New geometry and consequences for bike fit

The Reverend

Likes Bikes and Dirt
Is that average for 120mm bikes or average for all bikes?
Those vague remarks in reviews suck.
And I wonder about that site overall. For example, the snide comment about the variable length chainstays shows an arrogance which is unattractive.

To assume that everyone wants the same size CS regardless of preference or bike size calls into question their sensitivity to review bikes. One size fits all rarely does.

It looks sweet so I'd definitely want to ride it and see for myself.
 

creaky

XMAS Plumper
To assume that everyone wants the same size CS regardless of preference or bike size calls into question their sensitivity to review bikes. One size fits all rarely does.
Snide comment about the flip chip setup to change angles by 0.2degrees seems reasonable though !

JD, looks like a good sizing for you. Only come in the old lady’s hair colour though?
 

The Reverend

Likes Bikes and Dirt
Snide comment about the flip chip setup to change angles by 0.2degrees seems reasonable though !

JD, looks like a good sizing for you. Only come in the old lady’s hair colour though?
Agree about 0.2°, you'd need to be a very sensitive to notice that anywhere..

Regardless, it looks lovely and the proof is in the riding.
 

Nerf Herder

Wheel size expert
I haven’t read the whole thread ... first few posts after the OP only. Apologies if I duplicate comments that have already been discussed.

There was another thread about long and slack where I posted a Cy Turner (Cotic) interview where he talks about his new geo designs vs old designs.

Paraphrasing ... it’s new ... older designs arent wrong or bad and new designs are not the be all / end all ... but they are different. My old designs are awesome, but my new designs are awesome in a different way ... proceeds to explain why.

I use this only to raise a new question. Should you expect new geo to feel like old geo? And consequently should you ride the same way on a bike with old vs new wave geo? I would think intuitively that the different geo makes you ride and feel differently ... maybe where you feel cramped ... you should actually feel cramped because they have brought your hands closer to your torso or centre ... this aimed at making you ride differently, much like being centred makes you corner differently and having a steep ST makes climb fracking infinitely easier, (not faster)

Maybe instead of trying to make the new feel like the old ... it’s a matter of adapting your style or feel or perception to the new norm of shorter reach. Rider Adaption was also another take away from the Mr Cotic interview.

All that said, I’m a very adaptable rider and understand we are all different, new geo definitely has pluses and minuses. Hope you can get comfy on your rig
 

hifiandmtb

Sphincter beanie
I think the main issue is that new school geo is the only geo available now. Steep seat tubes in particular.

They don't always work for everyone & make less sense for shorter travel bikes with less sag.
 

Big JD

Wheel size expert
I haven’t read the whole thread ... first few posts after the OP only. Apologies if I duplicate comments that have already been discussed.

There was another thread about long and slack where I posted a Cy Turner (Cotic) interview where he talks about his new geo designs vs old designs.

Paraphrasing ... it’s new ... older designs arent wrong or bad and new designs are not the be all / end all ... but they are different. My old designs are awesome, but my new designs are awesome in a different way ... proceeds to explain why.

I use this only to raise a new question. Should you expect new geo to feel like old geo? And consequently should you ride the same way on a bike with old vs new wave geo? I would think intuitively that the different geo makes you ride and feel differently ... maybe where you feel cramped ... you should actually feel cramped because they have brought your hands closer to your torso or centre ... this aimed at making you ride differently, much like being centred makes you corner differently and having a steep ST makes climb fracking infinitely easier, (not faster)

Maybe instead of trying to make the new feel like the old ... it’s a matter of adapting your style or feel or perception to the new norm of shorter reach. Rider Adaption was also another take away from the Mr Cotic interview.

All that said, I’m a very adaptable rider and understand we are all different, new geo definitely has pluses and minuses. Hope you can get comfy on your rig
Absolutely agree mate.

One thing though- I would like to see ETT and stack height compensated with the steep and slack new geo. My feeling of cramped was mainly the steep seat angle perching me up higher and the massive drop to bars. A setback post helped me get my legs in a better pedaling position and increase ETT but increasing the height of the front end with 400 spacers, riser stem and 40mm riser bars was diabolical.

New geo will take some getting used to and really work different muscles and encourages a review of how I ride. After so long off a bike - I need to change my fitness and flexablity as well. I cant jump on a new bike and expect it to feel like my 5 year old FS. I really struggled to fit on an XL Ripley with out making so many adjustments.

