Chinertown

Chinese Carbon MTB => 29+ & 27+ => Topic started by: ChrisCarbon on November 01, 2017, 06:36:30 PM

Title: CS-FS27 vs CS-FS29, same geometry?
Post by: ChrisCarbon on November 01, 2017, 06:36:30 PM
I am looking at these two frames at Xmcarbonspeed, and it seems to me like they have the same geometry.

Are these two frames the same really? Only thing that separates them is boost vs non-boost?

http://www.xmcarbonspeed.com/Productinfo.asp?f=1527

http://www.xmcarbonspeed.com/Productinfo.asp?f=1485

Title: Re: CS-FS27 vs CS-FS29, same geometry?
Post by: Bigboyblue64 on November 02, 2017, 09:19:49 AM
I really do prefer the Ican P8 frame to these CS frames. Has a pivot bearing at the dropout and BSA type bottom bracket. Really don't like press fit BBs. Carbon Dpeed seem a bit prehistoric to me!!
Title: Re: CS-FS27 vs CS-FS29, same geometry?
Post by: GuitsBoy on November 09, 2017, 12:51:10 PM
Just to give you the flip side of  the coin, doing away with the rear axle pivot both reduces weight and increases lateral stiffness of the rear triangle.   IMO this is more progressive than prehistoric.   Flexing seat stays are fine for lower travel, but certainly not ideal for longer travel, at least not without an obscenely high leverage ratio.  As for the bottom bracket, yeah, PF can be prone to creaking, however I've found relief with the wheels manufacturing threaded pressfit BB.  The mid tube is threaded, and forms a single solid BB tube, and has eliminated every hint of a creak from my cranks. Best 55 bucks Ive spent in a long time. 

Another issue with the FS27 and FS29 is that youre effectively limited to 100mm rear travel.  At least until someone finds a trunnion shock that will actually fit these bikes.

Anyway, after putting four or five hundred miles on my CS-FS27, you'd have a hard time convincing me to go in a different direction. 
Title: Re: CS-FS27 vs CS-FS29, same geometry?
Post by: ChrisCarbon on November 10, 2017, 02:09:30 PM
Anyone knows if I can fit a 130mm fork on the FS29 without any issuses..?
Title: Re: CS-FS27 vs CS-FS29, same geometry?
Post by: GuitsBoy on November 10, 2017, 02:13:02 PM
Cant say for 100% certain, but I have a 140mm fork on the FS27 and love it.  Might even try 150 one day.  The 140mm 27.5 fork with plus tires probably gives similar height as the 130 29" fork.
Title: Re: CS-FS27 vs CS-FS29, same geometry?
Post by: ChrisCarbon on November 10, 2017, 04:47:42 PM
I dont know so much about geometry etc, but if the frames have the exact same geometry, it should be possible to put the same travel forks on both frames?

Or am I missing something?
Title: Re: CS-FS27 vs CS-FS29, same geometry?
Post by: rideczech on November 11, 2017, 06:17:20 AM
Cant say for 100% certain, but I have a 140mm fork on the FS27 and love it.  Might even try 150 one day.  The 140mm 27.5 fork with plus tires probably gives similar height as the 130 29" fork.

You got some pictures of your build somewhere, or could you post some here? Cheers
Title: Re: CS-FS27 vs CS-FS29, same geometry?
Post by: GuitsBoy on November 11, 2017, 06:46:25 AM
Cant say for 100% certain, but I have a 140mm fork on the FS27 and love it.  Might even try 150 one day.  The 140mm 27.5 fork with plus tires probably gives similar height as the 130 29" fork.

You got some pictures of your build somewhere, or could you post some here? Cheers
I've been meaning to take some more recent pics, but here's an early one before I swapped out shocks, and moved to an eagle drivetrain.

(http://guitsboy.ihearyou.com/bikes/plus.jpg)

EDIT:

I have attached a pic of how the bike sits now.  Sorry about the lame backdrop, seems every other photo op from this weekend was ruined by photobombers.
Title: Re: CS-FS27 vs CS-FS29, same geometry?
Post by: Le Duke on November 15, 2017, 12:48:11 PM
I really do prefer the Ican P8 frame to these CS frames. Has a pivot bearing at the dropout and BSA type bottom bracket. Really don't like press fit BBs. Carbon Dpeed seem a bit prehistoric to me!!

Huh?

Cannondale, Orbea, Scott, Kona, Yeti and Specialized and half a dozen other manufacturers use this design for their low (100-120) travel bikes.