Before and after 19.5" vs 21" chain stay

[Andrew Wilson]

Just installed a 21" Med chain stay, Only a short ride but I really like the difference .
Here are before and after in case anyone is considering the same.
Per Robert's recommendation I went with the Med instead of the Large and I'm glad I did.

 

[LarryOz]

Looks great Andrew - and glad you like it. Little things like this add up to a better riding experience. You just have to spend the time figuring out what works best for you. Smart looking setup!

 

[super slim]

Just installed a 21" Med chain stay, Only a short ride but I really like the difference .
Here are before and after in case anyone is considering the same.
Per Robert's recommendation I went with the Med instead of the Large and I'm glad I did.
View attachment 8753 View attachment 8754

What is the new height of the BB above the lowest seat position with and without a seat cushion!

On my Silvio 28 (v3.0) with a 100mm chainstay extension, I am happiest with the BB being 160 mm (6.3") above to seat lowest position (no cushion), and 130mm (5.1") with cushion!

What height difference are others happiest with?

 

[Andrew Wilson]

What is the new height of the BB above the lowest seat position with and without a seat cushion!

On my Silvio 28 (v3.0) with a 100mm chainstay extension, I am happiest with the BB being 160 mm (6.3") above to seat lowest position (no cushion), and 130mm (5.1") with cushion!

What height difference are others happiest with?

With the original 19.5" chain stay it was 5" from C/L of BB to about 1/2 way into the cushion( I estimated the cushion's compression under weight this way)
With the 21" chain stay it's now 7.25" measured the same way.

 

[velocio]

With the original 19.5" chain stay it was 5" from C/L of BB to about 1/2 way into the cushion( I estimated the cushion's compression under weight this way) With the 21" chain stay it's now 7.25" measured the same way.

Does anyone know what the 19.5" and 21" measurements refer to? Is it the distance from center of BB shell to center of dropout? BTW, that same measurement on my S40 is about 7".

I don't see different length chainstays, or any chainstays, listed for sale on the Cruzbike website. Are they also available for the S40? I'm untall (5'6.75") and an unfortunate aspect of the Cruzbike design is that as the chainstay is rotated into position for a shorter rider the BB also gets higher. I dislike the high BB for the distance to the ground (it's pretty close to waist height), but more importantly for the bend it imposes at the hips. I'm more "bent over" on the S40 than on my racey DF, though the S40 has everything rotated by 90 degrees or so. I'm taller than 50% of the adult population of the U.S., but probably well below the average height of a Cruzbike rider (judging from photos of forum members). In my more perfect world the S40 would be offered in more than one one-size-fits-average-or-bigger-males size or the S40 would have a a seat angle of 30 degrees and a seat pad or seat incline adjustment to get to 40 degrees, if the rider wanted. I'm considering getting the extra thick Ventisit pad to move myself forward in the seat, rotating the chainstay downward. A little anyway.

All that said, I'm still in lust with my S40!

-Jack K.

 

[Andrew Wilson]

Does anyone know what the 19.5" and 21" measurements refer to? Is it the distance from center of BB shell to center of dropout? BTW, that same measurement on my S40 is about 7".

I don't see different length chainstays, or any chainstays, listed for sale on the Cruzbike website.

-Jack K.

They are measured C/l of dropout to C/l of BB.
Send them an email at
support@cruzbike.com
They dont put everything on their website but have about any part you would need.

 

[Seth Cooper]

With the original 19.5" chain stay it was 5" from C/L of BB to about 1/2 way into the cushion( I estimated the cushion's compression under weight this way)
With the 21" chain stay it's now 7.25" measured the same way.

The link below is to a post with a pic of my bike when I switched to the 23", with a pic of the 19.5" for contrast 3 posts up. With my body, my 23" stay setup is BB to seat of 7.5", about the same as yours. It is definitely twitchier than the 19.5" but I got used to it eventually, and it is faster for sure.

https://forum.cruzbike.com/threads/newbie-with-build-questions.12161/#post-147154

 

[Andrew Wilson]

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Looks great Andrew - and glad you like it. Little things like this add up to a better riding experience. You just have to spend the time figuring out what works best for you. Smart looking setup!

Thanks, Only have ridden a couple of short rides but I really like it.

 

[Winded Lowrider]

I might be able to guess, but why do you like it and why did you make the change?

 

[Andrew Wilson]

I might be able to guess, but why do you like it and why did you make the change?

A couple of reasons, I wanted to drop my bars a bit without going to the curved slider. I didn’t want to go with the large chainstay and didn’t know that they made 3 sizes. The 21” chainstay was the perfect comprise.

 

[Winded Lowrider]

Does the higher BB change the handling? I like mine lower for hill climbing..as the BB gets above the seat, issues start to surface when climbing. Higher BB is certainly more aero.

 

[Andrew Wilson]

Not any real hills here to climb so I can’t comment on that. I didn’t notice any difference in handling at all but was told that I would notice the difference if I went with the longest chain stay. That’s another reason that I went with the med.

