Dreaded Tyres

[Davrav]

Well...Admiral dont charge any extra (just a note on the policy)...whoo-oooh!

I now have to sort the rears...although both The Touota Service Manager (who arranged the local tyre company to remove these for his T180/SR280 customers) and the manager ftom the Tyre fitters were sure that having the back two support rings in place wouldnt make any significant affect on ride or handling!

The tyre guy said the rings are do close to the rims that there wouldnt be a big difference...on fact tyres themselves can be different in weights..and if you apply the law of centrifugal forces a larger weight applied to the outer circumference of the rotating wheel (i.e an heavier tyre) would change the forces as well! They were both sure the Rav would handle it no bother! I tend to agree ( having studied centtiguga/centripetal forces as part of my degree)...but I will still get them done incase I get a rear puncture whilst somewhere else in country...in which case my Club Toyota AA recovery would take me to a dealer with the machine!!!

On a different subject...whilst tslking to Afmiral insurance..I enquired about adding a tuning box...and for upto a 30% power increase, they quoted £55 extra premium.

Does that seem reasonable?

I don't think it's the 'spinny round and round' forces that we need to consider, it's the mass added to the 'bouncy up and down' effect that can cause problems.

Very non-scientific Davrav

[Stupidmia]

Googled it and agree...it is more about vibration (something else I studied years ago)...so its about road contact than centrifugal forces.

Cheers for the replies...got there in end.

Just got to decide which Geolanders are best...given 30 odd quid diff in price

[Davrav]

Just got to decide which Geolanders are best...given 30 odd quid diff in price

I've stuck with the original G91As and have been happy with their service in a variety of conditions.

[Big Kev]

Well...Admiral dont charge any extra (just a note on the policy)...whoo-oooh!

I now have to sort the rears...although both The Touota Service Manager (who arranged the local tyre company to remove these for his T180/SR280 customers) and the manager ftom the Tyre fitters were sure that having the back two support rings in place wouldnt make any significant affect on ride or handling!

The tyre guy said the rings are do close to the rims that there wouldnt be a big difference...on fact tyres themselves can be different in weights..and if you apply the law of centrifugal forces a larger weight applied to the outer circumference of the rotating wheel (i.e an heavier tyre) would change the forces as well! They were both sure the Rav would handle it no bother! I tend to agree ( having studied centtiguga/centripetal forces as part of my degree)...but I will still get them done incase I get a rear puncture whilst somewhere else in country...in which case my Club Toyota AA recovery would take me to a dealer with the machine!!!

On a different subject...whilst tslking to Afmiral insurance..I enquired about adding a tuning box...and for upto a 30% power increase, they quoted £55 extra premium.

Does that seem reasonable?

I don't think it's the 'spinny round and round' forces that we need to consider, it's the mass added to the 'bouncy up and down' effect that can cause problems.

Very non-scientific Davrav

Absolutely brill explanation Davrav...ah know ye didnae mean it, but haven't laughed so much since ah heard the price for one runflat tyre.

Ferrari are advertising for a suspension dynamics technician....STICK TAE YER DAY JOB :D

Big Kev

[Davrav]

I don't think it's the 'spinny round and round' forces that we need to consider, it's the mass added to the 'bouncy up and down' effect that can cause problems.

Very non-scientific Davrav

Absolutely brill explanation Davrav...ah know ye didnae mean it, but haven't laughed so much since ah heard the price for one runflat tyre.

Ferrari are advertising for a suspension dynamics technician....STICK TAE YER DAY JOB :D

Big Kev

I went to the 'Big Kev School of Physics'

Nuff said, I'll be leaving now..........

[Hoovie]

wouldn't worry about Big Kev and Fizziks. People from Glasgae still get scared when (if!!) they see that yellow ball thing in the sky ;)

I'm lucky, I see it quite often from my bedroom window (but then I do overlook Bonny England that way :D )

[Hoovie]

Here is a little question that I have after reading this discussion and the comments about unsprung weights etc .....

