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PostPosted: Fri Apr 27, 2007 2:49 pm 
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[quote="youngs_modulus]

DocRay: I agree with 95% of what you say, but I think you're wrong for taking DaveS to task for not having designed bicycles. Industry experience is great, but engineering principles extend across industries. I agree with you that DaveS is wrong about the R3 headset bearing seats, but his assertions are reasonable. Wrong, but reasonable. The bicycle industry does not attract the best and brightest. It attracts those who are willing to work for 65%-80% of a typical salary in order to do something they love.
[/quote]

After you've read a few posts from cyclists who have damaged frames because the integrated headset was improperly adjusted (too loose), you might change your mind.

Please elaborate on the wrong but reasonable comment, it seems contradictory. Do you really think a thin piece of aluminum is the preferred bearing seat? FWIW, LOOK used removeable seats even when the entire head tube was aluminum and could easily have had the seats machined into the headtube on frames like the KG381 and KG461. I assume it was an engineering judgment to prevent possible problems.

Some brands initially machined the seat into the head tube on their aluminum or Ti frames, only to switch to removeable seats after all the problems incurred in the first year. Litespeed wisely abandoned the integrated headset after a few years. Chris King, of course, is famous for his tirad against the integrated headset on any frame.

Now that I think of it, I'm also skeptical about LOOK's use of a carbon fork crown race too.

One problem I've noted is manufacturers have notoriously poor instructions included with frames, forks and headsets (including LOOK). They gloss over the adjustment of the headset, only telling the user to "eliminate play". Integrated headsets need to be adjusted as tightly as possible without inducing excesive drag as the fork is turned. The top cap requires quite a bit more torque on it than would be used with a caged ball headset like Campy's. Failure to do that can result in frame or bearing seat damage.

I'll agree that if you like the ride and handling of your R3, that's great. I found the geometry in the 49cm and 51cm (which I owned) to be unreasonably short in the front-center with too little steering trail. There is no other brand that makes frames with such a short F-C. The excessiely short chainstays also caused problems with my triple crank (for climbing the Colorado mountains). Unless the shift from the middle ring to little ring was made from the third largest cog (or smaller) the chain would drop off the little ring and jamb between the little ring and the frame. A chainwatcher won't fit onto the downtube either. I was so unimpressed that I sold mine after 200 miles of use.


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Posted: Fri Apr 27, 2007 2:49 pm 


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PostPosted: Fri Apr 27, 2007 3:36 pm 
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roberto wrote:
When anyone tells me a frame with 5 or 10 mm longer seat stays and using a different fork rake is the "same" frame as a production bike I just nod my head and laugh. Aint drinking any of that Koolaid myself.


You may want to check out some recent threads about this. O'Grady's R3 was not the long wheelbase version. The fork was different, but anyone can buy an alpha Q fork. So what about the R3 cyclocrossers?

All those P3s are just falling apart? Can anyone update us on the failures CSC has had with Cervelo so far?

Perhaps Wilier's are better? Painting an aluminum frame to look like carbon fiber for Ballan?
At least I'm drinking lemon koolaid and not a urine sample.


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PostPosted: Fri Apr 27, 2007 3:51 pm 
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DaveS wrote:
After you've read a few posts from cyclists who have damaged frames because the integrated headset was improperly adjusted (too loose), you might change your mind.

Please elaborate on the wrong but reasonable comment, it seems contradictory. Do you really think a thin piece of aluminum is the preferred bearing seat? FWIW, LOOK used removeable seats even when the entire head tube was aluminum and could easily have had the seats machined into the headtube on frames like the KG381 and KG461. I assume it was an engineering judgment to prevent possible problems.

Some brands initially machined the seat into the head tube on their aluminum or Ti frames, only to switch to removeable seats after all the problems incurred in the first year. Litespeed wisely abandoned the integrated headset after a few years. Chris King, of course, is famous for his tirad against the integrated headset on any frame.



This is not an issue. I have yet to hear of a single issue with the headset bearings. LOOK used removable seats on the aluminum frames because of potential to ovalize when ridden without proper adjustment, but the R3 supports are then supported by the carbon fiber head.

