[PICS] How close can the rim be to the caliper?
09-21-2014, 09:21 AM
#27
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I doubt you'd ever see that much flex even with aftermarket wheels, if it flexes enough to contact with the clearance you have then your wheel bearing would be shot, only way that could ever make contact. many recommendations for minimum clearance are because most calipers are a floating mount design, a new set of pads will bring the caliper closer again to the wheel, but yours are fix mounted so the clearance you have will never change.
personally I think it's a really bad idea to use a small spacer and eliminating the hub centric mounting... I think that will cause more problems than leaving them as-is... the wheel bolts are spec'd to and rely on hub centric mounting. spacing them just beyond the hub will cause excess stress to the wheel mounting bolts. torque will need to be increased for bolt centric mounting, torque required can be substantially more than with hub centric and wheel bolts are really not intended to be bolt centric. all bolt centric wheel mounting will use larger diameter studs, not M12 bolts... you will probably have to torque them beyond the safe limits of the bolt to secure them properly or you'll get movement that again will increase the stress on the bolts, either scenario is not ideal...
bottom line is I think it would be much safer as-is VS using small non hub centric spacers... you def have enough clearance there with a fixed mount caliper
personally I think it's a really bad idea to use a small spacer and eliminating the hub centric mounting... I think that will cause more problems than leaving them as-is... the wheel bolts are spec'd to and rely on hub centric mounting. spacing them just beyond the hub will cause excess stress to the wheel mounting bolts. torque will need to be increased for bolt centric mounting, torque required can be substantially more than with hub centric and wheel bolts are really not intended to be bolt centric. all bolt centric wheel mounting will use larger diameter studs, not M12 bolts... you will probably have to torque them beyond the safe limits of the bolt to secure them properly or you'll get movement that again will increase the stress on the bolts, either scenario is not ideal...
bottom line is I think it would be much safer as-is VS using small non hub centric spacers... you def have enough clearance there with a fixed mount caliper
Whats is your reccomendation on this:
The hub that the wheel sits on, on our cars is 8mm (according to another member). I hacnt measured it, but i will tomorrow.
Lets call it 8mm for the purpose of what im about to write.
I wanted to get 5mm spacers.
The spacers are 66.6 in the centre. They are 5x112. 5mm thick. Not hub centric, BUT they will fit on the hub with 3mm to spare, to take the load of the rim. So kinda "existing hub centric" if that makes sense.
What are your thoughts on that setup.
Obviously, i would get bolts that are 5mm longer to compensate.
09-21-2014, 11:49 AM
#28
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I wouldnt recommend 5mm spacers w/ 3mm hub... it will put too much stress on your bolts. 3mm spacers is the max I would go.
09-21-2014, 12:45 PM
#29
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having just 3 mm left is not enough. the first few mm's of the rims bore is tapered so it will leave virtually no support. unless your a fan of random self ejecting wheels I wouldn't use 5mm spacers at all here.
the only way to space these wheels 5 mm safely would be to have the center bore of the wheels opened up and then have custom spacers made. IE: bore the wheels to say 73 mm, then have a custom spacer made with a 66.6 mm inner bore and an 8mm protrusion that's 73 mm OD. that would positively locate the wheel hub centric and solve all mounting problems correctly and safely. it won't be cheap or easy but that's the only way I know of to properly add 5 mm backspacing to these wheels. when I do this I usually make the spacer a tight fit to the wheel itself so the spacer in effect winds up just being fixed to the wheel, for all intents and purposes it becomes part of the wheel assy and this is now equal to a wheel with the correct backspacing and has none of the drawbacks of conventional wheel spacers as long as you use longer bolts to match the extended depth.
again, they are perfectly fine as-is as far as the brake spacing is concerned
the only way to space these wheels 5 mm safely would be to have the center bore of the wheels opened up and then have custom spacers made. IE: bore the wheels to say 73 mm, then have a custom spacer made with a 66.6 mm inner bore and an 8mm protrusion that's 73 mm OD. that would positively locate the wheel hub centric and solve all mounting problems correctly and safely. it won't be cheap or easy but that's the only way I know of to properly add 5 mm backspacing to these wheels. when I do this I usually make the spacer a tight fit to the wheel itself so the spacer in effect winds up just being fixed to the wheel, for all intents and purposes it becomes part of the wheel assy and this is now equal to a wheel with the correct backspacing and has none of the drawbacks of conventional wheel spacers as long as you use longer bolts to match the extended depth.
again, they are perfectly fine as-is as far as the brake spacing is concerned
09-21-2014, 05:51 PM
#30
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I ran 5mm spacers on the front and with my wheels I could not get them to center on the hub so Roswell and turbocad6 are correct as far as centering a wheel on the hub with 5mm spacers. Some wheels may center but 3 mm is not enough of a margin.
