cormacf

Noob racer, narrowing down options for a first purchase.

Lugs are pretty, and I've been lusting over some of those gorgeous NJS paintjobs. It's tempting to buy one of those used kierin frames in good shape and build it into something classic-looking. It's not going to be cheap, though.

For a fraction of the cost of that NJS-like build, I could get a TK3, Sonik, Pre Cursa, or some other entry-level AL track bike coming in around $1000 complete. It SEEMS like it would be a much more practical bike -- more money left over for classes and race fees, sellable for close to what I paid for it, more aero, likely stiffer, no hidden damage from some kierin racer with ginormous quads, etc.

Will the AL track bike be objectively better? If so, I can use that to get myself over the emotional hump and buy the less-pretty bike that costs less than a wheelset.

Trakhak

Will the AL track bike be objectively better? Good question. It would likely be measurably stiffer with respect to torsional and lateral forces. Whether that amount of increased stiffness would translate to its being objectively better for sprinting and handling is something else. Amateur riders with limited budgets tend to opt for aluminum, though, and have done so for at least a couple of decades.

New road riders planning to race criteriums often ask a similar question, though in such cases it's usually carbon versus aluminum. There, the reasoning is that new racers sometimes hit the pavement and thus should consider buying a frame that's not going to be too expensive to replace, if it comes to that.

cormacf

Thanks for bringing that up. I'm not super-worried about crashing out, because I'm too old and timid to to to squeeze in that gap when it's questionable, BUT I would not be surprised AT ALL if I plopped over at zero mph clipping out. That, plus the general driving the frame back-and-forth makes me think I should buy something I can afford to scratch up. Thank you!

2500W

The purpose of a frame should be prioritised in solving the popular dilemma. Top sprinters need to perform at speeds over 74 kmh or accelerate an over 100-kg load to 71-72 kmh in some 20 sec. So the frame should be stiff and light, no matter would it resist a houndred of events.

Amateur sprinters would need a frame to resist over time rather than to be so stiff and light. "Steel is real" is said and its Fatigue Strength of 370 mpa and Ultimate Tensile Strength (UTS) of 690 mpa remain unattainable by any alu alloy. Numbers: Cold-drawn 4130 Cr-Mo Steel >

As for aluminium alloys utilized in framebuilding, I recently found too wide range of these. If mentioned, their four digits can only predict the presence of major alloing elements such as Mg or Zn. However, any mechanical property of given alu alloy, especially its Fatigue Strength, cannot be predicted by customers since the temper designation of this alloy is just absent.

-- 6061 > This anonimous material is likely most often mentioned in the frame specifications. It may be also named as "aluminum," "aluminum alloy" etc. Even in the most common T6 temper condition, its Fatigue Strength remains in the under 100-mpa range. I once broken up a cheap alu ahead stem adapter.

-- "Alumisonic aluminum" as stated by All-City, leads to Alumisonic Guitars where the alloys used include the 6061-T6 > aluminium.

-- 6066 > Utilised by Fuji, also mentioned by them as "A6-SL." No temper designation.

-- "Aluxx" as stated by Giant, is believed to be the very rare 6011 alloy. It may contain a tangible amount of Zn, up to 1.5 per cent, in contrast to another alloys of the 6000 series. Data on a couple of mechanical properties, just in the T8 temper condition, vere found in a sole source so far -- 6011-T8 > .

-- 7075 > Again with no temper designation, it is seen in the new Argon 18 Electron (27.2 seatpost, complete bike). The older frameset with aero seatpost was made from 3005 aluminium.

-- Columbus Airplane Alloy as stated by Cinelli. Ceeway.com > clarify the raw tubes to be 7005-T6 > After welding, a certain heat treating and artificial ageing process is suggested to restore the original strength.

In contrast to all that, the high-end Ambrosio Nemesis rim is clearly designated as "5086-h38" > that means the material used has 150 mpa Fatigue Strength.

Trakhak

Engineers in all fields, including bike design, are well aware of the properties of steel, aluminum, carbon, etc. They choose the appropriate material for the application. No one seems to object to the existence of aluminum structures outside the world of bicycles. Why is that?

