Help needed, Nitto B105AA handlebars and Nitto NTC-A stem not compactible??
03-04-20, 01:24 PM
#1
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Thread Starter
Help needed, Nitto B105AA handlebars and Nitto NTC-A stem not compactible??
Hello,
I have Nitto B105AA handlebars and Nitto NTC-A Dynamic 10 stem for my RIH build, both clamping size 25,4 mm.
I can't install the handlebars because of the last bend, I can't rotate clamps narrow part to bars' inside curve because the stem's base hits the drops. I tried from other direction too...
I tried to pry stem's clamp open a bit to no avail, it seems like I would have to use extreme force to get the clamp open enough. I can instal the stem backwards easily because the drops are not in the way while rotating. Looks like the Nitto stem tool is not suitable for this type of stem either.
Do I have any other options? Is this stem not compactibe for some reason, maybe the drops are too low to let the stem rotate in desirable position? Do I have to pry the clamp open very hard? I think I would crack it if I try that.
Thaks for your opinions!
I have Nitto B105AA handlebars and Nitto NTC-A Dynamic 10 stem for my RIH build, both clamping size 25,4 mm.
I can't install the handlebars because of the last bend, I can't rotate clamps narrow part to bars' inside curve because the stem's base hits the drops. I tried from other direction too...
I tried to pry stem's clamp open a bit to no avail, it seems like I would have to use extreme force to get the clamp open enough. I can instal the stem backwards easily because the drops are not in the way while rotating. Looks like the Nitto stem tool is not suitable for this type of stem either.
Do I have any other options? Is this stem not compactibe for some reason, maybe the drops are too low to let the stem rotate in desirable position? Do I have to pry the clamp open very hard? I think I would crack it if I try that.
Thaks for your opinions!
03-04-20, 01:52 PM
#2
Zip tie Karen
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Two Thoughts...
...since I've come across this recently. Mine was removing the Nitto I-Beam stem from an early '70s Fuji. The typical shape for the clamp portion of the stem has a significant taper from the top center of where the handlebar fits (centered) to the bottom center of the handlebar. This old I-Beam stem didn't have a taper.
You said that you were able to move the stem (using this taper) along the backward orientation of the bar, but not in the forward where I'm guessing that the curve of the bar interferes with the quill portion of the stem. Where following the contour of the handlebar becomes impossible, then you need something creative.
- remove the stem bolt
- find a long bolt or threaded rod that can fit through completely
- find two thin nuts that fit the bolt/rod threads
- position the two nuts between the openings of the stem
- thread the rod from one side, through the nuts, and out the other
- counter rotate the nuts carefully to widen the stem clamp enough to get around the blockage. Carefully
- Voila (art attached).
You said that you were able to move the stem (using this taper) along the backward orientation of the bar, but not in the forward where I'm guessing that the curve of the bar interferes with the quill portion of the stem. Where following the contour of the handlebar becomes impossible, then you need something creative.
- remove the stem bolt
- find a long bolt or threaded rod that can fit through completely
- find two thin nuts that fit the bolt/rod threads
- position the two nuts between the openings of the stem
- thread the rod from one side, through the nuts, and out the other
- counter rotate the nuts carefully to widen the stem clamp enough to get around the blockage. Carefully
- Voila (art attached).
Last edited by Phil_gretz; 03-05-20 at 06:49 AM.
03-04-20, 01:55 PM
#3
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They used to make tools designed to spread stem clamps a bit. The other problem is that you need to turn the bars until you find an angle that works. That takes patience. Don't push it. You will eventually find the right angle.
03-04-20, 02:55 PM
#4
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Orient the bars so that the inside (i.e. tighter) bend is at the bottom of the stem, where the clamp is narrowest. That should work.
03-15-20, 11:13 AM
#5
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Thread Starter
Thanks for your help!
Finally got time to try. Scratched the bars a some more and now I'm scratching my head. And cursing Nitto.
Well, the opening is very thin, a little less than 4 mm. I can't find any thin nuts to fit the opening, they should be thinner than 2 mm each... I pried the opening with screwdriver to about 5 mm, the stem advances a bit more, but still a long shot from success and I got a hard time removing it back.
The reason I bought new stem and bars is that I would be comfortable that it is not crashed, fatigued, scratched and I would be able to use force while sprinting without any fear. I am not very comfortable spreading the stem's opening using excessive force. Can't the aluminium crack or get damaged while doing this? How much can I pry?
I still think there's no way to find the right angle, I can clearly see the path I need to follow, but I can't rotate the stem that way. On the other hand, Nitto should be a good manufacturer, how can they design the stem in such way? I am puzzled.
Finally got time to try. Scratched the bars a some more and now I'm scratching my head. And cursing Nitto.
Well, the opening is very thin, a little less than 4 mm. I can't find any thin nuts to fit the opening, they should be thinner than 2 mm each... I pried the opening with screwdriver to about 5 mm, the stem advances a bit more, but still a long shot from success and I got a hard time removing it back.
