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Looking to buy a new gravel bike. Sizing confusion help

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Looking to buy a new gravel bike. Sizing confusion help

Old 06-07-23, 01:17 PM
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Looking to buy a new gravel bike. Sizing confusion help

I've been riding a 56cm Trek Checkpoint ALR5 for 5 years now and ready to upgrade. I'm a guy who's 6foot (183cm) tall and has an cycling inseam of 80cm. I'm looking to buy a few different brands but they have this sizing system of S,M,L, etc. I'm right in between a M and a L for the bikes/brands I'm looking into. Just not sure which size to buy; and I'm gonna spend a shxtload, around 5 grand on a new bike. Is a M gonna be too small for me? Well, I guess this totally depends on which brand I end up buying. Hmm

BTW, i will get fitted to this new bike as I did for my Trek years ago.

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Old 06-07-23, 01:40 PM
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Originally Posted by eaglesandcycling
I've been riding a 56cm Trek Checkpoint ALR5 for 5 years now and ready to upgrade. I'm a guy who's 6foot (183cm) tall and has an inseam of 80cm. I'm looking to buy a few different brands but they have this sizing system of S,M,L, etc. I'm right in between a M and a L for the bikes/brands I'm looking into. Just not sure which size to buy; and I'm gonna spend a shxtload, around 5 grand on a new bike. Is a M gonna be too small for me? Well, I guess this totally depends on which brand I end up buying. Hmm

BTW, i will get fitted to this new bike as I did for my Trek years ago.
Then let the shop help you figure out which size to buy.

Where's the problem?
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Old 06-07-23, 01:44 PM
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I'm 5'-9" and ride a 53-54. In S/M/L designations, I'm pretty consistently a M. My best guess is that L will probably be the best size for you, but with the amount of money you're spending taking the step to get properly fitted is a good plan.
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Old 06-07-23, 03:41 PM
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Originally Posted by Eric F
I'm 5'-9" and ride a 53-54. In S/M/L designations, I'm pretty consistently a M. My best guess is that L will probably be the best size for you, but with the amount of money you're spending taking the step to get properly fitted is a good plan.
I appreciate your input, thanks!
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Old 06-07-23, 03:41 PM
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Originally Posted by Koyote
Then let the shop help you figure out which size to buy.

Where's the problem?
I plan to buy one of these bikes online here in Europe. Will be shipped to me..
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Old 06-07-23, 07:28 PM
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Originally Posted by eaglesandcycling
I've been riding a 56cm Trek Checkpoint ALR5 for 5 years now and ready to upgrade. I'm a guy who's 6foot (183cm) tall and has an inseam of 80cm. I'm looking to buy a few different brands but they have this sizing system of S,M,L, etc. I'm right in between a M and a L for the bikes/brands I'm looking into. Just not sure which size to buy; and I'm gonna spend a shxtload, around 5 grand on a new bike. Is a M gonna be too small for me? Well, I guess this totally depends on which brand I end up buying. Hmm

BTW, i will get fitted to this new bike as I did for my Trek years ago.
First, is that your pants inseam or your actual cycling inseam? I am guessing the former?

When I bought my gravel bike, I found this explanation by Santa Cruz very helpful:

Body Dimension

Not all bodies at a given height are the same. If you have longer legs and a shorter torso than the average person your height, that may push you towards the smaller of the recommended sizes. If you're all torso and arms, most likely you'll want to size up.

​​​​​​
Lastly, the height-based size guide is just an approximation. You do not need that as you already have a bike which you have ridden for 5 years. Does it fit you reasonably well? If yes, you can start by comparing the respective geometry numbers of your existing bike and your target bike. Then you can also consider, for example: (1) how your fit has evolved over the course of the 5 years riding your existing bike; (2) existing cockpit setup, e.g., stem length and angle, headset spacers needed, seat post setback, saddle rail clamping spot, etc.; and (3) whether you would like to go a bit lower, higher, more or less stretched out, etc.

Last edited by SoSmellyAir; 06-08-23 at 01:28 AM.
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Old 06-07-23, 07:48 PM
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This website can help: https://geometrygeeks.bike
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Old 06-07-23, 08:38 PM
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Originally Posted by eaglesandcycling
I plan to buy one of these bikes online here in Europe. Will be shipped to me..
Got it.

