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Old 09-19-12, 09:37 PM   #1
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Very short stem and fully loaded front panniers

I'm looking at steel (631) Dawes Sardar expedition touring bike to replace my old (1986) Diamondback Ascent on the local equivalent of ebay. I mainly use the bike for commuting/grocery shopping including heavily loading the front panniers. The Dawes has drop bars and my old Diamondback has riser bars.

The Dawes has a 56cm top-tube and I'd need to put a very short stem (80mm or less) on it so that I couldreach without stretching. The Dawes would be at the upper limit of what I can ride. My Diamondback is a very small frame, with a seatpost a mile high and I really need to put a long stem on it. I'm 169cm tall with a longish torso.

I can't afford to buy a new touring bike such as a Surly Long-Haul Trucker. The Dawes is currently the price of a Surly frameset. I had planned to put a long stem and drop bars and bar-end shifters on the Diamondback. Touring bikes are not common in New Zealand, especially second hand.

Would putting a very short stem on the Dawes adversly affect the handling so that it would be hard to control with full panniers?
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Old 09-20-12, 06:56 AM   #2
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I see on their website that they offer 3 sizes? I'm assuming you're talking about the largest size (22"/56cm). You could possibly just order the smaller size. (18" or 20")

I haven't really loaded the front end up on either bike, but hopefully this will be helpful information:

Specialized langster: shortened the 120 mm stem by 20 mm and it made the bike almost unridable because it was so twitchy (without a load)
Surly LHT: went from 100 mm stem to 70 mm stem and it rides almost the same, a little bit more responsive maybe but not dangerously so.

I can only assume that it's due to the stretched out wheel base and perhaps the fork rake of the LHT. I really haven't ridden enough frames to give you useful information on that.

If that's really the only option you have I'd imagine a wider set of handlebars would help.
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Old 09-20-12, 10:41 AM   #3
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Would putting a very short stem on the Dawes adversly affect the handling
so that it would be hard to control with full panniers?
No..
but wider bars may help.. but how you pack has the biggest influence,
Bags dangling and sloppy load is not good.



even with a load aboard,above a very slow speed, i steer from my butt.

leaning over to make the corner.. my hands do more steadying
than turning it as if the rudder tiller.. ..

maybe turn the bars to avoid going thru rubble and glass..

Last edited by fietsbob; 09-20-12 at 02:33 PM.
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Old 09-20-12, 11:01 AM   #4
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I haven't noticed any problem on my cross-check.
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Old 09-20-12, 11:22 AM   #5
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the moment arm of your handlebars does not change much when you shorten the stem. Think about the relative distance of your hands to the center of the steerer, and you will see that pretty clearly.
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Old 09-20-12, 11:35 AM   #6
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OP, if you set the handlebar high enough, the head tube angle will offset the long top tube by moving the stem rearwards at a rate of 1cm for every 3cm of stem height increase. However, I don't know if your bike will come with adequate steerer tube to raise the bar, as googling shows them to be very short. If you can raise the stem/bar, then you may be pleasantly surprised to learn you don't need as short a stem as you have guessed.

Changing to a shorter stem will make the steering feel different until you learn to operate differently, which should only take an hour of bicycling. Eighty millimeter stem length is not terribly short - Surly specs 75mm or 90mm on all complete bikes below size 54cm.

http://surlybikes.com/bikes/long_haul_trucker
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Old 09-20-12, 11:37 AM   #7
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Originally Posted by unterhausen View Post
the moment arm of your handlebars does not change much when you shorten the stem. Think about the relative distance of your hands to the center of the steerer, and you will see that pretty clearly.
Very good explanation.
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Old 09-20-12, 12:09 PM   #8
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Originally Posted by unterhausen View Post
the moment arm of your handlebars does not change much when you shorten the stem. Think about the relative distance of your hands to the center of the steerer, and you will see that pretty clearly.
Yes, that moment doesn't change much, in fact if you take it at one point in the rotation, it doesn't change at all, as moments can be translated without modifications, but that's assuming that your arms are coming in directly over the handlebar. The more sloped your arms are the more you're going to be pushing forward on the handlebars which stabilizes the bike to some degree.

There is also something to be said for translation, as stem length increases, the handlebars translate more, sometimes this larger motion gives the rider more precision. Usually it doesn't really matter, and there are certainly downhill stems that have the handlebar nearly touching the steerer tube. In those cases the handlebars are wide to give extra precision (and leverage), but they don't translate much at all. You can imagine if the bars were very short how awful it would be to control. Conversely if you had a really long stem and a narrow handlebar, that wouldn't be so bad either.
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Old 09-20-12, 01:07 PM   #9
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I wouldn't worry about it. The stem on our tandem is about that length and we've had the front rack and panniers heavily loaded for camping trips without any problems.
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Old 09-20-12, 01:55 PM   #10
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Quote:
Originally Posted by gnome View Post
I'm looking at steel (631) Dawes Sardar expedition touring bike to replace my old (1986) Diamondback Ascent on the local equivalent of ebay. I mainly use the bike for commuting/grocery shopping including heavily loading the front panniers. The Dawes has drop bars and my old Diamondback has riser bars.

The Dawes has a 56cm top-tube and I'd need to put a very short stem (80mm or less) on it so that I couldreach without stretching. The Dawes would be at the upper limit of what I can ride. My Diamondback is a very small frame, with a seatpost a mile high and I really need to put a long stem on it. I'm 169cm tall with a longish torso.

I can't afford to buy a new touring bike such as a Surly Long-Haul Trucker. The Dawes is currently the price of a Surly frameset. I had planned to put a long stem and drop bars and bar-end shifters on the Diamondback. Touring bikes are not common in New Zealand, especially second hand.

Would putting a very short stem on the Dawes adversly affect the handling so that it would be hard to control with full panniers?
Not much if you're seated down since your CG (center of gravity) will remain neutral close to the BB area. Only when you stand up to climb is when you may experience some handling issues due to your CG being a bit further back due to a shorter stem. When I toured with my old MTB hardtail, I had an Azonic Stubby stem (40mm) and never seemed to effect handling much. My normal stem length is 90mm.
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Old 09-20-12, 03:35 PM   #11
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I wouldn't worry about stem length, IMO it's more important how the panniers are positioned, I like the bulk of the load on the front to be behind the steering axis (that is a straight line through the steering head to the wheel axle) & as low as possible, that slows the steering down making the bike feel more stable & helping to make it relaxed ride, obviously the positioning can be adjusted to taste but back & low is a good starting point.
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Old 09-21-12, 01:37 AM   #12
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Thanks for the replies. sounds like it will work ok. now to see if the Dawes doesn't go higher than I'm prepared to bid.
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