Rough ride due to skinny shallow front tire. What is the largest tire that I can put on that wheel. I am willing to put a bigger fender on the bike in order to make a bigger tire fit.

Per Tire Rack, for a 2001 330ci you could use 235/35-19 front and 245/35-19 in the rear. Wider tires for the same profile increase the tire's effective diameter(think wheel well gap above the tire) and will change both the odometer and speedometer readings. Additionally, the wider tires may cause rubbing of the fender or other components while turning unless the fenders are flared out.
Caliper clearance should be checked, usually M3 uses bigger calipers than stock. While they may look cool installed, there are several disadvantages to lolwer profile tires such as harsh ride, unforgiving of potholes/speedbumps, wider width is worse for snow application (cause that floating feeling). The 2008 wheel will have the tire pressure monitoring system (TPMS) .
Both have a bolt pattern of 5-120.

Pull the front pully cover off and remove the rear wheel fender - the belt goes on the front pully first. raise the back of the bike in the air so the rear wheel spins freely. Make sure the transmission is in neutral. start at the bottom and put the belt on the bottom of the pully and spin the wheel clockwise(toward the front of the bike) and allow the belt to feed onto the pully. put the covers back on and ride. I can change a blast belt in about 10 minutes.

Look at the sidewall of both tires. There will be a 'MAX PSI' embossed on the tire. It will probably say Max 45 PSI. At 45psi the bike will ride like a rock. At 15psi it will ride really squirrely. Find a psi at which you feel the bike handles well and rides well. One rider may weigh 125 pounds and the next rider may weigh 300 pounds. The best psi for each rider will be different due to weight. Chances are that 30 to 35 psi will do the trick.

If anything, you need better rear springs. Springs support the suspension not the struts. Struts just keep ride smooth and stable. Get bigger/heavier duty rear springs.

Hi.


Standard tires are already oversized in 03 model. This are the maximum standard allowed, probably the same as what you already have:
Front - D402F MH90-21 54H
Rear - D401 150/80B16 71H
(front: 80/90 - rear :150/80-it was 130 in 02 model)

Without modification you cannot use any bigger tire. By changing wheel, belt and pulley, you can mount at rear up to 200 at rear (see job done on the 06 softail here).

At front you need to replace wheel and to move the fender. The result is not always great when you do modification to front wheel. The best thing to do is buying a spacer kit.

Regards

Ginko.

Congratulations on learning to ride the bike. I use the rear gears mainly i.e. the gears on the right hand side. Each rear gear makes a little difference so it makes it a little easier to go uphill. (When the chain is on the back smallest cog wheel it's hardest to pedal and easiest on the largest. The reverse is true of the front cog wheels) If you come to a very steep hill you should use the front gears i.e. the lever on the left hand side. This makes a bigger difference to the effort needed to climb a hill. When you have put the front gear into the easiest position, (on the smallest cog wheel) you can still use your rear gears to make it easier still. For going on flat ground or downhill most people keep both sets of gears on the hardest gear. (The front gears on the largest cog wheel and the rear one on the smallest) However there's no rule that says you have to. Use the one that feels you're using just enough energy to turn the pedals and in time you won't have to even think about the gears. I hope this helps.

The pedal should not be able to reach the front tire. Sometimes one gets their toes to overlap the front wheel on a racing bike but that's because they have intentionally short wheel base and a steep for angle. Which way is the fork on your bike pointing? It should be angled or curved forward.

Look at the bike icon on this posting for an example.

first take off the brake caliper takes a 10 mm socket..Next jack front of bike up just enough to take pressure off front tire...take off the axle nut lbit more to take pressure off axleock washer and flat washer...Next remove two axle support nuts from the right side of bike 1/2 in socket. now jack bike up a hair more to releave pressure off axle push, hammer with a rubber hammer or what ever it takes to drive it through. jack bike up so it clears fender. Sometimes the tire won't clear the fender bolts if so just release air from tire and it will clear. good luck. Its not hare at all.

Try warming the tire up. Put it in the tub with super hot water it will make it stretch easier. I did this with a twelve inch kids bike it worked sweet.

Big tires:

1. Hard time for your drive train (clutch, cv joint, tranny, diff gears) , power steering, brakes
2. Slow acceleration
3. possible fender damage
4. turning radius problem
5. increase body roll and instability
Advantages:
1. good ground clearance
2. softer ride
3. Enhanced off-road ability

tires your planning to buy can fit into your existing rims.
My personal opinion is for you to go for the bigger tires!