Is it illegal to put super singles designed for trailers on to the steer axle?
I have been offered a cheap pair of 385/55/22.5 on rims but they are a trailer type but have a steer type tread pattern. Any reason why not■■?
Many do put them on but i dont know where you would stand insurance wise if owt went wrong,
I think the s/s meant for the front are expensive for a reason
I had a Bridgestone trailer on my n/s second steer axle and it was holding up well, when I needed a n/s front steer I had another to match it as I figured they’d not scrub off so quickly. The handling was a bit on the wayward side and it did wander about. I stuck it for a few months but got them both put on the second steer axle with conventional steers on the front. MOT’s were not an issue with the trailer tyre on the steer.
385/55/22.5?
the standard super single tyre is 385/65/22.5
There is some recent change in legislation which a young and enthusiastic tyre fitter was explaining to me today, apparently some Super Single tyres are now marked “FLT” or somesuch, which means that they can only be used on non-steering axles, and having them on the steer axle of a tractor unit is an MOT fail.
Harry Monk:
There is some recent change in legislation which a young and enthusiastic tyre fitter was explaining to me today, apparently some Super Single tyres are now marked “FLT” or somesuch, which means that they can only be used on non-steering axles, and having them on the steer axle of a tractor unit is an MOT fail.
i used to run my magnum with super singles on the front harry and i found them to be very cost effective compared to the original 295
Your truck will fail the mot unless you get the plate changed to say that your running supers on the front! The trailer tires marked with FRT(free running trailer) are indeed only to be used on trailers and not as steer tires,saying that i did run them on my actros and it passed the test with them on.
Be warned though,trailer flat faced super singles are not the same as steer super singles,they have a different offset. they’ll eat steering joints and king pins.
shuttlespanker:
385/55/22.5?the standard super single tyre is 385/65/22.5
Low height unit.
Shoshaye:
Your truck will fail the mot unless you get the plate changed to say that your running supers on the front! The trailer tires marked with FRT(free running trailer) are indeed only to be used on trailers and not as steer tires,saying that i did run them on my actros and it passed the test with them on.Be warned though,trailer flat faced super singles are not the same as steer super singles,they have a different offset. they’ll eat steering joints and king pins.
They are on 120 offset rims which is ok for Volvos, is that what you mean?
Possibly lol,im not to sure,i only know because mine on the front of the scania were purchased for the trailer but were actually steer wheels.
Harry Monk:
There is some recent change in legislation which a young and enthusiastic tyre fitter was explaining to me today, apparently some Super Single tyres are now marked “FLT” or somesuch, which means that they can only be used on non-steering axles, and having them on the steer axle of a tractor unit is an MOT fail.
Bridgestone call them an FRT (Free Rolling Tyre) which to quote their brochure:
In the case of trucks, an FRT (Free Rolling Tyre) is a tyre which may only be fitted on trailer or tag axles and not on drive or frontsteer axles.
More detail in this link: bridgestone.eu/filelibrary/E … nglish.pdf
I suspect if a steer axle blowout caused an accident and it was discovered that you were running a tyre on there that was not recommended by the manufacturer then you might be in a bit of trouble…
Paul
Both of my tyre suppliers have said the same thing:
Steers only on the steer axles, Free rolling on the mid lift and trailers.
I put my ex front steers on the trailers to finish them off.
The mid lift bridgestones were part worn when I got them about 2 years ago!
Still not been cut yet.
I’ve got them on the steer axle of mine, were there when I bought it, but I’ve been told they have an adverse effect on fuel consumption, any thoughts?
Harry Monk:
I’ve got them on the steer axle of mine, were there when I bought it, but I’ve been told they have an adverse effect on fuel consumption, any thoughts?
Unless you genuinely run heavy on the front axle there’s no benefit a lot (probably most) are on purely for cosmetic reasons which I personally don’t like anyway. I do notice them on Magnums a lot though so don’t know if they’re preferred because of the bigger heavier cab.
Place I used to be at had them on and the front axles and were genuinely uprated it was because they had double deck box trailers that would often be part unloaded on the first drop leaving them heavy at the front. Unless there was any reason like that I’d not have them, they speed up kingpin wear and that’s one of my least favourite jobs anyway.
had em on two of my erfs never liked driving them thought they seemed to be harder to hang on to… also if you had someone a little bit careless driving they appeared to get a lot more scuffs and nicks on sidewalls…
Shoshaye:
Your truck will fail the mot unless you get the plate changed to say that your running supers on the front!
No it wont Shoshaye. you can up grade from 295"s to supers with out a plate change if you up grade and fit 385"s on the front you cannot put 295"s back on with out again a plate change and a bit off messing around plus if you decide to plate change to 385"s you get a extra .5 tonne on which axle its fitted too but only one axle, not if you have them on midlift or tag axle and steer axles toghether only one axle will be uprated to say 7.5t front axle instead of a 7ton axle etc "and before spanky mandy adds what about a 7.5 ton axle to 8t… 
most mot stations dont normally bother as its a up grade in tyre size and rated for a extra weight carrying. only time they bother “vosa” is if the tyre is sticking out of the arch this includes the side wall of the tyre as well if they want to be funny its a fail, Ie volvo daf can run the same offset of 120. scania have a diffrent offset to them all, thats why you see most scanias fitted with spatz as the offset is wrong instead of buying the correct offset which is …mm
frt , means free rolling tyre… 
This place does the steel wheels with the right offset fairly cheap, have used them a couple of times for trailer wheels with an unusual offset, sure they’d advise on what you needed for anyone that wanted to fit them.
Harry Monk:
I’ve got them on the steer axle of mine, were there when I bought it, but I’ve been told they have an adverse effect on fuel consumption, any thoughts?
I’ve had them on 3 XF’s since the first one bought new in 2000,I can’t see any disadvantages to running on them at all,no affect on fuel as far as I can see,the 06 XF is doing anything upto 10 mpg on fairly light work, I still have an 04 plate XF that’s done 775,000km running on rural Irish roads and still on it’s original kingpins!
I find that they make the unit much steadier with less roll on the road,on narrow country roads they stop you getting pulled into the verge as fast and they tend to wear more evenly.I used Bridgestone s/s steers until about 2 years ago as the price of them now is too much compared to the Dunlop 244’s that I use now.
The other major advantage of them is that when they are worn you can regroove them and put them on the middle axle of a trailer,a worn 295/315 steer is of no use on the drive axle so you’ll always get more from the super single.
In answer to the op it may not be illegal,although someone mentioned a new law,but a proper s/s steer will handle better than a trailer s/s but it depends on the tread,I find the Dunlops good and wide with a straight tread and a good altenative to a Bridgestone.
Cold Up North:
shuttlespanker:
385/55/22.5?the standard super single tyre is 385/65/22.5
Low height unit.
not necessarily, most 55s I’ve seen lately have been on normal height trucks with air suspension on steer axle.
Had them on an FH doing Maroc. Would feather off into the dust on the old roads & were slippery in the wet. V. Good on modern highways. IMO.