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#1
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small frame, stem insertion problem
I just bought a Soma Rush frame, 51 cm, with a Soma threaded fork. I
bought it from thebikebiz, they installed a Miche Primato headset. I had planned to use a 100mm Dura Ace quill stem, one of the "aero" stems Peter White has on this page: http://www.peterwhitecycles.com/stems.asp When I installed the stem, it went in so far as to just cover the markings for minimum insertion (on this stem is says "MAX" and has a series of vertical lines) and then stopped. However after about a quarter of a mile the stem would loosen and slip, leading me to believe that the expander bolt was tightening inside the steerer at the top of the butted section, as described on Sheldon Brown's page he http://www.sheldonbrown.com/handsup.html under "too low! danger!" This loosening happened several times, after repeated tightening, messing around, taking to bike shops, friends, etc, before I googled the problem and found a post by Sheldon with a link to the above page. (no thanks to the two shops here who didn't spot this first) Since it exactly describes the problem I believe that is the case, although when I called thebikebiz the person I spoke to was surprised that that Soma fork was butted. I emailed Soma but haven't heard back if their forks are butted. So, the solution seems to be to raise the stem a little bit. Which I did, and now the stem has not come loose after much more riding than a quarter of a mile. BUT the stem is now raised ABOVE the minimum insertion mark, about 10mm or less. Soma's threaded forks, according to their site, have 50mm of threads. Thebikebiz said that they probably cut the steerer for such a small frame combined with this Miche headset, so there are even fewer threads. After careful measuring I am convinced that the expander bolt is BELOW the threads on the steerer, so I don't think that I am in danger of breaking the steerer at the threads. I went to both bike shops near me, and the bike co-op, and could not find a stem that had a SHORTER insertion length. Someone at one of the bike shops said I would be alright, and would not likely break my stem. So finally, after all this, my question to rec.bicycles.tech is, is that right? Am I asking for a bad crash? Or am I reasonably safe? There is about 55mm of stem inside the steerer. If this is dangerous, in other words if I am in danger of breaking the stem, what are my options for stems? I've done a lot of shopping around, all the quill stems I could find seemed to have as long an insertion length. Does anyone know of a stem with a short insertion? From reading other posts, it seems like the problem tends to be finding LONG stems, not short ones. Thank for any help and any ideas! Yamada |
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#2
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small frame, stem insertion problem
On Apr 15, 4:25 pm, wrote:
I just bought a Soma Rush frame, 51 cm, with a Soma threaded fork. I bought it from thebikebiz, they installed a Miche Primato headset. I had planned to use a 100mm Dura Ace quill stem, one of the "aero" stems Peter White has on this page:http://www.peterwhitecycles.com/stems.asp When I installed the stem, it went in so far as to just cover the markings for minimum insertion (on this stem is says "MAX" and has a series of vertical lines) and then stopped. However after about a quarter of a mile the stem would loosen and slip, leading me to believe that the expander bolt was tightening inside the steerer at the top of the butted section, as described on Sheldon Brown's page hehttp://www.sheldonbrown.com/handsup.html under "too low! danger!" This loosening happened several times, after repeated tightening, messing around, taking to bike shops, friends, etc, before I googled the problem and found a post by Sheldon with a link to the above page. (no thanks to the two shops here who didn't spot this first) Since it exactly describes the problem I believe that is the case, although when I called thebikebiz the person I spoke to was surprised that that Soma fork was butted. I emailed Soma but haven't heard back if their forks are butted. So, the solution seems to be to raise the stem a little bit. Which I did, and now the stem has not come loose after much more riding than a quarter of a mile. BUT the stem is now raised ABOVE the minimum insertion mark, about 10mm or less. Soma's threaded forks, according to their site, have 50mm of threads. Thebikebiz said that they probably cut the steerer for such a small frame combined with this Miche headset, so there are even fewer threads. After careful measuring I am convinced that the expander bolt is BELOW the threads on the steerer, so I don't think that I am in danger of breaking the steerer at the threads. I went to both bike shops near me, and the bike co-op, and could not find a stem that had a SHORTER insertion length. Someone at one of the bike shops said I would be alright, and would not likely break my stem. So finally, after all this, my question to rec.bicycles.tech is, is that right? Am I asking for a bad crash? Or am I reasonably safe? There is about 55mm of stem inside the steerer. Since this is Usenet and I'm not liable, I'll venture that you'll be fine. Seems that everybody I knew in the 80s ran stems a smidge higher than the min insertion mark without a problem--you'd think that they figured in a window of error considering various headset stack heights, right? Seeing as you're on a 51, I'm guessing you're not a 250# brute? And the thing is below the threads? I sure wouldn't worry about it. Ride and enjoy. |
#3
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small frame, stem insertion problem
So, the solution seems to be to raise the stem a little bit. Which I
