rear hubs/discs

[bobbrown]

Rear brakes project

I have looked at the rear brake disc/hub set up in some detail and I am embarking on a project to replace the current set up with a two part system.

Machine a separate hub with out the disk in aluminium which allows the fitting of a standard one piece disc of similar dimensions and position as the current disk such that standard calipers can be retained.
This will mean that the whole hub setup does not need to be changed when replacing the discs
The discs I have in mind are readily available and can be had standard, grooved, drilled or both, cost vary but the starting price is some where around the £20.00 to £30.00 a pair
Hub cost? I’m is a little uncertain and it would depend a little on numbers but the cost is unlikely to exceed £100.00 including bearings etc a side
This will also allow upgrades to the rear setup e.g. bigger calipers/discs

The hub it’s self will be machined from aircraft quality aluminium and be fitted with studs (much like the MKII Escort group4 rally front hubs) still retaining fitment for current wheels etc and retaining the current position of wheels etc
The reason for fitting studs as apposed to using the current bolts id they are easier to make other wise it would mean the fitment of a bush to take the current bolt.


I am after some feed back before I proceed to getting the prototype machined up so any input welcome good or bad

Bob

[Sy V]

Bob

Geoff and I were discussing your recent endeavours at Castle Combe on Saturday.
You certainly have my support, albeit it moral only, especially with stud fitments.
I will say this though, because it would be remiss of me not to, I am awaiting some info from a fellow Elaner who we met on Saturday who has drilled and grooved rear discs (so I'm assuming they have integral hubs) that were sourced from a firm who sell on e-bay. £90 a corner was mentioned.

At this juncture, that's all I can say as I have yet to hear back from him and I don't have his name.

[bobbrown]

Drilled and grooved rear discs are available and the price you quote is about right for the ones I have seen (£172.09) along with the plain ones (£116.33)
Which I think includes delivery and VAT so the ones on ebay are not that much of a bargin
http://www.powerstop.co.uk

You still have to add in bearings and seals so the total cost goes up buy that amount every time you change the disc, which is not very often and is usually done due to corrosion rather than anything else.


bob

[Monty]

This is a great idea

Hub cost? I’m is a little uncertain and it would depend a little on numbers but the cost is unlikely to exceed £100.00 including bearings etc a side
This will also allow upgrades to the rear setup e.g. bigger calipers/discs
Bob

When you say unlikely to exceed £100 is that per hub or a pair?

Just that my rear disc/hub are only a few year old and in perfect condition so it would depend on price for me

[bobbrown]

Cost is down to a number of factor one being volume like the more the lower the cost
Material costs are minimal even using a high end alloy its down to setup and machining times but these are quite low these days with modern CNC machine tooling
Now I know this is never going to be hi volume but the more that can be made the lower the cost is going to be.
The same is true of the bearings I know I can get a good discount but this goes up the more that are ordered.

I am aiming at £50 a side but this may have to be revised

Bob

[F1 LOTUS]

Go for it Bobbers!
For some time now I have been contemplating the same upgrade. I think this modular approach has great potential firstly as an alternate source to the somewhat hard to find / expensive stock item, secondly as the basis for a 'big brake' upgrade (Elanlover ).

If you can design the hub to take a readily available (for export) disc then this should increase global interest as you'd only need to ship the lightweight aluminium part?

Studs - Possibly consideration will be required for the thread-length when using the space-saver wheel? Alternately, you could design for a key-locking thread insert instead?

One thing I also intend to do is source low-friction bearing and seal options - again if these are 'standard' they can also be bought locally to save shipping costs for overseas owners.

You're probably doing this anyway - provide cut-outs to enable bearing race removal.

Hub material - choose something suited to hard-anodizing?

Costs - Aluminum keeps increasing in price and you'll need a decent-sized billet for a 1-piece (Hobsons choice?) hub design - I'd get some ballpark costs ASAP...

Hope this helps - good luck!


Monty - what kind of a racer are you? Think of the unsprung weight-saving

PS - You're not ex-Lola Bob Brown are you?

[chris.t]

sounds like a plan Bob, although i've just changed mine, I'll have a pair if you go ahead.

[Monty]

Monty - what kind of a racer are you? Think of the unsprung weight-saving

It comes down to money for me hence i`ve only done 1 trackday this year anyways the back end is lighter as i don`t have the space saver or the softtop anymore


Bob, if you can keep the price near the £50 per hub then i`m in

So will the hub have lugs to attach the disc ie the hub acts like the bell

All we need now is a better rear caliper to go with it

BTW i got rear bearings of ebay IIRC £5 a side

[dapinky]

I just thought i'd stick my oar in with a suggestion (not that any of it affects me, 'cos i don't want/need any )....


