Rear tire for front use - Wrist Twisters
 4Likes
  • 2 Post By Bigdaa
  • 1 Post By badmoon692008
  • 1 Post By Quadiak
 
Thread Tools Display Modes
post #1 of 18 Old 06-29-2018, 02:57 PM Thread Starter
Milites Gregarius
 
Quadiak's Avatar
 
Join Date: Apr 2016
Posts: 116
Rep Power: 1
 
Rear tire for front use

I believe my friend may have lost his marbles, so I want to post this here and get opinions on what he plans to do.

He is riding a 2017 m109r suzuki cruiser and apparently the on the forums he frequents, a bunch of people are running Avon or metzler 160/60zr18 tires on the front of their bikes to replace a 130/70r18 tire. Not only are they running rear tires on the front but they are also running them in reverse rotation.

I told him today I didnt think this would be a good idea, because tires are engineered to run a certain location and direction. Am I wrong to tell him this? thoughts?

Quadiak is offline  
Sponsored Links
Advertisement
 
post #2 of 18 Old 06-29-2018, 04:46 PM
Discen
 
Diablo's Avatar
 
Join Date: Apr 2018
Location: Buderim
Posts: 200
Rep Power: 1
 
I tend to agree with you, but I'm not an expert.
Mcromo is very knowledgeable on this subject, I'm sure he'll have something to add.

Diablo is offline  
post #3 of 18 Old 06-29-2018, 04:50 PM
Left of Centre
 
K1w1Boy's Avatar
 
Join Date: May 2011
Location: Auckland, NZ
Posts: 3,505
Rep Power: 1
 
I agree with you, I wouldn't do it, but nothing surprises me anymore about tyres since the "dark side" thread on here a few years back which featured cruiser guys running square-shouldered car tyres on the back of their bikes...

K1w1Boy is offline  
 
post #4 of 18 Old 06-29-2018, 07:18 PM
"Whose ABBA ZABBA?"
 
Bigdaa's Avatar
 
Join Date: Jan 2006
Location: Goleta, California
Posts: 17,127
Rep Power: 1
 
Those rear tires are "identifying" as front tires. That makes sense to some people in this day and age.
g00gl3it and Supernintendo like this.

In my opinion, the M1 rifle is the greatest battle implement ever devised.
General George S. Patton
Bigdaa is offline  
post #5 of 18 Old 06-29-2018, 08:55 PM Thread Starter
Milites Gregarius
 
Quadiak's Avatar
 
Join Date: Apr 2016
Posts: 116
Rep Power: 1
 
Quote:
Originally Posted by K1w1Boy View Post
I agree with you, I wouldn't do it, but nothing surprises me anymore about tyres since the "dark side" thread on here a few years back which featured cruiser guys running square-shouldered car tyres on the back of their bikes...
I have heard of that and I just cant wrap my brain around a square tire on the back of any bike!!!

Quadiak is offline  
post #6 of 18 Old 06-29-2018, 09:00 PM
919 Rider
 
Islandboy's Avatar
 
Join Date: Dec 2016
Location: Flinders island
Posts: 2,212
Rep Power: 1
 
A drag bike.

Islandboy is offline  
post #7 of 18 Old 06-30-2018, 05:40 AM
rmb
Let's go!
 
rmb's Avatar
 
Join Date: Aug 2009
Location: Sussex Couty NJ
Posts: 7,650
Rep Power: 1
 

Awards Showcase
Wrist Twisters Event Attendance Wrist Twisters Event Attendance Wrist Twisters Event Attendance Wrist Twisters Event Attendance 
Total Awards: 9

The reason the rear tire is mounted backwards when installed on the front is due to the braking force. The normal force applied to a rear tire is under acceleration; when the tire is on the front the force applied to the tire is under braking only, exactly opposite of the acceleration force on the rear.

rmb is offline  
post #8 of 18 Old 06-30-2018, 11:24 AM Thread Starter
Milites Gregarius
 
Quadiak's Avatar
 
Join Date: Apr 2016
Posts: 116
Rep Power: 1
 
Quote:
Originally Posted by rmb View Post
The reason the rear tire is mounted backwards when installed on the front is due to the braking force. The normal force applied to a rear tire is under acceleration; when the tire is on the front the force applied to the tire is under braking only, exactly opposite of the acceleration force on the rear.
what about tread design and potential hydroplaning issues?

