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Should big riders use a carbon stear tube?(13 posts)

Should big riders use a carbon stear tube?Griff
Jul 18, 2001 4:02 PM
I am 6' 210. Should I be using carbon or alloy stesr tube in my carbon fork? Also any recommendations on a carbon fork for big riders?

thanks. Griff
re: Should big riders use a carbon stear tube?brew108
Jul 18, 2001 6:15 PM
Just put a reynolds ouzo pro w/ carbon steer tube on a 58 cm frame and noticed a significant amount of flex in the front end. Got the fork on the advice of a lighter rider and didn't account for the weight difference: I am 6'1 and 180lbs. One thing to consider is the diameter of the steer tube. I have a 1". Heard it is a lot stiffer with 1 1/8 in tube.
If you have a 1", go with the alloy steer tube. If not maybe someone with a 1 1/8 will care to post.

Hope this helps.
re: Should big riders use a carbon stear tube?Griff
Jul 18, 2001 7:22 PM
Sorry, I left out a key piece of information, the tube would be 1" in width.
Griff
re: Should big riders use a carbon stear tube?Hank
Jul 18, 2001 9:59 PM
check out AME - very solid fork and you can get it with a ti steerer
linkHank
Jul 18, 2001 10:03 PM
here's a link. Andy Hampsten and the people at Moots are crazy about them

http://www.alphaqfork.com/
re: Should big riders use a carbon stear tube?tr
Jul 18, 2001 10:29 PM
I'm 6'1" 200lbs and i have a reynolds carbon steerer(1 inch) on my neo pro De Rosa and it seems as solid as my steel fork. The front end of the bike would bounce around more on cobbles or rough roads, but i attribute that to the front end being light, it doesn't feel or look like the fork is flexing more. If the fork has the same dynamic and static characteristics as a non carbon steerer, it should be fine.
re: Should big riders use a carbon stear tube?G
Jul 19, 2001 5:08 AM
I range between 190 and 200lbs. Have a Ouzo Pro(1 and 1/8in. model), and find it plenty stiff. What you also need to watch out for is the amount of spacers you use. More than 2cm worth and you may have trouble. I have heard that a lot of manufacturers recommend using only up to 2cm of spacers with carbon steerer tubes. Sometimes I wonder if this type of stiffness issue couldn't be solved with a stiffer stem/bar combo. Someone more knowledgeable may want to respond about this.
Reynolds limit on spacers is 3.81cm (nm)PsyDoc
Jul 19, 2001 6:43 AM
nm
Not steerer concernixiz
Jul 19, 2001 6:29 AM
Flex has nothing to do with steerer material
but the design of the tube and crown
The steerer is held securely by the Headset and it sees mostly shock and hardly any bend - unless you have a bad headset. So all the talk bout carbon steerer flex is so funny.

I agree that you should have no more than 1cm (read your fork manual) of spacers between the HS and stem.

Flex comes from long stems and fork legs and bars
What do you expect the bars are getting thinner walls, stems are lighter and softer material and now carbon forks.
Flex at spacers, stempeloton
Jul 19, 2001 7:44 AM
You can feel a steerer flex depending on what material it is made of. The steerer can flex around the spacers and stem above the headset. This is due to the fact the stem and spacers aren't one solid piece, and flex can occur between them where they are not attached by anything more than the force exerted by them from the headset cap and star flangled nut (or locking mech in a carbon steerer). This is why many manufacturers of carbon steerers will reccomend that no more than 2 cm of spacers are used. Any more can cause excessive flex between the addition number of spacers which can cause the carbon steerer to fail.

For a big guy I wouldn't reccomend a carbon steerer. You have an additional failure risk involved, which could be hard on your wallet and your body. An alloy steerer also won't flex as much as a carbon one will so a big guy will get better steering precision from an alloy steerer.

I can't remember if it was Bob Roll or Paul Sherwin during the Giro who stated that they don't think that they would have been interested in a carbon steerer during their pro careers. Their reason was that they would take a couple extra grams for extra security in a hard out of saddle effort like a sprint.
Not entirelyixiz
Jul 19, 2001 7:55 AM
The stem clamp has a lot to do with the securely fastening the stem to the steerer. The expansion or star nut is only to compress (lightly) the stem prior to tightening the stem bolts. You can actually remove the top nut after the stem bolts are tightened and wont feel any different.

Some steerers are better than others
MY AME has an aluminum insert that further strenthens the junction between the steerer and the stem and uses a custom top bolt.
truepeloton
Jul 19, 2001 8:13 AM
The stem does contribute to the spacers being held down, and the headset in adjustment. The force below the stem where the spacers are would still be the same though for a system in proper adjustment. This would still allow for the same amount of flex of the steerer between the spacers, stem, and headset regardless of clamping force. I did neglect to include the fact that the stem does help to hold the spacers and headset down, but the effects of flex on the steerer remain true.

Also very true is that some steerers are better than others. Carbon varies a lot by construction and who put it together. As a whole though when used in steerers it is a little more flexy than an alloy steerer, and lighter as well. If you are a lighter rider, the weight savings is great and the flex probably won't be an issue with you. A heavier rider though may be better off with a stiffer steerer for better ride quality. And let's face it, if you are 200lbs is a couple of grams on your steerer really what is slowing you down? I fall in the latter category myself, and I have never blamed a slow race on the weight of my bike! :)

Different parts work best for different riders. You just have to ask what you be best for you.
Thanks for the infoGriff
Jul 19, 2001 6:54 PM
Everyone, thank you for yor imput. This site is marvelous for us that are just getting into biking. I have recieved a ton of great info.
Regards, Griff