scooby_si

Just wondered as i'm now running a 5mm spacer which is possible a shade more than is needed for da wheels (radius R2's) 2 fit over me freshly fitted 4pots so i just wondered if other than taking care when putting nuts on there woz any implications of using spacers?
Si

stockcar

if you're running std wheel studs you can get into a situation where you do not have enough thread holding the wheel on causing stud failure in the long term (gpN studs / nuts will solve this problem or correct offset wheels)
you can also put extra strain on things like wheel bearings but this is less common.
what disc/caliper do you have & wheel size??

scooby_si

I've just fitted subaru 4pots discs etc & the wheels i have are Radius R2's which ment the lettering on the back of the spokes would just catch the calliper so a spacer woz required & chap doing em had sum 5mm uns already which he said woz biggest u can get for standard nuts although i kud get away with a smaller un he reckoned they cost £50 a set so all good i trust
Si

scooby_si

NB those r 7x17's but as i say it's the lettering on the back which catches
Si

RON

£50 sounds like a lot for four 5mm spacers, I paid about 4 quid each for 3mm ones.

scooby_si

i aint paid £50 the 5mm uns were thrown in 4 free with da 4pots but he reckoned this place wood charge around £50 if i wanted a 3mm or wotever sized un so r spacers all the same as the 5mm uns were quite well engineered it wood seem & screwed on2 da hub or wotever u call it we yer 3mm jobbies the same?
Si

Markus

As said, spacers will mean less bolt for nut to hold onto, so longer studs (where would I get group N studs from?) would be a good idea. I run 15mm yes, I did say 15mm, spacers on the fronts of my car, mainly due to fapping huge calipers (as anyone who's seen them can testify) I could have go away with it if I had changed the wheels to one with different offset, but I had just purchased the wheels (MY01 wheels) and did not want to spend more cash changing the wheels.

I did umm and Ah about this before getting the spacers fitted, but I've had em on since feb and not had problems (touch wood) yet.

stockcar

give me a ring / mail re; gpN studs & nuts (or most other things if you wish!!)
alyn - as performance 0191-4103770

Hoppy

Anyone running spacers and/or longer studs needs to rethink their priorities. Why do people persist in pi55ing about with wrong-size components when there are plenty of excellent products around that fit without any hassle or safety issues? Beats me.

Richard.

PS Markus, I ain't pointing a finger and I know the agony you've been through. Hope it works out long-term, mate. And I know you know what you're doing

Dave T-S

My thoughts on spacers are well known too (and also not having a pop at Marcus)

And as for running the wheelnuts with 5mm less thread inside them, you really do put a very low value on your life

Dave T-S

Oh, and while I have my critical head on, Si, is there any chance you could use the Queen's English on here instead of that annoying text message type spelling?

scooby_si

50z ! 5h4|| 5t0p r!t3 /\/0w
lol
So how easy is it to fit longer nuts or whatever then? Surely as long as there is still ample thread on nut & it's tight against the wheel there is no risk of er what the wheel flying off cause nuts sheer or something init????
Si

scooby_si

So what's wrong me priorities being to stop quickly c/o bigger breaks surely that is a cunning plan on the safety front?!?!?
Si

scooby_si

BTW Hoppy where in midlands are you just noticed yer midlands location fancy coming to Next Cov area meet
Si

Hoppy

Si, I've just read that link. You're all mad! Sounds like a hoot, but I'm actually a long way from you lot and I wouldn't want to get my car dented by flying wheels but cheers for the thought.

Best regards,

Richard.

PS Dave, don't click on that link - you wouldn't approve

Dave T-S

Si
You need longer studs, not nuts.

It's all an engineering stresses issue. A stud is designed to take X stress along the whole of the thread that is inside the nut (about 18mm on a Subaru). If you have a 5mm shorter stud you are reducing the contact area of the thread from 18mm to 13mm, a substantial decrease.

There are many factors governing threads - thread pitch, tip and root radius, whether they are rolled or cut threads, whether or not the steel used is high tensile or not, loadings, but the bottom line is that a wheel stud is a very highly stressed component - it has to deal with the nut clamping force plus lateral and rotational wheel loadings.

If you reduce the number of threads that are being gripped by the nut - which you have - you are increasing the load and stress considerably on the remaining thread. Yes, there are safety margins built in, but you are eroding them by having less thread inside the nut. Once you exceed the load that the stud can take, it will snap off like a carrot.

Wheel studs get severely abused by pneumatic wheel guns - I have lost count of how many Impreza wheel studs I have seen that have been done up too tight, only to shear off once someone attempts to undo them.......

