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Hi,

First post here after long time reading! wink

I'm looking at a new road bike and I'm in between sizes compared to my current bikes.

Looking at reach and stack, the 2 bikes line up like this;

Size 55 - Reach 386mm/ Stack 555mm

Size 57 - 394mm/ 572mm 

 

If I take my current Canyon Ultimate it looks like this;

Size Medium - 391mm & 567mm

 

Whilst I really love the Ultimate, it's as long on the reach as I would want to go, and I haven't felt the need to go lower on the stack/front end.

 

So my question, if I have to compromise on reach or stack on the new bike... which would be the best way to go?

I am leaning towards the Size 55 as I figure the reach is ideal and I can use some stem tricks to bring up the bars if I need to.

Thoughts??

 

 

 

 

8 comments

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Pilot Pete [100 posts] 3 weeks ago
1 like

Got t9 be the smaller frame, you are only talking 5mm difference in stack. And the bars/ stem combination could make up the 12mm in reach...

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CarlTV [6 posts] 3 weeks ago
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Pilot Pete wrote:

Got t9 be the smaller frame, you are only talking 5mm difference in stack. And the bars/ stem combination could make up the 12mm in reach...

 

Oops, my bad, just edited the post as I had the reach and stack the wrong way around!

But, I agree going smaller seems the better option... just concerned about the 12mm reduction on the stack... figure the 5mm reduction in reach will make it slightly easier.

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Pilot Pete [100 posts] 3 weeks ago
1 like

Well, it depends what stem and bars you have on your current setup. If you are replacing them you should be able to get a combination that will get your hands in pretty much the same place.

For example, a stem with a different angle could raise the bars slightly, spacers under the stem could raise them instead of/ as well as the change in angle. So to take up your 12mm, rather than putting 12mm of spacers under the stem, you could take up some of that with a different angled stem and perhaps only have 5-6mm of spacers under the stem, which would look aesthetically better. It all depends on what you currently have - if you’ve got a steeply up angled stem already it’s going to be difficult!

Something else to consider is the depth of the top fork bearing cover (the bit under any spacers covering the top bearing). If that is pretty low you may be able to get a deeper one to take up some of the gap. Again, this will tend to look better than a load of spacers. Something like this for example https://www.evanscycles.com/pro-ud-carbon-20mm-is-top-cover-EV213653

Stem length and/ or bar reach (from the tops to the bends - and then the drop can be varied to suit what you are comfortable with) can make up the difference in reach.

I have three bikes which are all close, but subtly different and I am quite happy adjusting to each one as I ride them. It’s less that 5mm in each measurement. If you get it close it will suffice, it doesn’t have to be exact to the mm, just make sure you aren’t over-stretching if you were already at the furthest comfortable extent on your old setup.

I have found that I spend most time on the hoods, so getting those close to my benchmark ideal setup was most important. The tops position is ever so slightly different between bikes (but as that is the most upright position it is less important as I can’t be over-reaching on the tops). 

The drops are almost identical on each bike as I went for the same drop on each bar (shallow, as I’m no spring chicken!)

Hope this helps.

PP

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alotronic [607 posts] 3 weeks ago
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As above, I would go small and check you have some fork above the headset to play with. I go small to get a leg fit and then add a longer stem to get longer as I have *relatively* short legs.

To be really pedantic one thing reach doesn't account for is seat tube angle - a steeper seat tube will bring you forward more relative to the BB. It's only mm's and can be ironed out by layback but I start with seat tube angle and virtual top tube, then work with reach and stack, then HT length and wheelsbase and try and merge them all together in my mind into one complex formula where I ususally group a bunch of frames and then buy the cheapest or by colour  1

Avatar
Jimmy Ray Will [1005 posts] 3 weeks ago
2 likes
alotronic wrote:

As above, I would go small and check you have some fork above the headset to play with. I go small to get a leg fit and then add a longer stem to get longer as I have *relatively* short legs.