If you get your information off of vendor's sites like Chris King and Litespeed , then expect a lot of misinformation. Chris King makes headsets, of course he's anti-integrated head sets. Litespeed is now famous for hyping a technology one year, and attacking it the next. I have many friends with Tuscany frames, none have had headset issues, all know how to check a headset before a ride.

You are preaching to us about frame advice after admitting to buying a frame without even trying it?

I'm curious, what type of engineering do you do?


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PostPosted: Fri Apr 27, 2007 4:01 pm 
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Most companies do specials of some form or other for Roubaix... Trek with the damper rear, some go back to metal.

That race is great to watch, but I would HATE to have to need anything that those guys do as I ride round day to day. No company needs to produce roubaix type road bikes for the masses as it's just not reasonable for anyone to expect a road bike to do what they are expected to do at Roubaix.


There's no shame in that Cervelo built non-standard R3's for Paris Roubaix. They also took care of their customers with the huge failure that was the 2.5...


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PostPosted: Fri Apr 27, 2007 4:03 pm 
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DocRay wrote:

This is not an issue. I have yet to hear of a single issue with the headset bearings. LOOK used removable seats on the aluminum frames because of potential to ovalize when ridden without proper adjustment, but the R3 supports are then supported by the carbon fiber head.

If you get your information off of vendor's sites like Chris King and Litespeed , then expect a lot of misinformation. Chris King makes headsets, of course he's anti-integrated head sets. Litespeed is now famous for hyping a technology one year, and attacking it the next. I have many friends with Tuscany frames, none have had headset issues, all know how to check a headset before a ride.

You are preaching to us about frame advice after admitting to buying a frame without even trying it?

I'm curious, what type of engineering do you do?

Okay Doc, communication course, advice
number one: do not play it personal (''kind of engineer...''), even if other people do...
number two: do not try to ignore facts that are playing in DaveS his head (''This is not an issue''), because maybe it is, we all know that headset failures don't happen from one day to another, but gradually over time.
number three: do not try to use logic sounding sentences as an argument on its own, but discuss about it (''Chris King makes headsets, of course he's anti-integrated head sets'')
happy discussion!

_________________
Bianchi EV3, Master Olympic, Pinarello Asolo


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PostPosted: Fri Apr 27, 2007 4:14 pm 
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DaveS wrote:
youngs_modulus wrote:

DocRay: <snip> I agree with you that DaveS is wrong about the R3 headset bearing seats, but his assertions are reasonable. Wrong, but reasonable.


After you've read a few posts from cyclists who have damaged frames because the integrated headset was improperly adjusted (too loose), you might change your mind.

Please elaborate on the wrong but reasonable comment, it seems contradictory. Do you really think a thin piece of aluminum is the preferred bearing seat?

Yes, I think that a thin piece of aluminum is a reasonable bearing seat in this application. Cervelo markets the R3 as a high-end, no-holds-barred racing frame. Most owners will have the experience to know that they can't ride on a loose headset, even for a little while. Inevitably, some owners will not know this and will damage their frames. A high-end machine requires high-end maintenance, which I think is reasonable in this case, especially given that weight is a primary design criterion for this product. As you surely know, what's reasonable for any given product is largely a function of the predefined design criteria for that product. In my engineering judgement, the aluminum seat/race is reasonable in this application.

Now, how can I say that your complaint about the bearing seat material is wrong but reasonable, and how is this not a contradiction? Well, I just mentioned engineering judgement. That's an opinion, no matter who it comes from. I disagree with your opinion that aluminum is inadequate in this application, but I understand why you think so and I think yours is a supportable conclusion. If you suggested that, say, 6/4 Ti was the only valid material from which to build a bicycle, I'd say that you were both wrong and unreasonable, as it's perfectly fine to build a bike from steel, 3/2.5 or aluminum (among many other options).

While I don't mind non-replaceable aluminum bearing seats in my R3, there's a solid argument to be made in favor of replaceable bearing seats made of another material (or the use of a standard headset). You're making that argument. Again, this is something about which reasonable people can disagree. One point on which we do not disagree is that replaceable aluminum seats would be better.

<snip>

Quote:
Now that I think of it, I'm also skeptical about LOOK's use of a carbon fork crown race too.


