In-between frame sizes - Giant TCR

scotthunter

Hello,

Sorry for another sizing post.

I currently have a Medium-Large Giant TCR race bike with the 110mm stem that came with the bike.

I am 5"10.5 / 5"11 (179cm) with an inside leg of 33.5" (85cm). The size chart puts me on the corner of the blue shaded area on the Giant size chart. I am guessing my legs are proportionally slightly longer than my torso as I am on the far right of the normal zone.

https://images.giant-bicycles.com/b_whi ... gsheet.jpg

I have slammed the stem (well, have 12.5mm spacer between headset and stem) and have no back pain and feel comfortable on the bike. My saddle is 76cm high from the BB centre to the top of the saddle. However, I do feel slightly stretched with my hands on the hoods when climbing seated. Downhill feels just right. I can't adjust my saddle fore-aft more forward as this gives me pain above my knee when pedaling hard. It's already 3/4 forward, and this feels right for me.

My problem is, the general consensus appears to be go down a size and run a longer stem if in the middle of two sizes, but my inside leg measurement alone would put me beyond the medium and onto a ML.

The measurements of the medium TCR are top tube 550mm + 100mm stem. ML is 570mm + 110mm. Therefore the reach is another 300mm on the ML with the stems that come with those sizes.

Do you think I will get used to the stretch over time, or should I really be running a 100mm stem, or even consider getting a Medium with a 110mm stem for my next bike purchase?

And what are the pros/cons of downsizing a stem? I like do a lot of climbing standing up and short stems put me more upright, which I prefer. But downhill, I prefer the more relaxed steering of the longer stem. I have both stem sizes but can't decide which one to settle on to best complement the type of riding I do (I am naturally a better climber).

Thanks in advance.

photonic69

Try a shorter stem - much cheaper than a new bike!

I'm 182cm and same inside leg as you and ride a M/L Giant Defy. It's the perfect size for me. I'd feel an M would be too small. My stem is 100mm. I'd feel that 76cm saddle height would be too much for me and cause me back issues. I can't recall actual height offhand but I have a feeling it is around 72-74cm. My saddle was at 76 on my other bike after a bike fit and I found I wasn't comfortable so lowered it a bit and it was spot on. Lowering will bring you slightly forward too.

If I was you I'd try 100 (or 90)mm stem and lower saddle to 74cm as a starting point. Without seeing you on a bike it would be impossible to say otherwise.

scotthunter

At 76cm I can pedal backwards with my heel without rocking my hips. So I am not sure if dropping the saddle by 2cm would be a good idea.

PhotoNic69 wrote:

Try a shorter stem - much cheaper than a new bike!

I'm 182cm and same inside leg as you and ride a M/L Giant Defy. It's the perfect size for me. I'd feel an M would be too small. My stem is 100mm. I'd feel that 76cm saddle height would be too much for me and cause me back issues. I can't recall actual height offhand but I have a feeling it is around 72-74cm. My saddle was at 76 on my other bike after a bike fit and I found I wasn't comfortable so lowered it a bit and it was spot on. Lowering will bring you slightly forward too.

If I was you I'd try 100 (or 90)mm stem and lower saddle to 74cm as a starting point. Without seeing you on a bike it would be impossible to say otherwise.

matomp9

Try the stem. It's £15-20 and if it doesn't work, so what (comparatively).

It's exactly what I did too. The TCR felt perfect except towards the end of rides when I became conscious of 'reaching' for the hoods which exacerbate a pre-existing and chronic back issue I have (but am largely able to ignore). I was worried that I'd feel a bit cramped given that the 110 mm stem was perfect for 80% of my ride ... but for £15 thought it was worth trying. Hey presto, it worked. I certainly don't feel cramped when setting out and have lessened the reaching feeling towards the end of a ride (still feel shit but that's my flexibility).

Another point to bear in mind is that the size M has a significantly lower stack 20mm or so if I recall correctly. So that would be the equivalent of slamming your stem completely and some. If your happy with your stack height then, in my view, this underscores the new stem option as the correct one.

FYI I'm 5"11' tall with an inside leg measurement of 33" and a saddle height from BB of 735mm.

A shorter stem will make the handling more responsive. But at 100mm I wouldn't suggest it'd become twitchy. All personal preference but most say you'll be fine as low as 90mm.

luv2ride

Yeah, definately try a 100mm stem before doing anything else. I'm currently swapping between a 100mm and (stock) 110mm stem, partly due to the Shimano r685 shifters fitted have a longer hood reach than the Sram hoods on my other bikes, otherwise all dimensions between the bikes are the same. The 100mm stem doesnt seem to effect the handling much at all, but seem to make it a bit comfier for riding on the hoods. Truth be told, ive convinced myself i really need a 105mm stem, but don't think they do such increments outside of the pro peloton

photonic69

scotthunter wrote:

At 76cm I can pedal backwards with my heel without rocking my hips. So I am not sure if dropping the saddle by 2cm would be a good idea.

I got my specs slightly wrong. I went from 760mm to 745mm. My legs are longer than your as well 875mm or 34.5" Not lost any power and my back and knees feel better for it. You got nothing to lose by trying it. It's free after all.

DeVlaeminck

Narrower bars might be worth a go - I have found that can help a bike feel less of a stretch to the hoods.

Captain Fagor

FWIW, I have exactly the same height, leg length and saddle height (760mm) as the OP and have ridden Medium TCRs for more than 10 years. My current TCRs (2011 and 2013) run a 120mm stem and a 9.5cm drop between the saddle and the top of the bars.