 

[Mathew Fy]

Higher BB is certainly more aero.

That's not always correct. Shorter riders will probably be less aerodynamic with the longer chain stays.

"Probably the most important lesson we learned was that Maria needs to stick with the standard chainstay size. Not only did the data show that using the large chainstay cost her Watts, but the camera angles were very useful in showing how the longer chainstay put her knees into the clean airstream above her shoulders, more than a lower chainstay put her heels into the clean airstream below the seat."

https://cruzbike.com/blogs/blog/cruzbike-at-the-a2-wind-tunnel

 

[ChaleJake]

That's not always correct. Shorter riders will probably be less aerodynamic with the longer chain stays.

"Probably the most important lesson we learned was that Maria needs to stick with the standard chainstay size. Not only did the data show that using the large chainstay cost her Watts, but the camera angles were very useful in showing how the longer chainstay put her knees into the clean airstream above her shoulders, more than a lower chainstay put her heels into the clean airstream below the seat."

https://cruzbike.com/blogs/blog/cruzbike-at-the-a2-wind-tunnel

What size (19 or 21, other) is a standard chainstay? I am close to the same height as Maria. Thanks

 

[Andrew Wilson]

19 is the standard as far as I know

 

[Ken Rudd]

Are there objective standards for choosing different lengths? For example, certain inseam should equate to certain chainstay length, or is it more subjective, for example comfort and riding style?

 

[Andrew Wilson]

That I dont know.... I'm sure a lot is personal preference.

 

[TalleyHo]

I'm finding this thread to be most interesting because I've been grappling with the same issue because I intend, once the new V20s to come out, to get a frame kit and transfer the bullhorn and bar-end shift set up on the S2.0 (see avatar) that has been my pride and joy for 6 years now. I'm so excited!!! The avatar here shows that bike with a 150mm cc extender, long since replaced, with a 100 mm cc ext. And that newer arrangement is perfect and I want to replicate it with the V. I suspect I may also replicate the seat angle to about 30 degrees as that angle for me is the sweet spot between balance and aero but we'll, I may love the speed and stay stock with seat which then might persuade me to consider drop bars.

So here's my question; can I assume that the cc length for my S2.0 which is 21 inches, also, at 21 inches, yield the same ergonomic arrangement with the V that I want to match. That measurement is wheel axle to crank axle, oc? I also want to know, does CB provide the buyer with the cc desired or do you need to order that extra if you need a med or long size?

BTW, the reason I intend to strip the S2.0 0f it's fabulous components is because I discovered a distinct wheel misalignment of about 1 1/2 degrees in the vertical axis and I don't trust the bike anymore. I suspect the issue has been there all along and was in denial of looking close; no wonder, perhaps, it was such a beast to tame. Anyway, I've been longing for a longer legged machine and I welcome to extra speed. So the S is now relegated to indoor trainer and functional sculpture; life is good.

I should also mention that I've just relocated to Greensboro NC where there's a strong bike community and year round cycling. The V I expect will be well exposed here and hopefully a boost to both recumbency, in general, and CB. Also, has anyone else felt with misaligned wheels in the vertical?

 

[Andrew Wilson]

Welcome to North Carolina.
I would advise that you email your questions directly to Cruzbike. Robert is very responsive and has helped me a lot.

 

[paco1961]

I'm finding this thread to be most interesting because I've been grappling with the same issue because I intend, once the new V20s to come out, to get a frame kit and transfer the bullhorn and bar-end shift set up on the S2.0 (see avatar) that has been my pride and joy for 6 years now. I'm so excited!!! The avatar here shows that bike with a 150mm cc extender, long since replaced, with a 100 mm cc ext. And that newer arrangement is perfect and I want to replicate it with the V. I suspect I may also replicate the seat angle to about 30 degrees as that angle for me is the sweet spot between balance and aero but we'll, I may love the speed and stay stock with seat which then might persuade me to consider drop bars.

So here's my question; can I assume that the cc length for my S2.0 which is 21 inches, also, at 21 inches, yield the same ergonomic arrangement with the V that I want to match. That measurement is wheel axle to crank axle, oc? I also want to know, does CB provide the buyer with the cc desired or do you need to order that extra if you need a med or long size?

BTW, the reason I intend to strip the S2.0 0f it's fabulous components is because I discovered a distinct wheel misalignment of about 1 1/2 degrees in the vertical axis and I don't trust the bike anymore. I suspect the issue has been there all along and was in denial of looking close; no wonder, perhaps, it was such a beast to tame. Anyway, I've been longing for a longer legged machine and I welcome to extra speed. So the S is now relegated to indoor trainer and functional sculpture; life is good.

I should also mention that I've just relocated to Greensboro NC where there's a strong bike community and year round cycling. The V I expect will be well exposed here and hopefully a boost to both recumbency, in general, and CB. Also, has anyone else felt with misaligned wheels in the vertical?

View attachment 8765
View attachment 8765

Exactly what do you mean by vertical misalignment? Not parallel to the plane of the frame?