Wheel bolts, head profiles, worth a discussion?

Factory Mk1's use a bolt with a rounded R3 (whatever that means..) head
Most aftermarket seem to be 60 degree taper (ease of manufacture?)
Rounded head must give a smaller contact patch when torqueed up
Taper must spread the load better, assuming the wheel taper matches the nut taper.....
Been playing with some engineers blue (ooh arh missus) to see how well the 60 degree seats
on some aftermarket alloys that are currently fitted.
Third option is a floating 60 degree captive washer built onto the wheel bolt, so will likely self centre
better.
I have use all three options over the years, think the VW R3 radiused bolt is best.
About to buy some longer ones, to give me a better insertion depth for my Ibiza rally car, out next weekend.
Can't find any discussions on the pros and cons of each on here
Anybody care to share their knowledge and experience
Not a very exciting subject, but always open to learn new stuff
Also, on sticky tarmac tyres the forces involved are large.. even in October..
Jon

 

Rounded head should have a matching rounded seat surely?

 

Not sure that's correct, I see your logic, but did VW ever have rounded seats?
Jon

 

The steels did, I'm sure, and the likes of BBS RA too.

 

Steels, logical as they are a pressing. RA's, good to know. So maybe VW made an R3 type initially for the steelies/RA's
with a larger contact patch. Did all VW alloys have this, I can't remember seeing it.
Aftermarket stuff is a taper
Jon

 

It always (in my experience) was on bl/rover stuff that steels were the round shoulder, then on alloys it was a captive (usually) conical washer, or a sleeve type nut again with a washer. Revolution wheels used to be like that.
I'm sure I have a set if vag bolts with washers on the polo with alloys, and even lockers too.
Most aftermarket stuff is conical shoulder, my new tow were as were the alloys for the bmw bought new. someone used round on the borbets and made quite a mess.

 

Lengths no issue, just ordered some to suit the spacers the car has to run to clear the big calipers. Interested in more comments please
Jon

 

There is an R14 curved fitting too.......

 

The 14" BBS RA Alloy wheels are as you say RJ taper fit and they are considerably longer (I have a set on my mk2) also my old mk2 Scirocco had speedline VW dealer option wheels radius type bolt seat.

 

Being a rally, off road guy, the rims are whatever I can get my hands on. Typically 10 sets are in my shed at any one time. Tyres are >>>> than the cost
of the rims, so I use whatever is around, cheaply.
No such luxury as being a compomotive man.. Ot whatever..
Most seem to be 60 degree, hence me using some engineers blue on a taper nut
Jon

 

Not all VW ones have a ball shape. I have an OE set from my south african Golf CITI and these are 60 degree taper.
Interesting these were fitted with SA only pattern steelies, which are still collecting dust in my shed.
Maybe VW sourced locally in SA?
Car long gone now
Jon

 

All MK1 and mk2 std are all ball type seat type as std in my experience, aftermarket vary. Use BMW wheels on the Hillclimb MK1 and they are taper seat, and I believe all BMW are taper......im talking older models here as I have limited knowledge of anything made after 1990 lol.

I've used ball seat nuts on taper no problem, but as I recall if you use taper nuts in a ball seat it can squeeze the 'point' of the seat up and locks the nut on the stud, then the whole stud and nut comes out. You have to grind the end of the nut off to get them to work properly again.

I don't use bolts just long studs and nuts, always fit long studs as that allows you all sorts of options with spacers and wheel combinations. On the front I try and make sure the center sits on the hub shoulder or use hub centric spacers to get the off set right, like when using Vauxhall or Renault wheels. On the back don't worry too much about bore sizes or offsets.

Surprisingly Demon Tweeks are not badly priced on studs and nuts and you know you will get them next day generally.

 

Agree with everything TonyB has said on this, any more opinions?
Jon

 

I would say the bore size should match as that takes part of the shear forces as designed by the manufacturer, otherwise you are putting this force on the wheel bolts alone. Also offset wise the increased load on the wheel bearing, only my opinion but might be worth considering.

 

For those with a lathe and spare odd pistons collecting dust, you can make 'custom' spigot rings for free
using the ali tops of the piston. LOL
Jon

 

Years ago I would have agreed with Valvemiester, and if possible I always would, especially on the fronts.....but over the years needs must and I've run wheels and spacers (although I limit then to 15mm these days) without the centre bores engages on race cars with slicks etc. and never had an issue, so don't worry that much these days.

Good call on the pistons Jon, although I tend to but the plastic ones off eBay these days they do the job, and as above I'm not convinced they do that much, the studs seem top do the work.

Good trick I used to use was to use MG 15" Tomcat wheels, far cheaper than VW wheels. You need a 10mm spacer to correct the offset and machine the centre bore out a few mm (can be done with a sanding drum as its not much) but work ok 20>40 quid a set a few years ago, although I think they have become more expensive now.