Rehash (not a drug in Schweiz)
Julien, I'm not sure you've seen this but here's a letter from Cane creek I posted a while back.
Cane Creek replies
First off I'm not trying to PO anybody, here's the reply I recieved from Cane Creek today. I usually don't like to copy a private email for a public forum but Joe said: "feel free to share this email and its information with any other current or potential Cane Creek customer" So that's what I'm doing. I couldn't copy his attachments, sorry.
Thanks for your email. My name is Joe Ward.
I was first made aware of the two "Double X/Intense frames" threads on mtbR yesterday morning. We have had many emails and phone calls pertaining to this matter.
I apologize for any delay in our response to your email, but as with any technical or customer service issue with which we deal, we wanted to gather as much information we could about the situation so that we could make intelligent commentary on it and address it properly. We pride ourselves on high quality, well thought-out, well designed, innovative products that enhance your ride, supported by the best possible customer service we can provide. Our goal is to offer the highest levels of customer service possible not only in the bicycle industry, but in any industry.
I would like to explain some of our thoughts on message board forums and the mtbR forums, in particular. We admire and respect what Francis has built with the mtbR site and think it is a great source for information and communication. At times, these forums can also be sources for disinformation as well. Ultimately it is the consumers/participants in the forums that have to gather information and formulate their own opinions and make their own decisions as to the accuracy of the information. It is our feeling that the forums need to remain primarily for the consumers and not a place for us, as manufacturers, to participate and be "homers" for our products, trying to influence you as consumers/riders in any way. There are plenty other avenues for us to accomplish that type of marketing communication. As a general rule, we avoid participation in these forums heavily so as to keep them "pure" for consumers/riders. Occasionally, we will "chime in" to answer a question about factual issues, or if someone is looking for some specific information.
We choose to handle our business and communication directly with our customers (including OEM's, retailers, and consumers) rather than on internet message boards. We welcome any and all questions about our products, business practices, feedback and input by email, phone, and even face to face where possible.
It is also our practice to handle any and all technical issues with frame manufacturers with direct communication and professionalism, not in a public forum such as a website message board.
We have received very little information from Intense Cycles with regards to this issue. The only communication we have had is a request from Intense for dimensional tolerances of the cups of our Double X family of headsets, which we provided.
Within our family of Double X headsets, we offer a total of six models:
Double X: (OnePointFive standard/steerer, 20mm insertion aluminum cups)
Double X short: (OnePointFive standard/steerer, 10mm insertion aluminum cups- designed for manufacturers who chose not to machine the head tubes to the 20mm insertion standard)
Double Xc: (OnePointFive standard head tube, 1-1/8" steerer, 20mm insertion aluminum cups- designed in direct response to consumer feedback for riders who wanted to use 1-1/8" steerer forks with their OnePointFive frames)
Double Xc short: (OnePointFive standard head tube, 1-1/8" steerer, 10mm insertion aluminum cups-designed in direct response to consumer feedback for riders who wanted to use 1-1/8" steerer forks with their Cannondale HeadShok frames)
Double Xc Flush: (OnePointFive standard head tube, 1-1/8" steerer, 20mm insertion aluminum cups- designed in direct response to consumer feedback for riders who wanted to use 1-1/8" steerer forks with their OnePointFive frames with the lowest possible stack height…to keep the front end as low as possible)
Double XcR Flush: (OnePointFive standard head tube, 1-1/8" steerer, 20mm insertion steel cups, retainer type ball bearings- new model designed in response to OEM requests- for riders who wanted to use 1-1/8" steerer forks with their OnePointFive frames with the lowest possible stack height…to keep the front end as low as possible)
You can check out these headsets here: Double X headset family
With all of that background information presented, I will address the specific issue about which you have asked. The comments from Phillip Strong of Intense are listed in italicized type below, followed by our information.
Some observations on the One Point Five interface standard:
1. The One Point Five standard defines the diameter and tolerance for the bore in the head tube "the standard specifically does not cover the diameter of the headset cups," to quote from the standard drawing, "HS CUP OD NOT SPECIFIED". The diameter specified for the head tube is 1.9516" to 1.9532" (49.57mm to 49.61mm).
