Jump to content
  • 0

CVRW tyres


webley455

Question

I need replacement tyres on my Fox, it currently has the original Dunlop Runflats which are starting to crack.

I have been offered some new 12x20 bargrips.

can these be fitted to the Fox instead of the 11x20’s or are they likely to cause damage to the vehicles running gear?

 

Link to comment
Share on other sites

Recommended Posts

  • 0
16 minutes ago, Terra1936 said:

what makes them run flats? 

The original Fox tyres were Dunlop Trackgrip Runflats, they have very thick sidewalls and a bead spacer to keep the tyres tight on the rim if the tube was deflated. Later on they were replaced with Michelin tyres which were not runflats but were fitted with Henderson inserts which are very thick and heavy and also inflatable. But will keep tyre on the rim in case of punctures.

Link to comment
Share on other sites

  • 0
9 minutes ago, tankdiver said:

Fitting the inserts for run flats can be  a hard chore i had to do two on a ferret   which took a whole morning . It may take a little less time for a younger guy  as I was in my  70s at that time. Hope  I dont have to do them again

Laurence

When I worked in REME Workshops, the trick with runflat inserts was to squeeze them together in to a figure of 8 shape and tie with rope ( probably a ratchet strap would do.) Think we did this with a hydraulic press, then it is easier to push into the tyre and when in place cut the rope. Also you need the jacking screws to pull the beads apart.

The Henderson inserts used in the Michelin tyres on Fox are a different ball game and they were sent out to a tyre specialist to put in.

Link to comment
Share on other sites

  • 0

The red wheel nuts hold the 2 halves of the wheel together NEVER undo them unless you have let ALL the air out of the tyre. You could run without run flat inserts and use a standard commercial vehicle flap instead, this will prevent the inner tube getting nipped between the 2 wheel halves when putting the wheel back together.

Edited by johnwardle
Extra text added
Link to comment
Share on other sites

  • 0

Thanks for the suggestion. I think I'm on this forum to learn? That is why I asked questions. Your information has been very helpful and I can see by your collection that you have a lot of experience in  your stable. My Unimog has the lugs painted red and I found the red on the Fox similar. 

Link to comment
Share on other sites

  • 0

I have the same on my Militants and Eager Beaver (I think the EB has the same rims as the Fox) split rims. In the Militant manual it states to paint the rim nuts red and wheel hub nuts white as standard not just for parade show.

Red is to highlight a danger as in think twice if you are taking the wheel off the hub. It would be dangerous with a high volume tyre at reasonable pressure.

Its also convention to avoid mistakes when in a rush for example.

Iain

Link to comment
Share on other sites

  • 0

Fitting the inserts for run flats can be  a hard chore i had to do two on a ferret   which took a whole morning . It may take a little less time for a younger guy  as I was in my  70s at that time. Hope  I dont have to do them again

Laurence

 

Richard I found the method on fitting the  rubber inserts the same  as you did after several attempts but they are an awkward lump

Laurence

Link to comment
Share on other sites

  • 0

Regarding the red nuts if they are taken off with even  a little air in them air in them it may kill you . when I was teaching mechanics I ,used a picture from Dunlop  tyres on the imprint of death  which was a tyre fitter blasted into the ceiling of the workshop when not using a cage.  So be careful when working on tyres even push bikes.

Laurence

Link to comment
Share on other sites

  • 0
8 hours ago, Terra1936 said:

Back to the original topic, are there any issues running a Fox without the run flats? 

DSC_3309.JPG

Hi

I am led to believe that the Eager Beaver used the same wheel without run-flat inserts.

Here is the parts book page with the list of bits for the wheel though sadly there is not an illustration. It shows what could be two types ? And states that it is a "Dunlop HB133 modified".  I don't know what the modified refers to maybe someone way more qualified than me could comment. It does show that the wheel is fitted with standard 11-00 x 20 Michelin XL tyres with a "Flap, rust , slip". Considering that these vehicles could motor along on roads at reasonable speeds, not just potter around a yard, I would say the fox would be OK.

I hope that helps a bit.

Iain

EB parts.jpg

Link to comment
Share on other sites

  • 0
16 hours ago, Richard Farrant said:

When I worked in REME Workshops, the trick with runflat inserts was to squeeze them together in to a figure of 8 shape and tie with rope ( probably a ratchet strap would do.) Think we did this with a hydraulic press, then it is easier to push into the tyre and when in place cut the rope. Also you need the jacking screws to pull the beads apart.

The Henderson inserts used in the Michelin tyres on Fox are a different ball game and they were sent out to a tyre specialist to put in.

Like this ?

A set of tyre levers won't get that out....

 

image.jpeg

image.jpeg

Link to comment
Share on other sites

  • 0

Runflat tyres are for operational reasons, the enviroment the vehicle would be expected to be in. In civvy life Tyre size matching, Radial or Cross ply. Ply Rating, Tonne Mile per Hour rating, Maximum Speed rating and pressure, are the important things. As well as general tyre care looking for blebs, cuts, Sidwall cracking, nails etc. This applies whether you run motorway tread patten, Offroad patten, Snow, Quarry or soft ground low profile or any of the specialist tread pattens available. Wheels come in various guises, different offsets, different J sizes, centre diamiter stud spacing and stud numbers, spigot mounted, tapered nut and washer, split rim, tube, tubeless,1 piece  2 piece 3 piece and 4 piece. With various rim locking methods. All need to be treated with equal RESPECT. Air pressure above 3psi can pierce the skin and cause health problems, high pressure air or any tyre fill needs to be treated with caution. Handling instructions are available and should be read.

Edited by john1950
correction
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...