# CAAD9 vs Synapse Geometry - I don't get it?



## RJP Diver (Jul 2, 2010)

Ok - coming back to riding after a long time. Never really had a good handle on implication of different frame geometry at the time, and have forgotten what little I did know! 

Looking for a new road bike for 25-50mi rides a few times a week. Not worried about all-out speed, racing etc. Just some performance/fitness riding. So I'm looking at the CAAD9 and the Synapse at a shop today and the LBS guy tells me that the geometry of the Synapse is "more relaxed" than the CAAD and might be better suited to the type of riding I'll be doing. Was stopping in briefly on way back to office at lunch, so didn't have time to get into why's and wherefore's.

So I come home and look at the website and am now even more confused, as there are only a few measures that differ between the two, and even most of those differences don't look like much. So can someone please point to the measures that are the ones that are different enough to warrant one frame being cited as providing "A more upright riding position giving riders comfortable, predictable handling."

CAAD9 / SYNAPSE (58cm size for both)
Horizontal Top Tube Length: 57.5 / 58
Measured Size: 56 / 55
Seat Tube Angle: 73 / 73
Head Tube Angle: 73.5 / 73.0
Chainstay Length: 40.5 / 41.5
Fork Rake: * / 5
Bottom Bracket Height: 27 / 27
Wheelbase: 99.6 / 102.0
Trail: 5.3 / 5.1
Standover: 82.2 / 82.2
Bottom Bracket Drop: 6.7 / 6.7
Front Center Distance: 60.1 / 61.5
Head Tube Length: 17.5 / 20.0
Stack: 57.9 / 59.9
Reach: 39.9 / 39.7

Note that components, stem, bars, seatpost, etc are all the same between the two bikes as well.

From a physics standpoint, I can see how the longer wheelbase will provide more comfort/forgiveness on transmitting the road to my body, and that it will be a bit more stable from a handling standpoint. 

I guess I'm struggling with the "more upright, less stretched out in the cockpit" idea on the Synapse. Now I'd think that with the same top-tube length/reach/stem measurements that how far I'm stretched out will be the same between the two. Or am I missing something? Beyond that, will a 2cm difference in stack height provide a noticeably "more upright ride?"

Appreciate any help/insights. Remember, I'm a newbi... so please explain in "duckies and horsies" to the extent possible.

Ray


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## ph0enix (Aug 12, 2009)

Just ride both bikes and you'll know for sure. I don't see how understanding the difference in the tube lengths and the angles is going to give you an idea what it's like to ride the bikes. The CAAD is aggressive and the Synapse is super comfortable. Aside from the different geometries, the Synapse uses S.A.V.E. stays which dampen the road quite nicely.


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## RJP Diver (Jul 2, 2010)

ph0enix said:


> I don't see how understanding the difference in the tube lengths and the angles is going to give you an idea what it's like to ride the bikes.


So, are you saying "_I don't see how..._" in the sense that you don't KNOW the answer to my question. Or is it that you DO KNOW the answer to my question, but are declining to actually answer it, in favor of telling me "just ride them both"?

 

Of course, ultimately I will ride a bunch of bikes before making a purchase. However I'm certain that - if you do know the answer to my question - you might understand the fact that I'd like to get my arms around the relationship between frame geometry and ride characteristics.

:thumbsup: 

Ray


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## hontors (Oct 4, 2009)

Check out the Specialized Sectuer series.


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## jlyle (Jul 20, 2007)

Head Tube Angle: 73.5 / 73.0
Chainstay Length: 40.5 / 41.5
Wheelbase: 99.6 / 102.0
Head Tube Length: 17.5 / 20.0

The above are the important differences in the specs. The Synapse's longer chainstay length and wheelbase give a "softer ride." [A shorter wheelbase is quicker and more suited for crits than long rides.] The head tube angle and longer head tube length give you a more upright position on the bike - less tiring on longer rides. For your stated use, I would highly recommend the Synapse over the CAAD.