The SCTB in XXL has the best combination of geo/ measurements for me personally. The bike will be able to deliver more than I can.
 

Nerf Herder

Wheel size expert
Definitely agree you big lugs get the raw end ... a little unrelated, but an XL we ordered with custom geo just didn’t arrive the way we expected. We had agreed drawings as well ... in the end the limitation was the tube length, but the manufacturer didn’t even bother telling us
  1. he didn’t have access to the right tube length
  2. what he was making would be different to the drawings
  3. that he went ahead and just weld what he had together

Similarly head tube length was also a take it or leave it affair ..
No scaling for size ... it’s just 1 size fits all ... other factories will be better (much much better) but then you get additional cost and people don’t what price differences between sizes.

This is really why you guys get screwed.
 

Paulie_AU

Likes Dirt
Anyone here gone long reach and thought it was too long? Was it a dog or just a little more to handle?

Background:

Current bike is 160mm 27.5 with 425 reach with a 60mm stem so I will call that a dodgy 485 reach to bar center (acknowledging head angle stack change etc.) I originally went to order a longer bike as it appeared I was between sizes, but in the end the medium was at a killer price so I went for it and have ridden it for 3 years. It feels short in a number of situations, but I can race it at a pretty good clip but I guess I could also ride shorter bikes in the past too without spontaneous explosions occuring too often.....but almost always in race runs :(

New bike I have ordered (but isn't coming out for a month or two due to not being released yet) is a slack 160/150 29er with 485 reach and I intend to run a stem in the 30 - 40mm range. So a dirty 515 to 525 reach. Slacker than my current bike too so my dodgy reach number with stem will be effectively a little shorter. New bike seat angle is steep (77.8deg) so ETT will be 25mm longer than current bike which sounds good but I could handle longer to be honest. The thing that seems a little off is at 175cm tall with long arms it seems that apart from Pole etc. all the other brands would have me on a shorter bike. Hmmmmmmm. Rode a 480mm reach Pole machine in the carpark on the weekend and it felt sweet, but that ain't proper riding.

This won't be my only bike, I am still going to have my 27.5 150mm 65.5HA hardtail which is good fun. It measures up 15mm bigger than the duallie I will be replacing mainly due to stack being taller.
 

yuley95

soft-arse Yuley is on the lifts again
Anyone here gone long reach and thought it was too long? Was it a dog or just a little more to handle?

Background:

Current bike is 160mm 27.5 with 425 reach with a 60mm stem so I will call that a dodgy 485 reach to bar center (acknowledging head angle stack change etc.) I originally went to order a longer bike as it appeared I was between sizes, but in the end the medium was at a killer price so I went for it and have ridden it for 3 years. It feels short in a number of situations, but I can race it at a pretty good clip but I guess I could also ride shorter bikes in the past too without spontaneous explosions occuring too often.....but almost always in race runs :(

New bike I have ordered (but isn't coming out for a month or two due to not being released yet) is a slack 160/150 29er with 485 reach and I intend to run a stem in the 30 - 40mm range. So a dirty 515 to 525 reach. Slacker than my current bike too so my dodgy reach number with stem will be effectively a little shorter. New bike seat angle is steep (77.8deg) so ETT will be 25mm longer than current bike which sounds good but I could handle longer to be honest. The thing that seems a little off is at 175cm tall with long arms it seems that apart from Pole etc. all the other brands would have me on a shorter bike. Hmmmmmmm. Rode a 480mm reach Pole machine in the carpark on the weekend and it felt sweet, but that ain't proper riding.

This won't be my only bike, I am still going to have my 27.5 150mm 65.5HA hardtail which is good fun. It measures up 15mm bigger than the duallie I will be replacing mainly due to stack being taller.
I don’t have heaps of experience with different bikes but I don’t think reach is the best measurement for bike fit - probably more important for bike feel if that makes sense. When you are sitting down then ETT is more important and when you are standing up, you can easily shift your body around to find the right spot. Over the back on a steep descents and more weight up front for cornering or pumping.

In fact, I reckon - up to a point - more reach is better as you have more space to move around.

Sounds like your ETT will be very similar once you go a shorter stem so I reckon you’ll be fine.
 

Nerf Herder

Wheel size expert
Personally, I found 35mm stems too short for the new wave bikes ... and I had to go 50mm on both my Pole and my Psuedo pole.

