Bike Sizing - Previous Gen XC versus Latest

[ajnkzn]

Hi Team

 

Hope that you're all well (nerd alert on the below 😆).

 

Looking at a new previous generation (2021 - 2023) Cannondale Scalpel (full suspension) as my LBS can build one up for a great price. I plan on keeping this bike for a good while (3 years min) so want to get it right.

 

Use case will be XC marathon / stage races, gravel and non competitive trails.

 

I am 177cm tall, but with a long upper body so about a 180cm wingspan. 40 years old, reasonably fit and flexible / strong.

 

1) My current bike (Roscoe 7) is a Large with a Reach of 470mm, 770mm 25mm Rise Bars and 42.5mm Stem (effectively 512.5mm reach to bars yes?). Effective Top Tube is 646mm and Stack is 644mm. My saddle is probably 2/3rds forward on the rails.

 

I am finding that I have pressure on my hands when seated to the point that some of my fingers go numb after a few hours. I have also (for the first time) ever, found that my hands want to "blow off" the tops of my bars in the rough downhill stuff. It feels like the bike is too short for me, but surely it can't be. If you look at any manufacturer's recommended sizing I should be a Large. Brake lever angle, grips etc are all similar to what I've used in the past.

 

2) The "2021" Scalpel in a Large has a Reach of 455mm and I would fit a 60 / 70mm stem (effectively 515 / 520mm reach to bars?). ETT is 622mm and Stack is 601mm. Lower stack should increase my seated reach which should help with hand numbness (if my lower back can keep the weight off my hands with more "waist" bend. This is a very "traditional" sizing / cockpit build (relatively long stem etc).

 

2021 Scalpel in XL has a Reach of 475mm and I could fit a 40 / 50mm stem (effectively 525 / 535mm reach to bars?). ETT is 644mm and Stack is 610mm.  

 

3) The brand new 2024 Scalpel in Large has a Reach of 475mm and looks like it comes with a very short (40mm?) stem (effectively 515 mm reach to bars?). ETT is 625mm and Stack is 607mm. 

 

Comparing the 2021 XL and the 2024 L, apart from ETT on the 2021 being an inch longer, the old XL and the new L are very similar. Seat angle on the old bike is slacker than the new, so I would likely move my saddle forward of the midpoint anyway which would shorten my ETT for pedaling.

 

If I buy the 2021 XL, it may also allow me to fit a -1 degree angleset to slacken the head angle to a very modern 67 degrees (2024 bike has gone from 68 to 66.6 degrees).

 

Am I oversimplifying things or is there something to be said for going for the larger bike.

 

Lachlan Morton went from a medium Scalpel at the last Leadville 100 to an XL on the new 2024 Scalpel and was very happy with being more "in the bike" and the stability it brings.

 

Nerd rant off - any ideas? 

 

Edited 13 hours ago by ajnkzn

[guidodg]

there is NO way you would need an XL Scalpel with your measurements 😉

[ajnkzn]

That’s what I thought (and what everyone thought 10 years ago), but look at reach / ETT numbers on the latest crop of XC bikes 🥴

[thebob]

Scalpel hardtail or Scalpel full suspension?

[ajnkzn]

FS sorry. 

[DieselnDust]

Get the Large. The Roscoe has a long top tube so a stumpy stem and wide bar works with it.

Scalpel doesn't work well with such short stems. If you go for the XL you will have to run a very short stem and wide bar which is not a good thing on  marathon bike as the wide arm position place more pressure on the shoulders

[ajnkzn]

Thanks for the inputs so far guys. 

 

Agree that one can't go too short on stem as the 55mm offset on the Lefty Ocho does sharpen up the steering already.

 

I owned a 2019 Scalpel Si in Large with the Ocho and a 60mm Stem (445mm reach, 604mm stack and 624 ETT) felt pretty good so a Large 2021 can only feel better... 

[ridesleeprepeat]

I have similar measurements with a long torso and a 178cm height.

Two thoughts. If you are blowing your hands off in the rough stuff, look at increasing stack height (by fitting higher rise bars, not stem spacers). With geometries settling down a bit stack height is becoming more important for fit now after everyone chased reach for a few years. A more upright seating position will also help with the numbness.

Also, look at the bike's front centre measurement rather than effective TT. Effective TT accounts for seated dimensions BUT if the bike has a slack ST angle then the effective length to handlebars can feel shorter when standing on the pedals despite a roomy seated position. Takes a bit of maths if manufacturer doesn't list it but it's a useful measurement for comparison and gives an indication of where you will 'fit' in the bike's wheel base.

[ChrisF]

I am 3cm shorter than you, and alternate between M and L depending on the bike.

 

You are spot on for L in most brands.

