gycho77

Slx flexes a lot of because of the shape

wens

The under elbow pad spacers are actually faster than pads right on the bar, at least with enough separation in some cases. Besides, I'd rather have base bars low for standing starts so it doesn't feel like I'm trying to do them with my hip angle way too open.

Poppit

I tried and failed to get closeups of the Italian team pursuit bikes as they were things of beauty, Pinarello Maat frames, Campag wheels, here is a stock image of the team

dunderhi

The HT length is why I went to the trouble of getting my Pinarello XTRACK imported to the US. My 55cm frame has a 17.4cm HT. I also went with Argon18 for their adjustable HT.

gycho77

They are using Pinarello Maat
https://instagram.com/p/BCdosxckV9s/
I'm not sure about yhe model name

Koogar

I give you credit for actually using the rise and spacers to get your hand position where you need it - a lot of people will just slam that stem and then wonder why they're so uncomfortable, even though their track bikes look how a track bike is supposed to look

Still, I wonder how much the stack of spacers below the stem on the Tiemeyer impacted front end stiffness and placed the steerer at greater risk of failure.... Spacers and rise are useful for fine tuning, but not an ideal substitute for an appropriately sized HT.

TrackMonkey7

So you're saying Wiggo's set-up is wrong?

I understand that track being such a limited market, there can't really be as much geometry variation as there is in road, but I'm at a loss for finding a frame that fits me well for pursuiting. A lot of [track] bikes these days have very long top tubes - I presume - to stretch people out to get them more aero. Additionally, for road bikes, HTs are getting taller to make that stretched position more comfortable. Pacelining on the road I watch my buddies pass me and their arms are stretched out in front of them; this is pretty en vogue for the way a road bike fits these days and it just makes me think that if we shortened the cockpit up, people might stop complaining about back pain. /rant

Anyway, for me, these long TTs and tall HTs make it especially difficult to find a pursuit bike. On my current 2009 Fuji Track Pro, I need to run a 40mm stem, and extensions under the base bar and I still feel uncomfortable. I've come to the conclusion that I have proportionally long legs. At present, I'm looking at 52cm and even some 49cm frames to get the right reach and stack measurements.

I am sort of an aero nerd and I can see how running pads right on the bars isn't as 'clean' as running with some risers. One can imagine airflow getting bunched up across the surface of the base bar, yet with risers there's more open space for the air to travel.

To be honest for a pursuit bike, I'd rather have a super low HT and subsequently a low base bar and then adjust my fit through risers. Not only would it offer some cleaner airflow, but it adds another fitting variable to tweak things.

carleton

Yes.

But, I'm looking at it from a mass-start POV.

Just like there is no one bike for crits and TTs on the road, there probably shouldn't be for track.

How many people ride the same road bike in bunch races and TTs on the road? Why should we do the same on the track?

wens

That lack of cabling makes it a whole lot easier to swap bars, and we're cheap.

Dalai

Contradicting yourself @carleton. On one hand you are saying Wiggins bike is wrong as it isn't suitable for mass start yet say there should not be just the one frame for all track races?

TrackMonkey7

My Track Pro with a longish TT fits me like a glove with drops and feels great in the thick of a bunch race, not so much in a pursuit!

+1

I do wish that at least the companies who are known to offer good, accessible track frames did this. I say accessible because while the likes of BT, Koga and FES do this, good luck getting one. Planet X offers (offered?) both the Track Pro and the TOR, the latter intended to be more TT-specific. However, because of its even longer TT, I would have had to have gotten a 47cm in order to get acceptable reach.

himespau 

That is a cool picture. I thought the rifling was supposed to make it flex less.

taras0000

SLX flexes "a lot" because of it's diameter. Steel tubes featured in lugged construction all had to conform to certain external tube diameters to fit into the lugs available. Those diameters are relatively small compared to what is available today in steel, aluminum, or carbon. That's why it seems puny. SLX is a beefed up version of Columbis SL. It's essentially SL "Xtra". It was meant to be a stiffer version of the steel tubes available at the time it was introduced. Back then, it was as stiff as you could get in a lugged frame. What you see in the photo are reinforcing ribs. The reason the tube has that rifling, (the twisted ribs), is because when a bike flexes, it does so because the individual frame tubes twist. If you can align these ribs with the twisting forces, (to put the ribs in either compression or tension), you will best be able to make use of these minimal reinforcements. This is the exact same principle used in orienting carbon fibers within a frame lay-up. Back then, they knew the frame tubes twisted, but they didn't know exactly to what degree, or the force lines, so the twist rate of the rifling in SLX is just a guess as to what would work best.

queerpunk

good news everybody! wiggins doesn't race that bike in mass-start races.

he races a cervelo (it's a street fixie )

carleton

Yeah, I'm confusing 2-3 threads of the conversation.

dunderhi

Don't forget about Columbus SP. I think that was their stiffest offering. I replaced my 531SL frame with a SP frame and there was a world of difference. Then again, I replaced the SP frame with an early Cannondale which was absurdly stiff.

gycho77

So are you saying that Slx is stiffer than Sl in real life?
I have columbus SL track frame(80's track frame). So I want to know more about my tubing

himespau 

I think there's a new SL that's different from the stuff we had in the 80's. Don't know how it compares or what your track bike is made out of. I just think lugs are pretty.

TDinBristol

Some custom makers such as Serotta mixed SP down tubes with SL elsewhere to create a stiffer frame without unnecessary weight penalty where not needed, such as the top tube.

taras0000

SP was made from the same alloy as SLX, but instead of the .9/.6/.9 wall thickness of SLX, SP had 1.0/.7/1.0 wall thicknesses. SPX also came in longer lengths, as it was designed for larger frames. SP also came out shortly after SLX was introduced.

For anyone curious as to how wall thickness and diameter effect tube stiffness. Wall thickness will increase tube stiffness in a linear fashion. Increase wall thickness 20%, then stiffness increases 20%. Stiffness increases by the cube of diameter. So increasing wall thickness might slightly increase the tube stiffness, doubling the diameter will increase it's stiffness 8X. This is for bending along the tubes linear axis. Torsional resistance of a tube increases by the 4th power of a diameter, so this doubling of diameter on a tube will make it 16X more resistant to twisting forces. It is a the torsional loads that allow the linear flex of a tube on a bicycle.

carleton

Thanks for explaining the wall thickness.

When I had my first Tiemeyer made, I thought it was interesting that he asked me my weight and estimated max power output. He told me that he would use different tube thicknesses based on that to increase the stiffness when it was appropriate.

So 2 Tiemeyers may look the same on the outside, but the characteristics and weight would be different based on the owners' characteristics. That dude is a modern master.

wens

Hmm, I need to draw the fbd. Intuition is telling me that, since you have triangles, if you flex a frame something needs to be in bending. Going to need to put pencil to paper and figure out if I'm missing something.

700wheel

In addition to bending some frame sections are in torsion and shear, and often in combination.

dunderhi

When I was a teen, I really wanted one of these: Rigi

Road Version:


Track Version:

Muddlfuc

Took me a few seconds to work out that the seat tube was split... really messed with my mind for a sec.. interesting way of shortening the chain stays