Marek

I've yet to see, or see mention of, any Rotus schematics or loom diagrams. I do wonder if Dennis Hedges has any such information. I've been meaning to meet up with him, but times have been busy when I've been in the area.

Off to the skate park for some exercise.

I do like the Low Light Look. You've struck a nice balance. I'd argue mine are too low.

I can't say enough about how well designed, well made, and useful these lights are in the shop. https://www.streamlight.com/products/detail/stinger-switchblade

Having never driven a De Dion Caterham; but having extensively enjoying De Dion Alfas, this does not seem a limitation of the De Dion as a design, but rather in setup. The transaxle Alfas (Alfetta, GTV6, Milano/75) work best when run soft. Even on the track. Stiff or metal bushings and pivots are fine. But don't push the spring rates or over damp the rear of the car. As I am currently wrestling with an over-sprung Seven, I can understand the source of Farrah's comments. But I suspect what he is describing is less a 'disconnected' feel and more likely an unfamiliarity with driving from so close to the rear axle. It changes how the front communicates and I find that until a driver dials into that communication it can be harder for them to be precise in describing the front mechanical grip. @slowdude is on to something regarding modern and non-modern cars. Modern car all live in a narrow range of (safe, predictable, comfortable) behaviors. Cars from the 80s and before have a wider range of handling behaviors and driver feedback. I've found drivers without older car experience often struggle to be as comfortable driving or precise in describing car behaviors outside their experience.

@Chris D Spares from my long gone Europa TC. Let me know what you need. You might have my email/number, or Dan G. can give it to you.

Many online car communities have similar origin stories. For a time I was a member of Team.net, an online community of autocrossers which included a large contingent in the Rochester, NY area where I lived at the time. Their logo was clever. But my favorite was the back side of their t-shirt.

For those of us in Boston, NYC is the one place we can rely upon to make us feel better about our traffic and congestion. Not that Boston is actually better - it just covers a smaller area. We also don't have nearly the options for white glove parking. (Though I do know a group looking into putting a facility together. Let me know if you are interested.)

My Rotus is also 4 turns lock-to-lock. Given a choice, I would make it a bit faster. But I've not found it to be a particular distraction - especially give the ease at which the right foot contributes to rotating the car. But a 295mm wheel is a thought.

Nothing has struck me yet on the new wheel front. I did run across a local set of 8.5x15 wheels matching the current style. That would let me run 8.5 in the rear and move my 8" to the front. The left field option is to riff off the 80s Japanese connection of the car and pick up a set of Hoshino, Advan, or similar period wheels. The are unlikely to be light, but the look would be something!

What is the size of the wheel on your car? Mine is 320mm and the largest I would want. One size down would be nice and not add much steering effort.

Correct 7 on the front, 8 on the rear. For matching tire and wheel widths, I have been working from this chart: https://www.tiresandco.ca/tire-equivalence-advice.html The logical next step. And this doesn't have to be once and done. If a 205 turns out to have shortcomings, I'll go hunting a set of 8" for the fronts. After all, if I am satisfied with the rubber on the car that leaves one less thing to tinker with. Here is one of the few areas where this forum is tough for a Rotus (maybe non-Caterham?) - parts interchange. With the 80s Toyota running gear my bolt spacing is 4x114.5 (4.5"), meaning all the wonderful wheels discussed and for sale are of no use. Searching for wheels on AE86 and other JDM forums is an entirely different experience. Detailed specifics and concern for lightness are not regular themes. The answer is probably yes. Minimum pressures deserve more research and I will do some testing with alignment marks on the tire and rim to detect any sign of movement of the tire on the rim. Even with a narrower tire/squarer sidewall, I will want to experiment with low pressures. I am waiting for someone to leap in here and say, HEY, WAIT, XYZ tire has a soft compound on a soft sidewall... This deserves to be used as a tag line somewhere!

Time for an update. A bit of rain and a dry Saturday in the 50s made for a nice early February tire test. Changing nothing but pressures, I dropped my Toyo R888s from 32/34 to 18/24 cold for the first run. The improvement was immediately apparent and significant. Tramlining was less frequent and less sharp. Just the dulling of the effect was enough to make the car easier and more relaxing to drive; though the ability to set a line was only slightly improved. After getting some heat in the tires, at which point the fronts had risen to 20.5, I lowered them to 15 for the second run. Another step improvement with more of the same. Steering still required vigilance and (less) frequent corrections. For the third run I dropped the front to 12. This was the dramatic step. Tramlining as a persistent effect was gone. There was still the occasional pull which could be attributed to the toe setting. But for the first time, the front of the car would take a set and follow a line. Finally you could point it rather than guide it with constant corrections. The car was finally relaxing to drive. One of the charms of a Seven is how they pull you out of comfort zones. Let this experience be one of mine. Despite experience running race tires at low pressures, I saw this as a street car and was stuck in tuning it as such. Lesson learned. So what is next? @Croc asked about goals. I want a car with predictable enough handling that I am confident inviting others to drive it. I also want to run the same compound/construction on both axles. The car seems to want the 235s in the rear and they fit well. Given the difficulty putting power down, I am hesitant to go narrower. I might be able to fit a 245. In the front, a 205 has to be tried. It will answer so many questions and is one logical next step in the tire test program (another being to try the 225s on a 7.5" wheel - some research on options still needed there). Looking at Croc's tire catalog, the obvious option based on size availability is the Toyo R888R or Avon (providing there is availability). A LL rated tire, even in a harder compound, would be a fantastic experiment. But my research on that path is not finding good data or recommendations. LL rated tires seem to be very uncommon and not made in 225 and wider section tires. I still want to check rake and I might try the car again at 10 and with a hair more toe-in. But now we know the real goal is to get rid of the sidewall stiffness and reduce the tire's spring rate. Thanks to the group for the questions and encouragement; including someone who sent me helpful food for thought on checking whether scrub radius was playing a role (the answer is maybe as an aggravating factor, but not a primary cause).

