Lapland is the last wilderness in Europe with scenery that is outstanding on this planet. You are free to roam anywhere within 200 meters from the nearest house on uncultivated land. Please do not leave any signs of your visit and take only photographs amd memories with you. While summers are cool it can be hot on fine days in the valleys, but freezing temperatures can be expected at night. It can rain heavily for many days and you need warm woollen clothing and gloves in such weather. Gore Tex or other fully waterproof clothing is necessary.
Best time to go is from May 15 to September 15 but at both ends of this time you can expect night frosts that are not uncommon in the fells even in the middle of summer.
Mosquitoes can be a great nuisance in some areas in Lapland. You should have mosquito-netting and -repellants available in Scandinavia if you intend to do camping in Lapland. You do not need to worry about mosquitoes while riding your bike.
Main roads are good or excellent but can be winding and narrow in Norway where there are also numerous tunnels. Get a copy of Tunnelguide for Syklister (in Norwegian) from the Tourist Office.
There is excellent mountain bike cycling on dirt roads and mountain paths leading to the fells. Do not ride off road on the fells because you will damage the lichen that the reindeer use as food. Do not try to photograph the reindeer because you will scare the flock and it is hard work getting it together again. Ask the locals, they will have domestic reindeer in their backyard and you will get excellent photos there.
You do not need a fancy bike to ride in Lapland but be sure that it is in good condition because you will not find spare parts easily. Tires for mountain bikes and 700 C rims are widely available in the village shops.
There are endless possibilities of touring in Lapland: the Lofoten Islands have spectacular scenery with no steep gradients. Distances can be enormous for a cyclist but the Coastal Voyage of Norway is an excellent (though expensive) way to do island hopping. Norway is very mountainous but Finland has few hills of note. Camping is allowed everywhere within 200 meters from the nearest house on uncultivated land. Water in the rivers and brooks in the fells is generally safe for drinking but streams coming from glaciers are considered unsafe for drinking..
One last note: get yourself and your bike to Lapland. You will never forget your stay in Lapland.
Account of my trip to Nordreisa in Northern Norway