Compomotive MO Alloy Wheels

[longbow]

I'm looking into changing my wheels from Spiders to the MO 6 spokes and hopefully get the wheel widths and offsets spot on. At the moment I'm cursed with the Tuscan rear Spiders that do sometimes catch the arches. So, the plan is to get 18 x 8s on the front and 18 x 9s on the rear. I'll be keeping the R888s, 225/40/18 front and 255/35/18 rear. My planned offsets are; front - 35mm rear - 45mm. I've chosen these as I want to keep the front outside rim as far 'out' as it currently is, as it doesn't rub on anything and as the width is going down by 1/2" I might be able to regain some steering lock and remove the spacers on the rack. So, if the original is 42mm and the rim narrows on each side by 1/4", I need to go down on the offset by around 6mm, i.e. to 36, rounded down to 35. On the rear the 33mm offset is too low for an 8.5" rim, so if I was going to correct this the offset would need to up around 5mm, i.e. to 38mm. Since the rear rims are going to be 0.25" wider I need to bring the wheel in by a further 6mm or so, and so the offset needs to go up by 6mm to 44, rounded up to 45mm. Before I order these wheels can someone do a sanity check incase I've got this totally wrong!!

[APMAUTO]

speak to jonnyw he's just spec-ed a set for the cerb racer 10x18 and 9x18

[longbow]

Will do. Hey Andy, its me who's booked the Cerb in for its tappets on Mon 4th Feb! I'll be interested to see how easy/hard the job is, and look forward to coming down and meeting you. Just for your info the Cerbs going to Newlun next Tuesday for its headlight conversion, but it should be back by the end of this month. If it gets delayed, I'll let you know as soon as I can.

[Steve_T]

Windsor, an alternative view. The width of the tyre is not changing and you want the centre of the tyre to be in the same place as currently, so would the rear wheel offset not remain as it currently is? I've been through this a few times myself and first of all I concluded as you did, then I had a rethink and ended wanting to leave the offset the same. I have 17x8s on my car and my reasoning is that all I'm doing is getting a better fitting rim for the tyre width. I'm happy to be corrected by someone who's been through the alloy change thing. I'm thinking about changing the wheels too, so it would be good to understand the right way to approach things.

Steve.

[HarryW]

Looking out for the results of this with interest, after dallying with lots of options for summer wheels, I've come to the conclusion like you Mo6's are the way to go, particularly after seeing L1OFF's saggy with them on during arecent run out. I'm considering a 18x8 & 18x10 set up if the 10's can be made to fit the rear arches 9's if not, I also thought the 8's up front might negate the need for steering limitations. I may even go with the RL7 size of 17x8 to get away from making the steering any more boat like than seen without extra stops

Andy are you having to chop Jonny's inner arches to fit the 10's .

Windsor what's/where's the best price you've found so far , browsing I reckon on sub £1k for the wheels, perhaps nearer £900.

[HarryW]

Also forgot to add one of the reasons for looking at the rear in 10's was to see if 265 or even 275 rubber could be fitted with some stickier rubber for traction, any thoughts

[JensenA]

Wider rubber doesn't neccasarily mean you'll get improved traction, especially in the wet where wider rubber can actualyy make it worse. Be intersting to find out though.

[longbow]

Harry, the best price I have for two 18x8 and two 18x9 is £800 inc VAT and delivery - a guy on ebay called reyland - do a search and you'll find him.

[_Neal_]

Think this is the main Reyland site - has full wheel price list.

http://reyland.co.uk/

I like the look of these wheels - will do a search for pics (unless anyone has them to hand on a Cerb?)

[itsallyellow]

I have them on the racer also. 10x18 and 9x18

Mike

[itsallyellow]

I no its not a great indication as this is a pic when the car was very first in build but it gives you an idea.



Mike

[_Neal_]

Thanks for that Mike - they look good - kind of like a larger, updated version of the 16s that were on early Cerbs.

[morebeanz]

Steve_T said:

Windsor, an alternative view. The width of the tyre is not changing and you want the centre of the tyre to be in the same place as currently, so would the rear wheel offset not remain as it currently is? I've been through this a few times myself and first of all I concluded as you did, then I had a rethink and ended wanting to leave the offset the same. I have 17x8s on my car and my reasoning is that all I'm doing is getting a better fitting rim for the tyre width. I'm happy to be corrected by someone who's been through the alloy change thing. I'm thinking about changing the wheels too, so it would be good to understand the right way to approach things.

