As Swifty said Specialized does not have men's or women's bikes starting with the 2020 model year. Here is a link to their hyper buzz worded article on the topic "BEYOND GENDER".
To illustrate the truth of no more genders go to the website for Specialized shopping for Rockhoppers
- Filter for MODEL YEAR 2019
- Notice that men's bikes and women's bikes are listed.
- Remove the filter for MODEL YEAR = 2019
- Filter for MODEL YEAR = 2020
- Notice that the gender qualifier is missing from the bike names in the results.
- Leaving the MODEL YEAR filter set to 2020, flip the GENDER filter back and forth between Men and Women.
- Notice that the same bikes are in either Men or Women, or both.
No "Men's Rockhopper" or "Women's Rockhopper" only "Rockhopper" for 2020
At the bike shop you must have tried a different model or year of Rockhopper.
According to the sizing chart from an authorized Specialized dealer:
If you are 5'6" to 5'10" you would ride a medium.
If you are in the range for the size of bike you have I'd take it back to the shop and have them fit the bike to you.
No matter what the chart says if you are unhappy with the size you can exchange it.
Specialized has a 30 day return policy
From the Specialized FAQ:
Can I exchange an item if it doesn't fit?
We realize that buying items that are size-specific over the internet is difficult. Because of that, we offer a 30-day satisfaction guarantee on products purchased from our webstore.
Upon receiving your order, if you find the need to exchange an item for the same item in a different size or color, we can help. However, if you want to switch to a different item, then you'll need to return the item for a refund and order the new item separately.
We will send out the replacement item(s) on exchanges within five days of receiving the original item back. We will send it via Fed-Ex 2-Day air, at no charge to you, to the address from the original order.