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## CdaleNut (Aug 2, 2009)

ph0enix said:


> Aside from the different geometries, the Synapse uses S.A.V.E. stays which dampen the road quite nicely.



or just wait and get the CAAD 10 which has the S.A.V.E. stays as well


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## ph0enix (Aug 12, 2009)

RJP Diver said:


> So, are you saying "_I don't see how..._" in the sense that you don't KNOW the answer to my question. Or is it that you DO KNOW the answer to my question, but are declining to actually answer it, in favor of telling me "just ride them both"?
> 
> 
> 
> ...


I meant that I don't care to know what the significance of each number is. If the bike doesn't feel right under your a^%, it simply won't matter.


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## Bob Ross (Apr 18, 2006)

jlyle said:


> Head Tube Angle: 73.5 / 73.0
> Chainstay Length: 40.5 / 41.5
> Wheelbase: 99.6 / 102.0
> Head Tube Length: 17.5 / 20.0
> ...



While I would agree that those are the most critical dimensional differences in comparing those two frames, I'm with the OP: I 'm surprised (or skeptical) that a 1cm difference in chainstay length, or a 2.4cm difference in wheelbase, can have _that_ dramatic a difference in handling or comfort in a ~58cm frame.


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## dougmint (Mar 18, 2007)

jlyle said:


> Head Tube Angle: 73.5 / 73.0
> Chainstay Length: 40.5 / 41.5
> Wheelbase: 99.6 / 102.0
> Head Tube Length: 17.5 / 20.0
> ...


I own a Synapse and am picking up my CAAD9 4 next week. I wondered the same thing. I will post in a couple weeks, and let you know if the rides are significantly different.


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## dcl10 (Jul 2, 2010)

I have a CAAD9, and a Felt Z, which is a little more aggressive than a synapse, but same basic idea. In any case they are different in terms of handling characteristics, but not different enough that you would notice a huge difference. You really have to push it in the corners to be able to tell. For crit racing every little bit helps, so that's why I use a CAAD9 since it has a shorter wheelbase. For road/stage races a slightly longer wheelbase is more efficient, especially in climbs where shorter bikes can tend to bob and weave. That is also why TT bikes are built with lots of trail, to stabilize the bike and prevent any unnecessary side to side movement. Also keep in mind that what one manufacturer calls "relaxed" is anothers standard geometry. The Madone for instance, which is more or less a purpose built stage racing bike, is closer to a relaxed geometry frame than to a CAAD9. Ridley, BMC and others have standard headtube lengths that are 20-40mm taller than what you would find on most Italian and American brands. The same goes with HT angle, ST angle, Chainstay length, wheelbase, etc. There is a huge degree of variation in geometries depending on the manufacturer. In terms of position, both my bikes are set up with the exact same measurements, which are quite aggressive, the CAAD has a -6 stem, the Z has a -17 stem to make up the 20mm difference in headtube length, so it's not like its hard to get an aggressive position, just a matter of some minor upgrades.


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## neilcrumpton (Aug 5, 2010)

dougmint said:


> I own a Synapse and am picking up my CAAD9 4 next week. I wondered the same thing. I will post in a couple weeks, and let you know if the rides are significantly different.


dougmint - had a look around but didn't see a follow-up posting. I'm keen to hear you thoughts on the differences between the Caad and Synpase now that you've had the Caad for a few months!


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## ph0enix (Aug 12, 2009)

neilcrumpton said:


> dougmint - had a look around but didn't see a follow-up posting. I'm keen to hear you thoughts on the differences between the Caad and Synpase now that you've had the Caad for a few months!


dougmint must really love the CAAD9. I bet he's busy riding and doesn't have any time to post


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## DCD 2005 (Apr 4, 2010)

I just bought a CAAD9 after looking at a Synapse. IMO It's the head tube length that stands out. CAAD9 stack is lower and very noticable.


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