Are the Springs and/or Shocks on the T180/SR180 any different to the other RAV4s to take account of the Additional weight and characteristics of the BSR equipped wheels?

If they are no different to the non-BSR RAV4s (which is what I suspect), then really if you removing the BSR feature, then you are still keeping the vehicle within the design spec of the RAV4 Model and there is no legitimate reason for an insurance company to modify its premium (and this does seem to be the case for the better known and probably clued up ones)

If they ARE different (unlikely), do these need to be altered to take account of the reduction in wheels weights?

[CharlieFarlie]

Here is a little question that I have after reading this discussion and the comments about unsprung weights etc .....

Are the Springs and/or Shocks on the T180/SR180 any different to the other RAV4s to take account of the Additional weight and characteristics of the BSR equipped wheels?

If they are no different to the non-BSR RAV4s (which is what I suspect), then really if you removing the BSR feature, then you are still keeping the vehicle within the design spec of the RAV4 Model and there is no legitimate reason for an insurance company to modify its premium (and this does seem to be the case for the better known and probably clued up ones)

If they ARE different (unlikely), do these need to be altered to take account of the reduction in wheels weights?

Lets separate Gyroscopic effect from the suspension....

To explain the gyroscopic effect..

Remember those spinning wheel things where You used to push the handle in and it span ? Faster You pushed in the handle the faster it span ??

Then if You lifted it off the floor it would go to one side. Then You would correct it and it would go back past centre and go way to the other side ??

Imagine your car wheel is doing exactly the same thing.............

The heavier the weight the more severe the gyroscopic effect...

Take away the weight by lightening say the wheels, Tyres, Brake discs ect ect and You will get a lighter more responsive steering system...

The effect ? Different handling....

Suspension...

It has to deal with two major elements.

The sprung weight.

And the unsprung weight...

Sprung weight is every thing from the springs up. The car its occupants , luggage ect ect.

Unsprung weight is everything below the spring. Wheels,tyres,brake assembly's callipers ect ect.

Decreasing sprung weight will make a huge difference to the handling and feel of a car.....

The cars primary suspension function is to give a smooth controlled ride and very importantly keep the wheels in contact with the roads surface.

This is done by springs and the rates at which they compress ( Spring rates) Also there is complex valving within struts or shock bodies that are in simple terms like drilled washers which allow oil to pass through them at pre determined rates.

Car suspension is really very simply built. Its primary or more important function is to cope with the sprung weight of the vehicle...

Now the unsprung weight is the major contributor to how a car feels and handles.. Controlling unsprung weight is far more difficult to control than the sprung weight..

Reducing this unsprung weight therefore has a bigger effect as you are removing the difficult part that the suspension has to cope with...

I remember Kevin saying how a big benefit was felt when He removed the Run flats and the BST system.. Less or No thumping being felt over speed bumps and potholes.. Now the tyres play no part in this because as We know they are normal tyres with heavy BST rings and 3 to 4 kilos of lubricant inside....

All the benefits are attributable to removing unsprung weight..

Hoovie its unlikely that Toyota would have used different spring and damping rates on the T180 / SR180 to say an XT 5......

[Davrav]

Yeah, s'wot I said in post #51

[CharlieFarlie]

Yeah, s'wot I said in post #51

Yerrrrrrrrrrrrrrrrrrrrrrrrrrrr............................................ :D

[Stupidmia]

Sitting in Gates Tyre Services In West Cumbria whilst they remove my last two support rings...and only being charged £35 for them both to be removed;-)

The guy dealing with me actually went to find what diff was between the Bridgestone RFT and the standard 687 (or whatever it is) and came back saying it was the same apart from the symbol on the side and that they come with a tube of grease for the RFT version!!

Wonder if to get them nitrogen filled at £2 a tyre??

[Hoovie]

As I recall, your back tyres are ok, so are you getting new tyres or well, or getting the 'standardised' 687s refitted?

[Stupidmia]

Just 2 no Geolandar G051s....£283 including ring removal and inc. nitrogen in all 4 tyres.

