Hi all. So I've owned many trail bikes over the last 10 years, and I generally ride them very hard, mostly off road. I change the oil when the shifting becomes too difficult, and gear changes are missed. At this point it feels like there is a lot of friction on the shift lever. But once the oil is replaced, it shifts like butter again.
Here is a list of the oils that I've used over the years, in various small bore thumpers (with consistent results across different bikes) and how many miles it roughly takes to get to this point when the shifting becomes a problem:
10w30's
Valvoline Synpower: ..............200 miles (consistent over multiple oil changes)
Castrol Power 1:.......................300 miles (consistent over multiple oil changes)
Motul 7100:...............................300 miles (only used once)
10w40's
Valvoline Synpower:...............400 miles (consistent over multiple oil changes)
Castrol Power 1:.......................500 miles (consistent over multiple oil changes)
Shell Advance Ultra:...............800 miles (consistent over multiple oil changes)
Mannol Motorbike 4T:..........900 miles (consistent over multiple oil changes)
Comma 4 stroke (Part syn): 900 miles (consistent over multiple oil changes)
Motul 5100:...............................900 Miles (consistent over multiple oil changes)
Silkolene Pro 4:........................1100 miles (only used once)
Motul 7100:...............................1300 miles (consistent over multiple oil changes)
5w40's
Comma 4 stroke:.....................900 miles (consistent over multiple oil changes)
So there is a clear pattern in that the 40 oils are able to last longer than the 30 oils before the friction in the gear leaver becomes too much, and in some cases much longer.
My ultimate goal is to find an oil that will last the longest and at a reasonable price. But I don't know why some are lasting so much longer than others. Other than it might be something to do with the viscosity.
So does anyone know what might be happening here? Is it shear down? A breakdown of the additives? Something else?
Should I stick with 10w40 or would a different viscosity yield longer life?
Here is a list of the oils that I've used over the years, in various small bore thumpers (with consistent results across different bikes) and how many miles it roughly takes to get to this point when the shifting becomes a problem:
10w30's
Valvoline Synpower: ..............200 miles (consistent over multiple oil changes)
Castrol Power 1:.......................300 miles (consistent over multiple oil changes)
Motul 7100:...............................300 miles (only used once)
10w40's
Valvoline Synpower:...............400 miles (consistent over multiple oil changes)
Castrol Power 1:.......................500 miles (consistent over multiple oil changes)
Shell Advance Ultra:...............800 miles (consistent over multiple oil changes)
Mannol Motorbike 4T:..........900 miles (consistent over multiple oil changes)
Comma 4 stroke (Part syn): 900 miles (consistent over multiple oil changes)
Motul 5100:...............................900 Miles (consistent over multiple oil changes)
Silkolene Pro 4:........................1100 miles (only used once)
Motul 7100:...............................1300 miles (consistent over multiple oil changes)
5w40's
Comma 4 stroke:.....................900 miles (consistent over multiple oil changes)
So there is a clear pattern in that the 40 oils are able to last longer than the 30 oils before the friction in the gear leaver becomes too much, and in some cases much longer.
My ultimate goal is to find an oil that will last the longest and at a reasonable price. But I don't know why some are lasting so much longer than others. Other than it might be something to do with the viscosity.
So does anyone know what might be happening here? Is it shear down? A breakdown of the additives? Something else?
Should I stick with 10w40 or would a different viscosity yield longer life?