did, and now the stem has not come loose after much more riding than a quarter of a mile. BUT the stem is now raised ABOVE the minimum insertion mark, about 10mm or less. Soma's threaded forks, according to their site, have 50mm of threads. Thebikebiz said that they probably cut the steerer for such a small frame combined with this Miche headset, so there are even fewer threads. After careful measuring I am convinced that the expander bolt is BELOW the threads on the steerer, so I don't think that I am in danger of breaking the steerer at the threads. I went to both bike shops near me, and the bike co-op, and could not find a stem that had a SHORTER insertion length. Someone at one of the bike shops said I would be alright, and would not likely break my stem. My guess is that the fork was built "wrong." They used a fork column with a butted section at the base appropriate for a larger-size bike, not for the 50cm. It's possible that a fork for a frame that size doesn't even need to have a butted section. I'm not one to ever recommend having a stem higher than its minimum insertion mark, especially if it's a wedge-style (which fortunately doesn't appear to be the case here). But it really doesn't seem like you have a choice, if you can verify that the stem is bottoming out on the butted section of the fork column. --Mike Jacoubowsky Chain Reaction Bicycles www.ChainReaction.com Redwood City & Los Altos, CA USA wrote in message ... I just bought a Soma Rush frame, 51 cm, with a Soma threaded fork. I bought it from thebikebiz, they installed a Miche Primato headset. I had planned to use a 100mm Dura Ace quill stem, one of the "aero" stems Peter White has on this page: http://www.peterwhitecycles.com/stems.asp When I installed the stem, it went in so far as to just cover the markings for minimum insertion (on this stem is says "MAX" and has a series of vertical lines) and then stopped. However after about a quarter of a mile the stem would loosen and slip, leading me to believe that the expander bolt was tightening inside the steerer at the top of the butted section, as described on Sheldon Brown's page he http://www.sheldonbrown.com/handsup.html under "too low! danger!" This loosening happened several times, after repeated tightening, messing around, taking to bike shops, friends, etc, before I googled the problem and found a post by Sheldon with a link to the above page. (no thanks to the two shops here who didn't spot this first) Since it exactly describes the problem I believe that is the case, although when I called thebikebiz the person I spoke to was surprised that that Soma fork was butted. I emailed Soma but haven't heard back if their forks are butted. So, the solution seems to be to raise the stem a little bit. Which I did, and now the stem has not come loose after much more riding than a quarter of a mile. BUT the stem is now raised ABOVE the minimum insertion mark, about 10mm or less. Soma's threaded forks, according to their site, have 50mm of threads. Thebikebiz said that they probably cut the steerer for such a small frame combined with this Miche headset, so there are even fewer threads. After careful measuring I am convinced that the expander bolt is BELOW the threads on the steerer, so I don't think that I am in danger of breaking the steerer at the threads. I went to both bike shops near me, and the bike co-op, and could not find a stem that had a SHORTER insertion length. Someone at one of the bike shops said I would be alright, and would not likely break my stem. So finally, after all this, my question to rec.bicycles.tech is, is that right? Am I asking for a bad crash? Or am I reasonably safe? There is about 55mm of stem inside the steerer. If this is dangerous, in other words if I am in danger of breaking the stem, what are my options for stems? I've done a lot of shopping around, all the quill stems I could find seemed to have as long an insertion length. Does anyone know of a stem with a short insertion? From reading other posts, it seems like the problem tends to be finding LONG stems, not short ones. Thank for any help and any ideas! Yamada |
#4
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small frame, stem insertion problem
On Tue, 15 Apr 2008 14:25:09 -0700 (PDT), wrote:
I just bought a Soma Rush frame, 51 cm, with a Soma threaded fork. Excuse me if I'm being thick, but why would anybody (apart, maybe, from an NJS fetishist) buy a threaded fork? Kinky Cowboy* *Batteries not included May contain traces of nuts Your milage may vary ** Posted from http://www.teranews.com ** |
#5
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small frame, stem insertion problem
On Apr 15, 6:00 pm, Kinky Cowboy wrote:
On Tue, 15 Apr 2008 14:25:09 -0700 (PDT), wrote: I just bought a Soma Rush frame, 51 cm, with a Soma threaded fork. Excuse me if I'm being thick, but why would anybody (apart, maybe, from an NJS fetishist) buy a threaded fork? So they can use a beautiful stem. So they can use a practical stem like a Technomic. So they can change bar height on a tour.... The only reason to use threadless, IMHO, is that it's less of a hassle to source threadless bits these days is all. I have one bike set up with a Delta stem raiser and moustache bars--it sure would look better with a long quill instead. |
#6
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small frame, stem insertion problem
To avoid a cut too short steer tube and the purchase of new forks,
stems, etc to get the bars at the proper height. Threadless sucks plain and simple- at least until the F%^%^%ing bike companies spec uncut steer tubes on forks so the dealer can cut them or not to customers needs. On Apr 15, 7:00*pm, Kinky Cowboy wrote: On Tue, 15 Apr 2008 14:25:09 -0700 (PDT), wrote: I just bought a Soma Rush frame, 51 cm, with a Soma threaded fork. Excuse me if I'm being thick, but why would anybody (apart, maybe, from an NJS fetishist) buy a threaded fork? Kinky Cowboy* *Batteries not included May contain traces of nuts Your milage may vary ** Posted fromhttp://www.teranews.com** |
#7
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small frame, stem insertion problem
Hey!
