Wheel offset

[Jonathan Webb]

Hi,
Anyone know about wheel offset?
I'm looking for a spare wheel for our club trailer as it hasn't got one & muggins here volunteered to tow it. From what I can tell from AlKo documentation it appears to have a -30 offset. I can't get to the trailer yet, to look at the wheel properly as it's parked behind a load of stuff.

All the trailer supplies websites list wheels with no indication of +ve or -ve
(eg http://www.gttowing.co.uk/13quot;-RIM-5-X-112mm-PCD-4-5J-ET30/product/13RIM-5J5/BT550/112M/)

Where wheels have an ETxx value, presumably this would be expresssed as ETxx or -ETxx?

Secondly, if it is actually not -30 but a +ve offset, could I use ET40 or 45 or is that too different? Either as a spare for "get you home" use, or pair of nice alloys & have the current wheels as spares? The trailer is rated at 1500kg & is a triple-stacking dinghy trailer.
Cheers

 

[ajlelectronics]

It will be ET30. An ET45 may foul suspension parts, but offer it up?

 

[MCKDAVID]

if it's just a one off and you're concerned about a puncture, what about some of these roadside repair kits instead, that and use the AA cover. might be less hassle than trying to find a spare rim / tyre.

 

[ajlelectronics]

I have found out that most trailers and Al-Ko caravan chassis use the 13" ET30 4.5J 4x100 PCD wheel as standard. I am hoping that my Cheltenham is the same as I don't have a spare for my BT trailer, but the caravan does.

The offset is explained clearly on many internet sites, but in a nutshell, it is the distance of the mounting flange from the centre line of the wheel. Increasing the offset puts the wheel further inboard.

 

[normspanners]

http://www.uk-trailer-parts.co.uk/trailer-wheel-offset/

 

[normspanners]

I doubt it will be 4 x100 at 1500 kg seems a little twee from what I have seen usually those boat trailers are single axle for maneuverability.

 

[Jonathan Webb]

if it's just a one off and you're concerned about a puncture, what about some of these roadside repair kits instead, that and use the AA cover. might be less hassle than trying to find a spare rim / tyre.

This happened on the double stacker trailer. Luckily it had a spare...

I have RAC, but self-help & getting the boats to the kids when they need them is better than waiting by the roadside for hours whilst the kids are sat unable to participate.

 

[Jonathan Webb]

I doubt it will be 4 x100 at 1500 kg seems a little twee from what I have seen usually those boat trailers are single axle for maneuverability.

I'm beginning to wonder myself although I recall it being 100mm pcd when I was deciphering their parts last year when I refurbed the braking system. I had some info on my old phone but it didn't survive somehow. I'm writing to the manufacturers for guidance, but from what I've seen, customer service isn't a concept they've embraced. We're going down tonight to pull it out so I can look properly.

I saw that explanation, but it doesn't give examples of pos & neg values. I have an AlKo table printed off which has the right wheel size (only 4.5J x 13) for most of the appropriately-rated axles from their catalogue and they nearly all have a negative offset of around -30

 

[Jonathan Webb]

I have found out that most trailers and Al-Ko caravan chassis use the 13" ET30 4.5J 4x100 PCD wheel as standard. I am hoping that my Cheltenham is the same as I don't have a spare for my BT trailer, but the caravan does.

The offset is explained clearly on many internet sites, but in a nutshell, it is the distance of the mounting flange from the centre line of the wheel. Increasing the offset puts the wheel further inboard.

Thanks I understand the offset concept just that AlKo show it as a negative value & no-one else does.

 

[ajlelectronics]

I may be totally wrong here, but I thought that the offset was selected to put the wheel centreline over the wheel bearing. If I am correct, that would make anything less than about ET0 (Scimitar offset!) useless.

 

[normspanners]

From what I've seen, 1500-1600 is the crossover point where they go 5 stud and around 115-125 or so...

with 12mm studs yes it appears so ...
http://www.knottuk.com/fileadmin/Kn..._Instructions/Complete_File_for_Upload_11.pdf

doesnt seem much spread of the studs ie pcd for 1600kg though, iirc 139.7 - 5.5" max weight is supposed to be 1550kg ish

 

[Jonathan Webb]

FWIW, I tried a Polo alloy wheel at ET38 & it had plenty of clearance. By my calculations, the inner rim edge would be projecting 8mm further inboard & that is fine. I also can't see that unduly loading the hub/bolts. Which is good cos I picked up, locally 4 of them with good tyres for £50. Then paid £61 for a 10" tyre at the local tyre dealer!

 

[gaz_moose]

just watch the load rating on the tyres.

 

[normspanners]

also check the wheel nuts are correct for the allys,
a few days ago I was at the local farm and the young girl just announced 'there a wheel rolling down the white line, of the main road', we went to see and there was the wheel rolling for 1/4 mile exactly down the white line it stopped and fell over.
A newish tyre on a trailer 5.5 pcd no idea from what as the road was unusually empty.
stud holes showed witness to being run slack----- BUT NOT FOR LONG !!

 

[Jonathan Webb]

Gaz,
Checked that, same as the old tyres. I would go up a notch or two when they next get changed though.
Norm, re alloy nuts. Will check that - any idea how to tell? Cheers

 

[normspanners]

ally wheels sometimes dont have female tapers (countersinks) for the nuts and use flat faced nuts that centralise on the hub and wheel centre.
where most trailers use the wheel nuts to centralise the wheel.

 

[ukracer]

I have an even word problem. My trailer has old 1300 hubs fitted but I can't find out much info about them let alone find a spare.. Lol

 

[gaz_moose]

I have an even word problem. My trailer has old 1300 hubs fitted but I can't find out much info about them let alone find a spare.. Lol

is that Austin 1300?? or just 1300kg

 

[ukracer]

is that Austin 1300?? or just 1300kg

Austin.....

 

[colnerov]

Hi, PCD on them is 4 x 4 1/2" (or 114.3mm) and 61.5mm offset and they are peculiar to that car. There are other cars that use that PCD, mainly Japanese but others as well but not with that offset. Lower offsets will move the wheel out, making the track wider.

http://www.wheelfitment.eu/PCD/4x114.3.html

Colin