Whilst on my Zula... I went from a 70mm to a 43mm stem recently and loved it.

Seems counter intuitive that I enjoyed the shorter stem on the shorter reach / shorter overall bike ... but needed a longer stem on the long and slack.

The above Cotic interview had a section on this ... a layman’s Summary ... hand position fore or aft of the fork rake affected Leverage and therefore the force applied to the bars as the steering arc changes.s

I think this is directly opposite to Transitions SBG thing with reduced fork offsets ... which I anticipate means shorter stems. I’m guessing.

Worth finding the podcast or YouTube.
 

Nambra

Definitely should have gone to specsavers
The above Cotic interview had a section on this ... a layman’s Summary ... hand position fore or aft of the fork rake affected Leverage and therefore the force applied to the bars as the steering arc changes.
My engineer’s brain always wondered how much real-world significance there is in the stem length / fork offset relationship. Obviously bar sweep acts to reduce effective stem length too. I can understand that shorter stems make for twitchy handling and longer stems make it easy to hold a line, but is a case of every person’s sweet spot is a personal thing or is there an effective stem length to fork offset ratio that feels “about right” for the majority? Bike type is relevant too isn’t it... an XC bike is likely to have a longer stem than a trail bike etc.

Probably overthinking things as usual, but I’ve always been curious - particularly when choosing a frame size. At 187cm it’s usually a L / XL decision with a longer or shorter stem to achieve desired bar position.
 

Tubbsy

Packin' a small bird
Staff member
A little review of a Pole and a Nicolai here:


Cy from Cotic's interview, while a long video is the most compelling explanation I've seen about the new-school geo:


A bit rambling but very interesting if you have a bit of time and a concentration span on your hands.
 

ashes_mtb

Has preferences
Read right through this thread and am pretty confused trying to get my head around modern geo.
I'm 193cm and fairly long legged.

Best fitting bike I've had was old school geo (70/73) from 2007:
Seat tube: 510
ETT: 620
Reach: 420
Stack: 560
Running 60mm stem and 20mm spacers.

Manufacture fit chart suggests I should be on an XL but I've got a dodgy lower back and don't like being stretched so considering a large with the following spec:

Angles: 66/76
Seat tube: 450
ETT: 625
Reach: 475
Stack: 610
Same 60mm stem and assume I'll slam it given the higher stack height.

To me the ETT would still be the biggest indicator of how stretched out I'd feel in the saddle? I assume the slacker HA would pull the bars in closer but that would be offset to an extent by the higher stack height and stem moving closer to the top of headtube?

The frame I'm looking at is a good buy but isn't built up so can't test it.
 

ashes_mtb

Has preferences
You fail to consider the seat tube angle. That makes a huge difference to how reach feels.

I'm afraid you'll only know by trying a modern geo bike out.
Damn, yes I did.

The SA on the old school geo pushes the seat tube back about 50mm from where the ETT measures to. A steeper seat angle will bring it forward from there.

Is that what you meant?

Appreciate feel changes with new geo but I'm just trying to get the same riding position when seated so I'm comfortable. Figure I'll get used to the big wheels and different angles over time as long as I'm comfy and not stuffing my back.
 

peanut

Likes Dirt
I have to agree with hifiandmtb, the seat angle plays a big part in how the bike feels compared to the numbers on paper, and you only really find out when you ride it. Can you hire or demo the same bike from somewhere before you buy the frame?

I'm 187cm with long legs, my centre bb to top of saddle sits around 815-820mm (175mm cranks with saint flats) for normal pedalling.

I went from a 2010 meta (80mm stem 760 bar) to a 2020 norco sight (45mm stem 800 bar) to a 2019 trek remedy (60mm stem 780 bar) all were XL's, the remedy and meta are much shorter in the (reach & TT ) cockpit on paper but in reality the shortest seated feel was actually the norco even though it was longer on paper.
Naturally the stem length plays a part in this as does bar width but Seat angle does some funny things to seated feel, the steeper seat angle on the norco made me feel very upright & i felt my centre of gravity was higher when seated.
My seat to bar height drop was the same on all 3 but again the feel on the norco was different to the others.

I found the most reliable feel indicator for me was using a tape measure from centre of seat post directly under the saddle to the outside of the bars, which gave me the best idea of what the seated fit was going to be like compared to the current bike at the time, from there the stem length & stem spacers, bar rise & width could be adjusted to give the same feel you would like.
 
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