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  1. #1
    Senior Member Road Fan's Avatar
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    Steer tube v. Head tube?

    On my new frame, the head tube is 231 mm and the head tube is 169 mm. This seems like a way too long head tube. Most threaded headsets are about 40 mm stack height, and allowing 5 mm or so for a cable hanger, the difference should not be more than about 45 mm. But in this case the available difference is 62 mm - I'd need to add up to 2 cm of spacer with a threaded headset!

    Is it an absolute that I have the wrong fork, or is there any frame designer's rationale that I'm missing here? The builder recommends Stronglight A9 headsets, but there's no way an A9 will fit here without the 2 cm of added spacer. Could there be a purpose for this design that I am missing?

    Edits: I should add that while the frame and fork are supposed to be the product of a known modern constructeur, I bought them from his original custom bike customer. It is possible that the fork was switched by the original owner.
    Last edited by Road Fan; 03-08-12 at 07:12 AM.

  2. #2
    Randomhead
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    does it have a threaded steerer? If it is, the builder may just have gotten used to the standard practice with threadless steerers to leave them very long

  3. #3
    Andrew R Stewart Andrew R Stewart's Avatar
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    Shouldn't this question be directed to the original customer? Leaving the steerer long for added spacers is a time proven way to allow a higher stem height. Perhaps i missed it in your post but maybe the original customer wanted this added height without using a tall stem.

    The other possibility is that the steerer was to be cut during the bike's set up, and wasn't.

    Of course the form might not be original. Does the paint match? It would be odd to have gone to the effort to paint the replacement fork exactly a match (or repaint both frame and fork) but not cut the fork as well. Andy.

  4. #4
    Senior Member Road Fan's Avatar
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    Quote Originally Posted by unterhausen View Post
    does it have a threaded steerer? If it is, the builder may just have gotten used to the standard practice with threadless steerers to leave them very long
    Yes, it has a threaded steerer; the A9 is a threaded headset.

  5. #5
    Framebuilder
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    2cm is a bit more than you'd need for a cable hanger,decaleur, etc...but it's alway better to err on the side of caution when building a fork w/a threaded steerer for an unknown headset. That's probably what happened here.

  6. #6
    Senior Member Road Fan's Avatar
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    Quote Originally Posted by Live Wire View Post
    2cm is a bit more than you'd need for a cable hanger,decaleur, etc...but it's alway better to err on the side of caution when building a fork w/a threaded steerer for an unknown headset. That's probably what happened here.
    It could be that the builder did exactly that, then Customer 1 spacered it up to avoid cutting. The builder had the Stronglight A9 in mind for the bike, and Barnett's gives us the stack for that one. It's way less than 62 mm.

  7. #7
    Senior Member Road Fan's Avatar
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    Finally reached the prev. Owner. Was concerned about short arms, so he wanted a high bar placement.

  8. #8
    Andrew R Stewart Andrew R Stewart's Avatar
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    Bingo. All it takes sometimes is going to the source. Andy.

  9. #9
    Senior Member Road Fan's Avatar
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    but still, talking with the builder, it's not an optimal setup, and it may have caused the previous some handling issues.

    And besides, I was not looking for handholding or grade school advice, I was looking for some knowledge from frame builders.

  10. #10
    Decrepit Member Scooper's Avatar
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    I did the same thing with the steerer on my Waterford. I'm almost 70 and not as flexible as I used to be.

    - Stan

  11. #11
    Randomhead
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    Quote Originally Posted by Road Fan View Post
    but still, talking with the builder, it's not an optimal setup, and it may have caused the previous some handling issues.


    I've never heard of anyone attributing handling problems to an upright position. I see no significant difference between spacers on a threadless or threaded headset.

    Quote Originally Posted by Road Fan View Post
    And besides, I was not looking for handholding or grade school advice, I was looking for some knowledge from frame builders.
    I don't see any patronizing answers here, did you want something you didn't ask?

  12. #12
    tuz
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    2 cm of spacers isn't all that much on a threaded steerer. I can see a situation were you want to raise the bars a little with not too much quill exposed, while keeping a level top tube and/or standover clearance. I agree that it looks better with only the minimum amount of spacers.
    homebuilt commuter, mixte, road and track (+ Ryffranck road)
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  13. #13
    Randomhead
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    I have to say that back in the day, 2 cm of spacers on a threaded steerer simply wasn't done. That was one of the joys of f-building back then, you had to get the steerer length right. Nowadays, everyone is used to cutting their own steerers and using spacers.

  14. #14
    coprolite fietsbob's Avatar
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    Head tube is part of the frame , Steer tube is part of the fork.

  15. #15
    coprolite fietsbob's Avatar
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    I got out the thread cutting die on my touring bike fork, and cut it down more.
    and have almost 2" between the top nut and the headset?
    Found a steel bell i could take apart, and braze the base of the bell to a spacer tube.

    I use a tall stem and bury it far enough to span the cut thread to insure
    it won't break thru a thinned section where the threads are cut.

  16. #16
    Randomhead
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    generally, threaded steerers have plenty of threads, so I doubt he is complaining about that

  17. #17
    Andrew R Stewart Andrew R Stewart's Avatar
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    Roadfan- i don't think anyone is trying to hold your hand here. The replies are valid points. My second post was an 'atta boy" for going to the source.

    As far as handling issues go: center of weight and fore/aft balance can effect the stability of a bike. Have you found this bike to give you problems (like the speed shimmies?), is it changeable with your upper body placement? I've know of bikes that were wobbly for one rider but not another, or with one placement of load but not another placement.

