Stem Length

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ajlowin1983
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Stem Length

Postby ajlowin1983 » Tue Apr 02, 2013 17:21 pm

Hi guys

I'm a keen mountain biker but due to injury I'm only allowed on the road so I've purchased a Merlin malt-rs as my first road bike which I'm loving and the mrs is jealous now so we're off to bike her up the new triban 5a tmrw. First off I'm getting a lot of pain in my hands, mainly fleshy part of thumb. I ordered the bike online so not had a proper fit. I've messed about with moving bars up and down and I've adjusted my seat a bit which has helped. Now when I'm riding with my hands on the hood my elbows are locked whereas I believe they need to have a slight bend. I changed my mtb stem by 20mm which was fine. My current road bike has a 120mm stem, should I get a 100mm stem with a rise?

Thanks

richardrowan
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Re: Stem Length

Postby richardrowan » Tue Apr 02, 2013 18:51 pm

First post and newbie to road biking.

I'd been struggling with my riding position for the first couple of months - convinced that I was over stretching for the bars. I've since swapped my 120mm stem for a 60mm. A little drastic but I could feel the difference immediately - both on the bike and after a lengthy ride. Much more comfortable.

I guess I'm left wondering whether 20mm will make much of a difference.

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♠ChumBucket♠
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Re: Stem Length

Postby ♠ChumBucket♠ » Tue Apr 02, 2013 19:04 pm

I've just ordered a 70mm stem for my 54cm triban 5a, it comes with a 100mm as standard.

The 51cm is way too small for me, the 54cm is fine but I know it will suit me better with a shorter stem- the reach is just a tad long. :wink:
B'TWIN Triban 5A
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ajlowin1983
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Re: Stem Length

Postby ajlowin1983 » Tue Apr 02, 2013 19:22 pm

Chum bucket - how tall are you? The Mrs is picking up the new triban 5a in a 54 tmrw and I think she'll need a new stem. She is 5ft 7.

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lotus49
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Re: Stem Length

Postby lotus49 » Tue Apr 02, 2013 19:29 pm

May I just caution you about the effect on your bike's handling of changing the stem length too much?

Changing a stem from 120mm to 60mm is a huge change that suggests the bike may be the wrong size to start off with. It is also worth pointing out that a lot of people go from an MTB to a road bike and wrongly assume that their road bike is the wrong size when the real issue is just getting used to the different position.

If you have the opportunity to ask the advice of someone well-informed, do so. If not, read up on bike fitting or watch some of the many YouTube videos on the topic before you start making drastic changes to your bike.

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♠ChumBucket♠
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Re: Stem Length

Postby ♠ChumBucket♠ » Tue Apr 02, 2013 19:50 pm

ajlowin1983 wrote:Chum bucket - how tall are you? The Mrs is picking up the new triban 5a in a 54 tmrw and I think she'll need a new stem. She is 5ft 7.


I'm 5ft 6. :(
B'TWIN Triban 5A
Ridgeback MX6

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♠ChumBucket♠
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Re: Stem Length

Postby ♠ChumBucket♠ » Tue Apr 02, 2013 19:55 pm

lotus49 wrote:May I just caution you about the effect on your bike's handling of changing the stem length too much?

Changing a stem from 120mm to 60mm is a huge change that suggests the bike may be the wrong size to start off with. It is also worth pointing out that a lot of people go from an MTB to a road bike and wrongly assume that their road bike is the wrong size when the real issue is just getting used to the different position.

If you have the opportunity to ask the advice of someone well-informed, do so. If not, read up on bike fitting or watch some of the many YouTube videos on the topic before you start making drastic changes to your bike.


Thanks Lotus

I'm going from 100 to 70. I totally understand what you're saying & have spent many hours watching YouTube etc.
I've read lots on the subject also. For me it's a £20 trial (Deda stem from Wiggle) & worth the punt. I will continue to monitor it though. The difference in length is actually less than the diameter of the bars themselves.
B'TWIN Triban 5A
Ridgeback MX6

HenryTheHoover
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Re: Stem Length

Postby HenryTheHoover » Tue Apr 02, 2013 21:16 pm

I was in a similar position. Came from MTB to road riding. Bought the 54 triban which felt too streatched out. Swapped the 100 mm stem for a higher rise 60mm Which was a good reach but felt just a tiny bit twitchy but certainly rideable

