We just moved into our new (to us) house this week. It is a great riding area with lots of hills and nice bike lanes and so forth. The only issue that I have is that the road from our house is gravel for about 150 yard before it turn into pavement. While I can walk the bike on the gravel, there are times that I would like to ride it if possible. Is there a tire that will hold up without giving me flats?