Quadiak is offline  
post #9 of 18 Old 06-30-2018, 01:34 PM
"Whose ABBA ZABBA?"
 
Bigdaa's Avatar
 
Join Date: Jan 2006
Location: Goleta, California
Posts: 17,127
Rep Power: 1
 
I guess people are so full of stupidity these days that they will ignore the directional arrows on MC Tires because they "know better" fucking retards.

In my opinion, the M1 rifle is the greatest battle implement ever devised.
General George S. Patton
Bigdaa is offline  
post #10 of 18 Old 06-30-2018, 05:30 PM
rmb
Let's go!
 
rmb's Avatar
 
Join Date: Aug 2009
Location: Sussex Couty NJ
Posts: 7,650
Rep Power: 1
 

Awards Showcase
Wrist Twisters Event Attendance Wrist Twisters Event Attendance Wrist Twisters Event Attendance Wrist Twisters Event Attendance 
Total Awards: 9

Quote:
Originally Posted by Quadiak View Post
what about tread design and potential hydroplaning issues?
That could be an issue, most important thing is the tire construction is designed for force on one direction. I personally wouldn't do it.

rmb is offline  
post #11 of 18 Old 06-30-2018, 06:27 PM
jack
 
old fart's Avatar
 
Join Date: Dec 2016
Location: crossville
Posts: 31
Rep Power: 1
 
no hope for a dope

old fart is offline  
post #12 of 18 Old 07-01-2018, 10:30 AM
Pilus Posterior
 
Join Date: Mar 2013
Location: Sacramento
Posts: 2,160
Rep Power: 1
 
I have no idea about the direction, the braking force could be the issue, but the width of the front tire is very important. It's about the fall in angle, maybe not a big deal for some, but seem that how the bike falls into a turn is based on how wide the front tire is. The rear as to transfer a LOT of power, but the start of the turn is in the front.

If it were a good idea, I'd think the factories would do it.


Remember way back when the Ford Explorer was flipping over because of a small amount of air pressure? These are professional engineers that can test all these things and have tons of data.

The tread design in a turn would concern me if the turn angle wasn't an issue. Remember the tire is on the very end, so a small change in the angle make a big difference at the top.

KarlJay is offline  
post #13 of 18 Old 07-01-2018, 03:28 PM
McTavish
 
mcromo44's Avatar
 
Join Date: Oct 2007
Location: Calgary
Posts: 5,652
Rep Power: 1
 
This is a very interesting one.
First a bit of history.
Back in the Bias Ply era, it was common for manufacturers to dual mark tires for Front and Rear use, the respective indicator arrows being opposite.
Such tires were raced in this manner, Isle of Man included, with perfectly acceptable results.
This said in terms of also including heavy powerful race bikes with twin disc brakes, and not just low powered drum braked single cylinder 4 strokes.
If one accepts that the primary reason for doing so is to avoid stressing the tread overlap joint the wrong way, it makes sense
My recollection is that any such tire of the day also had what I will call a non directional tread pattern.
In other words, no matter which way the tire was mounted, the tread looked the same in terms of how it's footprint first contacted the pavement on the basis of the bike going forward.
A good example of this is the ancient set of Pirelli Phantoms that are on my sleeping 73 SOHC CB750, and the Dunlop K81s I used to run before the Pirellis, were just the same in terms of the above mentioned.
However, such tires were available in sizes "correct" for fronts or rears, meaning there was also a(n acceptable) match of tire size to rim width.
From the above, the key points are carcass design and tread pattern suitabilities re dual rotation use, and tire/rim width matching.

Ill also add in something here about so called Vd front tread orientation.
I just happen to have a current and originally tread patterned dedicated front Metzler Lasertec ready for my 73. (they were an awesome wet tire back in the day, some say the definitive wet tire)
Its V pattern is arranged as are modern sport tires, as in the outboard end of the tread openings lead in terms of contacting the road surface, with the root of the V trailing.