After a few weeks of riding this new length it actually started to seem a bit cramped up and too low so I decided I needed more height and some length back this time. In the end rather than risking buying x No. of stems I bought a ( cough! ) Ritchey adjustable 100 mm stem and whacked it on maximum height. This seems very nearly right bar possibly getting a compact bar at some point.
However interestingly I do now want a longer stem on my MTB. So the moral of the story is

1. Your position will definitely change over time.
2. Tribans can be a bit low for a lot of riders especially coming from MTB. You may need to consider more height to reduce reach also.
3. 60 mm might be a touch too short r.e. twitchyness

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KingOfTheTailwind
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Re: Stem Length

Postby KingOfTheTailwind » Wed Apr 03, 2013 09:52 am

I went from a 100m stem on my 57cm Triban when I bought it in the Autumn, to a 90mm Ritchey one shortly after. That turned out to be counterfeit so I replaced it with a 80mm Deda one, and I'm currently debating whether to buy a new 90mm one or just try the 100mm original again!

The 80mm definitely does feel twitchy, and I feel like I've too much weight on my arms.

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EPO Delivery Man
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Re: Stem Length

Postby EPO Delivery Man » Wed Apr 03, 2013 12:15 pm

Here's what you need to do. Start at the beginning.

Sit on the bike, and get your seat height and seat forward/rear position right for your legs. Then get the seat angle right, you may want the nose pointing down a bit or level or even up a bit. But what you must do is get the seat position right before you muck about with the stem length.

Once you have the seat position right for your pedaling, sit on the bike and adopt the riding position. Now check your elbows, are they locked? and if they are is it a lot-ie with stretch, or simply just locking out on the hoods or drops? if they are then you need to reduce the stem length by what you see fit. So if you have a 110cm stem with the bike and you are locking out, then a general rule of thumb is that the arms should have roughly 15 degrees of bend in them. So its not a lot, but they shouldnt be locked out. Base the reduction on what you think will give your elbows that degree of bend, so you might find its 80cm. A good way to do it is place your hands on the hoods, then bring them back an inch away from the hoods on the bar and watch to see if your elbows bend. Most peoples do and this is probably the ideal position where you want the hoods to be. If its an inch then youre looking at an 80-90cm stem. If its more then it might need a 70cm stem.

When you change the stem, the steering will change, a shorter stem makes the steering more twitchy and responsive, so be aware of this.

But whatever you do, dont f*ck about with the seat position and the stem length, as its too many variables, so get the seat position right first then the stem length.

HenryTheHoover
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Re: Stem Length

Postby HenryTheHoover » Wed Apr 03, 2013 12:19 pm

I had a similar problem r.e. too much weight on my arms.

I have mostly solved it by.

1. Raising the handlebars considerably.
2. Putting my seat back further. Basically I noticed I found it hard to sit upright ( no handed ) when I was tring to get biscuits and whatnot out of my jacket. I put my seat back far enough so I felt I could and that helped a lot.
3. Then dropping the seat height until I could spin my legs round really fast
4. I have just bought a wider saddle ( specialized 155 mm) . I had originally swapped the stock saddle for a charge spoon which had a nice shape but I wasnt sure whether it felt like it was sat more inbetween my pelvis rather than underneath it. I think that kept making me try to sit further back. Basically I think my ass was telling my brain to shimmy it back looking for better support where the saddle was widest but I was almost coming off the back and blatantly too far back from the peddles. Apart from some time fiddling about I have only done 1 decent length ride so far on the new saddle. Although I am not sure yet if it is the holy grail of perfect fit I have become much more static on the bike and could actually feel my sit bones sat on something rather than straddling.

HenryTheHoover
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Re: Stem Length

Postby HenryTheHoover » Wed Apr 03, 2013 12:26 pm

Forgot something.

I am not sure the hoods on the Tribans are positioned in the best place on the handlebars. To get the hoods looking right there is a drop in the handlebar height from the flats down to the hoods. I have cranked my bars up to level off this drop. It feels so much better in regards to supporting my hands however the hoods now look like they are pointing up a bit high. It seems to be the lesser of two evils

racingcondor
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Re: Stem Length

Postby racingcondor » Wed Apr 03, 2013 13:04 pm

Not sure about the geometry on the Triban but I'm 5'11 and ride a 54 frame (it's a compact sportive type frame) with a 120mm stem.

I worry that anyone on a stem shorter than 100mm ought to be looking at the next size down and seeing if they can raise the bars far enough rather than shortening a too long bike.

Henry - Modern bars don't tend to have the bottom of the bars parallel with the ground (classic C bend bars did). Get the tops flat, then the transition from the tops to the hoods, then cable and wrap. Don't worry about the position of the far end of the bars.

