stem length query

jon1981

Hi,

Is there a minimum stem length size you can fit? I have a Giant TCR, small, with a 90mm stem. I feel stretched out on it when on the hoods and there's little forward travel on the seat rails left. I know giant do a 60,70 and 80mm stem but before I go for a proper bike fit, is there a rule of thumb around stem lengths in relation to frame size for stability of the steering ?

It felt fine in the shop but I guess it's only after a 70km spin that I've felt the difference , also according to the Giant website and based on height it should be the right fit but I guess it doesn't factor leg and body proportions.

Jon

Alek

You can fit even a 50mm stem if you need to, but the shorter you go the twitchier handling will become.

From your description it seems that the best option would be go for a XS frame, Giant makes this size in many models.

But: do you have this bike for long? Maybe you're just not used to the position... If you went by the manufacturers sizing I wouldnt change the stem before giving 2-3 weeks yourself for acclimatisation.

jon1981

Alek wrote: »

You can fit even a 50mm stem if you need to, but the shorter you go the twitchier handling will become.

The best option would be go for a XS frame, Giant makes this size in many models.

Yeah, though the guide says i'm way too large for the XS. I reckon 90->80mm might make a difference but I'd be worried at how extra twitchy it would make the bike.

JBokeh

You'll notice the steering will get really twitchy if you put a stem shorter than 90mm on it. Is there a big drop between the saddle and the bars? Your levers could be mounted a bit low on the bars too, causing you to need to reach forwards to keep your hands on them. A bike shop could give you a lend of a few stems to try out before you buy one, just assure them that you buy one from them, and not turn around and buy it off the internet

I wouldn't try adjusting reach by moving the saddle forwards and back, that could have repercussions for your knees later on, the saddle adjustments are mainly to get your legs in the correct position to pedal.

JBokeh

You'll notice the steering will get really twitchy if you put a stem shorter than 90mm on it. Is there a big drop between the saddle and the bars? Your levers could be mounted a bit low on the bars too, causing you to need to reach forwards to keep your hands on them. A bike shop could give you a lend of a few stems to try out before you buy one, just assure them that you buy one from them, and not turn around and buy it off the internet

I wouldn't try adjusting reach by moving the saddle forwards and back, that could have repercussions for your knees later on, the saddle adjustments are mainly to get your legs in the correct position to pedal.

Alek

Sorry, I edited my post while you have already replied... In this case you may try a -10mm one, but maybe give it some time before

Cee-Jay-Cee

80mm isn't too much different from your 90mm stem and won't adversely affect the steering. If you have to go any a shorter then the frame is too large for you and you'd be better off trying to get a smaller frame.

jon1981

Alek wrote: »

But: do you have this bike for long? Maybe you're just not used to the position... If you went by the manufacturers sizing I wouldnt change the stem before giving 2-3 weeks yourself for acclimatisation.

a few days

It could be position alright. It's more aggressive than I'm used to. Perhaps I'll get the bike fit done anyway, it might be something else I'm not considering.

jon1981

JBokeh wrote: »

You'll notice the steering will get really twitchy if you put a stem shorter than 90mm on it. Is there a big drop between the saddle and the bars? Your levers could be mounted a bit low on the bars too, causing you to need to reach forwards to keep your hands on them. A bike shop could give you a lend of a few stems to try out before you buy one, just assure them that you buy one from them, and not turn around and buy it off the internet

I wouldn't try adjusting reach by moving the saddle forwards and back, that could have repercussions for your knees later on, the saddle adjustments are mainly to get your legs in the correct position to pedal.

There is a big drop between saddle and bars. Perhaps the bars could be rotated more upwards. Something I can try.

jon1981

Cee-Jay-Cee wrote: »

80mm isn't too much different from your 90mm stem and won't adversely affect the steering. If you have to go any a shorter then the frame is too large for you and you'd be better off trying to get a smaller frame.

Yeah, though I can't imagine that's the case as I'm 4 cm over the height of the XS frame (by the Giant size guide). I might see if the shop can let me try out an 80mm if the bike fitter recommends this.

jon1981

The issue I was really feeling was in the shoulders. Both shoulder joints were very sore after the cycle. Also the handlebars seem wider than my other bike, i'll measure the width later.

Andy Magic

What model TCR is it? I have a TCR myself and on mine you can flip the attachment for the saddle so you can more it more forward. I wouldn't be a fan of making the stem shorter as the steering would be dreadful.

Agent Smyth

jon1981 wrote: »

There is a big drop between saddle and bars. Perhaps the bars could be rotated more upwards. Something I can try.

Try flipping the stem

jon1981

Andy Magic wrote: »

What model TCR is it? I have a TCR myself and on mine you can flip the attachment for the saddle so you can more it more forward. I wouldn't be a fan of making the stem shorter as the steering would be dreadful.

It's the TCR advanced 1 - so you can flip the top of the set post, the piece that is setback? I have attached a pic.

jon1981

Agent Smyth wrote: »

Try flipping the stem

The stem is a straight stem, sure sure what good that would do?

eeeee

I have an 80mm stem and the handling is fine. It depends on your proportions rather than height, to go by height or leg length I should be on a much larger frame, but my body is short proportionally so I take a smaller frame.

I suppose only a bikefit will really get you comfy.

jon1981

gadetra wrote: »

I have an 80mm stem and the handling is fine. It depends on your proportions rather than height, to go by height or leg length I should be on a much larger frame, but my body is short proportionally so I take a smaller frame.

I suppose only a bikefit will really get you comfy.

I hope so!

JBokeh

TCR is meant to be a race geometry bike so you'll find theres not much stack height, meaning a bigger saddle to bar drop. Might be worth doing some stretches for your flexibility too if you're feeling a bit beaten up by the bike after a longer spin

cython

jon1981 wrote: »

The stem is a straight stem, sure sure what good that would do?

Definitely? This image of the 2016 model looks like there's a slight angle on it, and if that's downwards at the moment there may be some height to be gained.

Agent Smyth

jon1981 wrote: »

The stem is a straight stem, sure sure what good that would do?

I could be wrong but I doubt it's a straight stem(flat), it looks straight because of the headtube angle, most bikes when you flip the stem you bring the handlebars up a couple of cm

jon1981

cython wrote: »

Definitely? This image of the 2016 model looks like there's a slight angle on it, and if that's downwards at the moment there may be some height to be gained.

Oh right I can see it now. Would that position be allowed? Would there be compromise to handling?

cython

jon1981 wrote: »

Oh right I can see it now. Would that position be allowed? Would there be compromise to handling?

Define allowed? The rules might not like it but functionally there is nothing wrong with it. If you were to draw a free body diagram, there is little difference in forces really between moving a downward facing stem further up the steerer as opposed to flipping the stem. Realistically the only difference would be in the leverage against the headset bearing, etc. but the rotational control would be basically the same. It may handle a bit differently, but not dangerously so or anything.

jon1981

So I got a bike fit today and it made the world of difference. I'm no longer cycling with my arms locked out or hunched over. Flipping the stem was required along with removing some spacers and the difference was instant. The saddle surprisingly to me needed to be raised a good bit more.
I do have to work on my posture which in turn means strengthening my core. Looking forward to my next spin on the bike.