I’ve found this device very helpful when comparing stems with different quills, angles, and extensions: http://yojimg.net/bike/web_tools/stem.php
On Thu, Oct 10, 2024 at 1:08 PM 'John Hawrylak, Woodstown NJ' via RBW Owners Bunch <[email protected]> wrote: > Leah > > Let's try this explanation and 1 definition > > When I say a Technomic stem, I mean a quill stem with a stem length which > is at an angle of 73° with the quill or -17° with respect to a line > perpendicular to the quill. It is the standard road bike stem which makes > a drop bar horizontal even though the stem is in a head tube angled at > about 73° to the horizontal. Your 2 Technomic stems are this type > > A 225mm quill Face Platter (FP) stem with a 135mm stem length *puts the > stem clamp (hence your bars) *in the same position as a Technomic with a > 289mm quill and a 139mm stem length, due to the 100° angle of the stem tube > from the quill to the clamp. If on a work bench, you placed your 280mm > Technomic with a 100 mm stem length on top of the 225mm FP stem you would > see the following: > The FP stem clamp is 9mm higher than the 280mm Technomic > The FP stem clamp is 39mm further out than the 280mm Technomic > The top of the quill on the 280mm Technomic is below the FP stem clamp by > about 9mm, even though the FP quill is 55mm less than Technomic 280mm quill > > Does this help?? The math is geometry and trigonometry, with the > dimensions and angles of the stems. > > The bottom line is if you 'slam' the FP stem in the steerer tube (like > your 280mm Technomic is currently) the bars will be 9mm higher and 39mm > further out than the 280mm Technomic with a 100mm stem length. Slamming > a stem into the butted section of the steerer is a possible cause of the > ticing since the expander bolt is not properly anchored. > > Additional questions are welcome. Can provide distances for you 225mm > Technomic with 120 stem length to compare to the placing on top of the FP > stem. > > You may want to raise your 280mm Technomic stem by 20mm to clear the > butted section and see if the noise goes away. I realize the bars will be > higher than you want, but see if the noise goes away. > > John Hawrylak > Woodstown NJ > > > On Thursday, October 10, 2024 at 2:35:53 PM UTC-4 Bicycle Belle Ding Ding! > wrote: > >> Well, I don’t do this kind of math. You’re saying my new 225 mm stem is >> going to be 289 mm? That will be too tall. But I can’t see how it can be >> off that much, even given the angle. I understand that the angle will make >> the reach shorter. I do not understand how the angle makes the quill TALLER. >> >> On Thursday, October 10, 2024 at 11:14:09 AM UTC-4 John Hawrylak, >> Woodstown NJ wrote: >> >>> Leah >>> >>> A Nitto 225mm quill Faceplatter stem with a 135mm stem length is >>> equivalent to a standard Nitto Technomic stem with a 289mm quill and a >>> 139mm stem. Here is a comparison with your 2 Technomics >>> Quill length stem length >>> FacePlatter 225/135 289 (Eff) 139 (Eff) >>> Technomic 225 225 100 >>> Technomic 280 280 120 >>> >>> Also the Faceplatter raises the bar height by 61mm compared to a 225mm >>> quill Technomic if both the 225mm quill Technomic and the 225mm quill >>> Faceplatter stems are inserted the same amount. >>> >>> I calculated these results using the 100° stem angle and a 135mm stem >>> length for the Faceplatter and a 73° stem angle for the Technomic. The >>> Faceplatter looks like a Technomic 280/120 stem with 19mm longer stem >>> >>> It looks like the Faceplatter stem results in a higher bar height and >>> the bars further out than either of the 2 Technomics. The higher bar >>> height may help with the 19mm longer bar extension compared to your >>> Technomic 280. >>> >>> Any questions >>> >>> John Hawrylak >>> Woodstown >>> On Wednesday, October 9, 2024 at 5:12:02 AM UTC-4 Bicycle Belle Ding >>> Ding! wrote: >>> >>>> John, >>>> >>>> The initial stem was the Tallux 12 cm, 225 long. >>>> >>>> The stem I had in the parts box and just installed is Nitto, 10 cm, 280 >>>> mm. That 280 was bought before I started club riding and wanting the bars >>>> lower. That 280 is slammed in the the steerer now. I’ll raise it before I >>>> ride it, but that Faceplater in 225 should arrive soon. And when it does, >>>> I’m going to find that slot and put Krazy glue in there. And thanks for >>>> pointing out that there would be a slot! >>>> >>>> To all of you: what would I do without you? I’d be out there with my >>>> ticking and loose headsets with my wedges fighting for purchase in the >>>> narrowing steerer! A whole mess out here. >>>> >>>> Also, why don’t any of you live here. I could use a mentor over here! >>>> Leah >>>> >>>> On Oct 9, 2024, at 2:30 AM, 'John Hawrylak, Woodstown NJ' via RBW >>>> Owners Bunch <[email protected]> wrote: >>>> >>>> Leah >>>> >>>> Just to amplify what Noah pointed out on the internal butting in the >>>> head tube, if you have the stem QUILL all the way down, then you need to >>>> raise the stem so the expander bolt is above the butting. >>>> *If* raising the stem quill, to clear the internal butting, results in >>>> the bars being too high, *then* you need a stem with a Shorter Quill, >>>> but the same stem extension. Per the 2019 catalog, Nitto makes the >>>> Technomic stem ("NTC") in QUILL LENGTHS of 150mm, 225mm, and 280mm. The >>>> RBW site shows only the 225mm version (Tallux). >>>> >>>> Also, the 40mm hole Will and Nitto mentions, may be a slot in the >>>> sleeve in the center of the sleeve, NOT the ends of the sleeve. This would >>>> NOT be visible with the bar in the stem. You may want to slide the bar out >>>> of the stem to verify if the slot exists. >>>> >>>> If your new face platter stem has a shorter quill than your existing >>>> stem, the face platter stem may solve the slammed stem problem. >>>> >>>> John Hawrylak >>>> Woodstown NJ >>>> >>>> -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. 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