Folding Bikes - Titanium - does it improve or worsen performance - does it improve comfort?

I'm in the process of moving parts between 3 Bromptons, two Titanium and one steel, and figuring do I sell/keep a Titanium-based bike for long day rides. I'm not bothered about weight or rust, but on speed and comfort.

I've read Sheldon's muse that Ti is springier and that on areas like curved forks it will make things a little comfier, and on rigid triangles it has no performance impact, but what's anyone's view on this?

I can make a touring-specification Brompton which is a S6R with SRAM rear hub and Sclumpf Mountain Drive, and make the forks, rear triangle and the seatpost either Steel or Titanium, in fact I can pick Ti/steel for each of these 3 components separately (e.g. Ti forks, steel triangle, steel seatpost). I'll sell what I don't want. I don't need 3 Bromptons, this is a matter of do I sell/keep Ti.

Views?

Ti won't rust :)

Ti won't rust :)

Yes I know that, but to be frank, the value of the rusted part isn't much, up to that point its a strength/rigidity/performance discussion.
If, say, the Brompton steel rear triangle is rusted to the point a scrub and paint isn't enough it costs about 110ukp to replace and instantly remove any hidden damage.
So Titanium's anti-rust features aren't important.

I bought Ti for simply easier to carry the folded bike. So back to my question - what is the impact on comfort and performance?

I'd do a blindfold test, but I doubt the difference can be felt.

titanium is springy, but when drawn into tubes and welded together, not so much. Especially when the triangles are small and the tubes are oversized.

Two thoughts:

1) The amount of flex in the rear triangle is minuscule compared to the amount of give in the tyre, and in the case of the Brompton, the rear suspension block. The material of which the rear triangle is made, is immaterial. The fork has more give to it, but it is still small compared to the tyre contribution. So for first line comfort, the tyres dominate completely.

2) The material properties can have an impact on how impacts are transmitted through the frame to the rider; a springy material will have a more pronounced filtering effect compared to a stiffer material. So high frequency portions of road impulses will travel less well through titanium than steel, and this may have the effect of feeling less jarring. It is the high frequencies that cause discomfort. For the short tubes of the Brompton, the effect is probably too small to be detected by the seat of your pants.

Thanks, my next purchase is some Ergon grips, Velox rim tape, fit same Marathon Plus tyre, and then make my steel B the same front-ends as my Ti frame and then ride and make a performance judgement.

c'mom boys and girls..its 3 times more expensive, it has to feel better ......

otherwise what Jur says ... its hard to draw conclusions when you compare "big bikes" to our clownbikes .... A titanium frame is usually designed different than a steel or alloy carbon frame... every material needs their own small details to be taken care off, but when done right, every material has their small advantages ...
again for our bikes... not so much

thor
who is lusting for a 20 inch titanium folding/take apart bike

I'd do a blindfold test, but I doubt the difference can be felt.

titanium is springy, but when drawn into tubes and welded together, not so much. Especially when the triangles are small and the tubes are oversized.

Ride blind folded :eek:


c'mom boys and girls..its 3 times more expensive, it has to feel better ......

I think when I considered buying a Ti Brompton I worked out the effective weight saving of around 1kg was approx £500. That's an expensive KG!

I know for the hardcore racers they spend thousands for weight savings but I would prefer to carry an extra £500 in my pocket and put up with carrying a 1kg heavier Brompton or purchase second standard Brompton even :p

Regards

Jerry

When Sheldon wrote that stuff too most TI bikes were built with standard size tubing found with steel. Litespeed did make a bike (can't remember the name of it back in Sheldon's day, the Blade?) that used larger diameter tubes that riders said was a very stiff ride. So Sheldon never rode a TI bike made that way. And modern ti bikes are now constructed to be less flexy, but still springy enough to make the ride comfortable.

If a steel bike is taken care of it won't rust. I have several steel bikes and most of them are at least 23 years old and one is 27 years old and that one was rode a lot by me including riding it in the rain. I use to own a 79 Schwinn Traveler I bought new to ride on the wet sand of So California Pacific ocean, which meant it got drenched a lot of times with salt water! All I did was go home and hose it off but that's it, and that bike sat outside of my apartment where it got rained on. Then I stored the bike for about 15 years and when I moved I pulled the BB out to check for internal rust which there was some, but still usable, but I decided to leave the bike behind since it needed new components because the salt corroded the aluminum and there was some surface rust as well. But your talking about a lot of abuse and the darn frame wasn't rotted. So I have no problem with using steel

thor
who is lusting for a 20 inch titanium folding/take apart bike

sign me up!

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.

Ti UFB project [PDX] is wanting investors , to make a Ti Brompton frame..
10K each.. SRP, for the proposed bike.

Ti Brompton seat post seems to be supplanted by aluminum
due to sourcing and cost issues on the current X spec list..

An Alu seatpost failure looks painful.

I own 2 Ti seatposts.

The problem with Ti seatposts is they are slippier, they slip more easily, I've had more issues than steel seatpost. Another reason to go steel on a long-distance touring configuration.

An Alu seatpost failure looks painful.

I own 2 Ti seatposts.

The problem with Ti seatposts is they are slippier, they slip more easily, I've had more issues than steel seatpost. Another reason to go steel on a long-distance touring configuration.

titanium also tends to stick to other titanium bits if left in contact without some anti seize used.

but seatpost failures from the seat post splitting down the circumference are quite rare. Usually the frame, seat post cap or saddle clamp gives up before the seat post does. If it happens, it's usually because someone had too much fun with a drill.

