Thanks, Rob. I’m pretty small potatoes, but I’m flattered that you think I have a social media presence. 😊
Paul, I know, I feel conflicted, too. I really should talk to Riv but can’t bring myself to do it. I ordered the stem at a time that Riv was struggling and needed business. Instead of getting it through SomaFab, I had Riv order it. I just can’t make them handle it! I’v gone to Soma, and if the Soma route doesn’t work, I’ll be spending another $130 on the same stem, I suppose (when it comes back in stock). And what of my bar? I have to hope it’s not compromised from the damage the stem inflicted. Sigh. I know user error could certainly be a factor here, but honestly, I doubt if I’m capable of over-tightening a bolt. And it’s pretty straightforward how to clamp stem to bar, so I am confident I did that right, too. Unbelievable as it is, I think it’s just a faulty stem. It’s 2020 - we’re used to being disappointed! Leah Sent from my iPad > On Jun 26, 2020, at 9:47 AM, Paul Brodek <pcb.ha...@gmail.com> wrote: > > > Having been in the bicycle components business, I'm a little out of sorts > thinking about how to address this post. > > I'll start out by saying that I think Nitto is one of the best parts mfrs in > terms of design, QC and attention to detail. > > I'll also say that I've used Nitto stems with this design for decades, both > on my own bikes and hundreds/thousands of builds/repairs, and never seen this > happen before. There has always been enough space between the nut and ledge > to allow slight rotation of the nut. But I've never seen the nut as much as > score the ledge, much less wear away enough metal to allow the nut to rotate. > > From being on the mfr side, I know that the observations of one, or even > many, humans to hundreds/thousands of examples may mean little compared to > the hundreds of thousands of units the mfr has produced and shipped. Well, my > saying "I've never seen that before" means little in the big picture. Me or > someone else saying "I've seen that often" would mean something. "I've never > seen that happen before" doesn't mean much, because there's always the chance > the item in question has QC issues, and maybe there's a first time for > everything. But even though I know my saying "I've never seen that before" > doesn't necessarily have much meaning, I do want to say I've never seen that > happen before. I did say I'm out of sorts here... > > I've always thought the nut/ledge dimensions and fit were sub-optimal, but I > never saw it cause a problem, and I assumed Nitto designed it that way for a > reason. But I always wished that fit were better/tighter, that the nut had > very little room to rotate. I always thought the ledge should 1-2mm closer to > the top of the nut, and maybe a little taller/deeper as well. > > Looking at it kinda forensically, I can think of a few possibilities here: > 1. Bolt hole is drilled too low > 2. Hole position is correct, but casting is off, with too much space between > nut/ledge, or ledge is too shallow to resist nut turning > 3. Stem hardness is below spec, softer metal more susceptible to allowing nut > rotation > 4. Nut is undersized, so too much space between nut/ledge > 5. Bolt was significantly over-torqued during installation > 6. Bolt was initially tightened without ensuring nut was flush with stem > face, with the nut point digging/fretting into the stem, starting the gouge > that allowed the nut to rotate > > I might have missed something, but that's all that comes to mind. I don't > know enough about how Nitto mfrs stems, acquires parts and does QC to know > which of the mfr-related issues are possibilities. > > The hole in OP's stem doesn't look any lower than the hole in the > half-a-dozen Technomics I've got scattered around my desk, but fractions of a > mm that my eye might not spot might matter here. None of my stems are crappy > enough that I'd be tempted to try to duplicate making a gouge like that > myself, but by eyeball it doesn't look like my gouge would be any deeper. > > If it were my stem, I'd reckon there's plenty of metal there, and use a new > nut/bolt, install with two wrenches, and be aware of proper nut orientation > and proper torque. Using the triangular beveled nut, and matching bolt, from > a Tech Deluxe doesn't work at my end, either. The bolt is definitely too > short. If I leave out the thin washer that goes under the bolt head, I can > get maybe half a turn, not nearly enough threads, even with a bar in