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Calling the stem police.(13 posts)

Calling the stem police.Juanmoretime
Jan 15, 2003 6:48 AM
How short of a stem length required before you should start considering another frame. My current setup is a 59 frame with a 57.5 top tube. I found a steel 60 that has a 59.5, I would have to probably use a 90 or 100mm stem. The standover height would be no problem. What's everyone thoughts, should I look for a different frame?
re: Calling the stem police.KeeponTrekkin
Jan 15, 2003 6:59 AM
My mechanic advised me that for a frame my size (58.4 TT), I should not go below 120 mm as handling would degrade. The 120 mm worked for me so I never tested his advice.
General rule of thumbNessism
Jan 15, 2003 7:36 AM
Just a WAG (wild ass guess) on my part here.

Ideal frame/stem size

48-51 = 90 mm
52-53 = 100 mm
54-57 = 110 mm
58-61 = 120 mm

..not on an Italian frame, add 20 mm to each. nmSpunout
Jan 16, 2003 4:51 AM
re: Calling the stem police.MR_GRUMPY
Jan 15, 2003 9:29 AM
I've always thought that, the shorter the stem, the quicker the steering. 2cm is a big change. A 90mm stem is for small people.
don't forget the STA...C-40
Jan 15, 2003 9:38 AM
Don't forget to compare the seat tube angle when comparing TT lengths. Each degree is about 1.3cm in this size. Add length to the frame with the steeper STA when comparing.

A short stem will not "degrade handling". The steering would be a little quicker, but it's mostly a matter of what you're used to. If all your bikes had 90mm stems, you wouldn't know the difference.

Most folks would think that a stem shorter than 100mm on this size of frame would be too short. I've used stems from 100mm to 120mm on my 54cm frame, depending on where the saddle is positioned. A 120 seems darn long to me. I'm experimenting with a further back saddle position for future Colorado mountain climbing, so I just put on a 100mm to keep the reach the same. One thing about short stems, they are certainly stiff.

If you're using many steering tube spacers, you can always flip the stem to eliminate the spacers. A 10mm longer stem is generally required when the stem is flipped. The steep angle might not be as pretty, but it will be stiff setup.
Is there a rule of thumb...serbski
Jan 15, 2003 5:39 PM
regarding spacers/stem length? What I'm getting at is I currently go with a 115mm stem and 2cm of spacers. If I were to lose the spacers and flip the stem so it's angled upwards, how much "shorter" would my reach become? Is there a formula such as: the stem length must increase X for every cm or spacer removed (allowing of course that the stem is angled upwards)? In short, what length stem would I need to get rid of my spacers and keep my sadddle to bar drop the same. Hope I'm making sense in my non-technical way. Thanks...
spacer removal....C-40
Jan 16, 2003 6:29 AM
When spacers are removed the reach is increased by .3cm for each 1cm of spacer.

Flipping a stem is a little more complicated. In general, you must use a 1cm longer stem after it's flipped to get approximately the same reach.

The exact amount of rise that occurs from fliping a stem is tough to calculate because the center of the extension does not intersect the center of the stem clamp area. Most calculations assume that it does.

If you've got an 80 degree stem with 2cm of spacers, the bars will raise about 4cm when the the stem is flipped. If you remove the 2cm of spacers, the bars will still be about 2cm higher than before. A flipped 125 stem would have a reach of 111mm. Add 6mm for removing the spacers and you get a total reach of 117, which is about 3mm longer.

A flipped 84 degree stem (like a Ritchey)would be about 1cm lower than a flipped 80 degree.
Jan 16, 2003 4:11 PM
I flipped a 110mm Ritchey WCS and found that the height increased about 18mm.
re: Calling the stem police.Wild Bill
Jan 15, 2003 11:09 AM
My personal experience tells me that whatever is comfortable for "you". Remember that "you" are an individual. No two humans are the same.
I ride a 52cm. frame with a 53.5 TT, my stem is a 130!!!! I am 5'7 little short legs and a long upper body. Some riders the same height as me ride 54-56cm. frames with stem lengths 100-110.
As you can see we are all different, so if you feel comfortable then go with it.
if it's comfortable, it's finelaffeaux
Jan 15, 2003 2:44 PM
I have long legs and a shorter torso, so I have to run shorter stems. My road bike has a 59cm TT and a 100 stem, and my 'cross bike has a 110 stem with rise. Both bikes great well. I'd worry if the stem was a 60 or 70, but a 90 or 100 seems like no big deal to me.
Jan 15, 2003 4:54 PM
I understand that custom builders like Landshark's Slawta design their sizing with a 12 cm stem as a general guideline.
re: Calling the stem police.tarwheel
Jan 16, 2003 5:09 AM
I've ridden with stems as short as 7 cm on a 57 c-c frame, and 9 cm on a 56 c-c frame. I now use a 10 cm/90 deg on my 57 frame, and a 12 cm/105 deg on my 56 frame (which has about the same reach due to the rise). As others mentioned, the bike will steer much quicker with the shorter stem. So the handling can be a little twitchy, but you get used to it. I prefer the feel of a longer stem, though. A 10 cm stem doesn't feel twitchy to me, but then again I've never gotten used to riding with a long stem.