As for the use of a 160/60R18 Rear backwards instead of a 130/70R18 dedicated Front, a few observations and comments.
The ideal rim width for the 130/70R is a 3.5, with an allowable range of 3.0 to 4.0.
My guess is the m109rs front rim is a 3.5, and would be surprised if it wasnt.
Some quick fishing about indicates that the ideal rim width for the 160/60R18 is 4.5, and that the allowable range is 4.25 to 5.0.
My guess is that 160/60R18s come on 4.5 wide factory wheels.
So the use of a 160/60R18 tire on a 3.5 factory m109r front rim will result in rim pinch of 1.0 in terms of ideal rim widths, and 0.75 in terms of the 160/60R18s minimum allowable 4.25 rim width.
Both are huge amounts of rim pinch, and there is no way that carcass stability wont be adversely effected.
Said rim pinch will also change the profile of the tires contact patch, by effectively narrowing it and steepening its sides, effectively making it more front tire like.
There will be rolling circumference difference, but likely not all that much, and my guess is the 160 will be a bit taller, including the effect of narrow rim pinch.
At least the treading, if Vd in any way, will be in the right direction, that said in terms of tread overlap and water evacuation.
Textbook its not, but for those that are doing it, it seems workable.
Id run away from it personally, especially because of the extreme rim width mismatch.
My question is Why are they even doing it?.
I hope its not just for looks, because there is plenty of tire varied and good tire choice.
Quadiak, Ill bet theres a bunch of us that would like to hear from you about the Why? of your friend.

mcromo44 is offline  
post #14 of 18 Old 07-01-2018, 06:43 PM Thread Starter
Milites Gregarius
 
Quadiak's Avatar
 
Join Date: Apr 2016
Posts: 116
Rep Power: 1
 
Quote:
Originally Posted by mcromo44 View Post
This is a very interesting one.
First a bit of history.
Back in the Bias Ply era, it was common for manufacturers to dual mark tires for Front and Rear use, the respective indicator arrows being opposite.
Such tires were raced in this manner, Isle of Man included, with perfectly acceptable results.
This said in terms of also including heavy powerful race bikes with twin disc brakes, and not just low powered drum braked single cylinder 4 strokes.
If one accepts that the primary reason for doing so is to avoid stressing the tread overlap joint the wrong way, it makes sense
My recollection is that any such tire of the day also had what I will call a non directional tread pattern.
In other words, no matter which way the tire was mounted, the tread looked the same in terms of how it's footprint first contacted the pavement on the basis of the bike going forward.
A good example of this is the ancient set of Pirelli Phantoms that are on my sleeping ‘73 SOHC CB750, and the Dunlop K81s I used to run before the Pirellis, were just the same in terms of the above mentioned.
However, such tires were available in sizes "correct" for fronts or rears, meaning there was also a(n acceptable) match of tire size to rim width.
From the above, the key points are carcass design and tread pattern suitabilities re dual rotation use, and tire/rim width matching.

I’ll also add in something here about so called “V’d” front tread orientation.
I just happen to have a current and originally tread patterned dedicated front Metzler Lasertec ready for my ‘73. (they were an awesome wet tire back in the day, some say the definitive wet tire)
It’s V pattern is arranged as are modern sport tires, as in the outboard end of the tread openings lead in terms of contacting the road surface, with the root of the V trailing.


As for the use of a 160/60R18 Rear backwards instead of a 130/70R18 dedicated Front, a few observations and comments.
The ideal rim width for the 130/70R is a 3.5”, with an allowable range of 3.0 to 4.0”.
My guess is the m109r’s front rim is a 3.5”, and would be surprised if it wasn’t.
Some quick fishing about indicates that the ideal rim width for the 160/60R18 is 4.5”, and that the allowable range is 4.25 to 5.0”.
My guess is that 160/60R18s come on 4.5” wide factory wheels.
So the use of a 160/60R18 tire on a 3.5” factory m109r front rim will result in “rim pinch” of 1.0” in terms of ideal rim widths, and 0.75” in terms of the 160/60R18’s minimum allowable 4.25” rim width.
Both are huge amounts of rim pinch, and there is no way that carcass stability won’t be adversely effected.
Said rim pinch will also change the profile of the tires contact patch, by effectively narrowing it and steepening it’s sides, effectively making it more front tire like.
There will be rolling circumference difference, but likely not all that much, and my guess is the 160 will be a bit taller, including the effect of narrow rim pinch.
At least the treading, if V’d in any way, will be in the right direction, that said in terms of tread overlap and water evacuation.
Textbook it’s not, but for those that are doing it, it seems workable.
I’d run away from it personally, especially because of the extreme rim width mismatch.
My question is “Why are they even doing it?”.
I hope it’s not just for looks, because there is plenty of tire varied and good tire choice.
Quadiak, I’ll bet there’s a bunch of us that would like to hear from you about the “Why?” of your friend.
first of all, thank you for the exceptionally informative post.

