Front tires on the rear?

[Garnet]

I'm searching for new tires for my /2 conversion. It calls for 3.50x18 front and rear. The closest I have found in a good tire is 100/90 x 18 Avon Roadrider universal (can be used on front or rear).

While I am happy with them, they are not super in the cold and wet, and I live and ride in a place that is cold and wet a lot. They are very good when really hot.

I have read a few good reports about the new ContiGo http://www.conti-online.com/generator/w ... go_en.html .
Problem is they only make the 100/90x18 in front. I have run a front on the rear of my R26 but it is 100 lbs lighter and only 15 hp. The Conti appears to have the same tread pattern front and rear.


Would it be insane to run a front tire on the rear of 460 lb bike at speed?

[Deleted User 287]

Insane is a relative term.

What kind of brakes do you have on the front?



Photo courtesy of Nathan at the other Boxerworks!
http://boxerworks-service.com/fabricati ... conversion


That rascal:

[mattcfish]

The issue is tire profile. Front tires have a more "triangular" profile for proper steering while rear tires are flatter for stability. Putting a rear tire on the front would cause obvious handling issues. Putting a front on the rear....not so sure what that would do.

[Garnet]

Insane is a relative term.

What kind of brakes do you have on the front?

Old fashioned ones.

[Garnet]

The issue is tire profile. Front tires have a more "triangular" profile for proper steering while rear tires are flatter for stability. Putting a rear tire on the front would cause obvious handling issues. Putting a front on the rear....not so sure what that would do.

The universal Avons that I run now have a nice round section which makes a nice rear:


The /2 was designed run the same tires front and rear, in fact the wheels are interchangable with splines on the front wheel as well.

[Deleted User 287]

Insane is a relative term.

What kind of brakes do you have on the front?

Old fashioned ones.

I could have used one of those once, a long time ago. A panic stop on my conversion rig, several years before the internet came to be and I met folks like Duane that told me to grease my control lever pivots and give me some clue on adjusting front drums.

So after I snapped a brake cable, I panicked and bought a used set of R65 flakes and the complete used front brake system from the same R65. I sent the swingarm and wheel/rotor/caliper off to somewhere in Chicago, where tabs were welded on for the caliper.

But I pulled a chair exclusively, so I was happy with good old Block K's.

[Duane Ausherman]

To run the same tire on front and rear is normal, but only if the profile is similar to the original, which was a rear tire.

[Major Softie]

Triangular profiles are probably not a good choice on the rear, both for handling and for traction/wear. A rounded section front tire would probably be fine, but the big question is: what direction do you run it? Many modern tires have carcasses which are designed to best deal with forces in only one direction - especially front tires. So, it may be best to run the front tire in the opposite direction when placed on the rear, as front tires deal primarily with braking force while rears primarily with acceleration forces. However, many modern tread designs are designed to only go one direction for water shedding....



So, good luck.

[khittner1]

Garnet---I have no insights on the how a front ContiGo would work for the back of your rig. But, if you're not committed to a "modern" tread pattern, Heidenau, as well as some of the Asian tire makers, still make "universal" front/rears in a 3.50 x 18 size. Check smalltires.com [url]http://www.smalltires.com/categories/mo ... scription=

Konrad

[barryh]

Front tires don't have to be triangular. Even within the range of permissable rim sizes the tire profile will change according to the width of rim it is mounted on. The profile will be slightly flatter on a wider rim so you might want to consider tire and rim sizes accordingly. Also front tires tend to have a lower load rating than rears so it worth checking you have enough head room there.