Geometry Comparison Tool - GEOMETRYGEEKS.BIKE

[MrJacques]

For those who like to compare bike geo, here's a nice tool. You can compare sizes and different bikes

 

https://geometrygeeks.bike/

 

If you bike isn't there you can also add it.

[thebob]

I find Bike Insights a better tool myself:

 

https://bikeinsights.com/

[MORNE]

I like this one a bit better because it gives a visual overlay of the geometry of the two chosen bikes. I do these myself in cad when time permits but use this on the fly for quick reference:

 

https://bikeinsights.com/compare

[MORNE]

I find Bike Insights a better tool myself:

https://bikeinsights.com/

Jinx

[ChrisF]

Thanks guys, much appreciated.

[MrJacques]

Thanks

 

I don't completely trust the charts. Comparing a Levo SL (L) which I took for a test ride to my friends Fuel Ex (L) the Levo felt longer, despite the charts saying it has a shorter reach. Stem length could be the reason. Anyway, the charts are interesting, but it's still better to hop on the actual bike for a real comparison.

[MORNE]

Fork travel (A2C stack), stem length, bar width, saddle height, saddle setback, saddle to bar drop - all affect reach. Those charts are all accurate if the frames are overlaid directly. All the above can be used to tweak fit.

 

Your friend large felt longer because it has different components and settings in some or all these places mentioned. The frames reach is the frames reach...thats designed and built in, and that is what is reflected in most of these charts....the geo numbers as recorded from manufacturers websites.

 

If you know your numbers you can build a bike off these numbers without ever throwing a leg over it. I have done it a few times.

Edited December 16, 2020 by morneS555

[Grease_Monkey]

Thanks

 

I don't completely trust the charts. Comparing a Levo SL (L) which I took for a test ride to my friends Fuel Ex (L) the Levo felt longer, despite the charts saying it has a shorter reach. Stem length could be the reason. Anyway, the charts are interesting, but it's still better to hop on the actual bike for a real comparison.

Remember, overall length of the bike is wheelbase, reach refers to how long it feels when you stand, effevtive top tube (ETT) will be how long it feels when you sit.

 

I have made the mistake of going for a Medium bike by just looking at the reach which was longer than my previous large. What I didn't look at was ETT which was much shorter - I could bever get comfy and it ended up being the most expensive mistake I made in a while.

 

Test ride all bikes you are thinking of and go for the one you feel most comfortable on. And by test ride I mean an actual ride, not around the parking lot.

[NickGM]

Just adding this as it's a similar type of resource... 

 

https://whatbars.com/

[Pure Savage]

Good to see, I thought the new Supersix was almost identical to the 2017 and was spot on.

[DieselnDust]

There's a lot of subtle things that makes bikes which look similar on paper feel different when you're on them.

Fork rake in size small road bikes is usually around 50mm and 43 to 45mm for medium and bigger. Often the small will have a slightly longer wheelbase as a result of the extra rake and slcker head tube.

Handling will also be slightly slower.

 

the seat post set back plays a big role to. It's not reflected in the ETT or reach measurements but the set back  can be anywhere from 0mm to 40mm depending on the post specced on the bike. This influences the layback measurement and hence ETT.

 

BB drop affects the stack measurement so can't rely solely on headtube length.

 

try the https://www.velogicfit.com/frame-comparison tool

I also use my own spreadsheet that accounts for saddle seatback and stem rise.

[Jewbacca]

Yoh... I just look at a bike and think, that looks rad, then briefly look at the  numbers to see if I can roughly set it up as I like, yes, boom, job done. Shreddies!

 

This just seems heaps complicated!

[MORNE]

Yoh... I just look at a bike and think, that looks rad, then briefly look at the numbers to see if I can roughly set it up as I like, yes, boom, job done. Shreddies!

 

This just seems heaps complicated!

Says the guy who can buy a medium in anything and ride it off the floor without hassle....or walk into any store and find the shoe you like best in your size? I so envy you.

You know how much it sucks walking into a store and always asking “whats the biggest size you have?” Rather than just shopping for what looks the best.

The struggle is real if you are sized on the fringes. The numbers become critical lol. And then you are on record here saying things like xl/xxl bikes look like they are designed by toddlers and sortof resemble farm gates haha.

 

Ps: this is exactly how i knew we could build my 203cm cousin that XL dartmoor primal instead of him being flogged a XXL trek Marlin. And it ended up being perfect for him.

Edited December 17, 2020 by morneS555

[ChrisF]

Also gets interesting for those on the fringe between sizes .... now add in the fact that manufacturers are not consistent with sizing ...

 

With the Scott the L worked for me. On the Giant the M is perfect.

 

 

Certainly thee most expensive mistake when you get this wrong !!

[Jewbacca]

Says the guy who can buy a medium in anything and ride it off the floor without hassle....or walk into any store and find the shoe you like best in your size? I so envy you.

You know how much it sucks walking into a store and always asking “whats the biggest size you have?” Rather than just shopping for what looks the best.

The struggle is real if you are sized on the fringes. The numbers become critical lol. And then you are on record here saying things like xl/xxl bikes look like they are designed by toddlers and sortof resemble farm gates haha.

 

Ps: this is exactly how i knew we could build my 203cm cousin that XL dartmoor primal instead of him being flogged a XXL trek Marlin. And it ended up being perfect for him.

hahaha Yet I still got made fun of for being short by tall okes my whole life!!

 

I do take for granted that I am an easy fit. 44/45 shoe, Medium clothes and most bikes, no knee issues.... I will tell you a secret though... BIG Spez bikes look the best. They aren't just big versions of a bike, they are each designed from the ground up NOT to resemble a barn door or toddler drawing.

 

Everyone should just buy an Evo and be done with it..... 

[TCTG]

 

 

There's a lot of subtle things that makes bikes which look similar on paper feel different when you're on them.

Fork rake in size small road bikes is usually around 50mm and 43 to 45mm for medium and bigger. Often the small will have a slightly longer wheelbase as a result of the extra rake and slcker head tube.

Handling will also be slightly slower.

 

the seat post set back plays a big role to. It's not reflected in the ETT or reach measurements but the set back can be anywhere from 0mm to 40mm depending on the post specced on the bike. This influences the layback measurement and hence ETT.

 

BB drop affects the stack measurement so can't rely solely on headtube length.

 

try the https://www.velogicfit.com/frame-comparison tool

I also use my own spreadsheet that accounts for saddle seatback and stem rise.

So whats the best way forward to determine proper sizing for a specific make/model of bike? There is no way a bike shop will let you ride try out their bikes on a trail for good feel. I struggle with this because bike manufacturers standards are all different.