Can you give any examples of an aluminum frame breaking under a track sprinter? The only frame I know of that broke in a sprint was a steel Reynolds 531 frame, the one that famed British sprinter Reg Harris destroyed, actually ripping the bottom bracket away from the down tube.

Among the many great qualities of aluminum for bike frames: it's trivially easy to build durable frames while maintaining weights below those of equivalent steel frames, and the large-diameter tubes usually used in modern aluminum frames resist twisting forces from sprinting better than the necessarily smaller-diameter tubes of steel frames.

I spent almost 40 years riding and racing high-end Reynolds and Columbus steel road and track frames, from the mid-'60's to 2005, and then ditched them in favor of aluminum. Steel's fine; I just prefer the handling and immediate responsiveness of aluminum bikes.

2500W

* Engineers in bike design are well aware of the properties of different aluminum alloys.
-- Buyers are not, indeed. So engineers could offer 7075-t6, 6011-t6, 6061-t6 or even the inferior "6061." Manufacturers, however, are actually on the market, they are merchants, they are decision makers on what alloy to provide and and what manufacturing process to run.

* No one seems to object to the existence of aluminum structures outside the world of bicycles. Why is that?
-- It is Fatigue that plagues the world of thinny bike frame tubing, in other words, 60-160 mpa vs 370 mpa.

* Any examples of an aluminum frame breaking under a track sprinter?
-- Do they use alu frames in training? If so, they probably prevent failures by replacing frames, for instance, after 5000 km.

* The only frame I know of that broke in a sprint was a steel Reynolds 531 frame.
-- Possibly a light version around 2000 gram. My older frame is Tommasini (? Columbus Cyclex) weighing around 2600 gram.

* It's trivially easy to build durable frames while maintaining weights below those of equivalent steel frames
-- Are we climbing an uphill? Curiously, this certain feature attracts the folks. My Giant setup with road fork and front brake, weights 7.6 kg. And Columbus Zona (under dealer's brand name Swift-Art) with entire brake set and two flip-flop freewheels, is around 9.6. One kg up or down while my torso retains at least 8 kg overweight!

* The large-diameter tubes usually used in modern aluminum frames resist twisting forces from sprinting better than the necessarily smaller-diameter tubes of steel frames.
-- If frames are of high quality and resist after 20,000 km or some 5-10 years in regular use. Enough manufacturers do not accept warranty claims in cases of frames affected by "extreme use" or tear-and-wear We discuss cheap ones.

Trakhak

Real-world data from 1997 fatigue testing of 12 carbon, steel, titanium, and aluminum racing bike frames (see link below): two aluminum frames and one carbon frame survived the tests: none of the steel or titanium frames survived.

(In corroboration: sometime in the early '90's, I happened to ask our Trek sales rep what effect, if any, their having introduced their aluminum frames to the lineup had had on their business. He said, "We noticed that as our sales of aluminum bikes increased, frame warranty claims decreased.")

12 High-End Frames in the EFBe Fatigue Test

2500W

Too impressive feedback. N.B. however some manufacturers put a rider weight limit e.g. "100 kg" or "250 lb" (the later means for me a lean, 110-kg guy plus 3 kg winter apparel).

Below are some aluminium track frames and a complete bike that are currently available in the internal EU market (avoiding the custom agency). All of these are offered between 400 and ~1000 EUR. Please share your belief on which of the listed are likely to be reliable enough. Thanks.

-- Cinelli Vigorelli, Columbus Airplane alu (i.e. 7005-T6)

-- Argon Electron 18, 7075 alu

-- Giant Omnium, Aluxx alu (i.e. 6011, likely after T6 temper)

-- All-City Thunderdome, Alumisonic alu (likely 6061-T6)

-- Look AL 464 F (brake holes are advantage), 6061 alu

-- Aventon Mataro (bike), 6061 alu

-- Aventon Cordoba, 6061 alu

Trakhak

If it were me buying the bike, first, I"d check the fit and geometry---some bikes (in particular, those drilled for one or both brakes) are designed for fixed-gear road riding (e.g., with a longer wheelbase) and might therefore be less inappropriate for velodrome racing

I'd also get a confirmation from the companies whose frames I was considering that their warranties are unambiguous, that they'll honor the warranty for a rider of your size and strength. Track sprinters are the hardest on bike frames, so sprint frames should have been optimized for the brutal forces that they undergo with even the biggest and strongest racers, but it's worth making sure.