Do they actually use a carbon race, or a carbon crown race seat?
I understand your skepticism, but Easton has been making forks with carbon crown race seats for years...I use one of their EC90SL forks with such a seat on my own regular-headsetted Litespeed. It works fine. I've never encountered anyone who had a problem with a carbon crown race seat. That's not to say there are no problems, but they are certainly not epidemic.

Quote:

One problem I've noted is manufacturers have notoriously poor instructions included with frames, forks and headsets (including LOOK). They gloss over the adjustment of the headset, only telling the user to "eliminate play". Integrated headsets need to be adjusted as tightly as possible without inducing excesive drag as the fork is turned. The top cap requires quite a bit more torque on it than would be used with a caged ball headset like Campy's. Failure to do that can result in frame or bearing seat damage.



YES! I totally agree. I suspect people are worried about "overloading" their headsets by applying too much preload, but in fact the danger from having 10% too little preload far exceeds that of having 50% too much preload. Headset bearings are annular and designed to take a large axial load, but people generally adjust them until play is just eliminated, as you say. There's nothing wrong with having a headset that turns a little more stiffly than necessary--you won't feel it while riding and it's cheap insurance against a pitted headset (or worse, in the case of integrated headsets).

Quote:

I'll agree that if you like the ride and handling of your R3, that's great. I found the geometry in the 49cm and 51cm (which I owned) to be unreasonably short in the front-center with too little steering trail. There is no other brand that makes frames with such a short F-C. The excessiely short chainstays also caused problems with my triple crank (for climbing the Colorado mountains). Unless the shift from the middle ring to little ring was made from the third largest cog (or smaller) the chain would drop off the little ring and jamb between the little ring and the frame. A chainwatcher won't fit onto the downtube either. I was so unimpressed that I sold mine after 200 miles of use.


Yeah, I agree mostly. 54cm is the first size where the dimensions start to look normal to my eye. A 54 has a 54.5-cm top tube, and I'd much prefer a 55 or 55.5 cm top tube. The chainstays are fairly short (40 cm) but that's not really a problem for me. If I rode a 49 or 51, I probably wouldn't buy an R3 either.

Personally, I'm neither surprised nor troubled by the fact that the R3 doesn't deal gracefully with a triple crank. As I said before, it's a no-holds-barred racing frame, and for most racers, a triple is low on their lists. If it were me, I'd probably run a compact crank rather than a triple, especially given the short chainstays.

Finally, you complain about inadequate trail on smaller R3s. They've got 73-degree head tubes (72.5 degrees in the smallest size), which is pretty reasonable. I would assume they're using forks with 43-45mm of rake, which would result in reasonable trail numbers. Some manufacturers use forks with more rake in the smaller sizes to avoid toeclip overlap (an outdated term, but still an issue), but I don't believe Cervelo is doing this. So in the smaller sizes the wheelbase gets pretty short, but I don't see any unreasonably low trail numbers. Longer front center might be a good idea, but I don't see the "too little steering trail" you mentioned.

As an aside, I'm amazed by how many riders in Paris-Roubaix are said to use forks with increased rake "for greater shock absorption." Increasing fork rake decreases trail, which thereby decreases stability. An increase in fork rake will get you a tiny increase in fork deflection (look at the governing equations from beam theory) and a much larger decrease in stability. It's hard to build an unrideable bike; zero- and even negative-trail bikes are perfectly rideable as long as you don't try to ride no-handed. I'm sure these guys go faster because they're more confident in their modified equipment, but objectively, there's nothing there.

Cheers,

Jason


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PostPosted: Fri Apr 27, 2007 4:19 pm 
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de zwarten wrote:
Okay Doc, communication course, advice
number one: do not play it personal (''kind of engineer...''), even if other people do...
number two: do not try to ignore facts that are playing in DaveS his head (''This is not an issue''), because maybe it is, we all know that headset failures don't happen from one day to another, but gradually over time.
number three: do not try to use logic sounding sentences as an argument on its own, but discuss about it (''Chris King makes headsets, of course he's anti-integrated head sets'')
happy discussion!


DaveS was the one who chimed in about being a professional engineer to justify his opinions. I'd like to know what his qualifications are. Engineering degrees are not universal. For all we know, he designs toilet tank flappers.
There have been discussions about Chris King and headsets. This should all be taken with a grain of salt, as with the Litespeed anti-carbon campaign, or the Rivendell anti-racing bike campaign.

