Titanium question
 

I got a titanium seat mast for my Bike Friday and was pleasantly surprised by how much it absorbed bumps and such (not the reason I initially bought it). So now I am wondering if anyone has a titanium steerer mast on their small bike and whether you find the same cushioning capability translates to the handlebars? It's not an inexpensive upgrade but would be worth it to me if it cut the vibrations way down. It's probably about the same price as a titanium handlebar but I actually have a bar I love that weighs less than many titanium ones do, so don't want to change it out. My steerer mast, otoh, is steel so it's heavy. Anyone using one on any bike?

Titanium, magnesium, and carbon fiver all do a good job of attenuating higher frequency vibrations. Although weight is usually the initial appeal of these materials, their ability to absorb vibration is a equally valuable.

That's great. One more question, if I may? The seatmast flexes and for the seat that is terrific but do I need to be concerned about flexing on a steerer mast of titanium? If it helps, it will be about 13" long.

Whether you like or dislike the flex is up to the rider. As long as you don't break the part, then it shouldn't significantly affect the steering.

If you climb out of the saddle a lot, and pull hard on the bars, then the flex could potentially reduce your power & efficiency. But, it shouldn't negatively impact normal riding.

What does your mast look like? I have a Bike Friday Gooseneck. But, the stem part appears to be a straight tube. If that is the case, you may be able to purchase simple 3Al/2.5V titanium alloy tubing. What thickness? It may be cheaper than purchasing a stem.

It's a pakiT mast. Currently has the following, which I cut down a little:

If you have a local metal supply shop, you can ask them. They'll normally cut, or sell you remnants.

You may need to do some cleaning and polishing.

This is 0.070, about twice your thickness.

https://www.ebay.com/itm/Grade-9-Tit...S/123147916963

This appears to be sold by the inch (in 6" increments).
https://www.titaniumjoe.com/index.cf...55:0.035:SMLSS

With a variety of sizes and thicknesses.
https://www.titaniumjoe.com/index.cfm/products/tubing/

It is possible the tubing is $25, and the plastic end plug is $100. :foo:

Bwaa haahaaha. There has to be SOME difference between these tubes and the stuff BF, Brompfication, etc., all sell for exhorbitant amounts, right? The one on ebay is actually almost perfect in length, I could live with it. Being twice as thick will make it heavier, obviously, but it would still be considerably lighter than my steel version at half thickness, right? No point in getting something that weighs more. With shipping it is around $45 which is eminently manageable - but again, I don't believe you ever get something for nothing so why is this so cheap compared to the ones the bike folks sell? Just markup or is there a difference structurally or in finish or something? Thanks, you are being super helpful =)

steel density 7.85
titanium density 4.5
aluminum density 2.7

(approx, depending on alloys)

So, going twice as thick with the titanium, will be heavier than steel. The Titanium Joe site had a couple of thicknesses available.

There are a couple of Titanium alloys, but they should be similar. 3Al2.5V is perhaps the most common. There is also a 6Al4V. The 6/4 is stronger, but more expensive and harder to find. Nonetheless, the metals being used for the stems should be similar whether you buy them from BF or a metal supplier. And a straight tube, no welds or added parts should make it pretty straight forward.

I don't know about prices. Both metal suppliers and bike stores have markups. But, BF should be able to get pretty good prices on raw materials.

There will be some minimal machining on the posts. Cutting, rounding edges, polishing, etc. But, it can't be that much.

Bike Friday also has to support the business, employees, and turn a profit, so nothing can be given away for free.

Some of the internet suppliers are also selling off remnants. It is quite possible that bike manufacturers have troubles acquiring remnants. One could get them from companies like Boeing, but perhaps it is hard to get a contract for just certain useful sizes.

I've owned a couple older Dahons with flexier front ends than the current models. Based on that experience I wouldn't be inclined to buy a steering mast that flexed more, regardless of weight savings.

Big fan of titanium although don't have a titanium bike but I do feel it is the best material for frames and many other components of a bike. Fuji-ta the world's largest bike manufacturer by a huge margin and dominating aluminium frame sales and produce a huge number of robot welded steel frames plus also a very significant player in carbon frame production for brands like Cannondale, GT, Raleigh etc actually seem to have a preference for titanium or at least are honest about the material properties.

https://cimg0.ibsrv.net/gimg/bikefor...fb8cb7f436.jpg
Titanium Bike Frame - Tianjin Fuji-ta Bicycle Co.,Ltd.

I feel the chart is a little unfair to titanium weight though as it used to be stated that titanium was about equal in weight to a high quality aluminium frame or lower end carbon frame. However maybe their chart is true for their specific frames as they are at the forefront of aluminium and carbon frame technology.

