Date: Wed, 7 Mar 2001 18:07:03 -0500
Reply-To: Derek Drew <derekdrew@RCN.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Derek Drew <derekdrew@RCN.COM>
Subject: Conclusion on 235/75-15s--Thumbs Down on 4th
In-Reply-To: <20010306181228.14336.qmail@web3901.mail.yahoo.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed
There are owners of 235/75-15 tires (with stock North American gearing)
that actually say they like that size notwithstanding the effect it has on
gearing and acceleration. Comments to this effect came came to me by email
after I cast doubt on the suitability of this size for *any* vanagon
owners, even syncro owners who go off road. It is, after all, somewhere in
the region of 3" taller or more than the stock tire that came on the vehicle.
The issue is important in deciding what tires and gears go together well
and which do not, a subject upon which I am still working. You will see an
appeal for additional commentary from owners of 235/75-15 tires and
215/75-15 tires below.
Since getting endorsements of the 235/75-15 tire sizes from some list
members, I have also subsequently received additional comments from list
members saying that while this tire is OK in gears 1, 2, and 3 it is not
very suitable in 4th. Says the owner below, "I would not recommend this
tire to anyone who lives near any hills." Added an earlier post about this
tire, possibly inexact quote: "It was fine around town but on the highway I
had a hard time even getting it to 70." This information is vitally
important, because it affects the way owners should gear their vans in the
future. Because the information about the undesirability of the 4th gear
seems well stated and genuine, I am inclined to assign a fairly high degree
of credibility in these statements. See an owners report at the end of this
email that lends support to this conclusion.
Accordingly, I am slowly deriving a principal that says that any gearing
setup which would cause the vehicle to travel at an actual speed in 4th
gear at 4,000 rpm of 78.8mph is a inadvisable setup unless some other
variable is attached to it, such as a larger engine than 2.1 MV. But it
seems to be slightly more acceptable that the vehicle may travel in 1st,
2nd, and 3rd gears 17.7, 32.5, 54.5 mph at 4000rpm, respectively, high
though those numbers may be.
For reference purposes, stock mph speeds for north american syncros with
4.86 final drive gears in gears 1 through 4 at 4000rpm are:
15.95, 29.28, 49.23, 70.95
So what we are saying is a jump from 70.95mph 4000rpm 4th to 78.8mph is
simply too great.
If you have any information that contradicts the conclusion above, or have
any impressions or observations to add, now is the time to do so as they
will affect a body of work that will serve as a reference point going
forward. In other words, it is important for you to post your feedback on
this issue if you have any to give. This also applies to how well you like
215/75 BFGs if you are running that size. Ideally, I need comments on each
gear rather than just "I liked the tire fine," but any comments are welcome.
The above mph@4000rpm numbers are based on actual speeds, not the false
speeds reported by your speedometers.
So far we will have at least 5 sets of vans running around North America
with the 16" trailing arms by the way, which vans are participating in the
16" project I am organizing for owners of previously 14" vans. These are in
addition to those other pure breed 16"s in the hands of Ben and David, as
those of you who watch this stuff already know.
At 10:12 AM 3/6/01 -0800, you wrote:
>derek,
>
>i read some of the "back and forth" about the tire
>size issue, as i found them on some of the chat rooms
>which your amendment below led me to. (sorry, crappy
>sentence) anyway,,, my plan has always been to go
>subaru in my van. the mechanic where i live has done
>one KEP conversion on an '85 westy. and having driven
>this vehicle made up my mind long before i purchased
>my syncro.
>
>so i knew that i would screw up the gearing by using
>the michelin ltx 235 75 15's. and yes it has. i
>would not recommend this to anyone if they live near
>any hills. the acceleration is not hampered at all
>except for fourth gear. actually i would call the
>effect of the tires on the first three gears, an
>IMPROVEMENT.
>
>on the interstate with all of our local hills, i find
>it best to cruise between 75 and 80 actual mph. this
>seems to minimize the deceleration up hills. please
>note that i do not ever lose speed to the point that i
>am not going at least the limit (70). but it does
>take a lot of planning to make sure that one has
>enough momentum up those hills.
>
>i definitely would not reccomend this to any one who
>was going to plan on using the wasserboxer
>permanently, as the highway thing takes quite a bit of
>thinking. the in-town driving is better, with
>increased mpg. and the rig currently still
>outperforms my '77 westy on the two-lane highways
>around here. but i am saving my cash for a future
>subaru as i had always intended.
_______________________________________________
Derek Drew New York, NY
CEO & Co-Founder
http://www.ConsumerSearch.com/
===========================
"Best Expert Review Site"
for product reviews on the Internet
Jan. 2001, PC World Magazine
==========================
80 South Street, 2nd Floor
New York, NY 10038
derekdrew@rcn.com
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