Biei and Furano in early May

Hi guys, I plan to visit Biei and Furano in early May, but people say that the best time to visit them is in July. Is it still worth visiting? If so, do I have to rent a car to visit the good spots? I plan to use bikes to save money.

Can anyone give an opinion to this?

The best is from mid-July to late July to see lavenders at Furano. Biei could be good even in August. Very few kinds of flowers bloom in Biei, Shikisai No Oka, in May.
http://www.shikisainooka.jp/green/calendar/
That is why you have not got an answer. No one has an experience to go there in such a period.

This is the page by Farm Tomita in Furano for the period from mid-Apr to mid-May.
http://www.farm-tomita.co.jp/farm/labo.asp?id=1
Quite likely, these pictures would be taken in mid-May. You should expect fewer flowers than these if you come in early May.

Bikes for Biei should be one of the best methods to go around the region in summer.
http://www.yamagoya.jp/

There are other regions for flowers in early May in Hokkaido. Most people chose to go there instead of Biei and Furano. But, even though, there is no guarantee to see the best timing of flowers. The peak of blooming does not last more than a week or so. That is why I do not just say July at the beginning.
http://naru-hodo.com/archives/1173.html
http://www.visit-hokkaido.jp/general/detail/3

I would say that the landscape around Biei is nice also in May. I was there in July, but even if there are no flower fields it is still a nice landscape. But if you go because of the flowers, then as the previous poster said, it might be too early.

I also enjoyed the blue pond and the nearby waterfall. I went by car, so I am not sure how feasible these points are reachable by bicycle. Have a look at a map that tells you elevation profile (e.g. Strava). Continuing on from the waterfalls and up in the mountains you come to a nice onsen area. It is described on this web page here. We went to the one at the end of the road. From there also some hiking is possible but not sure if it would be already open when you go.

Bycicles in Biei are a good transport option. It is however a bit hilly. So depending on your fitness you might want to get an electrically assisted one.

Enjoy your trip to Hokkaido!

In early May, cherry blossoms, Sakura, will bloom in Southern Hokkaido. The peak is short, a day or so, but you may see it at some of the popular places; Shizunai, Matsumae, Hakodate, Noboribetsu, and Sapporo. A Sakura hunting by car could be ideal to cover a large area.

Sakura blooms in a rather cold season. Most people wear a coat to enjoy it. Even the landscape in Biei is nice, I could not recommend riding a bicycle there in Northern Hokkaido, wearing a coat. As LikeBike said, it is a hilly area. Climbing up might be OK, but downhills... So chilly I would expect.

Go there in summer, or go to the south in early May. This is a practical advice to you from me.

Thanks everyone for your help. We like nature a lot, even though there are no flowers in Biei, we might still consider doing it, with an electric bike if not a regular one.

@Luisjp: is your concern more about the temperature when going downhill rather than the strength to pass the slope?