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View Full Version : Need help with tire for Series 3 109 with parabolics



gotacohiba
12-17-2013, 03:15 PM
First off, I'm glad that I found this site as I'll be in need of a lot of advice from you experienced gents.

I just purchased a 1974 Series 3 109 2dr that is in dire need of tires.
The previous owner just installed new parabolic springs and shocks and said that it raised it about 2".

My question is, he said I could go with 255/85/16 BF Goodrich MT's, does that sound right?

I'm ok with the price if they will work, just don't want to special order then find out they don't work.


Thanks in advance for any input.

SafeAirOne
12-17-2013, 03:58 PM
I run 235-85-16s on my normally-sprung 109. The larger the tire, the larger the 109's turning radius (you can turn the steering wheel less turns before the larger tires rub on the chassis). I think that's really the only consideration for that tire size (255). That, and technically, your rim width should be within the tire's allowable range of rim widths.

Here's what 235-85-16's look like on a 109 3-door (including the bonnet-mounted spare)--255's won't be too much larger 33.1" vs. 31.7", and about 3/4" wider:

http://farm9.staticflickr.com/8252/8458367621_28c9f56dd3_z.jpg
http://farm6.staticflickr.com/5450/7427742472_4d7807af76_z.jpg

gotacohiba
12-17-2013, 05:32 PM
Will the 255's help me reach a better cruising speed?
Currently anything over 55 sounds like it's in a strain.

SafeAirOne
12-17-2013, 07:46 PM
Will the 255's help me reach a better cruising speed?
Currently anything over 55 sounds like it's in a strain.

Eventually. Larger tire/wheel assemblies allow you a higher top speed on level ground, but will require more "oomph" to get going and to maintain speed on hills.

Jim-ME
12-19-2013, 06:40 AM
I went from the 15" equivalent of 255's to the same tire Mark is running when I changed rim size. I have noticed a definite reduction in top speed at the same RPM's. I didn't want a mud tire which is why I didn't purchase the larger BFG MTs. I was a personal choice. If I could have purchased the BFG ATs in the 255 size I would have done it in a heatbeat. If you are happy with mud tires I'd recommend the 255 size because it will make a difference in top end speed..
Jim

Contractor
12-19-2013, 07:31 AM
I had 255/85/16 BFG MT's on my old 88 with Parabolics and loved them. No rubbing at full lock or off road when moderately articulated.

You might need to adjust the wheel stops some because of the additional width.

http://images1.snapfish.com/232323232%7Ffp%3B%3C5%3Enu%3D3244%3E8%3B5%3E559%3E WSNRCG%3D36357%3A9998325nu0mrj

rwollschlager
12-19-2013, 09:10 AM
here is a 2-door 109 with the 255/85's installed. See from post #115 on page 12 onward: http://forums.roversnorth.com/showthread.php?11472-1970-IIa-109-ex-mod-build-thread/page12

gotacohiba
12-22-2013, 06:49 PM
Thanks to those that replied, the 255/85/16's will go on tomorrow am

LaneRover
12-23-2013, 07:24 AM
Will the 255's help me reach a better cruising speed?
Currently anything over 55 sounds like it's in a strain.

Just remember that at any given MPH reading the truck will sound the same BUT unless you change the speedo it will not read the correct speed for the larger tires. For example 55 will actually be 58 or 60, 60 will actually be 65. Numbers used have no scientific value are just examples to show that with larger tires the speedo will read differently.

Or in other words your truck will sound like it is straining at any speed over 55 but you will be going faster than that.

We can all now discuss whether that matters or not - especially with the 'accuracy' of Rover speedos . . .

1961 109 WAGON
12-23-2013, 08:47 PM
Here is my truck with 255's with parabolics. 9070

alaskantinbender
02-24-2014, 12:47 PM
Thanks to those that replied, the 255/85/16's will go on tomorrow am

Somehow I missed this thread. How about a picture of your truck with the new rubber?

Here is mine with the 255/85/16 KM2's They are much quieter than the 34 inch Super Swampers I had on before.

9371