Draught excluder for 2007 CSR

[David aka Blue7]

Voila!

The insect mesh arrives folded so I thought I may have to iron out the creases but not necessary because the creases disappear within a short time once unfolded.  The light grey mesh gives perfect rear vision, I did wonder about doubling it up but decided against doing so.

https://www.amazon.co.uk/gp/product/B00SJHWMMU/ref=ppx_yo_dt_b_asin_image_o05_s00?ie=UTF8&psc=1

Caterham poppers along the bottom and I inserted an additional one at each end near the roll bar.  I used Gorilla tape on both sides of the perimeter and inserted 5mm (internal), eyelets & grommets into the sides and along the top.  Warning: don't use cheap eyelets & grommets, most of which are on Amazon, they are carp.  Use a reputable brand, I used Hipkiss brand from a ships chandlers on EBay, which made me chuckle because I didn't realise Hipkiss were still in business, I was their Accountant back in 1970, when we first introduced the eyelet & grommet kits in what was then cutting edge packaging ... bubble packs!  The punch kit will cut the holes but I used my own tool for punching holes in leather belts ... bought to insert additional poppers in my shower cap.

https://www.ebay.co.uk/itm/253399629156

I used velcro ties / strips circa 20 cm long threaded through the eyelets to attach to the roll bar

I cut holes along the bottom edge where the seat belt bolts are located but on reflection it doesn't seem necessary because once fitted the screen lifts above the top of the bolts.  I haven't tested it yet but it seems pretty sturdy ... while stationary and will easily roll up inside the half hood when not in use.  I will try it out on Sunday ... it should at least thwart rear attacks from wasps!

 

[David Brown]

That looks great Blue and interested how it works in practice. 

[David aka Blue7]

David, we have a week away in Bonar Bridge in a weeks time with four other 7's, there is bound to be a "spot" of rain so the rain / wind reduction qualities should get tested.  As you know, it is not rain that is the problem but the fine spray that gets sucked in through the back.  Remarkably, I have only used the half hood once this year and that was to drive back home after a service.

My design is a bit labour intensive and could be done cheaper.  My original idea was to use velcro strips at each side so that each end could be stretched and wrapped around each vertical roll bar.  It would also be possible to attach velcro strip to the boot cover and bottom edge of the draft reducer which would be cheaper than buying poppers from Caterham.  However, the velcro would probably have to be sewn in place and Maggie no longer has a sewing machine ... so it might be her Christmas present

Update: Just been for a spirited run and the draught reducer seems totally useless at reducing draughts but at 22c I am very thankful   However, I am not really bothered about draughts, it's main function will be to prevent rain getting in at the rear when deployed with the half hood and I am certain it will be effective at that ... but some suitable test weather is required.

Update 2, just used it on a 120 mile journey home in pouring rain and I have changed my  mind, it does reduce rear draughts but more importantly it prevents the fine spray entering the car from the rear.

I am working on a Mk 2 version using just velcro on 1.6mm THICK UV COLD CRACK RESISTANT CLEAR PVC SHEETING for WINDOWS BOAT COVERS

[David aka Blue7]

I have just completed a Mk2 draught excluder using 1.6mm thick pvc (similar to sidescreens), 25mm velcro and 50mm velcro, total cost £29.  Just been for a test drive and no problems at all up to 70 mph, no noise, absolutely secure and 1st class rear visibility.  It should be excellent in preventing ingress of spray when used with half hood, which is the only time I would use it.  It rolls up easily inside the half hood.  I have prepared a pdf file complete with instructions, materials, costs and photos but I am not sure it will upload.  If it doesn't I will have to upload individual photos and instructions in a further post.  PDF file is below, you have to right click it and choose Open in new tab or open in new window to open

Draught Excluder Mk2.pdf

Here are a few photos, the overlap at the bottom will be trimmed off eventually:

David

 

[David Brown]

Looks good and obviously better in the rain than mesh. 

[Darrenkidney]

Having seen the effectiveness of rear draught excluders on MGBs and Minis, I was thinking that my new (to me) 7 would get the same. However, I don't feel draught over the shoulders but rather coming around the sides of the screen - regardless of side deflectors. With doors on all is snug. In your experience does a "roll bar fill in" as described here solve my "buffeting across my nose" problem? 