Is there a possibility to alter the depth of the hub to allow wheels with a lower offset to still be in the same relative position to the suspension???

This may be an ideal oportunity to do something which will allow use of wheels with a much more readily availlable offset.

As i say.....just a thought from someone who doesn't want any, and doesn't know if my suggestion is viable, or even possible

[F1 LOTUS]

There's not much scope to dick around with this, also you'd need to address the front end which I believe has even less room? Like your thinking though
How long before Elanlover chimes-in with "can you do a 18" rear 17-pot caliper upgrade too...1...2...3...

[bobbrown]

Is there a possibility to alter the depth of the hub to allow wheels with a lower offset to still be in the same relative position to the suspension???

This may be an ideal oportunity to do something which will allow use of wheels with a much more readily availlable offset.

As i say.....just a thought from someone who doesn't want any, and doesn't know if my suggestion is viable, or even possible

There could be the opportunity to vary the wheel position to accommodate different wheel offsets but this I feel opens up another can of worms.
In any case you would still have an issue with the offset at the front

[bobbrown]

[

Bob, if you can keep the price near the £50 per hub then i'm in

So will the hub have lugs to attach the disc ie the hub acts like the bell

All we need now is a better rear caliper to go with it

I was thinking of using the same setup as the front with a small countersunk screw just to retain the disc or bell depending on what is the choice of rear disc

I was looking to do this with a standard readlly available disc that retains its position and size to the standard set up

[bobbrown]

Go for it Bobbers!
For some time now I have been contemplating the same upgrade. I think this modular approach has great potential firstly as an alternate source to the somewhat hard to find / expensive stock item, secondly as the basis for a 'big brake' upgrade (Elanlover ).

snip

PS - You're not ex-Lola Bob Brown are you?

Not sure of the availability of the disc I have in mind internationally but will be readily available in Europe as it’s a Vauxhall/Opel part


I must admit I had yet to consider the space-saver spare but will make allowance, mind you if you up grade the brakes front or back does it still fit?

Had made allowances for bearing removal

The bearings and seal are allready available from most bearing factors off the shelf but I want to keep these the same as standard as I do not intend to change the stub axle!

material wise either 6082 Aluminium (Al Si1 Mg Mn) or 2014 Aluminium (Al Cu4 Si Mg) probably the latter
130mm diameter is the minimum round bar as the diameter needs to be 120mm

No

[Monty]

[

Bob, if you can keep the price near the £50 per hub then i'm in

So will the hub have lugs to attach the disc ie the hub acts like the bell

All we need now is a better rear caliper to go with it

I was thinking of using the same setup as the front with a small countersunk screw just to retain the disc or bell depending on what is the choice of rear disc

I was looking to do this with a standard readlly available disc that retains its position and size to the standard set up

If your going for a one piece disc which fixes to the front of the hub wouldn`t that mean the hub depth would need to be smaller to compensate for the thickness of the discs mating face If thats correct is there room to make the hub depth shorter

[F1 LOTUS]

Pretty sure this is close to what Bob has in mind?
Should work a treat with either a 1-piece disc or a custom hat / disc combination. I really like this, I hope you can make it happen
It may well be possible to do something about wheel offset requirements for the rear, but the front is a different kettle of fish.

Any caliper upgrade will more than likely render the spacesaver NFG.

[bobbrown]

The drawing shows exactly what I propose

As for the spare space saver as it is a 14” rim it is going to be rendered useless after any brake upgrade that increases the size of the disc be it front or rear.

If the front brakes have been upgraded the only way to recover from a puncture on the front using the space saver would be to put it on the rear and move the removed rear wheel to the front.

[Nige]

Looks very interesting, I'll be keeping an eye on this. I currently have the grooved/spotted (not drilled all the way through) discs on the rear of my car and have changed rear discs and hubs and bearings a good few times.

[Sy V]

Bob

I now have the info (to which I alluded earlier) that I'll post in a separate thread.
I am in no way trying to compete with your idea, but I am obliged to present the membership with as many cost-effective options as possible.

I hope you understand where I'm coming from.

Sy V

[Monty]

The drawing shows exactly what I propose

As for the spare space saver as it is a 14” rim it is going to be rendered useless after any brake upgrade that increases the size of the disc be it front or rear.

If the front brakes have been upgraded the only way to recover from a puncture on the front using the space saver would be to put it on the rear and move the removed rear wheel to the front.

This should be a good project any thoughts on a better caliper

That was a reason why i dumped the space save and keep an S2 wheel in the boot

[addict]

just a quick question.

if the stub axel bolts on can another stub from say a nova corsa or even a golf fit ? as then the disc ands caliper would come with it.


you have i take it checked out the mk 2 golf gri rear set up for differences to the elan?