Disagree with 'don't need that much tensile strength'.
And yes, chains with lower tensile #'s do stretch and wear out quicker.
This is physics, and metal chemistry.
Match correct T.S. to your application.
<<<<<Tensile Strength…What's in it for you?
You may have already noticed that the higher the tensile strength rating of a chain, the progressively higher price tag it carries. That has to do with the costs of the component raw materials used in the chain, the manufacturing costs, heat-treating processes, the price of a barrel of Arabian crude oil, etc., etc., etc. The real question is…
"Why should you pay for a higher Tensile Strength chain?"
Here are the Main Benefits of Higher T.S.…. The useful life of any chain directly relates to the tensile strength number. The higher the number, the longer the chain will last, under the same conditions.
The higher the tensile rating, the less the chain will stretch and consequently, the less maintenance required to adjust out the resulting slack.
The greater the tensile strength the more ability the chain has to resist damage caused by shock loads imposed by hi-impact events in the drive train such as dumping the clutch at 12,000 rpm….landing full power-on from a triple…operating the drive system with excessive chain slack or loose sprocket bolts.
Here is the most overlooked, hidden benefit of high tensile: If you ride off-road, the eventual day will come when a rock of just the right size and shape finds its way in between a chain roller and a sprocket tooth. The higher the chains' tensile, the better your odds that the rock loses the contest and gets pulverized. You won't even know it happened. A lower tensile chain has a greater probability of losing the battle to the rock and the chain breaks apart.
So…. What should you buy?
The real questions you should be asking yourself………..and answer…..…are.........
1-How long are you keeping your Bike?
2-Do you like regularly adjusting greasy drive chains?
3-Do you enjoy gambling on unexpected breakdowns due to chain failure?
Category "One" Rider / Mechanic
If you are selling your machine soon, don't mind the hassle of constant chain adjustments or consider trail side emergency repairs a fun adventure…then your choice will be the lowest T.S. chain which will also be the cheapest to buy. However, it may prove much more expensive if it fails and takes out the motor cases or rear hub. But you have to be willing to take that gamble in the first place.
Category "Two" Rider / Mechanic
If you are keeping your bike for years; harbor a true disdain for adjusting chains; or prefer to limit your risks to Friday night poker or the madman next to you in a tight turn at speed…then your choice is clear…purchase well above the recommended minimum and get the highest T.S. chain you can fit into your budget…>>>>>
We're not talking a lot of $$ here either.
Even a real nice non o-ring standard chain with good tensile #'s is only $100-150, depending on what brand you like.