Hardware For S40 Stock Seat

velocio

Austrian roadside steckerlfisch (fish on a stick)
Hey Cruzfolk,

I have an S40 that I bought "used", which is to say the first owner assembled it and rolled it around a parking lot enough to know it wasn't for him. It was claimed to be a "custom build", which I now realize means the first owner assembled it himself from parts he collected. I recently swapped my original medium chainstay for a short (thanks again Jesse!) and after installing that I'm continuing on to (finally) remedy various bits on the bike that were not assembled to my liking by the first owner. This leads me to a question about the stock installation hardware for the S40's CF seat ...

My S40's CF seat is installed using 4 M5 x 20mm bolts and 4 Nyloc nuts (see attached photo). So, 4 bolts & 4 nuts, that's it. That can't be what Cruzbike intended ... Looking at the S40 assembly manual I can see a small steel washer between the bolt head and the CF seatpan. Better, but then why are the bolts so long? There's about twice as much bolt length as needed to include a 1 mm steel washer. I was looking at Thor's website and their suggested installation makes a lot more sense to me -- again see the attached photo. Is this overkill?

I would have thought that it'd be important to keep metal edges, like the edge of a small steel washer or the un-rounded corners of the frame's mounting "ears"), off the carbon fiber seat-pan. Thor's mounting suggestion also seems to suggest this is something to be avoided. My 20 mm bolts are long enough to include nylon and neoprene/rubber washers in the install.

Thoughts?

-Jack
Raleigh, NC
 

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Here are the instructions to fit the seat on my Silvio. I think it is the same seat.
 

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Bill K

Guru
I never installed the seat screws on my S40. It is the 2017 version which includes velcro between the frame and seat, and the velcro holds the seat just fine.
I just watched the "S40 complete assembly 2019" video on this site, and it looks like they no longer use velcro so things have changed a bit.
Maybe the M5 x 20 bolts are long enough so you can use velcro between the seat and frame.
 

super slim

Zen MBB Master
Hey Cruzfolk,

I have an S40 that I bought "used", which is to say the first owner assembled it and rolled it around a parking lot enough to know it wasn't for him. It was claimed to be a "custom build", which I now realize means the first owner assembled it himself from parts he collected. I recently swapped my original medium chainstay for a short (thanks again Jesse!) and after installing that I'm continuing on to (finally) remedy various bits on the bike that were not assembled to my liking by the first owner. This leads me to a question about the stock installation hardware for the S40's CF seat ...

My S40's CF seat is installed using 4 M5 x 20mm bolts and 4 Nyloc nuts (see attached photo). So, 4 bolts & 4 nuts, that's it. That can't be what Cruzbike intended ... Looking at the S40 assembly manual I can see a small steel washer between the bolt head and the CF seatpan. Better, but then why are the bolts so long? There's about twice as much bolt length as needed to include a 1 mm steel washer. I was looking at Thor's website and their suggested installation makes a lot more sense to me -- again see the attached photo. Is this overkill?

I would have thought that it'd be important to keep metal edges, like the edge of a small steel washer or the un-rounded corners of the frame's mounting "ears"), off the carbon fiber seat-pan. Thor's mounting suggestion also seems to suggest this is something to be avoided. My 20 mm bolts are long enough to include nylon and neoprene/rubber washers in the install.

Thoughts?

-Jack
Raleigh, NC
I added two S/S washers to my preowned S30, with Velcro as the major joining method!
I will add two rubber washers, as the nylon washers I have are too thick!

THANKS for the info!!!!
 
On my S40, the seat is attached with both Velcro and the m5 bolts and nuts. There might be a washer on the seat side, but I don’t recall without looking. The bolts are a bit long.
 

velocio

Austrian roadside steckerlfisch (fish on a stick)
Seems like the only wrong way to attach the seat is the way mine was set up -- using an M5 bolt with a 9mm diameter head in a 6-7mm diameter hole in the CF seatpan and no washer. Since I have the bolt length available I just ordered some stainless washers and some Nylon washers. My S40 is the original model, with Velcro between seat and frame, but I've always been a belt and suspenders kind of guy, so Velcro + bolts it is.

Thanks all!

-Jack
 
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