If your Trek fits well, look up the geometry specs. For the new bike, try to get a close match for the Stack, Reach, and Effective Top Tube numbers. Small tweaks can be accomplished by changing stem length and angle.
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Old 06-08-23, 12:47 AM
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Originally Posted by SoSmellyAir
First, is that your pants inseam or your actual cycling inseam? I am guessing the former?

When I bought my gravel bike, I found this explanation by Santa Cruz very helpful:

Body Dimension

Not all bodies at a given height are the same. If you have longer legs and a shorter torso than the average person your height, that may push you towards the smaller of the recommended sizes. If you're all torso and arms, most likely you'll want to size up.
​​​​​​
Lastly, the height-based size guide is just an approximation. You do not need that as you already have a bike which you have ridden for 5 years. Does it fit you reasonably well? If yes, you can start by comparing the respective geometry numbers of your existing bike and your target bike. Then you can also consider, for example: (1) how your fit has evolved over the course of the 5 years riding your existing bike; (2) existing cockpit setup, e.g., stem length and angle, headset spacers needed, seat post setback, saddle rail clamping spot, etc.; and (3) whether you would like to go a bit lower, higher, more or less stretched out, etc.


that figure is my cycling inseam... thanks for all of the input here, helpful!
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Old 06-08-23, 01:33 AM
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Originally Posted by eaglesandcycling
that figure is my cycling inseam...
Hmm ... an 80 cm inseam seems kind of short for someone who is 6 feet tall. The advice from Santa Cruz would suggest that you take the larger of the two sizes you are in between.

Originally Posted by eaglesandcycling
thanks for all of the input here, helpful!
Good luck shopping. Which gravel bikes are you looking at?
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Old 06-08-23, 02:19 AM
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Originally Posted by SoSmellyAir
Hmm ... an 80 cm inseam seems kind of short for someone who is 6 feet tall. The advice from Santa Cruz would suggest that you take the larger of the two sizes you are in between.



Good luck shopping. Which gravel bikes are you looking at?
Lauf and Pearson..
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Old 06-08-23, 06:43 AM
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Originally Posted by eaglesandcycling
Lauf and Pearson..
I have not heard of Pearson… But at least here in the US, the Lauf gravel bike options are absolutely screaming deals. The prices are extremely reasonable for the quality and build kits. And again – here in the US at least — the return privilege should pretty much eliminate any worries you have about sizing.
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Old 06-08-23, 01:14 PM
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Originally Posted by Koyote
I have not heard of Pearson… But at least here in the US, the Lauf gravel bike options are absolutely screaming deals. The prices are extremely reasonable for the quality and build kits. And again – here in the US at least — the return privilege should pretty much eliminate any worries you have about sizing.
Yah, check out the Pearson On and On ...
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Old 06-08-23, 04:05 PM
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Originally Posted by eaglesandcycling
Lauf and Pearson..
My wife got the Lauf Siegla about a year ago. Top quality bike, and their customer service was excellent.
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Old 06-09-23, 03:48 PM
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In general I prefer a bike that is slightly too large to one that is slightly too small. I found a number of local bike shops that rented "demo" bikes for a day. Not a cheap rental but it gave me time to evaluate a couple bikes before buying one.
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Old 06-10-23, 10:12 AM
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The 2019 model year is the earliest Trek Checkpoint ALR5 in Trek's archives: Checkpoint ALR 5 - Trek Bikes

The Lauf Seigla frame has a lower stack:reach ratio, and is longer and lower.
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Old 06-10-23, 11:32 AM
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Originally Posted by SoSmellyAir
The 2019 model year is the earliest Trek Checkpoint ALR5 in Trek's archives: Checkpoint ALR 5 - Trek Bikes

The Lauf Seigla frame has a lower stack:reach ratio, and is longer and lower.
hmm. guess i messed up the year, you're right.

so if my 56cm Trek fits me well I guess i should go with a Lauf Seigla Large, yah? then get a bike fit..
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Old 06-10-23, 11:48 AM
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Originally Posted by eaglesandcycling
hmm. guess i messed up the year, you're right.
No. The 2019 model year would have been released in 2018, so if you had bought it new, then you would have ridden it for about 5 years.

