Thinking about a wider rear tire

[Riko_imp]

Also, when i was doing research about modding a Triumph Thruxton I found a cuss of pictures of guys with 160 tires - 170 rear and 180 rear.

And on picture its hard to say wich is wich if you dont know it at front. Skilled eyes can always tell the difference between a 160 and a 180 tire of course.

But as I said, a 160 tire will already give you that bulky look you are looking for

As far as function goes, why would a 180 rear tire be that much more better over stock than a 160 rear tire?
Both tires are already way over the stock recommend size of 140..
If you talk about handling, you can read stories here on this board from a few ppl that have a 160 tire, but no 180 stories her.
On the Thruxton board you will find a bunch of user reviews about the change in handling by putting on a wider tire...and I think that the general conclusion is when you do it correctly (choosing the right size, front tire size, diameter size, aspect ratio, etc. etc.) there are little negatives but certainly also benefits to getting a wider tire.

A small quote from the Thruxton board:

Quote:That hit the nail right on the head. Wider tires don't handle like crap, they just handle differently. Depending on how you ride, the difference in a wider tire can be an improvement or a step down.

Taking things a step at a time:

1) Cornering: From simple geometry, for the same lean angle, a wider rear tire moves the back tire's point of contact with the road further to the inside of the turn. That means, for the same lean angle, the line between the back and front contact points is turned more towards the outside of the turn. Therefore, it takes more lean angle, and more effort, to make the same radius turn at the same speed. But that's not necessarily all bad.

If you are a racer, of course that's a bad thing. But if you are a cruiser or daily road rider type; that extra effort can actually make the bike feel more stable in the turns. It may not actually be more stable, but it feels like it.If you ride near the bike's limit, it can give a false sense of security. But if you always leave lots of margin in cornering, and it feels better, it can be a plus. Be careful, but - cornering is a tie.

2) Appearance: Wider looks bitchin'. Wider is a clear winner.

3) Wear: A wider tire has more surface on the ground so the stress on the tread is less. So wider is better.

4) Dry Traction: Wider is a clear winner. Not only is there more rubber on the ground to grip the road, but, since wider tires wear better, the tire can have a softer tread for better grip while still having a reasonable life.

5) Rolling Resistance: The same factors that improve traction also work in the opposite direction and increase rolling resistance. Increased rolling resistance lowers gas mileage, lowers acceleration, and lowers top speed. Wider is worse.

6) Straight Line Stability: It would seem like a tie, but real roads aren't flat. On a cambered road, the contact patch shifts to the "uphill" side of the road and tends to drive the bike "downhill". A wider tire amplifies this effect and makes the bike more sensitive to the road. Wider is worse.

7) Wet Traction: A wider tire has to pump water a greater distance to keep the contact patch dry and is more likely to hydroplane. Wider is worse.

8) Weight: Wider tires are heavier. More weight costs in mileage and acceleration. The additional weight is also unsprung weight, so it makes road holding worse. Wider is worse.

So there's at least some of the factors to consider when choosing a tire size. I apologize in advance to those who complain about my use of "mechanical physics".
Rest of discussion can be found here: http://www.triumphrat.net/twins-technica...yre-3.html

ps: you can always use this practical tool to compare the stock set up in size with the new tires and wheels:
http://www.tacomaworld.com/forum/tirecalc.php