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Mountain drop conversion stem question

Old 02-11-13, 06:11 PM
  #1  
likebike23
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Mountain drop conversion stem question

I have a vintage BCA, lugged steel mountain bike that I want to convert to a drop bar. It came with bullmoose bars, so I'm going to have to get a new stem. My problem is that i've got a fork that needs a 21.1mm quill. I was considering this stem: https://www.niagaracycle.com/product_...ucts_id=431025

Has anyone tried this stem for this application? I'm concerned that the stem might be difficult to get around the bends in the bar. Any tricks to get tough stems on drop bars without breaking anything? Thanks
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Old 02-11-13, 07:12 PM
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I have used stems with a similar clamp and some bars can be a real PIA to get that stem around. What is the clamp diameter? It is probably 25.4 which will limit your bar choice somewhat.

The description says it has a 180 quill, that might be pretty tall for a MTB conversion.

Something like this might be worth checking out.

https://www.ebay.com/itm/BICYCLE-STEM...item460b10359c

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Old 02-11-13, 09:30 PM
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Originally Posted by Bianchigirll View Post
I have used stems with a similar clamp and some bars can be a real PIA to get that stem around. What is the clamp diameter? It is probably 25.4 which will limit your bar choice somewhat.

The description says it has a 180 quill, that might be pretty tall for a MTB conversion.

Something like this might be worth checking out.
I've seen that adapter before, and it's definitely an option. The bars i'm planning to use have a 25.4 clamp area. One of the reasons i was considering the stem that I linked to is the 180mm quill length. I like my bars high anyway, and from what i've read, you want your drops pretty high on MTB conversions. Do you think machining the clamp area near the clamping bolt to mimic a road stem would be dangerous? From what I can see, a road stem is basically the same as a mountain stem, only a little less wide around the clamp bolt.
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Old 02-11-13, 10:14 PM
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Originally Posted by likebike23 View Post
I like my bars high anyway, and from what i've read, you want your drops pretty high on MTB conversions.
Part of that is due to the crowd that tends to do these conversions. The other part is that you're generally a size down from your road bike, so the bars will be about an inch higher to get the same fit.
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Old 02-11-13, 10:47 PM
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Originally Posted by ThermionicScott View Post
Part of that is due to the crowd that tends to do these conversions.
You missed a perfect opportunity to post a pic of your diamondback. Is the stem on that bike the one I linked to? Any problems getting it around the bends?
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Old 02-11-13, 11:48 PM
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Originally Posted by likebike23 View Post
You missed a perfect opportunity to post a pic of your diamondback. Is the stem on that bike the one I linked to? Any problems getting it around the bends?
Haha! It's very similar -- mine has two bolts. Because of the width (the clamp area is intended for flat bars), I had to file a chamfer around the lower part to get the bar through. That sounds sketchy, but I still have at least as much clamping area as my SR road quills. (Also, it helps to use traditional bend bars, rather than "anatomic" with their tighter curves.)

I can post a pic tomorrow.
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Old 02-12-13, 06:53 PM
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Alrighty, I think this is about as good of a picture as I can get with the handlebars still mounted. Sorry about the glare and graininess, but I think you can see how I rounded the edge all the way around, and made the deepest chamfer toward the bottom.

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Old 02-12-13, 07:29 PM
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Originally Posted by ThermionicScott View Post
Part of that is due to the crowd that tends to do these conversions.
lol
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Old 02-12-13, 08:38 PM
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Originally Posted by ThermionicScott View Post
Alrighty, I think this is about as good of a picture as I can get with the handlebars still mounted. Sorry about the glare and graininess, but I think you can see how I rounded the edge all the way around, and made the deepest chamfer toward the bottom.
thanks for the pic. I'm going to try and do a little machining around the clamp bolt with my Dremel-type tool. The way I see it, it's better than stretching out the clamp to failure.
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Old 02-12-13, 09:03 PM
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Indeed. I'm not big on the idea of "jacking" aluminum stems open wider in order to get the bars through them.
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Old 02-13-13, 01:05 AM
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I have a 21.1 insert riser stem that would work for your application. I'll snap some pics.
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Old 02-13-13, 02:15 PM
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Originally Posted by realestvin7 View Post
I have a 21.1 insert riser stem that would work for your application. I'll snap some pics.
That would be cool. Let me know what you're looking for, a trade maybe.
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Old 02-13-13, 08:29 PM
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Here's what I have.







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Old 02-13-13, 08:49 PM
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Originally Posted by realestvin7 View Post
Here's what I have
Looks nice. Are you looking to sell or trade? Can you send me a PM?
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