should experience while I'm Up North. Cheers, Richard