Does anyone know for certain what the OEM wheel bolt size is?
Lenght =
thread diameter =
thread pitch =
And as a bonus question, what is the lug bolt seat taper.

 

>>Does anyone know for certain what the OEM wheel bolt size is?
>>Lenght =
>>thread diameter =
>>thread pitch =
>>And as a bonus question, what is the lug bolt seat taper.
My stndard BMW kit will covert a Mini. Call me to order. PS lug seat type depends on wheels

Alex

 

>>Does anyone know for certain what the OEM wheel bolt size is?
>>Lenght = 32mm, ( approx. 1.25" )
>>thread diameter = 12mm
>>thread pitch =
>>And as a bonus question, what is the lug bolt seat taper.

So far it looks like 40 some folks including me are interrested in finding out so I guess I'll have to dig deeper and make some phone calls. I'm not about to mess with bolts, studs are the way to go that way I can use ultra light lug nuts.
More as I dig up the information

 

Thanks for the offer Alex but I believe my question was more direct.
I am looking at 190,000.00 PSI, 8.8 grade studs with rolled threads these are the type of details that interest me = safety, ease of use.
Still haven't confirmed the tread pitch or seat taper but I have a pretty good guess.

 

If you are interested a set of four wheel bolts weighs 270 grams or 9.5 ounces. No wheel lock included.
As measured on a mail scale with different multiple sets of four.

 

Roth, you bring up a very good question. I can say from experience that you better get the right info then the right stud/bolts. The lugs I got with my wheel set did not work on my MCS. They look similar but even the slightest difference will give you problems. I opt to stay with what MINI has because it works.


Peter

 

>>If you are interested a set of four wheel bolts weighs 270 grams or 9.5 ounces. No wheel lock included.
>>As measured on a mail scale with different multiple sets of four.
Make sure no locking lugs are used with ultra light lug nuts. The mass diffrence can make things feel out of balance.

Alex

_________________
Alex ext 294

800 522 8473

Tire & Wheel forum moderator

www.tirerack.com

alex@tirerack.com

 

Thanks Alex,
Very good point considering wheels and their performance. My aftermarket wheels came with chrome finished bolts that are 2mm shorter than my stock bolts. Everything else looks the same. The weights are identical for the set of 4.
The install instructions state not to use bolts that are too deep for the rims-holds the rim less tightly. Gotta match the bolt to the particular rim used for best strength. Not too much, not too little.

 

Thanks guys therein lies my quest all has been taken into account.
Think for a moment about driving (motoring) around all those twisties and your tire contact patch through friction is what is holding you on the road right, the more traction or lateral friction the tire imposes on the road the more confident you are about getting around that turn and not off the road. What is happening here is that those forces, weight transfer and velocity of the car plus rotational forces are on the outside wheels. All that force is being transfered from the wheel to the hub and multiplied by the distance from the contact patch to the hub center through lever action wherein lies a most important fastening device the wheel lug.
A somewhat simple little thing that is subjected to incredible stress's both shear and stretch. Now this has to be got right the first time so, the quest continues.......

 

>>A somewhat simple little thing that is subjected to incredible stress's both shear and stretch. Now this has to be got right the first time so, the quest continues.......

You'd only see a shearing force if your wheels were NOT hubcentric. Providing they wheels are a snug fit on your hubs, lugs provide a lateral clamping force. Think of them as a vise pressing the wheel to the hub of the vehcile.

Tirerack's BMW stud conversion kit will allow you to run 2 diffrent lengths. 58mm is standard, and 80 mm is the track length stud, designed for accomodating up to a 10 mm spacer. Each stud is $3.50, each ultralight lug is $3.50 each. Please do not run these lugs with wheel locks, it will change the feel of balance at you steering wheel.

Alex

 

There is more disscussion on this at http://www.MINI2.com but the stock bolts are 12x1.5 and are apx. 2" long, with ; of that being the threaded area. Studs longer than 2" of TOTAL length will stick out beyond the end of the lugnuts and prevent the hub caps on the stock wheels from fitting unless you are using wheel spacers at least as thick as what extends beyond the nut. When I converted mine I could not find any 50 mm or 52mm; studs but after some measurements I found that 1.75" studs offered at least as much thread engagement as the stock bolts, 9 full turns vs. 7.5, so that's what I'm using.

Seat taper is whatever the most common is 60 deg. I think.