The reason I bought new stem and bars is that I would be comfortable that it is not crashed, fatigued, scratched and I would be able to use force while sprinting without any fear. I am not very comfortable spreading the stem's opening using excessive force. Can't the aluminium crack or get damaged while doing this? How much can I pry?
I still think there's no way to find the right angle, I can clearly see the path I need to follow, but I can't rotate the stem that way. On the other hand, Nitto should be a good manufacturer, how can they design the stem in such way? I am puzzled.
03-15-20, 06:15 PM
#7
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Looks like Jantaras discovered the way that I was about to post up!
All good now.
One trick I sometimes use when the clamp actually has to be opened a bit is to insert an Allen key and twist it a twelfth of a turn. Then another key that is incrementally larger.
One shouldn't go wild here though. Often I do have to spread the clamp to remove a stem without scratching the center section of the bars (but try rotating to the best position first).
All good now.
One trick I sometimes use when the clamp actually has to be opened a bit is to insert an Allen key and twist it a twelfth of a turn. Then another key that is incrementally larger.
One shouldn't go wild here though. Often I do have to spread the clamp to remove a stem without scratching the center section of the bars (but try rotating to the best position first).
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03-15-20, 06:44 PM
#8
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Older Nitto Bar Design With Newer Nitto Stems
I've seen warnings several places online saying that newer Nitto stem designs are not compatible with B105 or B115 bars.
One thing that you could try is to file a very slight champfer on the outside edge of stem bore where it's hanging up. Also I grease the stem and bars. It's messy but assembly goes together smoother.
Another suggestion, I use clear plastic packing tape on the center section of the bars to prevent scratching during assembly and remove it when the stem is close to the proper position.
verktyg
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Don't believe everything you think! History is written by those who weren't there....
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03-16-20, 03:57 PM
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Just so you know you're not the only one - I had exactly the same problem with a Nitto stem, presumably the same model as yours. I couldn't get a standard drop bar through, but it worked just fine if the bars were backward or with a bar with a randonneur-type bend (ie drops are flared outward), so I thought maybe it was designed specifically for that. It was at the co-op, so I dealt with it by just grabbing a different stem and not spending any more time on it, which means I don't have any solution for you (unless you are fine with a randonneur bar). Just wanted to let you know that if there is an easy solution, you're not the only one missing it.
03-25-20, 04:37 AM
#10
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Thread Starter
Thank you all for suggestions and comments, much appreciated! 
As I have several projects that could use new stems and handlebars, I will order a new stem for these bars and new bars for stem. I dont want to file or spread the stem very much because I am afraid to compromise its strength. And I can't see any other easy ways to install it.
I believe a classic-looking stem like Technomic will suit the bars well.
How about the Dynamic stem, are there other dropbars that are compatible (except of randonneur type)? Are there any compatibility charts or something like that for Nitto parts?
As I have several projects that could use new stems and handlebars, I will order a new stem for these bars and new bars for stem. I dont want to file or spread the stem very much because I am afraid to compromise its strength. And I can't see any other easy ways to install it.
I believe a classic-looking stem like Technomic will suit the bars well.
How about the Dynamic stem, are there other dropbars that are compatible (except of randonneur type)? Are there any compatibility charts or something like that for Nitto parts?
03-25-20, 09:29 AM
#11
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I've used 2 opposed wooden shims to get a little extra spread on a stem clamp.
02-07-24, 12:37 PM
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I know this is a Cicada thread, but many of use this forum and these threads as an ongoing reference.
I wanted to add that Nitto had this problem solved many many years ago, with "Nitto Tool #3" and then "Nitto Tool #4".
As of this writing, Tool #3 is long gone, and Tool #4 may have been discontinued. I have no connection, but I have found RetroGression and Soma to be the best sources for Nitto parts.
https://velobase.com/ViewTool.aspx?I...85730&AbsPos=0
https://www.retro-gression.com/produ...reading-tool-4
I wanted to add that Nitto had this problem solved many many years ago, with "Nitto Tool #3" and then "Nitto Tool #4".
As of this writing, Tool #3 is long gone, and Tool #4 may have been discontinued. I have no connection, but I have found RetroGression and Soma to be the best sources for Nitto parts.
https://velobase.com/ViewTool.aspx?I...85730&AbsPos=0
https://www.retro-gression.com/produ...reading-tool-4
02-07-24, 01:16 PM
#13
*____*
I battled a pair of the same bars into a Nitto CR-52 a few days ago - bars definitely didn't come out of it looking brand new but a method similar to the drawing from Phil_gretz worked just fine for me! My version was using the bolt & a thin nut that fit inside the space of the stem to push on a thin piece of metal. I've also had success wedging whatever size hex wrench is slightly-too-big in for other bar/stems combos that gave me trouble.
