Here is a center post question from Kiran, one of our customers. It is in regards to his engine and our plans. I think his question and our response which is below it might help you or someone out.
Question: I bought the 200 rigid sportster plans. I plan on using a 1980's Yezdi classis 250cc 2 stroke engine, which has a built in transmission.
As you mentioned in one of your tutorials in response to a customers question on whether the center post has to be removed or not, could you please tell
me if there is any modifications I have to do on the 220 series rigid Sportster plans?
Answer: I reviewed the model and engine and I think you should be able to fit this with the frame. You will need to adjust the center post based on the engine and transmission spacing that you have.
Doing some searching, I found the photo below of a
It does have a center post but it is angled back towards
the seat. You should be able to do the same with the custom frame and
create enough of an opening there for the engine and transmission. The
center post provides a lot of strength to the frame and it is highly
recommended that you keep this to help distribute the loads that the
frame will see.
If you ultimately have to remove this post, then two vertical posts helping to support the frame should be added at the rear fork.
Here is another frame that we sell:
You can see that there is no center post, but the rear forks have two
supports to help transmit the loads and give rigidity to the frame.