Channel balance parts

Thanks for posting. Our S371-28 balance is the correct replacement for your Rollyson window. When placing your order, select the spring strength option of 2740. I'm afraid the top sash guide 18-124P is no longer available in black.

Sure, we could custom make this balance for you. Can you just tell me how many you need?

I'm not sure why this would happen. It usually occurs when the spring is too strong, but all the information you gave us points to the 2740 option. What is the weight of the sash your balance supports? Could it be that the original 2740 option was too strong? Also check the length of the metal channel to make sure they match up to the ones in the window. The company that manufactured the window you have went bankrupt, so they might have just used any size balance they had lying around to complete orders. It's an unfortunate but common scenario.