Suntour sp12-Ncx question for anyone with a Carrera Croasfire e...

MiffyWiffy

Finding my (electric) wheels
Aug 6, 2017
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12
36
uk
I'm looking to buy this for the bike, I'm guessing I need a 31.6 diameter post... but do I go for 350 or 400mm in length? Is there any downsides to just going for the longer one? I figure it'll just go all the way down if need be in the frame right?

Thanx.
 
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egroover

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Aug 12, 2016
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depends on how tall you are and how much is left in the seat tube when extended to the right height. Why not measure the existing one, see how much minimum is required and decide then
 
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MiffyWiffy

Finding my (electric) wheels
Aug 6, 2017
16
12
36
uk
Why wouldn't you just go for the 400mm as they're the same price? Isn't that just a longer post? Surely that just means it can extend further but go as small?

Maybe I'm missing something but the current post is 400mm... I was just worried about the suspension adding extra height? Or is it measured as an overall thing?
 

egroover

Esteemed Pedelecer
Aug 12, 2016
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If the current one is 400 and if you need it that big to allow the minimum amount left in the seta tube then get the 400. If you do not have the post that high and there is, say 150 mm left in the seat tube, then go for the 350mm one. That way you will save weight
If you're not sure and arn't bothered about weight saving, just go for the 400mm, you'll know it will be fine that way
 
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Deleted member 4366

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You're correct. the longer, the better. the only exception is when you don't have a seat tube that is long enough to accommodate the 400mm. modern trends are to have a bent seat tube. I guess I'm red blooded and old-fashioned because I prefer straight.
 
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egroover

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Aug 12, 2016
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Yep. I don't get why so many ebikes are fitted with suspension seatposts or why some owners feel they need them (on an ebike) If you didn't need/want one on a regular bike, I don't see how ebikes are any different. Why do they fit them to so many ebikes, is it because they think ebike riders are older and need the extra comfort ?
 

Tugwell Gibson

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Dec 30, 2016
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Yep. I don't get why so many ebikes are fitted with suspension seatposts or why some owners feel they need them (on an ebike) If you didn't need/want one on a regular bike, I don't see how ebikes are any different. Why do they fit them to so many ebikes, is it because they think ebike riders are older and need the extra comfort ?
Well speaking for myself. I ride my ebike a lot.more than u ever did my old bike. Also a lot further and faster. It was also a lot more expensive.so 70 quid on a suntour seatpost seemed a great idea. But I wasn't going to bother on a bike that did 10 miles a year and had resale of 50 quid.
 

LeighPing

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Mar 27, 2016
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Yep. I don't get why so many ebikes are fitted with suspension seatposts or why some owners feel they need them (on an ebike) If you didn't need/want one on a regular bike, I don't see how ebikes are any different. Why do they fit them to so many ebikes, is it because they think ebike riders are older and need the extra comfort ?
The way I see it is that, with an e-MTB especially, you get to go cross country, which as we all know is a bumpy ride. You have power assistance whilst pedaling. Which means you can comparatively spend more time sitting down than standing up, even whilst going uphill.

@MiffyWiffy - Personally, I prefer the Bikehut, basic suspension seatpost over the suntour SP12 NCX. Why? Because it's equally as comfortable, lighter, and comes with 3 springs for differing rider weights. All for the much cheaper price of around £12. Compared to around £55 for the suntour, provided that you get the right spring when you buy one. Additional springs are around £15.

Both springs, as you can see in the video, do make a big contribution to spinal comfort.. at any age. :p

Cross country riding, demonstrating both springs starts at 01:15

 

MiffyWiffy

Finding my (electric) wheels
Aug 6, 2017
16
12
36
uk
I go over a few miles of fields and it's horrible, so I wanted a bit more comfort.

I went with 350 as my current one is 350... Halfords lied to me and said 400. I have plenty left because my Seat is quite large, no idea why they ship them with the tiny nasty seats. I coulda gone 400 but they are sold out eveywhere...
 
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philliptjohnson

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Jun 12, 2017
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Speaking for myself I got an ebike because I had really bad back problems so it made sense for me to get a sprung seat for the first time when I got an ebike because it's easier on my back. I would imagine the thoughts could be similar for a suspension seat post.
 
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