 

Numb hands .... how much distance have you done on this bike ?  And how much on this saddle ?

 

I had a "fun" December .... just could not get comfortable on my saddle !!  Turns out the saddle was past its sell by date and had started sagging in the middle (no complaints, it sure did enough distance).  A bike fit with Irma discovered a few other things as well, few sessions with a fisio and I am back to enjoying my bike.

 

Point being, if the bike was right for many rides and there are new issues, take note and get to the root cause.

 

 

[Dappere]

Does your LBS have stock available to test in one or two sizes? I’m not too familiar with Cannondale, but a riding buddy of mine has a Cannondale in XL – he is 192 cm tall. I am 180 cm, and his bike is far too big for me.

For reference, I ride a Trek in M/L

[DieselnDust]

5 hours ago, ajnkzn said:

Thanks for the inputs so far guys. 

 

Agree that one can't go too short on stem as the 55mm offset on the Lefty Ocho does sharpen up the steering already.

 

I owned a 2019 Scalpel Si in Large with the Ocho and a 60mm Stem (445mm reach, 604mm stack and 624 ETT) felt pretty good so a Large 2021 can only feel better... 

on the hand blowing off issue....

I'm not 100% sure whats going here but things to check would be, 

• bars are too high and your wrists are rotating backward on long descents. A longer reach can help but lowering the bar a bit might be the answer. 29ers have high stack height pecially the longer travel bikes which isn't good and is worse for rides under 170cm
• Grips might be too thin resulting in too much clutching of the bar causing hand strain.
• bars may be too wide causing too much bed sideways bend at the wrist

[Prince Albert Cycles]

At 178 cm I am comfortable on my M Scalpel but on test ride on a customer’s Large I felt more comfortable.

As stated above I think XL will be too big for you

[ajnkzn]

1 hour ago, DieselnDust said:

on the hand blowing off issue....

I'm not 100% sure whats going here but things to check would be, 

• bars are too high and your wrists are rotating backward on long descents. A longer reach can help but lowering the bar a bit might be the answer. 29ers have high stack height pecially the longer travel bikes which isn't good and is worse for rides under 170cm
• Grips might be too thin resulting in too much clutching of the bar causing hand strain.
• bars may be too wide causing too much bed sideways bend at the wrist

Thank you. 
 

I’ve tried a lot of different things to get this right (three different bars, changed brake levers from the el cheapo Roscoe ones, different grips, etc etc). 
 

Funnily today my bars suddenly felt a bit wide (Burgtec Ridewide Alu 31.8mm that I’ve trimmed to 770mm). 
 

On my last Scalpel I had the standard Lyne  Alu XC bar and stem and never had the issue so it must be a combo of stack, bar width and possibly roll. 
 

Appreciate the advice. 

[ajnkzn]

2 hours ago, ChrisF said:

I am 3cm shorter than you, and alternate between M and L depending on the bike.

 

You are spot on for L in most brands.

 

Numb hands .... how much distance have you done on this bike ?  And how much on this saddle ?

 

I had a "fun" December .... just could not get comfortable on my saddle !!  Turns out the saddle was past its sell by date and had started sagging in the middle (no complaints, it sure did enough distance).  A bike fit with Irma discovered a few other things as well, few sessions with a fisio and I am back to enjoying my bike.

 

Point being, if the bike was right for many rides and there are new issues, take note and get to the root cause.

 

 

I’m a chronic bike changer but have done 1600km on the Roscoe including a Festive 500. 
 

Saddle is a really nice Fabric one (short nose with a deep cutout) and has been comfy and isn’t too old. 
 

Something isn’t quite right but the Roscoe is on its way to a new home - I was (as is usual for me 🙄🤣) trying to fit a square peg in a round hole using the Roscoe for trail, gravel and marathon MTB which it just isn’t really made for. 
 

Appreciate the time to advise and share your experiences - will def get a bike fit on the new bike. 

[ChrisF]

9 minutes ago, ajnkzn said:

I’m a chronic bike changer but have done 1600km on the Roscoe including a Festive 500. 
 

Saddle is a really nice Fabric one (short nose with a deep cutout) and has been comfy and isn’t too old. 
 

Something isn’t quite right but the Roscoe is on its way to a new home - I was (as is usual for me 🙄🤣) trying to fit a square peg in a round hole using the Roscoe for trail, gravel and marathon MTB which it just isn’t really made for. 
 

Appreciate the time to advise and share your experiences - will def get a bike fit on the new bike. 

 

N+1 is always an option.....

 

Strange how some bikes just puts a smile on your face when you ride .... enjoy

[ajnkzn]

Thanks Chris - pretty keen on the Scalpel and I think it’ll serve me for the next few years perfectly 🤘