Originally Posted by eaglesandcycling
so if my 56cm Trek fits me well I guess i should go with a Lauf Seigla Large, yah? then get a bike fit..
Not necessarily. You have to (1) compare the geometry numbers between the two bikes, especially stack, reach, and effective top tube; (2) evaluate how your current bike is setup, e.g., seat post setback, stem length and angle, spacers under stem, etc.; and (3) consider whether your torso can go lower and longer and your arms can reach lower and further. Although the components under #2 can be changed (e.g., during a bike fit) to compensate for the lower stack:reach ratio of the Seigla and to arrive at close to the same fit between the two bikes (e.g., shorter stem, higher stem angle, more spacers under stem), the result could be ugly and might affect handling.
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Old 06-10-23, 12:01 PM
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Originally Posted by SoSmellyAir
No. The 2019 model year would have been released in 2018, so if you had bought it new, then you would have ridden it for about 5 years.



Not necessarily. You have to (1) compare the geometry numbers between the two bikes, especially stack, reach, and effective top tube; (2) evaluate how your current bike is setup, e.g., seat post setback, stem length and angle, spacers under stem, etc.; and (3) consider whether your torso can go lower and longer and your arms can reach lower and further. Although the components under #2 can be changed (e.g., during a bike fit) to compensate for the lower stack:reach ratio of the Seigla and to arrive at close to the same fit between the two bikes (e.g., shorter stem, higher stem angle, more spacers under stem), the result could be ugly and might affect handling.

i really appreciate all of your feedback and help here.. im a total dumbass in all honesty with all of this fitting/sizing ****. and i really dont care to take the time to learn, in all honesty; i just LOVE riding simply.. but i guess i need to take some time to learn at least some of this..

thoughts on these 2 comparisons?:
https://geometrygeeks.bike/compare/l...-5-2018-56-cm/

https://geometrygeeks.bike/compare/t...a-2022-medium/
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Old 06-10-23, 02:16 PM
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Originally Posted by eaglesandcycling
i really appreciate all of your feedback and help here.. im a total dumbass in all honesty with all of this fitting/sizing ****. and i really dont care to take the time to learn, in all honesty; i just LOVE riding simply.. but i guess i need to take some time to learn at least some of this.
We can (1) take the frame geometry numbers for one bike, (2) get the component specifications (which I have inquired but you have not revealed), (3) do all the trigonometry to figure out where the cockpit touch points are, (4) walk through the frame geometry numbers for the other bike to find one or more frame sizes that is more-or-less "comparable" to the existing frame, (5) do more trigonometry to figure out how to get the cockpit touch points at roughly the same positions. But what is the point if you don't really care to take the time to learn?

Also, only you and a competent bike fitter can figure out how your body would do on a lower and longer frame. So best to get a bike fit from a competent fitter, preferably one with experience with Lauf Seiglas.

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Old 06-14-23, 12:39 AM
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use stack and reach date to choose M or L
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Old 06-28-23, 11:17 AM
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Originally Posted by eaglesandcycling
i really appreciate all of your feedback and help here.. im a total dumbass in all honesty with all of this fitting/sizing ****. and i really dont care to take the time to learn, in all honesty; i just LOVE riding simply.. but i guess i need to take some time to learn at least some of this..

thoughts on these 2 comparisons?:
https://geometrygeeks.bike/compare/l...-5-2018-56-cm/

https://geometrygeeks.bike/compare/t...a-2022-medium/
If you arent sure and fall between sizes, I would go with the smaller Medium option. I think its easier to make smaller bike fit better (stems, seat post etc).
I myself am 188cm and ride Giant Defy M/L with 120mm stem and this fits me very well and according to Giant chart, I should be on XL or at least L.
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Old 07-04-23, 06:21 PM
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lots of great info!
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Old 07-11-23, 06:28 PM
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Originally Posted by eaglesandcycling
i really appreciate all of your feedback and help here.. im a total dumbass in all honesty with all of this fitting/sizing ****. and i really dont care to take the time to learn, in all honesty; i just LOVE riding simply.. but i guess i need to take some time to learn at least some of this..
It's a lot to consider, and I feel like every time I understand it all, I find something else I did not consider. The trick is reading the geometry charts and learning which dimensions you like best. If you're getting the fitting at the same place you're buying the bike, they should be able to guide you more accurately than any of us on here.
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