Steve.

If you amend the offset too, I assume that effectively you keep the outside wheel edge static, rather than the tyre centre. Clearly this widens the track, and ought to give more turning circle, but my schoolboy physics suggests that this would change the load on the suspension components (springs and dampers) which may or may not be a good thing.

[longbow]

The idea of changing the offset is quite simply to correctly position the wheels and tyres in the arches. I'd like to keep the track as wide as possible both front and rear but avoiding any rubbing. Any other considerations will have to fall out in the wash!!

Edited by longbow on Thursday 10th January 10:10

[APMAUTO]

HarryW said:

Looking out for the results of this with interest, after dallying with lots of options for summer wheels, I've come to the conclusion like you Mo6's are the way to go, particularly after seeing L1OFF's saggy with them on during arecent run out. I'm considering a 18x8 & 18x10 set up if the 10's can be made to fit the rear arches 9's if not, I also thought the 8's up front might negate the need for steering limitations. I may even go with the RL7 size of 17x8 to get away from making the steering any more boat like than seen without extra stops

Andy are you having to chop Jonny's inner arches to fit the 10's .

Windsor what's/where's the best price you've found so far , browsing I reckon on sub £1k for the wheels, perhaps nearer £900.

harry arches are staying the same but with wafer thin edges running 265 slicks with a road tyre you may get away with no mods

[BCA]

They're on the wishlist - let me know how you get on... I was thinking of just getting some wider rears and leaving the front 17" RL7's - 265's are meant to work pretty well (IIRC they're reccommended with SP12's) - I cant see why wider couldnt be tried as long as pressures are adjusted correctly/ tyres are chosen carefully... we'd certainly be looking for gains in the area of straight line traction from it.

[touching cloth]

Steve_T said:

The width of the tyre is not changing and you want the centre of the tyre to be in the same place as currently, so would the rear wheel offset not remain as it currently is?

Yep that is the way I think of it too - it's tyres that rub and it's therefore their width and the offset being provided by the wheels that matters here, what width the rim is will really only dictate the angle (or not) of the sidewalls. However, Windsor did say he has rubbing as he has it at the mo, so if he leaves offset as it is now he will continue to have rubbing, so will need to adjust it.

However W, as I read it, you are adjusting too much on the rears because you are looking to correct for the change in wheel width which as above I don't think is necessary. You are also correcting off a Spider which wasn't right anyway so you might as well work of what is known to work on the rear. ASFAIK the original 16" Cerb wheels were an offset of 35 (front and back) and the rears ran 245 with no rubbing, so as you are running 255 then at best you only need to bring the wheel in by 5mm (half of the extra increase across each side), so I would say a 40 offset for the rear would be enough. As you are looking to maximise your track your 45 could bring it in 5mm too far (it could theoretically give you a narrower rear track than your front!)

The only caveat I would say is that the benefit of ordering up 45mm offset is that you could at least add a spacer to bring it out 5mm again if you felt you had room, ordering up 40 makes it harder to (i,e. having to remachine the wheel) to get it back to 45mm.

So, you take you chances

[HarryW]

What offset are the RL7's as mine fit very well and I could gauge any change from that point. Does anyone know what the spider offset is too as can rub and would help gauge the clearance a bit better .
I find the calculator here helps my limited understanding, although you need to know what you started with. http://www.1010tires.com/WheelOffsetCalculator.asp

What offset has JonnyW gone for on the rear as if he is running 10's then there is another 25mm to take into account over the 9's.

A set of those new Toyo R1R's and the jobs a goodun

Edited by HarryW on Thursday 10th January 21:35

[longbow]

Good point about the spacer - although not ideal using a 45 offset on the rear would allow me to correct with a thin spacer. If it still rubbed with a 40 I'd be screwed! So I guess I'll just have to order them and see how it all comes together...........

[Steve_T]

I think the RLs are a 35 offset Harry. An aside, but have you guys considered the weight of the MOs as a factor, a bit of googling points to them being quite heavy, having a similar weight to the spiders. Obviously the quality and strength will be significantly better.