Thought sbout normal 687s...bit would have had to order and they are pricey! Sod Bridgestone for what they have done in cahoots with Toyota!!!

[Stupidmia]

Had to get new ones coz they have to cut the others off

[crustyclam]

Sitting in Gates Tyre Services In West Cumbria whilst they remove my last two support rings...and only being charged £35 for them both to be removed;-) The guy dealing with me actually went to find what diff was between the Bridgestone RFT and the standard 687 (or whatever it is) and came back saying it was the same apart from the symbol on the side and that they come with a tube of grease for the RFT version!! Wonder if to get them nitrogen filled at £2 a tyre??

Glad you posted this, a potential option for me to travel there depending on what i decide to do, not too bad a trip from Warrington. How long did it take to sort out?

[Stupidmia]

Took about 1.25 hrs.

Workington is quite a drive from Warrington...unless you justify it by having a jaunt through the lake district (to see if the ride is improved).

They know what they are doing and cost is very reasonable...do I eould recommend them to anyone.

The best guy to speak to is Michael...really nice bloke and very helpful too.

[crustyclam]

Took about 1.25 hrs.

Workington is quite a drive from Warrington...unless you justify it by having a jaunt through the lake district (to see if the ride is improved).

They know what they are doing and cost is very reasonable...do I eould recommend them to anyone.

The best guy to speak to is Michael...really nice bloke and very helpful too.

Thanks, that is what i would do, make a day of it, a picnic and take my pooch for a good long walk.

[Stupidmia]

Whinlatter forest is a really nice walk and gives excellent views over Bassenthwaite and towards Keswick...our dogs loved it!

Not far off the main A66 either! Then pop to Keswick for food and let dog have a swim in the lake.

My kinda day if weather niceish

[coopersport]

Sitting in Gates Tyre Services In West Cumbria whilst they remove my last two support rings...and only being charged £35 for them both to be removed;-)

The guy dealing with me actually went to find what diff was between the Bridgestone RFT and the standard 687 (or whatever it is) and came back saying it was the same apart from the symbol on the side and that they come with a tube of grease for the RFT version!!

Wonder if to get them nitrogen filled at £2 a tyre??

Thanks for that Patrick. I've been looking for somewhere Oop North that can do the run flats removal should I end up going down that route. Mr. T want £265 to replace one tyre plus £136 'if' the ring is damaged. I asked about run flat removal and the reply was "Only the run flat tyre can be fitted to the vehicle." !

[Big Kev]

Sitting in Gates Tyre Services In West Cumbria whilst they remove my last two support rings...and only being charged £35 for them both to be removed;-)

The guy dealing with me actually went to find what diff was between the Bridgestone RFT and the standard 687 (or whatever it is) and came back saying it was the same apart from the symbol on the side and that they come with a tube of grease for the RFT version!!

Wonder if to get them nitrogen filled at £2 a tyre??

Thanks for that Patrick. I've been looking for somewhere Oop North that can do the run flats removal should I end up going down that route. Mr. T want £265 to replace one tyre plus £136 'if' the ring is damaged. I asked about run flat removal and the reply was "Only the run flat tyre can be fitted to the vehicle." !

Feeling kinda smug here....this is a Runflat Recent Posting, and I am not shaking with anger or putting in a post of my own....or is that what this is.....????

Kalm Kev

[coopersport]

Sitting in Gates Tyre Services In West Cumbria whilst they remove my last two support rings...and only being charged £35 for them both to removed

Thanks for that Patrick. I've been looking for somewhere Oop North that can do the run flats removal should I end up going down that route. Mr. T want £265 to replace one tyre plus £136 'if' the ring is damaged. I asked about run flat removal and the reply was "Only the run flat tyre can be fitted to the vehicle." !

Feeling kinda smug here....this is a Runflat Recent Posting, and I am not shaking with anger or putting in a post of my own....or is that what this is.....????

Kalm Kev

Stay kalm and feel smug. Thanks for all the runflats input, I've learnt soooooo much!