Bicycle Mechanics - Aluminum 1" fork

http://www.ebay.com/itm/380536488419?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Above link got me researching al forks. Then the Rinard data appears to show this flavor of fork as being pretty flexible.. flex measured in mm's.


Brand, Model Lateral Longitudinal Total Weight
Schwinn Paramount (1) 3.81 3.30 7.11 n/a
Merckx sloping crown 3.81 3.30 7.11 777
Colnago, straight blades 3.81 3.56 7.36 730
Kestrel EMS Composite (2) 5.33 3.56 8.89 526
Tange Silhouette, CrMo 5.33 3.81 9.14 590
Kinesis Easton aluminum 5.59 4.06 9.65 507
Dimension Carbon (3) 5.33 4.32 9.65 482
Time Carbon (2) 4.83 4.32 9.14 525
Look Carbon (4) 6.60 4.32 10.92 447
Fuji Titanium 4.75 4.37 9.12 n/a
SR Prism (2) 5.08 4.57 9.65 546
Trek OCLV 5.08 4.83 9.91 508

'Carbon love' as I term it.. blows off the bottom line. Carbon when it fails.. fails instantly... your toast. Easiest choice for my application is the Nashbar 220mm steer 1" threaded. Can't find anyone dissing it for breakage.. they could have a good lawyer.. who knows. Great value IMO.. but riding carbon would haunt me. Understand well.. I am not flaming anyone's choice of carbon.. just for me it's a non starter.

So.. the request of real world input from anyone riding this flavor of aluminum fork.. in the low 500 gram area for wt. Again 1" threaded. Problem appears to be finding one to buy and try.

I would be.. very interested in something steel.. at the 600 gr area. Some references around appear to say some of the older model bikes had decent wt steel forks. [?].

In 1996 I built up a Litespeed Catalyst using an SR aluminum blade and crown, steel steerer threaded fork and rode it for 30,000 miles. I presume it was pretty much identical to the Kinesis in your chart. It worked well enough and the flex wasn't an issue I could see. However, I got a bit concerned about it's integrity after all those miles. Aluminum has no "fatigue threshold" and it WILL fail after enough time and stress cycles no matter how low the stress. And, when aluminum does fail, it's pretty sudden so it "haunted" me too.

I replaced it with a Kestrel EMS Pro steel steerer threaded carbon fork that was more than equally satisfactory, and carbon has no finite fatique limit. It may fail suddenly but that's not a certainty the way it is with aluminum. The EMS is still in service 45,000 miles later showing no signs of any problems.

i have two newer bikes with 1-1/8" all-carbon Easton EC SLX90 forks and they seem to be a long term investment. They have 22,000 and 25,000 miles on them and i'm not worried about them at all.

Thank You HillRider for the in-depth response.

Went and read up on aluminum fatigue. In the end.. appears to me al when it fails that takes literally billions of cycles.. and gives advance warning of the breakage... ie, cracks and resulting bend of the weak area. [?] At least that is what I came away with sifting the data. Correct me if I am wrong.

Carbon breaks like an icicle... from what I can find.

Comparing apples to apples comes to mind. Who's flavor of al alloy.. who's carbon weaves and to what specs for either. QC largely isn't in this day and age. Coat of nice paint.. some internet blah.. and out the door. Let the lawyers deal with the mess later if need be.

Trek's catalogs somewhere around 1990 or so included a graph showing numbers of stress cycles to failure from testing their steel, aluminum, and carbon frames. Good, better, best, respectively. The German bike magazine Tour has repeatedly subjected frames from various manufacturers to stress cycle testing and got essentially the same results.

Kinesis aluminum fork on my mid-'90s Schwinn Peloton (bought new, ridden for tens of thousands of miles), other aluminum forks on a Specialized Langster and a Felt TK2, carbon fork on a 2005 Motobecane Le Champion, steel forks on lots of high-end steel racing bikes since I started racing in 1965. They all feel the same to me. I don't worry about longevity with any of them.

Had 2 AlAn 'supers', in the 80's 1 road, 1 cross... cross fork was excessively set in motion,
by putting the brakes on.. ( like an inch, at the tips ) ..

aluminum steerer, crown, blades and tips..,
only the bosses that were on the blades for the cantilever brakes, were steel ..

