hey any one run a 130/70/18 rear tyre ?

hey guys i was looking at my local tyre shop and he had a 130/70/18 rear tyre. i need a new rear tyre, has any one run this size tyre on a seca ?(i have a 120/80/18 on it atm) it looks like it should have heaps of clearance. will it fit ? any opions
cheers brenton

 

so noone runs this size ? not even any of the maxim boys ?

 

The maxims run 130-90-16 rear tires...

 

Some Secas run 120-70-18 rear tires. Mine does.

 

Well - a 130 rear should run in the swingarm without rubbing - as evidenced by our Maxim's. Pretty sure you have the same swingarm....

Anyway - the only issue you'll run into is a slight error in your speedometer casued by different tire diameters -- the 130/70-18 is 25.2" dia, and the 120/80-18 is 25.6" dia.

A quick calculation from here:
http://gs.tolan-hoechst.com/tirecalc.htm

tells me the new tire would cause the speedo to read 2% slow -- not a big deal

 

The speedometer is from the front tire - so the rear tire change won't effect that.

A maxim rear tire is 130-90-16.
A seca rear tire is 120-70-18

The difference in the diameter of the tire is important. The seca's rear tire will be nearly 2 inches deeper into the swingarm than the maxims. This is important to note because the swing arm's arms are not parellel - they spread slightly. Going deeper into the swing arm could make the tire rub.

Someone has already posted that one 130 tire they used rubbed the swing arm. They claimed all it did was wear off the side of the tire. They didn't seem too concerned about it - but it certainly doesn't sound like a good idea to me... the swing arm clearance was put there for a reason...

Woot.

 

*DOH*
Completely went past me about the speedo -- and I knew that too *slaps forehead*
Okay so I'm an idiot sometimes....

Yes - the 130 in my bike does rub on the sides of the tire a *tiny* bit -- after some 20,000 kms it's just sorta noticeable as a rubbing streak on the sidewall.

So the 0.4" diameter change shouldn't cause a problem.

Now the only thing I could think of is how the tire would change the riding characteristics -- I have this vague feeling of reading some time ago of how upping the tire size didn't really help much, but introduced some wobble and/or braking issues......

 

It's not just the additional 10mm in width... it's 10mm of width 1" deeper in the swing arm...

Each - is supposed to show 1"

16" diameter maxim tire, 18" diameter seca tire.

Code:

16"  --------#--------

18" ---------#---------

See how the 18" tire is bigger? If you measure from the axel along the swing arm 8" make a mark - then measure 9" Measure the width between the 8" mark and then the 9" mark. The swing arm is narrower between the later two points as the swing arm isn't perfectly paralel.

Rubbing isn't a good thing altus.

The handling properties of a larger tire aren't nessisarily better... but that's I guess my tangential rant

Also note that different manufactures make their tires slightly different sizes and shapes. Across the thread might be 130mm for all 130 tires but the profile of a particular 130 the tire may be flatter than a different 130 tire and rub more for example...

I guess the answer at this point - Brenton obviously wants to try this out and he's aware of the potential problems. Why not try it and take pictures... all I ask is that if it does rub that you seriously be careful, and that you ride the bike softly until you figure out how it is going to be affected by the change.

Woot.

 

how wide are the maxim rims ? are they still 2.15" (if thats what it is) the same as the seca rims ?
cheers brenton

 

how wide are the maxim rims ? are they still 2.15" (if thats what it is) the same as the seca rims ?
cheers brenton