Follow the steps here to ensure your rack ends up flat, level and secure. Once this is done, you can either hang panniers off it or bungee your load to the top.
If your frame doesn’t have the special lugs which are needed for bolting the rack to, you’ll have to take your bike to the shop and investigate brackets. As well as the p-clips mentioned on the opposite page, there is a whole range of specially made little gadgets for bolting the rack to the frame. The most common is a monostay adapter bracket, which allows you to bolt a rack onto the type of frame where the seat stays merge into one tube above the rear wheel. Rack-mounting seat collars can also save the day, especially on smaller frames. These replace the ring that you tighten to adjust your seat height, with a similar version that has additional threaded holes for the rack to bolt onto.
Step 1: Work out which end is the front – more confusing than you think! The stays will bolt onto holes in the top of the rack. The holes on the back are for attaching reflectors and lights to – in this picture, you can see a separate plate on the back. You may have to spread out the legs of the rack slightly to fit over the frame – the rack stays go on the outside of the frame on either side of the back wheel.
Step 2: Bolt the legs of the rack to the outside of the frame, just above the back wheel axle. Use a washer under the head of each bolt. Take special care on the right-hand side of the bike as the bolt must not protrude through the frame, where it may interfere with the sprockets. If it does, either use a shorter bolt or take the bolt out and add extra washers directly under the bolt head. Don’t tighten the bolts yet.
Step 3: Next, attach the stays loosely to the front of the rack. Two common kinds consist of a pair of thin, flexible stays or a stiffer pair of stays with a selection of different-length extra sections to be bolted on. The stays bolt into slots rather than holes, so that you can adjust the position of the rack to suit the shape of your bike. If you’re using shake-proof washers, you’ll need a spanner to hold them while you tighten the bolts.
Step 4: Next, fit the front of the stays loosely onto the frame. If you’ve got flexible stays, bend them gently so that you can get the bolts into the frame – take care not to crossthread the bolts. If you’ve got a selection of joining pieces, choose a length that allows the stays to reach the frame.
Step 5: With all the bolts loosely attached, you should now be able to pull the rack into place so that the top of the rack is level with the ground. Look from above too and check it’s pointing straight forwards. You may have to twist it into place.
Step 6: Once it’s in place, go round systematically and tighten all the bolts – on the bottoms of the legs, on the stays and where the stays join to the frame. Check again that the bolts on the bottoms of the legs don’t protrude through to the insides of the frame and interfere in any way with your sprockets.
Source : BIKE MAINTENANCE TIPS, TRICKS & TECHNIQUES
See also bike maintenance tips, tricks and techniques “Choosing the right gear”