23 ounce flywheel weights

[Ud_luz]

For the displacement the flywheel, at least in my Montesa, is smaller than most enduros.

[sweeper]

Originally Posted by Ud_luz

For the displacement the flywheel, at least in my Montesa, is smaller than most enduros.

Also correct.

The trials bike engine internalizes a lot of the crank effect in the crank itself.Coupled with a bore and stroke designed to rev quickly and smoothly just off idle.They don't rev really.Very low rpm in comparison to moto or modern enduro/offroad racing 2 stroke engines.

Its about torque.
The old trials bikes did have monster flywheels.

The thought I had after reading through the thread.How much weight can the engine handle out on the end of the crank.23 ounces is a lot of weight out there for an engine that is designed to really spool it up.



Bearing,case wise.What's to much?

[Ud_luz]

Originally Posted by sweeper

Also correct.

The trials bike engine internalizes a lot of the crank effect in the crank itself.Coupled with a bore and stroke designed to rev quickly and smoothly just off idle.They don't rev really.Very low rpm in comparison to moto or modern enduro/offroad racing 2 stroke engines.

Its about torque.
The old trials bikes did have monster flywheels.

The thought I had after reading through the thread.How much weight can the engine handle out on the end of the crank.23 ounces is a lot of weight out there for an engine that is designed to really spool it up.



Bearing,case wise.What's to much?

I would think if it's correctly balanced the additional weight shouldn't be an issue.

[sweeper]

Originally Posted by Ud_luz

I would think if it's correctly balanced the additional weight shouldn't be an issue.

Same rider who adds 23 ounces of flywheel weight to the bike isn't gonna be a guy that keeps it spooled up all day.Its a riding style modification.Some relief their to the added stresses to the original engine design.

If I was contemplating that mod,I would cross reference main bearings and rod bearing sizes between a trials bike engine with approximate cc as what I was modifying.

Factor in the trials bike is much lighter.And is designed to run at a lower rpm with an intake,exhaust and electrical system designed for smooth almost electric acceleration and decceleration.There is no hit and the engine will only rev so high.

There is a cutoff somewhere to how much weight you can add and still expect the lower end to hold up.