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Carbon Fork upgrade to Performance Steel Frame R-207(5 posts)

Carbon Fork upgrade to Performance Steel Frame R-207Jonathan C
Jun 28, 2001 10:29 AM
Hello everyone,

I have a 1997 Performance R-207 bike frame made of True Temper double-butted cromoly and a cheapo steel "Aprebic" fork. I believe that KHS makes the Performance frames and the fork is Taiwanese. The bike is equiped with full Ultegra and a set of Cane Creek wheels (Chrono front and Arrowhead rear). It weighs a hair over 21 pounds.

My twin brother just got into biking and purchased a new 2001 Litespeed Arenberg (he makes more $ than me) with titanium frame and a carbon threadless fork. He rode my bike and noticed that even though it is fast and smooth, owing to the steel frame and Cane Creek wheels we suspect, there is an insane amount of fork/headset flex. He noticed that on bumps the fork seems to flex backward towards the downtube and he found it rather disconcerting. After riding his Arenberg, I understand what he means. Furthermore when I pump out of the saddle, if I turn the wheel one direction, I can get my computer spoke magnet to hit the fork sensor. I think we have established that my fork flexes laterally and backwards. The Litespeed does not give an inch on bumps although the Cane Creeks may be superior to his Fir/Spinergy SR-3 wheels in acceleration.

My question is, is it worthwhile for me to add a carbon fork to my bike (threaded or threadless) or should I just save for a better frame? The bike is also slightly large for me but workable. I am 5'11" with a 31-32 inseam and it is a 56cm and it feels a bit spread out with a 100mm stem and seat mounted slightly forward on its rails. A 54 may be more suitable.

Are any cheap forks recommended? Supergo and Performance have Kinesis, the Performance Forte Allegro, etc., for $100 or less. Would these be a noticeable upgrade until I can get a better frame or are they flexible too?

Thanks in advance,

JC
Don't go cheap on the fork!!!Cima Coppi
Jun 28, 2001 11:39 AM
I have been hearing some discussion that a carbon fork tends to be weak at the joint of the crown and the steerer tube. I think based on this, if you go cheap, you'll get what you pay for; a broken fork on the road, and you left with a nasty crash. If you go with the carbon fork, stick to a high end manufaturer such as Reynolds or Look. Another thing to consider is you will need to change out the stem and headset to a threadless version.

Another option is to get a better threaded steel fork. That way you'll have a great upgrade, and you won't have to replace your headset and stem.
Your Inseam is a 31 or 32"??PsyDoc
Jun 28, 2001 12:54 PM
You are 5'-11" with an inseam between 31 and 32." Are you sure you measured your inseam correctly? Check Colorado Cyclist for info on frame fit ( http://www.coloradocyclist.com/bikefit/ ). The possibility exists that the 56 has too long a top tube and that is causing you to feel a bit stretched out. At 5'-11", I think you might find the 54 too small. You may want to look at bikes with a different geometry.
Your Inseam is a 31 or 32"??Jonathan C
Jun 28, 2001 2:00 PM
Psydoc,

I purchased the bike because of an excellent deal always assuming I might need to replace the frame down the road due to size/performance. The frame is the weakest part of the bike.

As for my dimensions, I have not done the official test with the book to the crotch. The 31"-32" refers to my size in slacks only and my height is about 5-10 and a half to 5-11, no shoes. I do have relatively long arms which give me a decent reach and my neck is pretty long although my torso is average. I do not suffer any back problems on long rides but I also do a lot of sit-ups so my back is in pretty good shape I suppose. My brother is not quite as fit and has back pains on long rides even though his bike is shorter and he is less hunched over.

I must admit that my twin brother's 53cm Litespeed Arenberg is a bit cramped but that is because the bike shop set it up that way (short stem, lots a spacers) because he is new to road bikes and wanted him to have easier control. Also, after the bike store owner measured my brother (my twin, nearly identical dimensions to me)he called for a 54cm but Litespeed only has a 53 or 55 in the Arenberg. He chose the 53 which may be a little small but he went that way instead of too large (55cm).

My top tube is much longer than the Arenberg but my stem is only 100mm to his 120mm. My seat is mounted forward on the rails and his is centered. Also, my seatpost is out about 4-5". My brother has a little bit more post showing.

I sat on a Cannondale 54 (r800) and thought it felt about right. When I told the LBS owner that I ride a 56cm, he shook is head. Indeed a 56cm Cdale seems bigger than mine. I think he sizes rather conservatively, though.

Anyway, apologize for the rambling message. I may need a slightly shorter bike, but not by much. It all depends on the frame design/brand I suppose. When I purchase my dream frame, perhaps not this season, I will be sure to get measured properly, perhaps even on the fit cycle. Right now I just wish I could eliminate the damn stem/fork flex.

JC
re: Carbon Fork upgrade to Performance Steel Frame R-207Leroy L
Jun 28, 2001 4:24 PM
If it were my problem, and I liked the bike, I'd upgrade the fork but not break the bank. There are a lot of good CF forks out there. You don't need to spend a lot on a fork.

But, from your frame size discussion it sounds like the bike doesn't really fit you. Maybe you ought to stop screwing around and get a new frame - say, check out GVH bikes, Airborne, eBay, etc. - and then build up something that fits you. Just my 2 cts. worth. Good luck with it.