I think when I considered buying a Ti Brompton I worked out the effective weight saving of around 1kg was approx £500. That's an expensive KG!

You can achieve 1KG saving for only $10 using few helium balloons.

;-)

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.

I'm not sure how fast I am on the Brompton. . . I can imagine a few possible reasons for being slower that combined might add up to something: suspension bob, hub gear friction, chain tensioner friction, flexy frame. . . plus small wheels. Also, crap brakes make for longer stopping times.
But perhaps there's something mechanically up with your Brompton like hub cone adjustment?

You can achieve 1KG saving for only $10 using few helium balloons.

;-)

But the aerodynamic drag more than offsets the decreased weight:p

But the aerodynamic drag more than offsets the decreased weight:p

just take a longer line

ok.. back to titanium .... what i posted made absolutely no sense whatsoever

You can achieve 1KG saving for only $10 using few helium balloons.

;-)

Imagine the drag, and the weight impact of a puncture.

All tires do not roll the same even on smooth as glass roads, this is a test done on a slew of tires that will disprove that idea: http://www.biketechreview.com/tires_old/images/AFM_tire_testing_rev9.pdf These tests were done in a lab thus the roughness or lack there of does not go into the equation.

All tires do not roll the same even on smooth as glass roads, this is a test done on a slew of tires that will disprove that idea: http://www.biketechreview.com/tires_old/images/AFM_tire_testing_rev9.pdf These tests were done in a lab thus the roughness or lack there of does not go into the equation.

Same brand name tire of all sizes should have similar rolling resistances. Even with the differences, it is not much. You're right. Not all tires roll the same way, but are you saying that a 26" Big Apple tire has significantly less rolling resistance than a 406 version of the same tire? :)

Bike Friday used a Ti tube to make a beam suspension for the seat post,
Softride used a specially designed composite to do something similar.

Same brand name tire of all sizes should have similar rolling resistances. Even with the differences, it is not much. You're right. Not all tires roll the same way, but are you saying that a 26" Big Apple tire has significantly less rolling resistance than a 406 version of the same tire? :)

I don't have a clue!!

the titanium beam is indeed springy, but so would be a steel tube .... carbon contraption or else....
its in the design parameters to be springy ....
that however doesnt mean that a titanium triangle is springy ...more than a steel or alloy triangle.... its all in the design of the tubes....
It does mean however that if you design a rear end with bend stays and maybe a lot of flex in one or more directions than titanium is a good material to start out with as it has great memory ( to spring back ) and low breakage ( compare to alluminum ....in that aplication)

thor

thor
"who is lusting for a 20 inch titanium folding/take apart bike"[/QUOTE]

Who MAKES a 20 inch Titanium folding bike? Besides that Brompton rear triangle...

thor
"who is lusting for a 20 inch titanium folding/take apart bike"

Who MAKES a 20 inch Titanium folding bike? Besides that Brompton rear triangle...[/QUOTE]

I think brompton now offers titanium for the seat post, rear triangle, fork and frame.

some one mentioned a Ti Minibike, but It didn't fold..
perhaps an S&S retrofit?

Tom Richey has a Breakaway coupled Ti/Carbon race travel 700c bike.


I believe Brompton has made a Russian sub contract for the back portion,
a China firm makes their forks.

who is lusting for a 20 inch titanium folding/take apart bike

I envisioned a Ti Moulton when I read this. Then I shuddered at how much Moulton would charge for that - $25,000?

there was an english? marketed ( russian made ??) Titanium bike with S@S couplers a while back.)( 2 years)??? They did however never answered to emails after the Interbike show in Vegas ...At the show they were somehow indifferent about things to say the least, might just be me or bad timiming when I visited them, but I dont loose the feeling it was a couple folks who enjoyed a biz trip to vegas more than the bike they were supposed to sell .... happens

there was an english? marketed ( russian made ??) Titanium bike with S@S couplers a while back.)( 2 years)??? They did however never answered to emails after the Interbike show in Vegas ...At the show they were somehow indifferent about things to say the least, might just be me or bad timiming when I visited them, but I dont loose the feeling it was a couple folks who enjoyed a biz trip to vegas more than the bike they were supposed to sell .... happens

That would be:-

http://www.qoroz.co.uk/bikes/


They have a travelling bike listed, but don't seem to have the 20" wheeler that i saw at the London Cycle show.

That would be:-

http://www.qoroz.co.uk/bikes/


They have a travelling bike listed, but don't seem to have the 20" wheeler that i saw at the London Cycle show.

most likely ... I hope I dont do them a big un service having a somewaht strange recollection of my vist on their booth .... might be cool folks who just didnt get the emails .... happens ....

thor
p.s. If I recall there were some finishing touches missing on the 20 inch bike

At the show they were somehow indifferent about things to say the least,
I took a Polish operated ferry from Copenhagen to a PL Port just over the Eastern German Border.

They had not gotten the customer service rapport thing much, yet, in 1991..

FYI was looking through my past postings, one thing I complained about was a Brompton when loaded with camping gear, a combination of top-heavy on the bike due to the camping gear, and the springiness below from the Ti meant it was not a good feeling riding a loaded Ti fork/triangle, and I wrote at the time that it would be better to have on a steel frame. Funny how I forget stuff.... In my last touring trip I used a steel frame and didn't experience the top-heavy skittish steering issue.

So I've got all I need to know, a touring type context really needs steel frame, a light commuting type context benefits from the Ti for carrying ease, this nothing really do with with the weight difference but the springiness difference.

That then finalizes all I needed to figure out.

OH just so you know Never use chrome polish on Titanium it is bad for the ti...