True, the focus of the standard is to establish dimensions of the head tube and the fork steerer, not the headset cups. However, there was plenty of opportunity for frame manufacturers involved in the standard discussion (including Jeff Steber of Intense) to voice any concerns about press fit dimensions in the development of the standard. If not at that time, there has certainly been opportunity since then as the headset press specifications are widely published (Sutherland's Handbook for Bicycle Mechanics). Cane Creek was a primary participant in defining the OnePointFive standard back in 2001/2002, and there was a great deal of feedback from frame manufacturers in defining the standard…with no concerns as to the outer diameter of our headset cups. You can learn about the history of the OnePointFive standard here: OnePointFive History
2. As manufacturers are free to define their own requirements for the cup OD, both the requirements and the actual parts tend to vary. Cane Creek specifies an OD of 1.9567" to 1.9579" (49.70mm to 49.73mm). We have had experience with two Cane Creek Double Xc Flush headsets causing the head tube to crack on the 6.6. These cups measured 1.9579"to 1.9585"(up to .0006" over Cane Creek's high limit tolerance). It should also be noted that the Cane Creek is a "deep" headset (20mm vs. 10mm insertion depth).
The cup outside dimension specification is actually 49.70mm to 49.75mm as listed in Sutherland's Handbook for Bicycle Mechanics. Our tolerance (49.70mm to 49.73mm) is toward the lower end of that specification. Even if one of our cups fell outside our upper limit by 0.0006" (which would equate to 49.745mm) it is still within the published allowable tolerance. Upon reading the above information about some cups that were measured over our high limit tolerance by Intense Cycles, we ran an additional Quality Control procedure on our current Double X inventory. We also requested some inventory to be returned from one of our dealers to be checked…"just to be sure", and we await its return. We would be happy to QC check the questionable units in the possession of Intense. After a complete and thorough QC procedure, all cups were found to be within the 49.70 (+0.03/-0.00) spec and all but the Double Xc Flush bearing cups stayed at the lower end of the tolerance range. The Double Xc Flush bearing cups averaged in the middle of the tolerance range. I have enclosed a PDF showing a sampling of our QC report.
3. Here at Intense, we tend to use the FSA Orbit Z 1.5R in this application. Although the FSA drawing allows the OD of the cups to be 1.9547" to 1.9587" (49.65mm to 49.75mm), the units we have measured run 1.9545" to 1.9565". The insertion depth of these cups is 10mm. We have had no problems in using this head set.
Even though Intense has measured cups from FSA that are at the low end of the tolerance, the high end of the FSA tolerance is actually greater than the Cane Creek high end tolerance (and even slightly above the dimension Intense says caused a problem in point #2). Sound engineering practice, which we choose to follow, is to base manufacturing standards on published tolerance specifications rather than a few measured samples.
4. Standard engineering practice for a locational press fit for this diameter part is to have .0004" to .0020" interference. While the actual size of the FSA sets as compared to the 1.5 Standard head tube diameter yields an interference of .0013" - .0049", the larger Cane Creek sets come in at .0047" - .0069". We are very concerned that the additional interference is causing undue stress in the head tube material.
As the original inventor of threadless headset technology, we have many years of experience in designing, producing, and selling threadless headsets. The press fit specified is in line with the press fits designed for all other sizes of headsets (1", 1-1/8", etc.). To ensure proper a proper press fit and good headset performance, a frame's head tube must be properly reamed and faced to the correct dimensions after welding. We as the headset manufacturer can only educate the frame manufacturers of this fact; we cannot ensure that it is completed upon each headset installation. We have produced thousands of OnePointFive style headsets for customers using many different brands of OnePointFive bicycles. There have been no other instances to our knowledge of this press causing head tube failure problems with these headsets. Additionally, of the millions of 1", 1-1/8", and 1-1/4" headsets we have produced through the years, there have been no instances to our knowledge of similar press fit problems. If there is an issue that needs to be addressed professionally, a public web post is certainly not the proper forum.
5. Due to the above concerns, Intense Cycles strongly recommends against using any headset with an OD above 1.9565". This specifically refers to the Cane Creek Double X series, as well as any other head set creating an interference of .0050 or larger.
See point #3 above. The FSA published tolerance is 49.65 to 49.75. We find it interesting that Intense would approve the FSA product that may fall outside of their established limit 50% of the time. The Intense upper limit of 1.9565" (49.695mm) means that all FSA headsets measuring 1.9566" to 1.9587" fall within the FSA tolerance, but not the Intense tolerance.
In summary, we are confident that there is not a problem with the compatibility of our headsets with any properly manufactured OnePointFive standard frame, and no cause for concern for customers of our Double X family of headsets.
I apologize for the length of this email, but wanted to be thorough in our explanation of this situation in order to address your concerns. We value you as a current and future customer of Cane Creek Cycling Components.
Please feel free to contact me or anyone in sales/customer service with any additional questions you may have, and feel free to share this email and its information with any other current or potential Cane Creek customer.
Thanks and best regards,
Cane Creek Cycling Components, Inc