Road fork, with brake bolted thru the fork crown was better, mounting for the brake
tothe crown, and the cable directly effecting the brake,
rather than pulling from the top, to the brake on the flexible fork blades..

SG, Regardless of material most forks are going to outlive the cyclist barring an abnormal event. I've had all three listed materials on essentially the same frame (Cannondale road) and feedback was similar, as was comfort.

Brad

They all feel the same to me.
That's been my experience too. I've had aluminum, steel and carbon forks on similar road bikes and they are pretty much interchangable to me. You want a better ride, fit bigger, lower pressure tires.

As to Trek's and Tour's fatigue rating, I presume the aluminum frames they tested are quite "overbuilt" if they outlasted a steel frame.

SG, Regardless of material most forks are going to outlive the cyclist barring an abnormal event. I've had all three listed materials on essentially the same frame (Cannondale road) and feedback was similar, as was comfort.

Brad

Same frame here too Brad. My take is about the same for feedback via the fork.. tires, their pressure, the seat, the grips and handlebar material ( I used carbon it last yr ) mean more to ride quality. Dumping a 1/3rd of a pound off the bike's wt has some appeal to me.

I have done essentially that HillRider.. larger tires. Same frame in MTB form with lower pressure 1.5" tires.. was faster than I anticipated also... the al fork not seeming to give as hard a feedback on the 'tar cracks' as my steel frame & forked winter bike.

Rigidity is how Aluminum frames survive, flexing can result in cracks.

AlAn's were famous for cracked lugs.. Italy was too far away for repairs.

As to Trek's and Tour's fatigue rating, I presume the aluminum frames they tested are quite "overbuilt" if they outlasted a steel frame.

I found a reference searching this morning.. the link: http://www.vintage-trek.com/images/trek/TrekAluminumFacts1987.pdf

Regarding your light steel fork question, my Eddy Merckx has a 1" threaded fork out of Reynolds 653. It weighs 650g. Just one data point but maybe useful.

Strangely the lightest fork was on an old Cannondale R900. Aluminum fork with an oversized 1 1/4" steerer tube. 460g. I'm sure there are carbon forks that are lighter, but I've never owned one yet.


SG, Regardless of material most forks are going to outlive the cyclist barring an abnormal event. I've had all three listed materials on essentially the same frame (Cannondale road) and feedback was similar, as was comfort.


+1

If you're really that worried (and you shouldn't be) your options are steel and Ti. I've had bikes with steel, aluminum, and carbon forks. They all rode similarly. Tire width and pressure has a much bigger effect on comfort than frame material. So I wouldn't worry about that either.

Buy whichever material you want. Personally I would buy based on weight and price. Can I suggest threadless though? It really is a better, stiffer system.

I am an older rider now and more concerned with safety for that unpredictable time that I put excessive stress on a fork (running off the road) - So I am staying with steel - But all have to admit - That really is a nice looking fork...

Can I suggest threadless though? It really is a better, stiffer system.

NO.. not this time around. :thumb:

Lacks the vertical adjustability I want to trial.. more stiffness seems to me also is anti-ride quality. [?]. And I have the components to burn now in 1".

That is indeed a lite fork at 470's range too. Thanks for that steel reference too.

I wonder if anyone knows what the al fork on the 90/early 90's Cannondale weighed? Mine came with the steel one.. around 740 grs in 63cm frame. Higher cost models came with al the catalogs stated.

Threadless has vertical adjustability (long as you don't mind the big knob when it's low).

Invest in a couple of cheap threadless stems of varying rises and you can even have adjustability without the knob when it's low.

Rather than another edit: per 'worry' about forks going south. Not really the issue.. worry.

Granted very few of any flavor is going to fail. Yet.. I remember well the 'hole I had to take on last spring as "she/it" came flying over the rise in the road.. more into my lane than "hers/it's". I mean it hit hard... I actually stopped and looked things over.. also thinking "she/it" might have see me stop and come back.. to get some edification of driving........:crash: :roflmao2:

Spokes break due to previous events.. mostly.. memories if you will. All of the bike is essentially that same.. but going head first into the rd from the icicle break is what I'm trying to avoid.