To be really pedantic one thing reach doesn't account for is seat tube angle - a steeper seat tube will bring you forward more relative to the BB. It's only mm's and can be ironed out by layback but I start with seat tube angle and virtual top tube, then work with reach and stack, then HT length and wheelsbase and try and merge them all together in my mind into one complex formula where I ususally group a bunch of frames and then buy the cheapest or by colour  1

 

I'd argue that the reach / stack measurement has been designed specifically to take into account differences in seat angles etc.

The reach is the measurement from the bottom bracket, so factor in your lay back and you can work out what stem you need to be running to achieve the same position.

With regards to the original question, I'd say your choice should be decided by how you are on your current bike. What length of stem are you running, and how many spacers are you currently running under that stem? 

If its a 130mm stem already, you'll regret going smaller, likewise if you have 40mm of spacers under your stem already, a smaller bike won't work for you. On the flip side, if your stem is currently slammed, then the extra room will be a blessing.

Personally speaking, running a bike with 110mm stem provides the best handling so I'd be pushing for whatever frameset gets you closest to that. 

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CarlTV [6 posts] 3 weeks ago
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I appreciate the help here guys, thanks.

 

My Canyon is integrated, and it's a 100mm stem at 6 degrees down.

I've done some calculations and worked out that if I get a 110mm stem on the new bike, but have it 6 degrees up, it'll put me at the exact same reach and bar height as what I have with the Canyon now.

 

Further to this, I think I'll give it a go of adapting to the lower stack first, and keeping with a 100mm stem and 6 degrees down.

I've also gone from 410mm bar width to 400mm.

 

The bike is on order as of today anyway, can't wait to get it! I'll keep you posted.

 

Anyone want to guess what bike I'm leaving Canyon for??

Avatar
kil0ran [1291 posts] 3 weeks ago
0 likes
alotronic wrote:

As above, I would go small and check you have some fork above the headset to play with. I go small to get a leg fit and then add a longer stem to get longer as I have *relatively* short legs.

To be really pedantic one thing reach doesn't account for is seat tube angle - a steeper seat tube will bring you forward more relative to the BB. It's only mm's and can be ironed out by layback but I start with seat tube angle and virtual top tube, then work with reach and stack, then HT length and wheelsbase and try and merge them all together in my mind into one complex formula where I ususally group a bunch of frames and then buy the cheapest or by colour  1

The guy who did my bike fit (30 years plus experience from the days where a bike fit probably involved a plumb line and a spirit level) said it all starts with the legs. Get the hip angle and knee over pedal bit right and work from there. With that in mind you certainly need to consider seat tube angle, and then it's a question of saddle setback and stem length to get the bars in the right place.

I've found with one of my bikes that my ideal position requires a 35mm setback seatpost (so yeah, it's a touch too small) and that limits your options these days. Don't just assume you'll be able to dial everything out with stem length and setback, a few mm reach can really make a difference to comfort. I guess that's why you see framebuilders offering so many sizes.

Avatar
alotronic [607 posts] 3 weeks ago
0 likes
Jimmy Ray Will wrote:
alotronic wrote:

As above, I would go small and check you have some fork above the headset to play with. I go small to get a leg fit and then add a longer stem to get longer as I have *relatively* short legs.

To be really pedantic one thing reach doesn't account for is seat tube angle - a steeper seat tube will bring you forward more relative to the BB. It's only mm's and can be ironed out by layback but I start with seat tube angle and virtual top tube, then work with reach and stack, then HT length and wheelsbase and try and merge them all together in my mind into one complex formula where I ususally group a bunch of frames and then buy the cheapest or by colour  1

 

I'd argue that the reach / stack measurement has been designed specifically to take into account differences in seat angles etc.

The reach is the measurement from the bottom bracket, so factor in your lay back and you can work out what stem you need to be running to achieve the same position.

Reach calculates the distance from the BB, so it explicitly doesn't factor in seat angle. Mental experiment: bike with 45deg and 90deg seat tube have exacty the same reach. You have to do the extra work to figure out what's best in terms of layback, which you have pointed out and is what I originally said  1