Trailer tyres sizes explained ?

[CompoSimmonite]

I want to put my little Yamaha quad on the road so need proper E marked tyres. It's a 1996 so with proof of age I can avoid MSVA test as over 10 year old
Rather than paying a small fortune for proper E marked quad tyres I've sourced a second pair of the narrower front wheels so can have trailer tyres all round. I should add this is a 125cc farm type quad and only does something like 30 mph flat out so trailer tyres are more than adequate.
Looking for tyres I find the sizes confusing. For example the ones I think MIGHT be suitable are listed as - 5.70/5.00-8. Obviously the 8 is rim dia but what does the 5.70/5.00 means as car tyres aren't marked in the same way ? Is it 5.70 the tread width and 5.00 the rim it'll fit (my rims are 8" x 5.5" wide) ? Could it mean the tyres are 5.00 high ?

Thanks.

Paul H

 

[CKJDJK]

Yes. 5.70 wide by 5.00 high by 8 inch rim. An older way of sizing tyre before the current % system on metric sizes.

 

[CompoSimmonite]

Yes. 5.70 wide by 5.00 high by 8 inch rim. An older way of sizing tyre before the current % system on metric sizes.

Great - that is what I wanted to hear. It'd then give me the rolling radius roughly the same as the original balloon tyres and similar to something like a 10" Mini radial (that was another option until I found out how much 10" Mini wheels fetch !)

Paul H

 

[CompoSimmonite]

Another question then.
What sized rim width is "recommended" for such a 5.70 wide tyre ? Are my 5.5" suitable ?

Thanks.

Paul h

 

[rtbcomp]

I had 750/16s on my Landrover, the 2nd figure is the rim diameter. Was this an even earlier method of sizing?

 

[gordon stephenson]

The 750 part is the width in inches.(7.5") the tyre height was not included,but usually around 75% i think.

 

[dannyp]

yes, they 750x16 is usally a crossply iirc, 16" rim 7.5" wide tyer

as for width of tyer your going to put on a rim there is a fair bit of give, the vw scene really thakes the **** with this and argue its legal but some people are stretching 165's so thats like a 6 , 1/2" wide tyer onto 8.5 and 9" wide rims

i'd think youd be fine putting a 5.7" tyer on any rim width between 5" and 6" tho imo when the tyer is narrower than the rim it dose look silly

 

[CKJDJK]

The profile of standard tyre is 80% of the width. A tyre size not stating the profile or height is assumed to be 80% although tread pattern and depth complicate the calculations particularly on off road tyres. Low profile tyre sizes start at about 75% down to tiny 30 - 40%. Industrial tyres often still use the old method of width/height/diameter. The letters refer to the construction and speed rating i.e. 185/65/14 HR is a radial of speed rating 130MPH. The tyre also has a load index which is how much weight the tyre can carry at Max psi. Also there is a DOT code of four digits which gives the tyres age in week number followed by year. i.e DOT 3612 is week 36 year 2012. Older tyres had a letter number code but such tyres by now should be scrapped due to the tyre degradation caused by Ozone and UV.

 

[Robotstar5]

I want to put my little Yamaha quad on the road ....

Has it got a solid back axle? (no diff) as using it on tarmac would make steering "interesting"

 

[CompoSimmonite]

Has it got a solid back axle? (no diff) as using it on tarmac would make steering "interesting"

I had a road registered Kymco quad a few years ago and horrible to ride on the road due to no diff.
This time I'm still sticking with the solid rear axle but reversing the hub flanges and using front wheels on the rear so the track will be quite narrow and therefore a diff unnecessary. Also such a narrow rear track configuration is deemed to be a "trike" rather than quad by DVLA so VED is £16 instead of £125. So as long as the contact centres are 460mm or less then it'll be classed as a trike.

Paul H

 

[Bill Edwards]

Another question then.
What sized rim width is "recommended" for such a 5.70 wide tyre ? Are my 5.5" suitable ?

Thanks.

Paul h

Yes, your 5.5" rims will be fine. You could go with a much wider tyre on that rim size with no problem, though you'd have to make sure the tyres couldn't foul the vehicle anywhere, and I don't know what the rules are on extending beyond the wheel arch on a quad.

The 750 part is the width in inches.(7.5") the tyre height was not included,but usually around 75% i think.

No, the 7.50 refers to both the width and the height.

yes, they 750x16 is usally a crossply iirc, 16" rim 7.5" wide tyer

You can buy 7.50 radial tyres new. The old sizes are not a crossply thing, however those sizes were more common in the old days when cross ply tyres were more common. 7.50 radial tyres are popular and I believe still fitted to some LR Defenders from new. They are different to most 'metric' tyres in that they're skinny, being only 7.50 inches wide. The nearest metric sized tyre with a similar diameter is I think a 235/80 which is a massive 9.25 inches wide instead!


CKJDJK - when unmarked the aspect ratio is actually 82%, not 80. Sorry if I come over as being a little pedantic, but I can't help but point it out!

 

[CompoSimmonite]

Yes, your 5.5" rims will be fine. You could go with a much wider tyre on that rim size with no problem, though you'd have to make sure the tyres couldn't foul the vehicle anywhere, and I don't know what the rules are on extending beyond the wheel arch on a quad.

I'd like a wider tyre but the price goes up quite a bit.
No problem with bodywork as it's being cut back and small trailer type mudguards fitted over each wheel. Basically due to health problems I can't ride my motorbikes anymore but despite the low speed the quad (similar to a 30mph moped) will still allow me to still enjoy riding. Two wheels at the front means the original brakes on handlebars aren't acceptable if I make it into a trike, albeit close coupled twin wheels, as they need to be foot operated. That suits me as limited strength in right hand is one of the reasons I can't ride a 2 wheeler. Just "won" a Vespa foot pedal on eBay so will make a balance bar system for the cable operated drums linked to the pedal.
I've had a number of quads in the past and after a lot of searching settled on a Yamaha YFM125 Breeze for this "project for the following reasons - cable operated drums all round, chain drive, 4 stroke engine, CVT gearing, reverse gear, potential for PTO (where optional hand starter fitted) so can run small additional alternator, swinging arm and kingpin rather than double wishbone and ball joint front suspension.

Paul H