The weird thing about titanium frames or parts is their complete lack of needing to be painted so its often easy to restore the finish to as new by polishing, the only other material that can look as new for decades is stainless steel. Also having great resistance to fatigue more so than even Steel means a very long life frame. Where as carbon frames are breaking frequently and hitting landfill its nice to see a material that not only produces a very long life, durable product but is easily recycled at end of life. Great for the environment just like cycling in general.

Creating butted titanium tubes is an expensive process so many titanium tubes are straight gauge for cost reasons. Doesn't seem to affect ride quality but clearly you sacrifice a weight advantage if you don't use butted tubes.

I guess my point is titanium is a fantastic material that seems to be out of favour due to carbon producing lighter frames and parts nowadays but for me far, far superior to carbon.

Seems an ideal material for a folding bike but I don't know of any mass market models at reasonable prices either currently or in the past. Today you get decent entry level titanium road and mountain bikes perhaps £1,200 here in the UK but no folding bike at similar prices.

Throw in price, or cost/ease to manufacture from raw material to finished product, on that chart, and steel is the overall winner. That's my reading.

are you on the Fuji-ta payroll?

I met someone in Portland that had done a Brompton-like fold on a Titanium bike.

He said that the titanium folding bikes significantly benefited by using oversized tubing as Titanium has different flex and strength properties than steel. This is probably especially true with using a monotube style construction.

Thus, a quality folding bike needs essentially a complete redesign to move to titanium rather than simple tube substitution.

Having discovered first hand how much more plush than steel a titanium seat mast is, it just seems to me titanium would make more sense on small wheeled bikes but maybe because the higher end ones are already more expensive than typical full sized bikes, it's not a winner in the market. Perhaps the Helix, should it ever actually get delivered, will change those perceptions.

I think that chart clearly shows titanium scoring highest as an average. Wouldn't mind being a brand ambassador for fuji-ta. I seem to be their unpaid ambassador I must admit, so getting some money for it would be nice. Fuji-ta seem to make the bulk of their export money from aluminium and carbon frames to western markets. Their titanium business is insignificant in comparison I believe but still good money but very niche. That's why I thought the chart was likely to be very fair in comparison to a chart produced by a exclusive titanium frame manufacturer. Fuji-ta make most of their money from steel, aluminium and carbon frames but still rate titanium the highest.

yes, Titanium as a raw material averages the highest, but we don't buy titanium material. We buy a frame made of a material. Throw in cost/ease of manufacture (translating into price) in the equation, and the result is not so clear cut or definitive. You know me, i try to be sensible about such things. I get the advantages of titanium frames and parts, but often it is also, as with other things, about cachet, prestige and a pecking order. And you know how i feel about that.

I spent a day on some pretty rough Texas chip seal pavement, my hands took a beating and my GPS was acting erratic from the vibration. I had between 55 and 60 psi in my front 1.5 (40 mm) width Schwalbe Marathon tire. The next day I dropped my pressure to between 40 and 45 psi in my front tire, but no change in the back tire which was between 75 and 80 psi. My hands and GPS were much happier at the lower pressure in the front tire. And I did not notice any additional rolling resistance.

Ha ha, we love and hate our chip seal :) Funny thing is you will ride on freshly paved smooth roads one week and a few weeks later they throw in the chip seal. Ride as fast as you can and hope your fillings don't fall off. Good testing ground for water bottle cages.

Its tricky. Road bike riders are slowly learning that wider tyres actually have lower rolling resistance than skinny higher pressure tyres (23c to current 25c, they will settle on 28c for a while ), but there are limits to everything. I want at least 28c for all of my bikes and as low a pressure as reasonable. I want to switch from schwallbe ones at 25c to panaracer mintus lites at 28c, but someone measured the panaracers and they are only 25c but sold as 28c ;( Maybe their tubes? Either way Id like a better choice in tyres at 451.

Maxxis Torch 37-451

I had not thought about water bottle cages, but if they start to crack from vibration, you REALLY need softer tires.

At Ti Cycles near Portland OR, they can custom fabricate things for you,,

Have an order in their Queue to replace the Al alloy folding mast from my Pocket Llama/..
they can do it in steel, powder coated or Ti..

Though they said the elasticity of a long Ti tube may not be as desirable steering
rather than under seat comfort...

Oversize tube diameters were used in that 1 prototype "Ultimate Folding Bike", to stiffen up some excessive flex.

with an intended 10K$ selling price..





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The mast on my pakiT is only 15" long so I am thinking the flex would be pretty minimal...

go for it, report back..
my bar mast project is just 16" tall