Wide lip wheels

My 70t's fuchs wheels have a much wider lip then the fuchs rims on my 73t. They appear to be the same width but have a different look to them. I heard that the wide lip rims are rarer and somehow better. Is this so and what 911 did the wide lippers come off of? Alex

Both rim sizes should be 6'' wide and usually 15'' diameter.
The wide rims are the "old style" rims, I believe used up to '71 or '72.
They look better (more than 7''), esp. polished, and are much more rare.
The drawback is, that they only have one "humb", and, as a consequence, need to be fitted with an inner tube.

From, I think, '73 on, due to increased performance and tyre capacity, Porsche changed to the "double humb" rims, used e.g. on all SC's as stock on the front wheels. These do not need any longer the inner tube.

I don't like the appearing of these later rims, as they look a bit 'poor'. On the other hand, they are more safe, there are no problems with tube setting etc.

My personal solution, once my bank account is in better shape, is to sell the old style 6x15 and go for 7x15, which are also "double humb" rims.
This makes a large difference in wheel balancing if you regularly go beyond 100 mph.
But for the time being, I am happy with my partially polished "odl style 6''".

Hope this helps.

Jens
'76 CIS with '73 body conversion

Is this to say that I am in danger due to not having inner tubes? The place that mounted the tires seemed to think the rims were ok without tubes but nobody thought to check. I have Yoko AVS's on it and so far they have given no problems on those rims but... Let me know further pearls of wisdom. Alex

I just had my early "deep" 15x6 fuchs restored by Wheel Enhancement and they mounted my Yokohama A008's on them while I watched...no tubes...I figure they know what they're doing and I have had zero problems thus far. They are technically tube-type wheels; however, it may also make a difference if you have tube-type tires or not. Virtually all road car tires sold today are tubeless construction.

[This message has been edited by campbellcj (edited 10-13-2000).]

Yes and No.

All tyres sold today are tubeless.
The tyres will match on the rims, and if they are not worn or cracked, will keep the pressure good enough.
Problems can occur by hard cornering though. As the "double humb" is missing, the tyre more easily bends over the rim edge. And without tube, you are loosing air immediately (like an exploding tyre), certainly making it mere impossible to keep the car on the road (as this will only happen by cornering).
The danger is minor if you fitted the original tyre size 185/70/15. But as they are hard to get these days and are awfully expensive, people usually fit 195/65/15 (like I do).
Better tyre grip is increasing the danger.

Does this make sense?

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Jens: enlighten us yanks--what is a "humb"?

Charlie '87 Carrera (In California)

I did post a question a while back on my Fuchs wheels with the same " different " rim setup. My car ( 1970 T ) has no tubes and while I don't drive 110% on the edge, I have had no problem ever with pressure losses. All the shops were I popped the question told me no one used tubes anymore....but then with a 30 years old car and most mechanics getting younger maybe they just don't know anybetter ( tube, what's a tube, dude ? ).
Anyhow, going hard in a turn, squeaking the tires, it's then not to exiting to ask yourself this type of question !!!
Could an "expert" outthere settle the tube issue ?
Thanks in advance.
Thierry

Charlie,

I have no idea, how to explain/translate "humb". It is a sort of chamfer inside the rim. I will try to find a picture to explain.

Thierry,

I agree with you. I have studied that topic, as I was confronted with the German authorities trying to re-register my car. As a consequence, in my papers it's clearly said that I have to use "H2" ("double humb") rims by going to larger tyre sizes (but don't tell anyone).
While consulting several tyre specialists, they ALL confirmed that and requested to use tubes as a factor of safety, although there is only a hand full of them who wanted to order and fit them onto my rims.

So may be, it's not that significant. But me, personally, do not want to experiment with safety on tyres as I sometimes rev my car to have fun...

Jens

Despite what I said earlier about not having problems with my 15x6 Fuchs w/o tubes, I am going to reinstall my (later, tubeless) 16x6 Fuchs ASAP because the extreme sidewall flex and squirm of the 185/70's feels really "sketchy" when I'm pushing the car. I have not had any pressure loss problems, but the rollover is unnerving after running 40-60 series tires for so many years. Plus, the 185/70 rubber is very hard to find these days, so I figure I'll store this set away and run the 16's with the 205/55's -- much better handling and plentiful tire choices.

[This message has been edited by campbellcj (edited 10-16-2000).]

OK Guys,

I now have some sketches explaining the "hump" (with a "p") and its purpose.
What I am missing is a website to place them.
So if anyone is interested, I can e-mail them.
Anyone to put them on a website to create a link?

Jens

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