The Scrapcento

[RedDevil]

Originally Posted by maczo

That's the option I'm considering the most, but I don't have an idea how to cover the caps once I get them. I'd like it to be light enough not to throw the tires off-balance, but still it has to be durable.

It depends on what they look like. Somewhere on this site I've seen pictures of caps that were cut so that only the ring with the hub clips remained, and a flat plate was mounted onto them. The originals had curved spokes.

Mine form a slightly convex plane with just some big gaps:

I was considering buying some thin Lexan sheet and cut triangles and a small circle from that and glue them in the spoke holes and center, level with the spokes.
I might also just cut big circles and make 8 radial cuts to allow the plate to bend inward towards the edges. Or I might just grind the caps flat and glue an uncut circle onto that.
If only I could find time for that and some 50 other urgent things to do...

[some_other_dave]

Duct tape. Cheap and easy, and holds up well for a while. When it wears out or starts falling off, just put more tape on! Tape the back side if you're worried about appearance. Maybe cut some plastic filler pieces from whatever you have laying around and tape them to the back of the wheel.

-soD

[Piwoslaw]

Originally Posted by maczo

Tire spats. At first I wanted to make them out of other material and have them mounted better. After seeing all the rust on the underside of the car I went with duct tape... should be safer

How stiff are they? Will they start to bend at 80-100 km/h, or whatever you normal max speed is?

[maczo]

Originally Posted by RedDevil

Somewhere on this site I've seen pictures of caps that were cut so that only the ring with the hub clips remained, and a flat plate was mounted onto them.

This is why I mentioned having the balance right. I'd be afraid that such a procedure would result in the weight not being distributed well (evenly).

Originally Posted by some_other_dave

Duct tape. Cheap and easy, and holds up well for a while. When it wears out or starts falling off, just put more tape on! Tape the back side if you're worried about appearance. Maybe cut some plastic filler pieces from whatever you have laying around and tape them to the back of the wheel.

-soD

I guess duct tape is the #1 option right now. I have been looking around for the cheapest / most aero caps but still haven't decided on any.

Originally Posted by Piwoslaw

How stiff are they? Will they start to bend at 80-100 km/h, or whatever you normal max speed is?

To be honest - I don't know. I assume that the mounting (a fair amount of duct tape) will provide quite a bit of flex before the spats start to bend themselves. As for how stiff exactly they are - as stiff as the top part of a Nałęczowianka 1.5l bottle

After mounting the spats I went for a test drive to see if they fall off or deform permanently - they withstood a few seconds at 120 km/h so I guess they will be OK at 80-90.

[AndrzejM]

Do you see any FE improvement with the spats?

[maczo]

Originally Posted by AndrzejM

Do you see any FE improvement with the spats?

I can't tell. Got no instrumentation and even tank-to-tank comparison wouldn't tell a thing, as this tank is being driven in very unfavorable conditions, compared to the previous one.

The best I could probably do is coast-down testing, which I might be able to perform either this week or in a month.

[maczo]

I bought two caps, will see how well the tape holds and if it's ok, I'll buy the other two. I didn't have time to tape them yet, getting ready for a rally this weekend. I'm keeping the caps on front wheels - would having them on rears be better / worse for FE?


Also, once again I improved my best FE (6.25 lhkm, 37.5 MPG) by a very small margin. I had an early fill-up because I'm switching to different tires for the rally and want to isolate the FE on those from regular ones. I have no idea whether the tire spats or the belly pan had any effect, there's too many variables.

And finally, I have been working on a Kammback 2.0 for a few months, but could only devote a few hours monthly. I'm still not sure how I will attach it once it's ready, but I hope I can do it with zip-ties.

[maczo]

Got really good mileage for the whole rally (close to personal best); the retread, undersized tires seem to roll really well and the car seems a bit more dynamic with them on. Since I used PnG all weekend, I think the lower weight of the wheels had more impact (positive) than slightly higher RPMs (negative). City driving was definitely limited on this tank as well. On the other hand I was not at all gentle on the gas pedal. I think another lesson learned here.

[maczo]

Finished the Kamm2.0 today. It's made of cardboard covered with cloth and fiber, glued with wood glue. I wonder how it will hold up to the elements.


Build quality and aesthetics - top notch, as always.


And now the aero package is complete with rear wheel (almost)full covers.

[AndrzejM]

Nice!