# Un-scare me about Orca head tube flex...



## randomguy (Nov 8, 2004)

I heard that the Orca may not descend as well as some other bikes because of the head tube flex. I am a bit concerned because one of my other carbon bikes (Giant Team Once TCR composite) had a super-flexy head tube and speed wobbles past 30 mph. Does anyone (anyone with an extensive frame of reference, that is) notice the bike holding them back going downhill, or is this just an unfounded rumor?


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## Dave in Driggs (Aug 16, 2004)

*Many factors can cause speed wobbles*

Hi Randomguy,

Given that I just got my new Orca about a week ago I don't have "an extensive frame of reference" but I thought I would share what I have learned. 

The shop I bought mine from has a team of riders and most of them ride Orcas. Every one of them that I spoke to loves their bike and, given that they often ride the same terrain that I do, this was important to me. One of our main rides is Teton Pass which has roughly 6 miles of 8 to 10% grade on the Jackson, WY side. It is very easy to reach speeds over 50 mph on the descent here. I don't think all of them would be on this bike if it were scary to descend on.

I think handlebars and wheels play a big factor in feeling stable on a fast descent. I had two sets of wheels for my previous bike; one being a very lightweight set of "climbing" wheels and the other a "heavy" 1700 gram wheelset. The lightweight wheels scared me anytime the speedo hit 35 mph. By simply going to a stiffer wheel I changed my old bike into a solid descender that I felt comfortable on at 50+ mph. Being comfortable in the drops is important as well. I definitely notice a stiff handlebar on fast descents.

Having said all of this, I realy like my Orca so far. I don't feel any flex in the headtube when I stand and climb. Even if I straddle the bike with both feet flat on the ground and torque the drops of the hadlebars I cannot feel any flex. 

Hope this helps.
-Dave


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## unobtainium (Feb 28, 2005)

I have had my Orca for a year. I have never had any wobble, shimmy, etc on 50 mph descents. I cannot detect any flex in the frame to speak of. Its noticeably better than my Litespeed Classic’s BB in this respect. The only problem I have ever had was when I heard a funny noise when riding it when it was 3 months old. The replaceable rear derailleur bolts (very tiny) had worked themselves loose and the hanger was about to fall off! These tiny bolts were not Loctited. I applied blue Loctite to them and I have not had a problem since. I highly recommend that all Orbea owners check that their replaceable hanger bolts are tight if not Loctited to avoid a possible major catastrophic mechanical failure, if not a crash.


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## filtersweep (Feb 4, 2004)

I'd love to see any evidence that any frame causes high-speed wobble. And don't point me do Jobst Brandt's post, since he has no science to back up his opinion, either.

I swear it is all rider induced. Many people naturally tense up while descending, and they literally shake the bike into a shimmy. The knee on the top tube unloads the BB- rather than "damping" the "resonating" frame.

I'm not trying to be argumentative- I'm just seeking the truth- and it seems there is scant science involved with this issue.


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## randomguy (Nov 8, 2004)

filtersweep said:


> I'd love to see any evidence that any frame causes high-speed wobble. And don't point me do Jobst Brandt's post, since he has no science to back up his opinion, either.
> 
> I swear it is all rider induced. Many people naturally tense up while descending, and they literally shake the bike into a shimmy. The knee on the top tube unloads the BB- rather than "damping" the "resonating" frame.
> 
> I'm not trying to be argumentative- I'm just seeking the truth- and it seems there is scant science involved with this issue.


Well, for the sake of truth, my shimmy's on the Giant were on the exact same routes I had normally ridden on my steel and aluminum frames with no shimmy. It is definitively not rider induced in many cases, at the very least not in mine.


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## jslopez93 (Aug 15, 2004)

9 months mo my orca and no speed wobble.

my friend who has an Onix did experience this at one 50 mile desent recently and he went back to the shop to try and figure it out. Will let you know what turns up from it.


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## stickboy71 (Jul 13, 2005)

I've experienced the death wobble (and not only on descents)!!!!!! I have a friend who experienced it as well. Neither of us are on Orca's any more. With each pedal stroke, the bike would wobble, no matter the speed (never experienced that on any of my other bikes). It was so bad that my arms would be sore after a ride because I was fighting to keep the bike straigh with each pedal stroke. Mine was a 57, and the friends was a 61. Maybe the smaller sizes don't have this issue.


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## xlalaw (Jul 10, 2005)

*probably a maladjusted internal headset*

I just put together a used Orbea Euskatel team bike for my son. There was slight flex in the headset until I realized I was missing the top washer. Once I put in the proper washer and adjusted the headset it rode great. It could be that the internal headset was not seated properly. Or perhaps it was not the proper spec headset. 

Its a great riding bike, and in fact it rides much better than my 2000 Trek USPS bike.


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## supercrank (Feb 20, 2004)

*no problems here*

I've had an Orca for about 4 months now, and have had no problems with front end flex or wobbling at speeds of 40-50mph. The frame size is 51cm, with an ITM 260 bar held by a 12cm ITM millenium stem riding on one 5mm spacer.

In terms of subjective front end stiffness, my current setup is stiffer than my old aluminum Bianchi XL EV2, but perhaps not quite as stiff as the Look 481SL I test rode. However, I couldn't tell you how much of that added rigidity was due to the different bar, stem and front wheel setup.


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