Hoppy
I see what you mean

scooby_si

Dont u lot like smilies or sumin lol.
Hmm yes i am now certainly guna look at either getting a smaller spacer but quite tempted by the group N stud thingamy, any1 no how much that is guna cost etc? Also where did u peaps get a spacer for a few quid from then?
Cheers
Si

scooby_si

Right i'm currently booked in on Wednesday 2 get sum bigger studs but i'm kinda tempted, admitedly partly by price of such fun & games should they fit straight in without need 2 take hub off? anyway i'm tempted 2 just go with a much smaller spacer & possibly even file the letters off the back of the spokes as it's only really them which catch the calliper so that &/or a tiny spacer, can u have 1 or 2mm, should be ok? In current form with the 5mm spacer i can just get 10 turns in of the nut which i'm told is wot's needed but dont wana risk it!
So is near group N kinda studs overkill if i can get away with pi$$y lill spacer if at all (once wheels have been filed)
Si

Tone Loc

iTrader: (1)

I looked into this when i wanted 4 pots behind my Prodrive superturismo wheels (i've since got some Prodrive ST2 wheels ).... i think the biggest issue is the fact that if the spacer is too big then the wheel doesn't sit on the hub spigot anymore. The spigot takes basically all the load.... the studs are there to hold the wheel to the hub only. Therefore if you move the wheel to far away from the hub the spigot doesn't locate in the wheel and as such the studs now take all the load .I wouldn't have a problem with 3mm spacers or similar as some of the spigot still takes the load but the 7mm needed for Subaru 4 pots were too big. I decided not to risk it.

Tony.

JamesS

Totally agree with above!

Take all the wheel nuts off and press the the wheel against the hub/disk, and you can feel it `bite`, take the wheel center cap off (first!) and have a look, std wheels take about 6-7mm. With a 5mm spacer this is clearly reduced to the point where the wheel will barely bite on the carier at all....not good IMHO. (Had `issues` here myself..........)

Hoppy

Si, you need at least 3mm clearance between outer face of caliper and inside face of wheel spokes. On hard cornering, there's some 'give' in the bearings and the wheel moves relative to the caliper and they can touch Causes pad knock-off as well (ie pedal sinks to the floor )

Comments about having sufficient to locate the wheel on the hub spigot are valid but I think having plenty of stud thread is more important. With this thought in mind, I have a spare set of Radius R3 wheels and these will accept nuts with a long threaded collar that slips inside the wheel mounting hole, giving about 5mm more thread. Got them from ScoobySport but I know many wheel specialists sell them although I was once quoted £4 each (mine came free with the wheels). I can send you one to try if you like, but these are not a proper fix for your problem and a bit of a bodge. But if it keeps your wheels on the car and on the road...

Cheers,

Richard.

scooby_si

Cheers m8 i'm off 2 Roger Clarkes later 2 hopefully rectify any issues so watch this space & cheers 4 da offer
Si

ScoobyDuck

iTrader: (1)

Hoppy - I have 2.5mm spacers on my '97, with the speedlines that would NEVER take 4pots. I've also now got some hooooge brakes (335mm)
Now, apart from some obvious problems with the brakes (which I wont go into here yet - I'll wait to see what the company does to fix them) I get a long pedal sometimes.

now pumping them once fixes the problem, but it's not a nice feeling! I'm wondering if i could be getting pad knock off (that's what it is in anycase!) in the way you describe above.

My calipers are alloy, so any hitting would show up with big gouge marks on the calipers - which are totally spotless. so I'm not sure that it IS happening!

totally lost confindence in my brakes & hence my car & hence it's no fun at-all. all coz some idiot cant make 3 big arrows go in the same direction ! [img]images/smilies/mad.gif[/img]

what do think?

Steve


[Edited by ScoobyDuck - 10/23/2002 8:52:18 AM]

scooby_si

Right i now have the 3mm spacer & there is now over 10 full turns of the nuts so that's now beyond the minimum & the sproget thingamy has the wheel sat on it amply so all is good it wood seem. There was also a slight wobbling of the steering wheel at certain speeds b4 which obviously wasn't a promising feeling but this now seems 2 have gone so i feel much happier & even if a 3mm spacer situation aint absolutely ideal it is a lot better than is was so thanks peaps for yer help
Si

Tone Loc

iTrader: (1)

I'd be happy with that too.... it's sat on the spigot and plenty of stud to go at. Jobs a good 'un .

Tony.

Hoppy

SD, you do get a little extra pedal travel on 1st application - see your instruction book, it will explain and outlines a test procedure.

But excessive travel as you describe sounds like pad knock-off - pedal to the floor, then pump again and all fine? It's the second stroke repositioning the pads correctly against the disk.

Then you turn, wheels moves on the bearings, pushes the pads out of correct alignment and next time you get the long pedal while the pots are re-flooded. Get your wheel bearings properly checked for excessive play. I have no experience of this, but from what I've read on here this is not an easy condition to diagnose unless it's excessive. ScoobySport know what they're looking for (and no doubt others I've not heard of).

Good luck,

Richard.

ScoobyDuck

iTrader: (1)

Richard,

yeah, I appreciate the pedal will be a little further down than before due it going up in pots.
what I get is when I go to press the pedal (sometimes) the pedal sinks 3/4 to the floor. you can still brake damn well from there, but it's not a nice feeling.
if you release & apply again, it's all fine. so I'm in agreement with you - pad knock off.

going back to the manufacturer this w/end as one caliper was made 1/2 upside down - so pistons are not pushing squarly against each other - so this might have upset the pads .. but I'm still trying to get them to call me to discuss replacing pad / disk / all of the above for new ... doubt it will happen - but I want a solid pedal - not one with a mind of it's own! [img]images/smilies/mad.gif[/img]

Steve
p.s. instruction book !? Eh !?!?


[Edited by ScoobyDuck - 10/24/2002 1:08:16 PM]

stockcar

you may also have a small amount of air in the system hard to say
alyn - as performance