RonKMiller
Dec 9th, 2005, 10:51 am
I get asked this question a lot, and here is my final answer!
Differences between 99 - 04 OEM LT seats vs. 05 - 06:
99 - 04 seats are a bit wider (1") at the rear, use thinner, more dense foam in the bottom, have a thinner lumbar support so you sit back a bit further. The 99-04 seats will not fit on an 05 properly and will leave a gap (a cosmetic issue only) of about one and half inches between the side panels, they will ride higher on the frame. 99 - 04 seat pans are made from plastic, 05-06 seats from a laid fiber material very similar to fiberglass, and are much stiffer and heavier. 99 - 04 seats used rivets to attach the vinyl, 05 - 06 use staples. 99 - 04 seats had five internal tie down points to secure the back of the seat to the frame where it meets the lumbar bolster, 05 - 06 have seven. Both have a commodity vinyl top cover. "Greige" (BMW speak for grey/beige?) showed up in 05. 05 - 06 vinyls do not have a grain, and are dull (meaning no shine) looking, have a bit more "grip" and are less slippery.
BMW changed the seat in 05 due to complaints from dealers that they were losing too many customers in the showroom to Honda Goldwings, especially from "vertically challenged" riders. Anyone with an inseam of 29" or less was struggling to get their feet down and securely planted - it made the bike feel very unwieldy - enough to turn off a lot of guys right from the start without even taking it for a test ride! Inexperienced riders especially felt that the bike was just too big/heavy/awkward for them. The taper of the seat was made more severe toward the front so that you could keep your legs closer together and have more stability. They also made the lumbar support thicker to push you further forward, also increasing confidence for short legged riders. The pan was made differently and sits lower in the frame, and the difference between high and low height settings lessened by 1/2". Even with all of this they still were able to make the foam a little thicker in the 05 seat in the center by making it less dense - to TRY to make it more comfortable - although this rarely works.
Bottom line, both LT seats are fair (IMHO) for riders up to about 200 lbs, but as you get over that weight range things go downhill (literally) quite fast. The OEM polyurethane foam is crushed and you are pretty much sitting on the seat pan. Foams have a specific indentation force (IF) and designers have to walk a tightrope when only working with one material - polyurethane. They are forced to work with commodity polyurethane since it is EXTREMELY inexpensive - about 50 cents worth goes into a BMW seat. If the designer specifies a foam with a high IF that is good news for heavy riders, but light riders will be sitting "on top" of the seat. Low IF means heavy riders will "bottom out". Contrary to popular belief, polyurethane seats do not "wear out" from use until they are about 20 to 30 years old. (unless a poorly made polyurethane was used from the start that had too much air entrained in it) At that age they start to decompose and literally turn into powder. Polyurethane tends to be very "springy" or resilient and has poor damping qualities.
Generally speaking the 99 - 04 seats are better for taller, heavier guys. The 05 - 06 better for shorter, lighter guys. However a tall, heavy rider with a short inseam may like the 05 - 06 seat better...
I think it is very difficult to define things from a "comfort" standpoint: It is what the individual feels is right. Kind of like buying a pair of good shoes.
Differences between 99 - 04 OEM LT seats vs. 05 - 06:
99 - 04 seats are a bit wider (1") at the rear, use thinner, more dense foam in the bottom, have a thinner lumbar support so you sit back a bit further. The 99-04 seats will not fit on an 05 properly and will leave a gap (a cosmetic issue only) of about one and half inches between the side panels, they will ride higher on the frame. 99 - 04 seat pans are made from plastic, 05-06 seats from a laid fiber material very similar to fiberglass, and are much stiffer and heavier. 99 - 04 seats used rivets to attach the vinyl, 05 - 06 use staples. 99 - 04 seats had five internal tie down points to secure the back of the seat to the frame where it meets the lumbar bolster, 05 - 06 have seven. Both have a commodity vinyl top cover. "Greige" (BMW speak for grey/beige?) showed up in 05. 05 - 06 vinyls do not have a grain, and are dull (meaning no shine) looking, have a bit more "grip" and are less slippery.
BMW changed the seat in 05 due to complaints from dealers that they were losing too many customers in the showroom to Honda Goldwings, especially from "vertically challenged" riders. Anyone with an inseam of 29" or less was struggling to get their feet down and securely planted - it made the bike feel very unwieldy - enough to turn off a lot of guys right from the start without even taking it for a test ride! Inexperienced riders especially felt that the bike was just too big/heavy/awkward for them. The taper of the seat was made more severe toward the front so that you could keep your legs closer together and have more stability. They also made the lumbar support thicker to push you further forward, also increasing confidence for short legged riders. The pan was made differently and sits lower in the frame, and the difference between high and low height settings lessened by 1/2". Even with all of this they still were able to make the foam a little thicker in the 05 seat in the center by making it less dense - to TRY to make it more comfortable - although this rarely works.
Bottom line, both LT seats are fair (IMHO) for riders up to about 200 lbs, but as you get over that weight range things go downhill (literally) quite fast. The OEM polyurethane foam is crushed and you are pretty much sitting on the seat pan. Foams have a specific indentation force (IF) and designers have to walk a tightrope when only working with one material - polyurethane. They are forced to work with commodity polyurethane since it is EXTREMELY inexpensive - about 50 cents worth goes into a BMW seat. If the designer specifies a foam with a high IF that is good news for heavy riders, but light riders will be sitting "on top" of the seat. Low IF means heavy riders will "bottom out". Contrary to popular belief, polyurethane seats do not "wear out" from use until they are about 20 to 30 years old. (unless a poorly made polyurethane was used from the start that had too much air entrained in it) At that age they start to decompose and literally turn into powder. Polyurethane tends to be very "springy" or resilient and has poor damping qualities.
Generally speaking the 99 - 04 seats are better for taller, heavier guys. The 05 - 06 better for shorter, lighter guys. However a tall, heavy rider with a short inseam may like the 05 - 06 seat better...
I think it is very difficult to define things from a "comfort" standpoint: It is what the individual feels is right. Kind of like buying a pair of good shoes.