secondly, and sadly, I believe these riders are strictly doing this just for looks. the m109r comes with a very wide rear tire stock and I believe these guys just want the look of a wide front tire.

thirdly, my friend..... well others have already jumped off that bridge and landed it.

Quadiak is offline  
post #15 of 18 Old 07-01-2018, 07:00 PM
McTavish
 
mcromo44's Avatar
 
Join Date: Oct 2007
Location: Calgary
Posts: 5,652
Rep Power: 1
 
Quote:
Originally Posted by Quadiak View Post
first of all, thank you for the exceptionally informative post.

secondly, and sadly, I believe these riders are strictly doing this just for looks. the m109r comes with a very wide rear tire stock and I believe these guys just want the look of a wide front tire.

thirdly, my friend..... well others have already jumped off that bridge and landed it.
Your thread really intrigued me, so I went at it.
It also struck a chord, in terms of my having previously explored using radials on correct rim widths on a modified SOHC CB750 chassis I have been sketching in.
A reversed 130 front would go on the back using a rim on the + side of ideal to slightly alter the profile. (the front would get a complete 919 clip, so plenty of room for ideal rim width for a 100 or 110)

I'm not surprised to hear that "looks" were the driver, but hey, if no one crashes as a result of it then I suppose it's OK, stupid as it is.

Yeah, once in deep, even further committed to the cause!

Anyway, at least you can have some fun with your friend, even if you just ask him about the rim pinch effect. LoL!

mcromo44 is offline  
post #16 of 18 Old 07-02-2018, 09:33 AM
(Quintus) Pilus Prior
 
badmoon692008's Avatar
 
Join Date: May 2013
Location: Neenah, WI
Posts: 2,222
Rep Power: 1
 

Awards Showcase
Extraordinary Ride 
Total Awards: 1

The only real concerns I'd have have been mentioned above. Tread possibly working against you in wet weather situations, and putting a far too wide tire on a narrow rim. Depending on the belt design, the tire itself may not be directional, only the sipes. I know at the track rear tires are frequently flipped at tracks that have many corners going the same direction to get more life out of them with no ill effects.
mcromo44 likes this.

Love is the feeling you get when you like something as much as your motorcycle - Hunter S. Thompson
I just mı̸̸̸̸̸̸̸̸̸̸̸̸̸̸̸̸̨ade you wipe your screen.
-2009 Suzuki GSX-R 750 Race Bike
-2007 Honda 919
-1995 Nighthawk 750 (Tboned)
-1983 KZ 440 (Sold)
badmoon692008 is offline  
post #17 of 18 Old 07-18-2018, 11:33 PM Thread Starter
Milites Gregarius
 
Quadiak's Avatar
 
Join Date: Apr 2016
Posts: 116
Rep Power: 1
 
I have trouble believing a tire manufacturer actually put this in writing, but there it is....

http://www.avon-tyres.co.uk/motorcycle/faqs
mcromo44 likes this.

Quadiak is offline  
post #18 of 18 Old 07-19-2018, 03:34 PM
McTavish
 
mcromo44's Avatar
 
Join Date: Oct 2007
Location: Calgary
Posts: 5,652
Rep Power: 1
 
Quote:
Originally Posted by Quadiak View Post
I have trouble believing a tire manufacturer actually put this in writing, but there it is....

FAQs | Avon Tyres
The Brits don't subscribe to legal paranoia as much as most do in other jurisdictions do.

mcromo44 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Wrist Twisters forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome