Originally Posted by
NigelHealy
Right so the considered views is Ti has no impact on rideability whatsoever? If that's true its wasted inside a S6R/Schlumpf build, I would be best keeping the Ti inside a M2L.
I'm doing my blind test possibly as early as the weekend, ordering some Ergon GR2-L next days, S6L vs S6L-X.
Right now I have 3 Brommies configured S6L/BWR, S6L-X/SRAM, and M2R-X, and a Schlumpf Mountain Drive. My plan is to make either a S6R-X/Schlumpf or a S6R/Schlumpf for long-distance touring and the question is purely impact on speed and comfort.
I'm definately keeping Ti on a S6L-X/BWR. So the fallout is do I end up with a M2L or a M2L-X.
There's something inside the Brompton making it slower, I average 2mph slower than the cheapest REI 27speed Alumium $600 bike I have which does most of the mileage. I'd prefer to use Brompton for flexibility of folding or riding to a more distant place to get the bus back but not at 2mph slower.
From what you're telling me, the Ti vs Steel will have negligible impact on performance so I might as well keep the Ti on a 2-speed where it will do the most good (carrying weight). Hopefully by this time next week I'll figure it out because I have to do an evening of parts shuffling to get to the 3 end configs. I need to move the BWR to Ti soon, the chain droops onto the frame when freewheeling on high hub gear, it will for sure ruin the paint if I keep it on the steel frame and I need to move it over and ride it to break-in the BWR and get it more efficient before I then rely on that bike as my regular day bike.
FYI, I picked up in the Brompton dealer the Steel seatpost vs the Ti seatpost - the factor of 3x on the weight is very noticeable.
It is not the Brompton that is causing you to ride slower. It is the smaller tires. In the perfect world where roads are flat and smooth as glass, tires of all sizes should roll with the similar rolling resistance characteristics. Unfortunately, most roads in the world I had toured thus far is anything but smooth as glass. The third world for instances, roads are rough. The reason you are slowing down a bit compared to a normal sized bike is because, roads have imperfections. These imperfections are easily overcome with bigger tires like a 26, 29er or 700c and treats it like small tiny hills. These same imperfections are not as easily overcome with smaller tires found on clown bikes. What these imperfections look like small hills to a 700c tire is large mountains to a 20" 406 tire. Imagine you have to go through a ton of these imperfections. Not a problem with 700c or 29" tires, but more so with smaller tires. So this is where you are getting your speed deficiencies. Most US roads are good enough that there is little performance penalties. I road with fast riders on Trek Madone and Cannondale carbons with skinny tires and I have no problems keeping up with around 22 to 25mph, but then suffer if they start riding in rougher roads where I do have to work harder.
This brings up your next concern. Will Titanium help you smooth out the roads with a folder. My answer is not as good as running wider tires like the Big Apples. You see, these minor road imperfections is what's causing the increase in vibration feedback from the road. Bigger tires obviously transmit less through was is called a pneumatic effect. Sheldon Brown article concentrates mainly on bigger bikes where the large diameter tires take most of the sting out of the road. The only way you can take the sting out of the rough roads I find is to run lower pressure tires. By the way, wide and lower pressure does not equal slow. In fact, what I found when I was riding with the faster guys is that, my Big Apples on my Mu SL were performing well at 65PSI with the best of both worlds -- comfort and speed. Comfort comes from the pneumatic effect, which is the tire's ability to envelope or swallow these road imperfections without having to go over it! Most modern tires are made with modern technologies that contribute to little rolling resistance. In fact, my brand new snow tires I have now on my car has the rolling resistance similar to the best all season tires! Never felt disadvantaged whatsoever. And the Mu SL is stiff! Made of aluminum but does not ride like one thanks to Big Apples. Plus I run a standard seatpost (no Thudbuster). Comfort is not on the frame material. It helps, but the main comfort is always on the tires first. And yes, I do vary tire pressure to reflect ride terrain. This approach is better and cheaper than buying Titanium which I suspect will not give much bang for the buck.
Btw, I have Big Apples on my full suspension bike that I use for touring and the ride itself in phenomenal on rough roads where my Fox shocks does not do anything much to smooth them out.
Hope this helps.