Club 80-90 Forums

Hi y'all

Got my mits on some nice audi alloys and want to fit some mud terrain tyres to my 1.9td syncro doka.
Questions -
1. As Im moving up 1" in wheel size I understand I need to reduce the profile of the new 15" tyre to 75 to maintain the same gearing.
Any one know what effect an 80 profile tyre will do to low down (1st&2nd) gearing? and would this put too much stress on an already fragile g/box.
Would they clear the arches ok?.
I live in a particularly hilly part of the country (N Cornwall) so dont want to take too much away from the lower gearing but would appreciate slightly more top end.

2. Looking at the BFGoodrich Mud Terrains the smallest size listed is 30x9.5xR15. Any one know if they have the right profile.

Lastly, any recommendations for good MT tyres ?

thanks

215/75/15 will up the gearing a bit and will fit without modifying anything. The 1.9td will not notice.

I have just gone 235/75x15 on Audi rims.

[IMG:640:480]http://i70.photobucket.com/albums/i104/ ... CN2048.jpg[/img]

No clearance issues, but I needed a 3mm spacer on the front. It depends on the offset of your wheels.

Pete Nice wrote:I have just gone 235/75x15 on Audi rims.

[IMG:640:480]http://i70.photobucket.com/albums/i104/ ... CN2048.jpg[/img]

No clearance issues, but I needed a 3mm spacer on the front. It depends on the offset of your wheels.

Maybe ok on road, but offroad your wheel arches are going to bend and tyres are going to shredd.

Thanks for your input so far guys....much appreciated !

Pete- How much did you notice the change in gearing ? did you go straight from 14" standard tyres ?. There are some pretty steep hills round here that I have to choose 2nd gear for so I have to be careful with aspect ratio. Also how does your speedo read.
cheers

I have only driven the van a couple of times with the new tyres on. I did go straight from stock rims to these.

It seems to go ok, definitely not fast! I am still doing work to it, so should be back up & running again by the week end. I will take it on an extended road test & see how it goes.

I will go off road & see what happens too...

Pete Nice wrote:I have only driven the van a couple of times with the new tyres on. I did go straight from stock rims to these.

It seems to go ok, definitely not fast! I am still doing work to it, so should be back up & running again by the week end. I will take it on an extended road test & see how it goes.

I will go off road & see what happens too...

Seriously do not go off road, its going to catch big time at the front and will damage the arches. Rear of the rear arch is going to be close. Mine has slightly bigger tyres and is raised and lighter and needed lots of mods.
Remove springs and refit shocks it will be obvisious where the problem bits are.

Andy - when you say "catch" at the front are we talking the tyres will foul the arch on upward travel or the larger tyres will drag mud/debris in ?
cheers[/quote]

a 215/75/15MT will catch the rear of the front arches just at full deflection in full load situations when new, and will also just catch a 205 spat and spit it off, this based on caravelle on original suspension/dokaNATO canopy original suspension both petrol, slight variations on body types loads etc. This is as big as I'd go without suspension/body mods.

Thanks for that Aidan
from my rough calculation the difference in tyre aspect ratio is about 1.5cm taller on the 235x75x15...enough to modify my wings should I find myself in an extreme position

All things considered I think the 215s will be better suited to my needs but Pete...them tyres rock

Don't take what I have done to be any good.

It was more of what was available at the time. The tyres are 29" tall & I was surprised that they fitted ok.

I drove it on road today now I have it running properly & it goes quite well. It did slow down going up hills a bit, but drop into third & it was off again. I should imagine it has not helped the gearing though.

My off roading in the past has been limited to green laneing, I don't go anywhere too mad incase I get stuck! I would like to try it out now it's all fixed agin, so might have a dabble. I normally keep my speed down to a crawl too. Fingers grossed I come back with tyres & arches!

I am going to sell it soon too, so I better not brake it...

Chilla wrote:Andy - when you say "catch" at the front are we talking the tyres will foul the arch on upward travel or the larger tyres will drag mud/debris in ?
cheers

Catch back of front arch very badly needs at least another 3/4"clearance, petrol battery box need mods depending on offset.

This is the same issue I was interested in re the 16" scorpion wheels - has anyone got any pictures of the mods needed to the front arches/trailing arms? (mines's a panel van rather than a DokA but I suspect that doesn't make any difference?) I'll hopefully get a look at Sonic's soon, but he said he was sending it away for a while... No rush I guess but I'd like to give the mods some thought for when I get some bodywork done (hopefully quite soon)

andysimpson wrote: petrol battery box need mods depending on offset.

DOes that mean the "battery holes" in my factory TD isn't as deap as an actual battery hole on a petrol? Seems pritty spacious so I'd always asumed it was the same size as a petrol and only the cab floor differed, is that not true then? Just cureous (I'm sure you'll be the first to tell me how much better a [factory] diesel is in this respect )

Syncro G wrote:

andysimpson wrote: petrol battery box need mods depending on offset.

DOes that mean the "battery holes" in my factory TD isn't as deap as an actual battery hole on a petrol? Seems pritty spacious so I'd always asumed it was the same size as a petrol and only the cab floor differed, is that not true then? Just cureous (I'm sure you'll be the first to tell me how much better a [factory] diesel is in this respect )

They are the same petrol and diesel but only petrol had battery there.