Shortshift

Indeed so. But without another data point, it's not possible to estimate the comparable stiffness value of the double-ended bar as, in this configuration there are three elements making up the total stiffness - the rotational blade at each end, and the torsion bar/tube running transversely across the car. We know the stiffness comparable (say, 66.1 lb) for the 'standard' torsion tube plus one blade but we don't know how much each of the blade and the tube contributes to the total, meaning we can't calculate the value for the double-bladed version. James

I've always been intrigued by the stiffness and sizing of the CC rollbars and their relationship to Simon's adjustable blade version (which I have had fitted since 2015). Based on the snippets of information above and looking at the data on the CC online parts store, I have invested 30 minutes of my life trying to make sense of things as follows: CC bar for Series 3 (listed in ascending size/stiffness order): Orange 1/2" (12.5mm)Blue 9/16" (14.3mm)Red 5/8" (15.9mm)Green 18mmCC bar for CSR: Orange 1/2" (12.5mm)Option 9/16" (14.3mm)Now, based (a) on the data point provided by Simon that the CC red bar is 66.1lb force (not sure what that is, actually, or how it is measured, but it matters not for comparison purposes) and (b) that, with all other parameters unchanged, the stiffness of a circular-section solid bar increases as the fourth power of an increase in its diameter, then using the S3 red bar as a datum we end up with: Orange 37% of datum, or 24.5lbBlue 65% of datum, or 43.0lbRed 100% of datum, quoted as 66.1lbGreen 163% of datum, or 107.6lbThen finally, using Simon's quoted figures for the adjustable blade we find that: When fully soft (42.5lb) the blade bar is a very close approximation to the CC Blue barWhen fully hard (70.5lb) the blade bar is only a squidge stiffer than the CC Red bar (and is nowhere close to the stiffness of the CC Green bar).This indicates that the original claim of the blade bar offering adjustability ranging from 'softer than CC's thinnest bar' through to 'stiffer than CC's thickest bar' looks to be somewhat questionable, which is kinda borne out by the number of people who buy the adjustable bar and end up fixing it in its softest setting. We now know that is pretty much inline with the Blue bar stiffness; oh for some adjustability below this point! I know that Simon has said he has no plans to restock the adjustable blade bars once the existing units have sold but I wonder whether a tweaked version, running from say 35lb to 66lb (so a slightly softer range than at present) might have broader appeal? I say that given the number of people who buy the bar and end up with it 'fixed' in its current softest setting (me included), and who would probably like to have the ability to make it softer than at present particularly in wet conditions, etc. James PS: no responsibility accepted for the mathematics deployed here. Firstly, it's still early in the day for accuracy and, secondly, my methodology involves a number of broad-brush assumptions, with no attempt having been made (for instance) to reflect the actual geometry of the CC bars in the stiffness calculations.

Anyone got anything CSR related (on retention, or whatever) that they may be thinking of selling? James

Anyone got anything CSR related (on retention, or whatever) that they may be thinking of selling? James

Now sold. James

BTTT - still for sale, it seems! James

It's true, I'm afraid. Is the later Blyton Park Novices' Day of any use? Or maybe look at other events which are sessioned, with a novices group running for twenty minutes every hour. All Club trackdays include free instruction and Simon tries to prioritise the lesser-experienced drivers. James

Hi Steve Yes, of course. Feel free to call me and I'll talk you though the dimensions, etc. Cheers, James

As the photos show, this is a two-piece grille with the '7' logo/badge. It is for an SV. The mesh piece is pretty much perfect; the wire frame with the Seven logo needs a bit of sprucing-up with a bit of sandpaper and a touch of paint. 30 minutes and you'll be done. Looking for £60 plus postage - that's about half the cost of buying a new pair of pieces. James

Surprised this hasn't gone yet; they are usually like rocking horse droppings to find... Open to reasonable (close) offers. James

Hi Jason - we chatted about a set when we were up at Blyton (I think it was!) so can I confirm my interest in a set, please? James

Mine is sufficiently flexible to allow access to the cap with the tongue still in place. In fact, the trailing edge of the tongue sort of 'latches' below the lip of the filler and is held out of the way during oil filling and level checking. James

Yes, I know, but it's not meant to be a track car... Ah well. James

Oh bugger, I give in - Pugwash, I'd like to take it... I'll message you separately. James

Are you on commission?? James

Stop it, please stop it... James

Will someone please hurry up and buy this so I can stop being unnecessarily tempted??!! James

This is a pukka Caged Roadsport cage (complete with FIA sticker) that has come off my newly acquired CSR, so it is perfect for one of those or an imperial SV. It may even fit to a metric SV - I'm happy to check dimensions. It allows the windscreen and side doors to be retained, if needed, and a full hood will also go over the top. It's pretty much unmarked as it has been fitted to a road-use car that has only covered 2000 miles in total. The pictures show it pretty well. These are around £1300 from Caterham Cars so I'm looking for £750 which I think makes it excellent value. Located in Warwickshire and probably best collected. Happy to answer any questions! James

Having a garage clear out and I uncovered this hardly-used decat/bypass/collector pipe that came off my Duratec R500. I am not sure but this might also fit other Duratec Sevens (420s?) - in fact, an owner of other 420s has confirmed this. It was on my car when I bought it and was used with the standard-fit exhaust/tailpipe. The total length is 50cm (see pictures), the OD of the four primaries is 50mm and the OD of the single outlet pipe is 64mm. As the pictures suggest, hardly used and virtually as new. Out of stock at CC at present (but their retail price is £371) so I'm thinking that £250 or thereabuts, plus shipping, would be about right. James

SOLD James

These were SV/CSR protectors that were cut down in length (to fit a cage) and are therefore too short to refit to an SV or CSR. However, they just need reducing in length (by around 35/40mm) to make them perfect for a standard S3 car where the required length is 415mm. One side is pretty much in perfect condition, the other has a few cracks including some near the ends which are quite minor and, anyway, will mostly be removed when the part is cut to S3 length. I've taken a photo of one end; it's similar at the other. The pre-drilled holes might line up with your existing side trim fixings but, if not, they are hidden behind the side trim - you just drill new holes where required. Allowing for the slight cracking, I'm thinking of £55 plus postage for the pair (over £160 new!). James

Have always used the occasional centre-punch method. Works for quite a while and when the effect does reduce, simply rinse and repeat. James

Thanks Roger! James

Any chance of a photo of the ingenious ECR/bahf solution? I think I understand but you know what they say about a photograph... James

link I guess it's for an imperial chassis. James