Regards from an Irish guy in Germany :-)

Darren. 

[SM25T]

Try a complete mesh to fill in the roll bar. Makes a big difference if you drive without doors. In the rain it reduces the amount of spray that is pulled in to the cockpit from behind. Black insect mesh available on line

[SLR No.77]

Darren the general opinion is that running screen-only is good up to about 40mph and you'll likely suck your eyeballs out at about 90! The wind deflectors that attach in place of the side screens help a little but not much, it's really a choice between screen and doors, or go aero.

Whether a drought excluder would be effective enough to try without doors you only try and see what happens. There's a lot of variables including whether you have a spare wheel and which seats you have fitted .... Tillett's reduce the draft around your neck compared to S-Types.

Stu.

[SM25T]

With screen and no deflectors .... no mesh, you cant breathe above 40mph. With a full mesh it is good to 70mph.

[Darrenkidney]

Thanks for responses. Right - I've decided to give it a go with mesh based on all comments so far! The next mini project is identified!

[BigCol]

Have a look here...

[Stewart Collier]

I did a similar one but instead of aluminum tube I used black curtain wire. I secured it using tie wraps and I stitched the black insect screen to it..S

[Darrenkidney]

I just built a quick and dirty prototype from HDF and cable ties and did a quick run. I think it delayed the onset of unpleasant cross-nose-buffetting without doors by about 25/30 km/h. Next to make it look as invisible as possible... will keep you posted!

[Frogman]

Have you thought about Lexan or similar?

[Darrenkidney]

Jip - just the shinyness puts me off. Wondering rather about a thin aluminium frame with a fly screen glued to it.

Pondering....

[R300 FNL]

Looks good Blue, wonder if a perspex sheet cut to size would be better than the PVC so there is no flex or requirement for the extended bottom section across the boot cover? I might give it a go since we have a bit of time to waste around the house.

[David aka Blue7]

I should have perhaps updated the instructions to say that I eventually trimmed off the excess that overlaps the boot cover so that it now just touches the boot cover.  The problem with using perspex is that would be difficult to store in the car whereas the pvc version just rolls up inside the half hood.  Similarly the above suggestions of using a "frame" is also probllematical when it comes to storing in the car. 

I still have some fly screen mesh left over from the mk1 version (which was far too contrived ... but worked), so I will have to make the mk2 version using the mesh instead of pvc.  It will be a welcome change from cleaning out our coal shed and painting the interior white, just to store logs instead of coal!

[Darrenkidney]

Being a relatively new 7 owner.... forgive the question: why would you want to dismount a framed screen when out and about and have to transport it? I was thinking that once it is mounted, it stays "forever".

My question is to avoid putting in the effort only to have "doh moment" a few minutes after a proud completion ;-)

[David aka Blue7]

Fair comment so to explain my reason for making a DE, it was to reduce the amount of fine spray that enters from the rear when driving in wet conditions with half hood erected.  When this topic first emerged under another thread there was a very amusing and valid comment along the lines of  "why would you buy a Caterham if you have an issue with draughts" 

On Aston Roadsters, you can buy a DE which is removable and there is a specific place in the boot to store it.  I have seen them on Porsches, Morgans (sorry Derek), and other soft tops and they are all removable or deployable at the press of a button.

I suppose that if you want a DE in place permanently then a fixed frame is appropriate but I wouldn't want such a device attached to my car permanently for aesthetic reasons and also I don't mind a cooling draught on a hot summer day ... not to mention all the stick I would get from fellow seveners    

So fair enough, if you want it in place permanently, by all means use a frame ... but bear in mind one important disadvantage ... it will increase weight 

 

[Darrenkidney]

Understand there are some minor weight and optical implications... ok for me. 
 

Strange thing with the draught .... I have nothing against buffeting and wind in general - nothing new for me. But for the first time I have a really unpleasant airflow across my nose with the seven... makes breathing hard. 

Let's see how invisible I can make a screen inside the rollbar. 

[David aka Blue7]

Given your above comment and looking back at your original post which indicates that you drive without sidescreens, I can't help wondering if the answer to your problem is better wind deflectors rather than a draught excluder?  There was a good post by Nick Woods circa November 2008, in which he explained the inadequacies of the CC wind deflectors and he supplied details of how to make more effective version,  I can't find his original post but I did save some details including the construction method here.