Remember to put an "OT" ahead of the subject so we know this is a bedroom problem couched in bicycle terms. Probably boasting about large stem size, so to speak. Maybe this belongs in "alt.sex" Jobst Brandt |
#9
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small frame, stem insertion problem
I cant blame the bike dealer if a steer tube is too short. They need
to pressure the makers to leave it uncut. Then it will fit properly. It is the fault of trek bianchi etc who have forsakern customers On Apr 16, 5:26*am, Kinky Cowboy wrote: On Tue, 15 Apr 2008 16:56:30 -0700 (PDT), wrote: To avoid a cut too short steer tube and the purchase of new forks, stems, etc to get the bars at the proper height. *Threadless sucks plain and simple- at least until the F%^%^%ing bike companies spec uncut steer tubes on forks so the dealer can cut them or not to customers needs. On Apr 15, 7:00*pm, Kinky Cowboy wrote: On Tue, 15 Apr 2008 14:25:09 -0700 (PDT), wrote: I just bought a Soma Rush frame, 51 cm, with a Soma threaded fork. Excuse me if I'm being thick, but why would anybody (apart, maybe, from an NJS fetishist) buy a threaded fork? Sounds like problems caused by the customer not requiring proper pre-sale service from the vendor, not the fault of bike companies. They're already making alternative model lines with longer head tubes and high quality stems in all angles from 0 to 30. If you get the right frame, it should easily be possible to select a stem which joins the bars to the top of the headset in a straight line; pretty much by definition, if you can't then you must have the wrong frame. The mistake you're making is to assume that the bike, out of the box, should suit every possible buyer. Who buys the base model from a car dealer? It's up to you to spec it how you want it, which likely means changing one or all of the contact point defining parts, saddle, pedals and stem. Kinky Cowboy* *Batteries not included May contain traces of nuts Your milage may vary ** Posted fromhttp://www.teranews.com** |
#10
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small frame, stem insertion problem
On 15 Apr, 23:25, wrote:
I just bought a Soma Rush frame, 51 cm, with a Soma threaded fork. I bought it from thebikebiz, they installed a Miche Primato headset. I had planned to use a 100mm Dura Ace quill stem, one of the "aero" stems Peter White has on this page:http://www.peterwhitecycles.com/stems.asp When I installed the stem, it went in so far as to just cover the markings for minimum insertion (on this stem is says "MAX" and has a series of vertical lines) and then stopped. However after about a quarter of a mile the stem would loosen and slip, leading me to believe that the expander bolt was tightening inside the steerer at the top of the butted section, as described on Sheldon Brown's page hehttp://www.sheldonbrown.com/handsup.html under "too low! danger!" This loosening happened several times, after repeated tightening, messing around, taking to bike shops, friends, etc, before I googled the problem and found a post by Sheldon with a link to the above page. (no thanks to the two shops here who didn't spot this first) Since it exactly describes the problem I believe that is the case, although when I called thebikebiz the person I spoke to was surprised that that Soma fork was butted. I emailed Soma but haven't heard back if their forks are butted. So, the solution seems to be to raise the stem a little bit. Which I did, and now the stem has not come loose after much more riding than a quarter of a mile. BUT the stem is now raised ABOVE the minimum insertion mark, about 10mm or less. Soma's threaded forks, according to their site, have 50mm of threads. Thebikebiz said that they probably cut the steerer for such a small frame combined with this Miche headset, so there are even fewer threads. After careful measuring I am convinced that the expander bolt is BELOW the threads on the steerer, so I don't think that I am in danger of breaking the steerer at the threads. I went to both bike shops near me, and the bike co-op, and could not find a stem that had a SHORTER insertion length. Someone at one of the bike shops said I would be alright, and would not likely break my stem. So finally, after all this, my question to rec.bicycles.tech is, is that right? Am I asking for a bad crash? Or am I reasonably safe? There is about 55mm of stem inside the steerer. If this is dangerous, in other words if I am in danger of breaking the stem, what are my options for stems? I've done a lot of shopping around, all the quill stems I could find seemed to have as long an insertion length. Does anyone know of a stem with a short insertion? From reading other posts, it seems like the problem tends to be finding LONG stems, not short ones. Thank for any help and any ideas! Yamada hi there, here's what I did in the past: cut (hacksaw) the stem, removing 2-3 cm of it, file the edges and re-assemble. Remember MAX I I I I I I I I I I stem limit goes up as much as you cut from the bottom. There's another passage if your stem is the Dura Ace pictured in this page http://www.peterwhitecycles.com/stems.asp You will have to transform it into one of those stems that have an expander that doesn't get inside the stem (like the Ultegra, same page). So, you'll have to find the appropriate expander first and cut the stem at the right angle. Otherwise you have to make longer slots to accommodate the old expander (or the stem will not expand properly and will not be sure). I have preferred the first solution (only one cut, hard to do it wrong, doesn't damage the stem), but YMMV The long inner bolt is always the same. All of this is not too difficult, but it has to be done properly to avoid damaging the fork column once the stem is assembled. Ciao Luca |
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