    You seem to have more questions or concerns then you're directly saying. Maybe I'm trying to see into your postings more then i need to (but as the service guy at the shop i work at that's my job, to understand what the rider is really saying but isn't describing in specific terms). We're here to help. Andy.

  18. #18
    Randomhead
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    I think it generally takes more weight movement than just moving the stem up a few inches to adversely affect the handling of a bike in a way that's noticeable to the rider. Granted, going to a more upright position is not making things better.

  19. #19
    Senior Member Road Fan's Avatar
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    Quote Originally Posted by Andrew R Stewart View Post
    Roadfan- i don't think anyone is trying to hold your hand here. The replies are valid points. My second post was an 'atta boy" for going to the source.

    As far as handling issues go: center of weight and fore/aft balance can effect the stability of a bike. Have you found this bike to give you problems (like the speed shimmies?), is it changeable with your upper body placement? I've know of bikes that were wobbly for one rider but not another, or with one placement of load but not another placement.

    You seem to have more questions or concerns then you're directly saying. Maybe I'm trying to see into your postings more then i need to (but as the service guy at the shop i work at that's my job, to understand what the rider is really saying but isn't describing in specific terms). We're here to help. Andy.
    I think I asked my questions. I didn't originally want to go to the source because I wanted some information to use in potential negotiation. There are a couple of odd features with this frame, and I was feeling like the steer tube problem was going to be my last straw, and I'd ask for my money back.

    As for the rest of your questions, I have not yet built and ridden this frame yet, so I don't know if I will have any handing problems. I don't plan to have my bars 3 cm above saddle, I haven't needed that. This one will have a tall SOH for me. I received it and am measuring everything to make sure I have or get the right parts. Previous owner was not forthcoming with pictures of the previous build, at least not with any details. And the builder said to be careful, that owner did some things he didn't plan for in the design. So I had reasons for my caution. And I chose to start asking my questions here to get some expertise from experienced frame experts.

    Honestly, I've never seen using an extended steer tube with a threaded headset before, since threaded stems are adjustable. I've only used it to leave room between the adjustable cup and locknut for a V-O cable hanger and perhaps a V-O decaleur. I'm using both, and have to allow an extra 12.5 m stack for those parts, perhaps with a spacer in between them. Like Fiets, I expected to see the steer tube trimmed to match the recommended (remember, I said the builder said he designed the bike for a Stronglight A9). So to see an extra-long steerer was a surprise and made me wonder what was going on. I considered benign and not-benign explanations. That's what I do in my job.

  20. #20
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    As my gut got bigger so did my frames, until even that wasn't enough. So I have several frames with threaded steerers and a couple of cm. of spacers. As Unterhausen points out, a few decades ago that would've looked stupid, but now it looks just like everything else.

    I've solved that particular problem by not eating anymore, but there you go.

  21. #21
    Senior Member Road Fan's Avatar
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    Quote Originally Posted by unterhausen View Post
    I think it generally takes more weight movement than just moving the stem up a few inches to adversely affect the handling of a bike in a way that's noticeable to the rider. Granted, going to a more upright position is not making things better.
    This is a very low-trail frame (>65 mm rake). I'm not yet familiar with its handling, nor am I a builder like some of you, but the builder was concerned when the original owner used such a high position. Owner 1 stated that the handling was a little sensitive at high speed. This was not borne out in Jan Heine's test (it was one of his more stable constructeur test bikes) or in the expectations of the builder of the bike. The builder thought the unusual sensitivity was caused by the small rise and rearward shift in the rider's CG. An unusual effect? Perhaps, but this is not a usual bike with 60 mm trail.

  22. #22
    Senior Member Road Fan's Avatar
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    Quote Originally Posted by Six jours View Post
    As my gut got bigger so did my frames, until even that wasn't enough. So I have several frames with threaded steerers and a couple of cm. of spacers. As Unterhausen points out, a few decades ago that would've looked stupid, but now it looks just like everything else.

    I've solved that particular problem by not eating anymore, but there you go.
    SixJours, we need to start a thread on that - "cyclists who stopped eating to get more aero/aggro!" Maybe a monthly column in Bicycling? "Stop eating to improve your centuries!"

    All of my bikes until now have been conventional road machines, so my sense of styling goes back a few (at least!) decades.

  23. #23
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    I stopped eating primarily because I was doing a pretty fair Jabba impression. And there's a whole damn subforum on that topic.

  24. #24
    Randomhead
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    My current bike has lower trail than I was used to, and it felt a little squirrelly to me at first. Never really noticed that at speed as far as I remember, but it's been a while. When I dropped 2 cm of spacers out, I noticed that I had more power, but it didn't improve the handling

  25. #25
    Senior Member Road Fan's Avatar
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    Unter, I can't really deny or confirm your experiences. This will be my first lengthy experience with a low trail bike, a big experiment. The previous owner felt it was a little touchy, and the builder attributed that to the raised bars, abobu 4 cm above saddle. I'll be riding it with bars level to 1 cm below, not 4 cm above. Different handling? I'll never find out.

    I do have my Trek 610 set up with a low trail fork, and I do not find it squirelly at all with 700x28s, it's very nice. Same for the old UO-8 (about 65 to 70 mm rake), with fat enough tires (27 x 1 1/4 are much better than 21 mm tubulars on that one).

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