To overcome this problem I had hub extensions made and they seem to be working fine. They fit inside the hub and the part that extends is the same diameter as the hub. I tried to do some ASCCii art but the software keeps reformatting it so that it makes no sense.
A local machine shop made them up for me for $55 ea + tax =$124.30.
To overcome this problem I had hub extensions made and they seem to be working fine. They fit inside the hub and the part that extends is the same diameter as the hub. I tried to do some ASCCii art but the software keeps reformatting it so that it makes no sense.
A local machine shop made them up for me for $55 ea + tax =$124.30.
Last edited by Mort; 09-21-2014 at 05:59 PM.
09-21-2014, 11:16 PM
#31
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Hmm, okay.
Got it. What everyone is saying makes complete sense.
Thanks for that.
I will explore my options.
There is a really good machinist shop here, so i will have a chat to them. They can make many things custom.
Thanks again for everyones advice.
Got it. What everyone is saying makes complete sense.
Thanks for that.
I will explore my options.
There is a really good machinist shop here, so i will have a chat to them. They can make many things custom.
Thanks again for everyones advice.
09-22-2014, 04:18 AM
#32
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C63 Coupe 507 Ed
09-22-2014, 03:51 PM
#33
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I believe that a wheel will completely fail and crack before it flexes that much. That is another issue, but these wheels likely aren't going to fail like that. They aren't rotas or xxrs..
I'm not being an *** here, but if you think you can hear a wheel groan turning your steering wheel then you either should see somebody or work for the gov't because that is crazy
1mm is enough.
OP --- throw the spacer on for that peace of mind. But also do not be so concerned if you end up without a spacer or the spacer isn't hubcentric so you get an unbalanced feeling and end up taking the spacer off. Properly torqued onto the hub, those wheels aren't moving.
09-22-2014, 11:21 PM
#34
Super Member
I'd wait to hear his response. As most people have mentioned here, they have had or experience wheels as close or even closer to the caliper without any issues. You aren't hearing your wheels groan and flex, your hearing rubber on the ground or suspension bits moving.
I'm not being an *** here, but if you think you can hear a wheel groan turning your steering wheel then you either should see somebody or work for the gov't because that is crazy
I'm not being an *** here, but if you think you can hear a wheel groan turning your steering wheel then you either should see somebody or work for the gov't because that is crazy
And, for the record, I have seen someone and it sure didn't help...
that's what my ride is for 
09-22-2014, 11:31 PM
#35
MBWorld Fanatic!
Anyway, regardless you aren't hearing a wheel flex. Could be the tires rubbing on the ground or even though the car is new it can still be suspension bits. Perfectly normal and nothing to worry about.
Likely the tires rubbing on the ground.
09-22-2014, 11:36 PM
#36
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I am thinking, for piece of mind, i will do a 3mm spacer.
That way, there is still 5mm of hub for the wheel to centre on.
This has become a good thread actually. Thanks for everyones input.
I have driven now about 500km (310miles) in total on these rims, and i havnt had a problem.
Driven up to 120km/h (75 miles) and no drama. Also cornering at speed, and no drama. no paint scraped off the caliper. Rims def not hitting.
That way, there is still 5mm of hub for the wheel to centre on.
This has become a good thread actually. Thanks for everyones input.
I have driven now about 500km (310miles) in total on these rims, and i havnt had a problem.
Driven up to 120km/h (75 miles) and no drama. Also cornering at speed, and no drama. no paint scraped off the caliper. Rims def not hitting.
09-22-2014, 11:39 PM
#37
MBWorld Fanatic!
^If you had an issue it would come in the first rotation of the wheel. Really the first 5th rotation based on the spokes...
Anyway, completely understand your wanting peace of mind.
Looks great btw.
Anyway, completely understand your wanting peace of mind.
Looks great btw.
09-23-2014, 07:35 AM
#39
Super Member
I had no idea what "hub-centric" vs. "lug-centric" spacers/wheels were - found this if anyone cares:
http://tires.about.com/od/understand...ric-wheels.htm
http://tires.about.com/od/understand...ric-wheels.htm