Here's an example -

http://www.bikeradar.com/road/gear/article/pro-bike-geraint-thomass-pinarello-dogma-2-36254/

HenryTheHoover
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Re: Stem Length

Postby HenryTheHoover » Wed Apr 03, 2013 16:30 pm

racingcondor wrote:Not sure about the geometry on the Triban but I'm 5'11 and ride a 54 frame (it's a compact sportive type frame) with a 120mm stem.

I worry that anyone on a stem shorter than 100mm ought to be looking at the next size down and seeing if they can raise the bars far enough rather than shortening a too long bike.

Henry - Modern bars don't tend to have the bottom of the bars parallel with the ground (classic C bend bars did). Get the tops flat, then the transition from the tops to the hoods, then cable and wrap. Don't worry about the position of the far end of the bars.

Here's an example -

http://www.bikeradar.com/road/gear/article/pro-bike-geraint-thomass-pinarello-dogma-2-36254/


I think my slightly crap description is confusing thing. I meant the tops not the drops. After riding for a while I sussed having the 'tops' level felt the best for support however it means the levers stick up in the air quite a lot. definitely higher than in the picture you have shown.( thanks for the link )

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Forward loop
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Re: Stem Length

Postby Forward loop » Wed Apr 03, 2013 20:32 pm

more responsive..twitchy..
as you drop down in stem length - with both hands on the drops/hoods - things wont feel too much different on your usual uk ride.

Core stability and proper familiarity with the bike becomes a bit more of a factor as stem length decreases though. you will notice the "responsiveness" more when you have one hand on the bar (eg when taking a drink - or even more so when you raise up to look behind you - and you drift across the road !) as you will be less able to maintain a straight line with one hand and a shorter lever (stem).

Its on Alpine like descents at high speed that the 'responsiveness" becomes more of an issue with both hands on the bars, small, but fast alterations to line will feel a bit "grabby" (for instance when a hairpins becomes tighter then you thought) and can be un-nerving. It can also happen with longer stems - but its not quite as acute
- its all about knowing your bike.

on smaller frames i would suggest 80mm is the shortest to use (a 52 cm frame would normally come with a 100cm stem)

I think moving the seat back by 5mm changes your centre of gravity and doing this means you put less weight on your arms and wrists. I did the same and much prefer it, I read somewhere that if you ride along normally on the hoods, then whilst coasting slowly remove your hands from the hoods without changing position, if you don't fall forward your centre of gravity is about right. If you fall forward then you probably need to move your seat back, you may also need to lower it to keep the right leg pedalling position. You should obviously set your seat height right before doing this.


This idea broadly originated from Steve Hogg - but you need to be pedalling against some resistance unless you have the core strength of a very strong thing.

racingcondor
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Re: Stem Length

Postby racingcondor » Thu Apr 04, 2013 11:38 am

Henry -

No problem. In the end it's a case of whatever works. I used that picture as most of Sky use Deda Zero100 and that's what I have so thought it would illustrate it well (typical that the picture I found though has different bars :roll: ).

I've always found flat tops and a flat transition to the hoods is comfortable and brings the levers fairly close in which makes for an easy reach in the drops, it will vary depending on the bars and the levers though.

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♠ChumBucket♠
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Re: Stem Length

Postby ♠ChumBucket♠ » Thu Apr 04, 2013 15:04 pm

HenryTheHoover wrote:Forgot something.

I am not sure the hoods on the Tribans are positioned in the best place on the handlebars. To get the hoods looking right there is a drop in the handlebar height from the flats down to the hoods. I have cranked my bars up to level off this drop. It feels so much better in regards to supporting my hands however the hoods now look like they are pointing up a bit high. It seems to be the lesser of two evils


I'll second that.

The hoods/levers should be further down the bars. As they come, to get the tops flat the levers would be pointing skywards! To have the levers/hoods where they should be, the bar tops have to face down. That picture of the Dogma is how I would like mine to be, I assume I will have to take the tape off & adjust the levers then re-tape?
B'TWIN Triban 5A
Ridgeback MX6

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♠ChumBucket♠
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Re: Stem Length

Postby ♠ChumBucket♠ » Thu Apr 04, 2013 15:06 pm

Also FWIW- My comfort & position is now much better with the shorter stem on & the seat moved back slightly. I'll continue to monitor & make minor adjustments as I go. :wink:
B'TWIN Triban 5A
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