the > stem. And even if the bolt were long enough, that wedge is beveled at the > top, and the Tech stem ledge is beveled to match, and the Tech stem ledge is > deeper. It's not as clean a fit on the Std. I'd feel better with standard nut > on the standard Technomic. > > But I'd also understand if somebody else would want to replace the stem. > > I would be interested to hear what Nitto would have to say if they examined > the stem. I'd be thrilled if Nitto redesigned the stem to make that nut/ledge > fit tighter. > > Paul Brodek > Hillsdale, NJ USA > > >> On Friday, June 26, 2020 at 9:07:51 AM UTC-4, John Hawrylak wrote: >> Leah >> >> The pictures of the stem shelf were perfect. Sorry to hear the bolt was too >> short. >> >> The direct cause of the of the circular divot is Nitto drilled the hole for >> the Stem Bolt TOO LOW in the stem clamp . The lower stem bolt/hex nut >> resulted in the hex nut not being close to the shelf for it's flat to have a >> large surface area to resist the turning force of the bolt. The hex nut flat >> rotated through the shelf as you tightened the bolt, producing the small >> circular divot, resulting in the 'stripped' feeling in you stated in your >> original post. >> >> The stem was not manufactured to the correct tolerances for the stem bolt >> hole to stem clap shelf distance. It's useable with a correctly tightened >> nut. However, I would recommend perusing a replacement stem via Soma/Nitto >> due to the manufacturing problem. Hopefully, Nitto takes this as a >> 'learning opportunity' and adjusts their process. >> >> The gouging on the inside of the stem and bar clamp area is troubling. Most >> likely it was due to the bars rotating in the stem clamp due to insufficient >> tightening torque resulting from the stem bolt hole problem above. It is >> possible Nitto had the gouged in the interior surface of the stem clamp >> during manufacture or left foreign material side the stem clamp. >> >> John Hawrylak >> Woodstown NJ >> >> >>> On Friday, June 26, 2020 at 12:25:17 AM UTC-4, Bicycle Belle Ding Ding! >>> wrote: >>> John asked for a photo when I swapped the bolts. I tried that >>> tonight...bolt is too short. Sigh. But he asked for photos that show the >>> shelf that the nut is supposed to rest against. (I think.) >>> >>> Here are photos of the area in question. I hope you can see what you were >>> looking for because I’m never taking that nut off again. I’m worried I’m >>> going to wear it out and it will let me know on my way down Killer Hill. >>> >>> >>> Sent from my iPhone >>> >>>>> On Jun 23, 2020, at 10:32 PM, CB <tuolum...@gmail.com> wrote: >>>>> >>>> Aside from BBDD's stem issue, a number have noted that the sleeved bars >>>> sometimes creak. I would expect that the sleeve is inflexible when clamped >>>> properly in the stem. The bars flex quite a bit, and the flexing may >>>> deform the inner bar a tiny bit at the ends of the sleeve and cause the >>>> creak. >>>> >>>> A similar effect might be expected between the stem clamp and bars for >>>> non-sleeved bars, but in that case tightening the clamp would reduce the >>>> deformation. >>>> -- >>>> Carl >>>> >>>>> On June 23, 2020 6:04:56 PM PDT, Joe Bernard <joer...@gmail.com> wrote: >>>>> The stem worked fine on her steel bar, I don't know if it has that burr >>>>> mark on it and I think it's long gone now. I don't imagine even my >>>>> slightly obsessive bike detective skills are going to ever solve how the >>>>> dang thing got in there, but I'd sure like to grab a piece of sandpaper >>>>> and knock it down! >>>> >>>> -- >>>> You received this message because you are subscribed to a topic in the >>>> Google Groups "RBW Owners Bunch" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/rbw-owners-bunch/FHIW1F5qAE0/unsubscribe. >>>> To unsubscribe from this group and all its topics, send an email to >>>> rbw-owne...@googlegroups.com. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/rbw-owners-bunch/C7B77792-357C-4EFB-BD5D-98BFE72DC947%40gmail.com. > > -- > You received this message because you are subscribed to a topic in the Google > Groups "RBW Owners Bunch" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/rbw-owners-bunch/FHIW1F5qAE0/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > rbw-owners-bunch+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/rbw-owners-bunch/4f4c4db6-0f48-42c7-b04f-3e8133178e85o%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. 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