Does frame material really makes a difference in terms of comfort and compliance? Part 1.

For the last 18 months, I have been testing various comfort improving parts. During that time I managed to select the best performing parts and based on them I have built my titanium benchmark bike, feeling very proud of the end result. Titanium frame seemed to be the obvious choice for the best comfort and I really felt the titanium magic. But then came the carbon Subito e-bike that made me rethink that assumption. This article is the start of a series of articles where I will try to find the real difference between different frame materials.  

Subjectively riding on a stock Subito e-bike felt much harsher than on my titanium benchmark bike. But when I transferred most of my benchmark bike components onto Subito (front wheel with tire, rear tire along with Redshift suspension stem and seatpost with SQ Lab Ergowave 612 Active saddle) the difference was significantly reduced. Then I started to measure the vibrations like I always do and instead of clear supremacy of my titanium bike, I saw both bikes going neck a neck.

At the rear, because of the Redshift suspension seatpost (which I call sometimes: a great equalizer that makes almost any bike very comfortable), the lack of any difference was understandable but Subito with Redshift stem was very close also at the front of the bike. It was so close, that I reckon putting the Wave handlebar instead of the stock aluminum one would put both bikes basically at the same, great level of comfort no matter the situation (both bikes have great forks that offers very similar, very high level of compliance so the only difference was the handlebar). To make things more interesting, I also compared both bikes with less efficient, but still very effective Canyon VCLS 2.0 flexing seatpost and (as you can see above), the results of both bikes were still exactly the same (but this also shows how important is the frame geometry – Subito offers a similar (to my titanium Escape) level of seatpost exposition that directly translates into more compliance but frame geometry is the big topic for another article…).

So is that results mean that frame material, when supplemented with the best comfort-improving parts becomes irrelevant? It certainly seems that way but objective numbers tell half of the story and the subjective feelings are as important. Or, for some, even more…

Subjective feelings

I have said many times that titanium subjectively translates into a significantly different but also better ride feeling. Titanium feels alive, springy, and simply more forgiving. It feels that way because titanium frames are usually made in a coherent way (no odd tube shaping magic that is a common thing with carbon tubes) and as result, the whole bike works coherently with the rider input. Carbon frames are made very differently because carbon allows you to make some parts very stiff and power-efficient (to make the bike seems very vast) whereas other parts are specifically shaped and made to offer a lot of compliance (especially at the rear triangle) and although you can’t feel it as much as with titanium, this trickery works well as the Subito bike shows. As a result, carbon bikes feel much more efficient and rigid but still can offer a surprisingly good level of comfort when needed (when properly designed, like Subito bike with many areas that are specifically made to flex). But those qualities are served in, let’s say, a cold manner because carbon, especially compared to titanium, feels very artificial, very muted. Some riders like that, but I still prefer a more engaging feeling of metal and especially the sensation that comes with a very well-made titanium frame.

To sum up

This is only the beginning of me trying to answer the question about the impact of the frame material on the overall comfort of the bike. Subito was a very interesting example that made me think about this topic (it had a very similar geometry to my benchmark bike), but it is not the best example to make final conclusions. First, because of the wheels, and by that, I mead the rear wheel that (because of the rear hub motor) I could not swap for my Spinergy wheels, and second, because (again because of the rear hub motor) the bike, and especially the rear of the bike was significantly heavier than in my benchmark titanium bike. This means that using the same tire air pressure in both bikes was not really the best solution (I did that for the sake of testing, but on normal riding, I would use more air in the rear tire of the Subito bike to avoid damaging the rim). Just out of curiosity I swapped the rear wheel for the QR wheel taken from my wife’s cross bike, and I got very similar results with the Redshift suspension seatpost, but also I discovered the real reason for Subito’s great agility. When I removed the heavy rear motor, the rear of the bike become less eager to move and the overall fun was reduced (the extra weight simply makes the rear more fun).

So now I will try to compare more similar bikes (non-electric ones) and this time I will use my new LAB to make more precise measurements (you will hear about my LAB very soon). The biggest challenge right now for me is to find bikes with different frame materials but very similar geometry, so I can take the geometry out of the equation. Then I will be able to compare both bikes both with and without comfort improving parts to really evaluate the frame material impact of the comfort of riding. But for now, it seems that using a lot of great comfort improving parts really makes the frame material itself quite insignificant in the overall level of compliance…