Banks Twin Link Rear Suspension

[JR73]

Yes, it was designed to fit on the standard chassis.

[MRN I J]

Does the twin link rear suspension system fit the standard chassis?

From the photos the upper link mounting bracket is attached to the chassis by the new shock mounting cross brace.
wonder how heavy it is, does it need plunging drive shafts

[jbcollier]

As said earlier, the geometry almost exactly matches the original set-up.  This means there is very little movement of the inner yoke on the output shaft as the suspension moves through its range of travel.  I believe a lister on the yahoo/io list measured it as just a few mm in total.  I have over 10k on mine and it is not an issue.

[BDA]

Yes, the Banks twin link rear suspension kit is designed for the standard frame.

[Bainford]

The website states that the stub axles are for the S1 Europa. Can anyone confirm that the original rear stub axles are the same across all series Europas?

TC axles use a larger U joint and 30mm inner bearing so no there are 2 different Europa axles.

Thanks for that info. Bummer about the larger u-joint. I was considering buying a set of these axels and modifying the bearing journal. I'll have to investigate the u-joint yoke and see what it may take to modify that, too.

[Pete]

 

[europa88]

Hi,

New member here.  My name is Neil from Sheffield England. 

Does anybody have any experience with the 'Banks Twin Link Rear Suspension system' which is available from Europa Engineering in England?

I am a retired engineer and instinctively dislike the Chapman fixed length driveshaft arrangement which seems to rely on double roll pins locking the spliced joint between the differential and the driveshafts, thus subjecting the differential and the Hardy Spicer joints to compression and tension forces which they were not really designed to withstand.

Does the Banks system eliminate this and leave the spliced joint to slide slightly with suspension movement as it should.

Any comments welcome, even if they are only to tell me that I have misunderstood the whole thing !

Neil Willatt

Hi Neil
Bit late to the party and my first post on this forum. I have a  Banks twin link on my TC Special fitted to original chassis and rear disc conversion...Its a game changer! One of the issues with the Chapman designed shimmed driveshaft arrangement is that some twisting torque is transmitted to the transaxle and bell housing. On 70's narrow radial tires (and crossplys) there is no issue. However when one puts sticky modern rubber on these cars the lateral forces appear just too much... for shall we say spirited driving. I broke the bell housing on my 5 speed on average twice a year before I decided to go a better route with the Banks Twin link. The other alternative is a Banks chassis with pick ups for rear A frames. My friend at Oselli engineering would weld up the bell housing and return it to me saying see you in a few months Neil! Its been on the car for nearly 20 years now and survived track days etc

Thoroughly recommend it

BTW seems a lot of Europa owners called Neil! My mate in Taunton UK is called Neil and has owned his TC since the late 1970's as have I

[europa88]

 

Forgot to say I also have CV joints as inners and UJ's for the outers.

[BDA]

  europa88!!

It sounds like you have an interesting car. Care to post some pictures of it?

[kram350kram]

Not knowing alot about the Europa rear suspension/driveshaft design and function and then looking at a stock C4 Corvette rear suspension/driveline, other than coil springs on the Europa and a leaf spring on the Corvette, both have radius rods and fixed length driveshafts with u-joints. The Corvette also has a third radius arm for setting rear toe. Comments? 

[BDA]

I'm not sure what you're looking for but I can give you my thoughts about the twin link rear suspension vs stock Europa rear suspension.

Chunky's motto was simplify and add lightness. Since the half shaft CAN be an upper link, he used it. It saved him from having to make a more complicated rear suspension that also would have cost more and be heavier.

Would a twin link suspension be better? Sure. Loads from the half shaft would not have to be absorbed by the tranny and the u-joints, and it allows you to use CV joints rather than u-joints. You would also be able to roll the car around without the half shafts installed. Is Chunky's original idea good enough? Yes, IMHO, it's not as good as a twin link rear suspension but it certainly works and works very well. Nobody ever complained about the handling of a stock Europa!

The stock suspension requires that you properly shim the inner u-joint yoke to the tranny, watch the u-joints  a bit more carefully, and probably a few other things whereas the twin link doesn't require any shims at all and you have half the u-joints which are loaded less so they require less maintenance.

[europa88]

europa88!!

It sounds like you have an interesting car. Care to post some pictures of it?

Yes I've owned it since 1979 when It was my dream car! I was 22 then and am now approaching 64. The car and myself are a lot different now!

[BDA]

Nice car, europa88! I'm hoping you'll get inspired and post more pictures and tell us how your car is different since you bought it.

[kram350kram]

BDA, thanks for the response.

Reason I was interested in comments, my current build is using a Porsche 5 speed and I am using the stock design of the Europa suspension and half-shafts with both inner and outer u-joints.  Nealwillatt's initial post discussing the Europa design and its shortcomings reflects the same concerns I had/have on my build with the Porsche transaxle. The Porsche trans-axle output hubs are only retained by internal c-clips like most front wheel drive axle-shafts. A good prybar can pop them easily out of the case. The Europa's driveshafts are retained on the hubs by roll pins. I would think both the C-clip and roll pin design can't really take much fore and aft movement of the driveshafts before the either the c-clips release or the roll pins shear, (regardless of accurate axle shimming of the roll pins). Apparently the stock roll pins don't shear if the shafts are shimmed correctly, at least that is what I have read.  There must not be a great load on these pins due to the overall geometry of the rear suspension.

Question is will the Porsche hubs (with their c- clip design) remain in the case or get dislodged during suspension movement? Any comments appreciated.   

[BDA]

I don't know anything about the Porsche tranny but from your description, it sounds like it is not designed to take axial loads so you will need a twin link suspension and CV joints. One option is to use VW CV joints, half shafts, and stub axles. A member of this forum, Jmarkusic, is working on that conversion for his car. Hopefully, he's going to post a tech article about it. Since weak stub axles are a concern to some, this is a promising solution to that problem. The VW parts are very robust.

There are two designs of twin link rear suspensions I'm aware of. One by Richard Mann in Australia. A friend of mine built it on his car but unfortunately, his car is not finished so I don't know how successful he was but I believe several people have used it with apparent success. As far as I know, his design is only for the suspension and does not address the drive train. Richard is a member of this forum, his handle is Lotus 47. I expect he would be glad to share his design with you. The other design is a kit made by Richard Winter at Banks. The parts business is now called Lotus Supplies (https://www.lotus-supplies.com). It utilizes a new rear cross member, CV joints at the tranny and u-joints at the upright. It expects you to use the stock uprights and stub axle. You are responsible for fabricating the half shafts from parts of the kit (when I bought his kit, that's what I had to do but that was over twenty years ago so that may be changed). If you were to use the VW parts I suggest, I would think that Richard Mann's design might be more appropriate - especially if your car has more torque and horsepower as I would expect given the Porsche tranny.

If you are interested in the VW and Richard Mann route, you can try PMing Lotus 47 and Jmarkusic (it is possible that he is using Richard Mann's design or even a third design so it would be worth asking him about it) for details. If PMing Lotus 47 doesn't work, his last known email address is rmann5 at ford dot com.

Good luck and keep us in the loop!