Thanks for extracting the thread, @JohnCh.

I am slightly dismayed by those lovely Thiel speakers oddly placed by the garage post.

The disassembly-on-arrival practice is typical across professional motorsports. Why take chances. There was a certain popular British 90s FF constructor of whom was said they only assembled the cars for ease of shipment and not actual use.

To close the loop.... Yes, ⅛" toe-IN. Caster is 3 degree positive; which is the factory setting. The dampers would likely benefit from a rebuild. That won't cure the problem, but there is an outside chance it is magnifying it. Looking at tire options, I am not finding a 215-15 in a suitable tire. So staying with a 225 front and going to a soft sidewall might be the best option as a 205 seems a too drastic change. But I am not finding options for 235 for the rear aside from the R888R. Avons appear unobtainable. A wider front wheel means a new set of wheels as the XXR 557 is no longer in production. And that makes this a bigger problem.

I hadn't considered rake - my math says you are recommending ¼ - ⅓ degree of rake (I am accounting here for the slight differences in our wheelbases). I don't have the caster numbers handy - but I will check those a well. Which leaves us with tire fitment/construction/pressures. From your comments, I am clearly running much too much pressure across the board; so your experiment is the right place to start. 12 psi is generally beadlock territory; but agreed it shouldn't be a problem for straight-line testing. Wider front wheels or a 215 on the current wheels looks like where this is headed - preferably with a switch to Avons or maybe a similar LL rated tire. Perhaps we'll have a break in temperatures in the next few weeks and I can report back the results.

<eyes averted> I see I missed a detail. Rubber on the car is 225/50-15, 235/50-15. A 225 is the limit for a 7" wheel - so some curve across the contact patch is a possibility as you suggest. Camber as delivered was 1 ⅓ degree. Now decreased to ⅓ degree. Toe was 1/16". Now increased to ⅛". The new settings are tame and non-controversial; so unlikely to be a major factor. The current R888Rs are the only rubber I've had on the car (and they are old), so fresh tires will go on this spring. R888Rs are a known quantity and seem very unlikely to be part of the problem. Which brings the question back to tire width. I've been thinking 205 or 215 and your comment on curvature reinforces my suspicion the 225s on a 7" are the root cause. As for tire construction, I am curious if you have any insights into how sensitive these cars are to the squareness of the tire shoulder. Though the R888R is not unusually square - so unlikely to be a factor here. Thanks for sharing some wisdom! </eyes averted>

Do you have any experience with Sevens tramlining after moving 13" -> 15", or wider tires, or modern compounds? My Seven left the factory with 13" Panasports, but came to me with modern 14.5lb 15x7/15x8s with 888Rs. Visually they do suit the car and drop a decade or two from its looks. But, as delivered, I've never see a car more desperate to explore the full possibilities of every single road imperfection! We've since shared some quality time on the setup pad and the problem has dropped from diabolical to just distracting. My next step is to reduce the front tire width. What would you anticipate on a 255whp Seven?

I was only half joking in calling my 1-series a winter beater. It hasn't seen many miles this year as my daily has been my 944S; in all its glorious 80s lines and 16v song. This is my second 944 and has been with me since 2011. The miles are high and in 2020 we gave it a father-son pandemic refresh. Very analog, very simple, yet still feels modern in a way few 80s cars do. Light, but not fast, by modern standards. It moves well and encourages you to carry momentum. Modern cars, with all their power, feel heavy in comparison and encourage you to point and squirt. The hatch is cavernous - swallowing a pair of road bikes by only taking off the front wheels. My previous 944 was once tagged my German Pickup for its ability to swallow anything. Another feature lost on modern cars. I'd have sold this car years ago to make room for the next experience. But it is too practical - at least that is my excuse. Since the refresh I share it with my son who has taken to commuting with it to his job as a Mercedes and classic car mechanic.

Patience is required. I wanted an M-Sport manual in a non-neutral color, non-black interior, and no nav/iDrive. After searching for 6 months I compromised on a 46k mile M-sport manual from South Carolina with dark grey/two-tone light interior with nav/iDrive. The iDrive was an unexpectedly pleasant surprise. Having spent time in other E82s, the extra complexity is worth the trade-off to have nicer controls. The M-sport suspension and interior/exterior trim was also worth the wait. This is the only car I have owned which I have not put a suspension on. Also in the network is a stunning 48k mile blue/red without iDrive (3 month search, a lucky pandemic-timing find on FB Marketplace), a high mileage Sedona Red from Georgia (5 month search) which needed paintwork, and a silver with higher mileage. Start looking now. I am skeptical we'll see a similar package of a car any time soon for the same reason we aren't likely to see any analog cars anytime soon - all the trends are towards complexity. These are simple cars by modern standards.

The N52 is a high point in BMW engine history. My favorite application is the E82 128i - a classic big-engine/small-body car. My winter beater is a 128i M-Sport manual. I have a network of friends with the same spec cars. Besides my Seven, it is the only other car I have with a network of owners.

Thats it! Welcome to the forum.

New Years Eve arrived with nice weather and clean roads - so why not a little afternoon blat? After returning and tucking the Seven back in the garage, my wife asks if I got her text to stop at the store.... But instead of jumping back in the Seven I take my Porsche 944S. Mistake. As I enter Sudbury, MA from Rt 20 eastbound I pass a lovely blue Caterham with bundled up passenger and driver clearly having more fun than I. This will be my story of how I just missed spotting a Seven in the wild while driving a Seven. Don't let it happen to you! (If the Caterham was yours, I was in the the red 944 you passed just before the intersection with Horse Pond Road.)