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Tandem Cycling A bicycle built for two. Want to find out more about this wonderful world of tandems? Check out this forum to talk with other tandem enthusiasts. Captains and stokers welcome!

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Old 07-15-09, 01:22 PM   #1
rwoods
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optimal stem extension?

Hi,

As I haven't been able to find any information on stem length in the forum, I'm hoping to solicit some advice on a purchase. My girlfriend and I have a mid-90's Trek T200, whose ergonomics are a bit too racy for me. Getting the handlebars at or above saddle height would be a great start. I've had a shim fabricated to enable using a 1" quill stem in the obscure 1-1/4" threaded steerer tube. I am trying to decide between a Nitto Periscopa and a Nitto Technomic. The Technomic comes in 8/9/10cm extensions. I think any of these four could get the bars in a more comfortable position.

My concern is that the short, high rise of the Periscopa would drastically alter the bike's handling. Making a similar change to my touring bike resulted in a very wobbly steering experience with a lightly loaded front rack. While we will probably not have any weight on the front of the tandem most of the time, it would be nice to keep the option open.

Also, I understand that the handling characteristics of a tandem are much different than a solo bike's, but I don't grasp the differences, so this is where I would like advice.

BTW, the current stem is about 12cm, and runs roughly parallel to the ground.

Thanks!
Rory
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Old 07-15-09, 03:38 PM   #2
joe@vwvortex
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I'd suggest getting a very inexpensive adjustable stem to try and figure out what length and rise would work best.

http://www.qbike.com/listing/Adjustable_Stem/
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Old 07-16-09, 05:48 AM   #3
DCwom
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+1 I agree, I did the same thing, and just last night decided it is time to go with a fixed extension and shorter stem. The variable stem allows you to experiment without ending up with a bunch of stems all over your garage...
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Old 07-16-09, 06:16 AM   #4
rwoods
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I like this idea, but I don't think I'll be able to find an adjustable quill stem with a quill long enough to get the bars comfy. So, let me ask this: do you think the Periscopa shown in my OP would have too little extension? Would it compromise the handling?

Thanks,
Rory
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Old 07-16-09, 07:11 AM   #5
masiman
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These adjustable stems might work for you with your 1" shim.

Avenir
Ultracycle
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Old 07-16-09, 06:39 PM   #6
rwoods
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Hmm...I guess I didn't state my question clearly enough.

My concern is that a stem with a short extension and/or high rise will compromise the bike's handling. Does anyone have any experience or knowledge that speaks to this?

Thanks!
Rory
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Old 07-16-09, 06:45 PM   #7
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I had gone with an adjustable stem on our old Cannondale MT 1000. I had the stem raised to it.s max angle, but it wasn't excessively short. It was much shorter than the stock setup. I do not recall having any handling issues as a result of that. The adjustable was nice to tweek positions. I would recommend it if you can find one that works.
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Old 07-16-09, 08:36 PM   #8
cornucopia72
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Quote:
Originally Posted by rwoods View Post
Hmm...I guess I didn't state my question clearly enough.

My concern is that a stem with a short extension and/or high rise will compromise the bike's handling. Does anyone have any experience or knowledge that speaks to this?

Thanks!
Rory
I am the captain on a triplet with a stem with very high rise. The handling is as good as one can expect on a triplet anywhere above 5 mph
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Old 07-16-09, 10:13 PM   #9
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In my experience, almost any change in stem length will affect handling somewhat. You have to decide what you can live with.
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Old 07-17-09, 11:36 AM   #10
justcrankn
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The rise won't affect the handling unless it gets too flexy. I have had a quill stem and an adjustable stem that weren't as solid as I would have liked.
The extension will change the way it feels a bit, but I am comfortable with either short or long.
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Old 07-19-09, 09:53 PM   #11
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1-1/4 Quill

Hi I Have the same bike that I just bought. The shim idea sounds good, I was going to take my 1-1/4 quill and cut off the angled stem then a then make it a threadless headset you can then change stems easily and will be easy to find any size.
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