Im trying to learn how to put an engine on my mountain bike with a spring. I'm very new to anything like this and have no clue what im doing.

[cloakedvillain]

But as it has full suspension, the motor chain tension will continuously be changing, so he'd need to run a jackshaft, which might not be the best if he's a noob just looking to slap a motor on his mountain bike.

On the other hand, that kcvale bike is sooo hot...

The travel is minor on those. Maybe 40mm, but the change in distance between the sprockets will be smaller than that because swingarms move in an arc.

Some basic trig and plotting the arc could find the actual change in distance but the spring loaded tensioner can assuredly take it up assuming there are no clearance issues.

But this is all tertiary as I am pretty sure op is trying to motorize a frame that doesn't have room for a china doll.

 

[Sidewinder Jerry]

But as it has full suspension, the motor chain tension will continuously be changing, so he'd need to run a jackshaft, which might not be the best if he's a noob just looking to slap a motor on his mountain bike.

On the other hand, that kcvale bike is sooo hot...

Your choices is a spring loaded tensioner or a shift kit to a rear derailleur with full suspension builds.

 

[Sidewinder Jerry]

The travel is minor on those. Maybe 40mm, but the change in distance between the sprockets will be smaller than that because swingarms move in an arc.

Some basic trig and plotting the arc could find the actual change in distance but the spring loaded tensioner can assuredly take it up assuming there are no clearance issues.

But this is all tertiary as I am pretty sure op is trying to motorize a frame that doesn't have room for a china doll.

Will look up some hard tail mountain bikes as well. Some of the old frames have plenty of room.

 

[Amwicr]

The travel is minor on those. Maybe 40mm, but the change in distance between the sprockets will be smaller than that because swingarms move in an arc.

Some basic trig and plotting the arc could find the actual change in distance but the spring loaded tensioner can assuredly take it up assuming there are no clearance issues.

But this is all tertiary as I am pretty sure op is trying to motorize a frame that doesn't have room for a china doll.

that's true, hadn't thought of that. Anyway we're probably getting ahead of ourselves since he hasn't even posted again.

wait how'd you know he don't got room?

 

[Sidewinder Jerry]

If your mountian bike doesn't have room; get a hybrid bicycle frame. Walmart has a wide selection to choose from or get a decent used hybrid bicycle. You can always put suspension forks on it and a suspension seat post.

 

[Amwicr]

I wonder if he'll ever come back...?

 

[Sidewinder Jerry]

I wonder if he'll ever come back...?

Many see what looks like fun to ride. Yet, find building to be too great of a challenge.

 

[Amwicr]

Many see what looks like fun to ride. Yet, find building to be too great of a challenge.

Which is sad, because it really only takes basic tools and knowledge, plus youtube. On my first build I was a total noob, and I learned a ton. Imo this hobby is a great entry into the world of wrenching.


And the cool thing is you can start simple, and as you gain confidence and skill, make it faster and better.

 

[cloakedvillain]

its been one day....

 

[Amwicr]

its been one day....

I personally have a hard time keeping off this place for a whole day