Then I'd go with whichever has the best frame warranty. If several have the same warranty (lifetime for the original purchaser, for both frame and fork), I'd go with the longest-established company with the best reputation. (My guess is that the particular version of aluminum used is of lesser concern. I've never heard of any track racers complaining about particular aluminum frames on the basis of the alloy formulation.)

The frame/fork warranty is a bit of a sore point for me. I've done most of my miles on a Specialized Langster fixed-gear (road geometry) bike since around 2004---or whatever the first year of production was. Turned out that the bike was a bit of a first-year lemon.

(What follows is whining, pure and simple.)

I loved---still love---everything about the way the bike rides, but, as I discovered the first time I flatted the front tire, one of the dropouts on the (aluminum) fork was welded a bit askew, so the wheel had to be canted in the dropouts to get the rim centered under the crown.

(I kept meaning to go back to the shop for a warranty replacement, but procrastinated---for 14 years. When I finally brought the bike back to the shop, they pointed out that the warranty was lifetime on the frame but only 3 years on the fork. Offered to sell me a carbon fork at the "discounted" price of $200. No thanks.)

That, and the frame has aluminum track ends that eventually deformed at the axle locknut contact points on the right side. As a result, the axle gradually slipped forward over time, so the chain continually slackened until it came off a few times. Luckily, I don't ride brakeless, so I was able to control the bike, but it was annoying. (I finally poked around my junk drawer and found and installed an axle retainer that I had saved from my first track bike, a Helyett Speciale given to me on my birthday in 1963, which fixed the problem.) (Specialized must have gotten complaints about the soft track ends, because they added steel plates to the track ends for subsequent model years.)

No one is going to run into problems like that with a modern track bike, of course. But most bike frames now come from factories in Asia, and European and American bike companies differ in their on-site quality control. Smaller companies may rely on each factory's internal QC, whereas larger companies are likely to have their own people overseeing production operations. (Not that that helped with my Specialized bike.)

(Which also, to resume the whining, started breaking spokes frequently, including in the front wheel, early on---so the wheels had clearly been woefully undertensioned at the factory. By the time the pattern of breakage became clear, I didn't trust the remaining spokes, so I rebuilt the wheels with all new spokes.)

2500W

Endless efforts and experience in building a decent bicycle! Two years ago I looked for a stiff enough frame with brake holes. I was about to buy a Look Madison 875 F, then some 1200-1400 EUR.

I eventually bought a SwiftArt/Zona 4130 frameset w brake holes; a Pake Rum Runner/Tange 4130, frame only, and completed it with a 375-mm Surly Steamroller 4130 fork; and a Giant Omnium al6011 frameset plus a compatible Enve 1-1/4 drilled road fork. Both 4130s are made of tubes larger than 28 DT and 25 TT in the older Tommasini 1980. Good geo I run after so far is presented in the three frames.

The second riding on SA finished with a fall, top tube was hit but it eventually does not affect any mechanical performance of this bike. 4130 is ethernal, I would say. However, the Front-Centre here stands at just 586 mm and 170-mm cranks plus cleats rearwards might be risky combination.

The only disadvantage I see in the Pake is the short rear dropout, 15 to 16 mm. I often change the chainrings so just very small range of these could be compatible with a chain that is already mounted.

So far I cannot find whether the Omnium is stiffer or not. Its current setup with the ~300-g Enve do not need even to push the pedals to feel enough deflection. Some pushing and pulling the narrow bars is sufficient to find a front deflection. Supposedly it comes from the fork blades rather than the steerer tube (+/- 10 mm spacer).