Of course headset, and all parts failures occur. Dave and Young's points are correct, little education is done to insure that a rider has a properly adjusted headset, but are manufacturers now responsible for the abuse of their products due to owner negligence?

By this line of thought, we should all be on steel frames and forks of the 90s era (which were pretty good bikes).

Thanks for the unsolicited advice , but I'll stick with my crappy Chinese Carbonello and enjoy my mediocrity, and only wish my bike had more 'heritage' and 'pedigree'.

So back to the original post and the thread:

1. When looking for a new frame, take into account parameters like: over-tightening of bolts, crashes, riding on a loose headset, remember, no matter how stupid the incident, it is always the manufacturer's fault.

2. Avoid integrated headsets. Chris King says so.

3. Racing experience does not affect a frame design, nor does racing success imply anything about a frame. Real racing frames are not for mortals like us.

4. Finite element analysis, CAD, crash testing, EFBe, Paris-Roubaix, pro tour etc. , are all just recipes for koolaid. What you really want to look for is a little shop run by Gepetto, who hand crafts his frames lovingly for weeks, ...for $1800.

5. Some frames are so well built, they don't need warranties, the less warranty, the better.

6. Check the history of the company, even if they had a design failure years ago with full replacement, even used frames, avoid the company, because all future designs are fruit from the tainted tree.

7. Whatever you decide, make sure that you sign on to Weightweenies and attack all other manufacturers over there choice of allen head finishes or whatever. In the absence of any issues that affected 1/1000, make one up.

ok, I'm done with this.


Last edited by DocRay on Fri Apr 27, 2007 4:51 pm, edited 1 time in total.

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PostPosted: Fri Apr 27, 2007 4:33 pm 
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youngs_modulus wrote:
Yes, I think that a thin piece of aluminum is a reasonable bearing seat in this application. Cervelo markets the R3 as a high-end, no-holds-barred racing frame. Most owners will have the experience to know that they can't ride on a loose headset, even for a little while. Inevitably, some owners will not know this and will damage their frames. A high-end machine requires high-end maintenance, which I think is reasonable in this case, especially given that weight is a primary design criterion for this product. As you surely know, what's reasonable for any given product is largely a function of the predefined design criteria for that product. In my engineering judgement, the aluminum seat/race is reasonable in this application.
[/quote]

I think there is a degree of expectation that a rider who purchases a higher-end frame either know how to maintain it, or employ someone who does.

One does not take his 72 Ferrari Daytona to Jiffy-Lube for tuning.


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PostPosted: Sat Apr 28, 2007 12:48 am 
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I'll just add couple of points and quit. After reading dozens of posts nearly every day on several forums, I can guarantee you that a great many high end frames are sold to people who have lots of money but no clue how to adjust a headset. Many can't install a chain, new shift cables or even tape their bars without taking it to a shop where a high-school-aged kid gets a shot at it.

As for the aluminum headset bearing seat in the R3 being supported by carbon, that's true but irrelevant. The headset bearing itself is totally surrounded by aluminum on the sides and bottom, no differently than a cheap aluminum frame with the seat machined into the head tube. The bearing itself has no contact with any carbon material. If the headset is ridden loose, damage occurs the same as it would with an aluminum frame.

Doc seems amazed that I'd buy a frame without trying it.

The last time I test rode a bike before buying it was 1992. I rode a prebuilt C'dale 2.8 for a few miles and bought it from a local shop. It was a pretty harsh frame (but light for the time) and I endured it for at least two seasons. It was also that last purchase I made from an LBS. I've owned about about 10 frames since I first starting building up my own in 1995 and I never rode ANY of them before I made the purchase. Finding some models at a local dealer in my size can be impossible. Out of all these frames, I've only regretted two - a '98 Litespeed Ultimate that I found to be particularly brutal to ride and the R3.

What kind of engineering did I do? After 5 years machining aircraft parts full time and another 5 years part time while attending college, I worked as a process engineer specifying the precision machining processes to manufacture metal components for nuclear weapons for 10 years. After the cold war ended and nuclear weapons production declined drastically, I transferred to a facilties engineerng position at the same plant, designing all types of industrial piping and HVAC projects for another 12 years. Now I'm retired.


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