I found a reference searching this morning.. the link: http://www.vintage-trek.com/images/trek/TrekAluminumFacts1987.pdf
That isn't a "reference", it's a catalog and an advertising brochure. Of course Trek makes the best possible claims for their frames. Do note that the "fatique strength" graph shows their aluminum alloy is above other aluminums but below "standard alloy steel". BTW, I had a 1992 model of that same bonded frame that I put about 20,000 miles on and then gave it to my son who still rides it routinely.


Strangely the lightest fork was on an old Cannondale R900. Aluminum fork with an oversized 1 1/4" steerer tube. 460g. I'm sure there are carbon forks that are lighter, but I've never owned one yet.
Yeah, there are lots of forks lighter than 460 grams. I have the two Easton EC90SLX all carbon forks I mentioned above. Easton claimed 295 grams and my two weighed 293 and 298 grams before cutting the steerers. The current version, the EC90SL, is claimed slightly heavier at 349 grams but I don't have and haven't weighed one of them.

'Reference' only in the sense of it being data about that subject. Almost all "reference" shades bias.. as I'm certain that trek brochure does.

HRider.. if I may ask... what weight range are you?

I'm 238 ish btw. But I am on 24H rims.. albeit 26".. that rear triplet lacing.

'Reference' only in the sense of it being data about that subject. Almost all "reference" shades bias.. as I'm certain that trek brochure does.

HRider.. if I may ask... what weight range are you?

I'm 238 ish btw. But I am on 24H rims.. albeit 26".. that rear triplet lacing.
I'm about 150 and ride two sets of wheels routinely, both 700c with 700x23 tires. One set is built using 32H CXP33 rims laced 3x with DT 2.0/1.8/2.0 spokes. The second is a pair of Shimano WH-R560 prebuilt wheels with 24 mm deep rims laced 16H radial in front and 20H, radial DS, 2X NDS, both with bladed spokes.

http://www.ebay.com/itm/380536488419?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

So.. the request of real world input from anyone riding this flavor of aluminum fork.. in the low 500 gram area for wt. Again 1" threaded. Problem appears to be finding one to buy and try.

I use this exact fork on my Gitane TdF after wrecking the original steel fork. Rides well and saves perhaps a couple of hundred grams too. The Kinesis alu road forks were popular just before carbon forks became the weapon of choice. I like mine so much I bought a couple of spares in case I want to upgrade other steel bikes in the future. Mind you, I think I only paid about $30 each for mine -new obviously. I would never ride a used alu road fork.

If you find these forks with long enough steerers, then you can cut the top threaded portion off, and use them in the superior threadless configuration. You'll need the top headset parts to match.

I miss the old school chro-mo forks of thin curved tapered steel, with forged dropouts.

yes, i have real world experience with this fork, albeit a 650c version. about 30-35 thousand miles and 18 years worth. absolutely no issues with it. recently had the top half painted and the bottom half polished to match the chrome job on the rear triangle of the frame.

i didn't realize that they were so light!

I would never ride a used alu road fork.

Got to thinking.. (dangerous I know).. but why not? Granted eliminating anything showing abuse.. etc. But another way of looking.. anything little used at least passed the initial go around. Interested to hear reasons for not... yes a fork is pretty critical to safety I well understand. Yet an al forks isn't going to icicle [?].

I hear the reassurances per carbon forks from your experienced responses. Admit to wanting to try one... granted many other things/variables can put one nose down likely more often than a fork. Would have to be the Nashbar.. not thinking this build will stay around for yrs. But who knows.. riding it might chg that.

Got to thinking.. (dangerous I know).. but why not? Granted eliminating anything showing abuse.. etc. But another way of looking.. anything little used at least passed the initial go around. Interested to hear reasons for not... yes a fork is pretty critical to safety I well understand. Yet an al forks isn't going to icicle [?].

There are still some that think that any material but steel is too fragile. Several posts regarding the Nashbar carbon fork have been favorable.

Brad