Sit bone spacing

steve_sordy

Wedding Crasher
Nov 5, 2018
8,993
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Lincolnshire, UK
I have never paid attention to sit bone size before, but I can no longer get the saddle that has been my favourite, the WTB Rocket V. I chanced upon it by accident when it came on a new bike, years ago now. The saddle that came with my current bike is one of Focus's own and using that one gave me a saddle sore. :eek:

I measured my sit bone spacing last night, first time for it. I sat on a piece of corrugated cardboard, drew a circle around the depressions, and then measured between them. I got 130mm. So what size of saddle do I need? The first saddle I looked at just said 140 mm wide, no mention of sit bones.

So I Googled "sit bone width to saddle width" and got this:


It suggests that you add 20mm to your sit bone width. But it looks like a roadie website to me, is it the same for mtb?
 

NULevo

Well-known member
Nov 7, 2019
539
341
Nottingham
Plus 1 for SQlab, spent ages trying to find a saddle to replace the Spesh one that came with the bike- pain after 20 mins. Spent ages researching and got an Ergon ebike saddle, only slightly better - pain after a hour or so and ended up sending it back.

Saw SQlab in MBUK as a 'most wanted' saddle and started to investigate. So many saddles and so much science!

Definitely worth a look, stuff like this:



The 610, 611 and 60x looked good for my needs and I ended up with 610 as it has more 'comfort' padding.

It says it can take a few rides to get used to their saddles and that is the case, I'm getting used to it after 4 rides so far. I found Amazon to be a good place to look if you need one quickly.
 

Gary

Old Tartan Bollocks
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Mar 29, 2018
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looks like a roadie website to me, is it the same for mtb?
Thing is. a proper roadie doesn't actually sit on their sit bones. in order to ride in an efficient fast (aero) position they need to be leant forwards and rotated on their pelvis so the sit bones are not actually taking their upper body weight. It helps sell expensive saddles to plenty naive road riders though.
a competitive mtb rider also rarely weights their sitbones
heavy/old/lazy Emtb riders probably do tho.
 
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Jackware

Fat-tyred Freakazoid
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Oct 30, 2018
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What saddle do you recommend for a non competitive, not overweight young motivated Emtbers? :unsure: :LOL:
 

Gary

Old Tartan Bollocks
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depends what in particular they dislike about the (probably) perfectly good saddle they're currently using ;)
 

Jackware

Fat-tyred Freakazoid
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That reasoning probably is what keeps bike shops and the online retailers in business though and forum owners ;)
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,993
9,395
Lincolnshire, UK
depends what in particular they dislike about the (probably) perfectly good saddle they're currently using ;)
The perfectly good saddle that I'm currently using is the same exact type I have been using for more than ten years, the WTB Rocket V Race. Problem is that they get damaged. The first three received damage to the wings in involuntary dismounts and the skin started to peel off. The fourth one was bought from Hong Kong after WTB stopped making them and before I needed one. I kept it in reserve for a couple of years and used the saddle that came with the Whyte (must find out which one that was) and then the Focus until I got a saddle sore for the first time. Despite it looking perfectly genuine, complete with pukka looking packaging, the Hong Kong saddle was probably a copy because after only five months, the top surface has started to crease quite badly in several places and it doesn't look as though it will be long before it will tear. I know I was lucky to chance upon the Rocket V so I thought I'd try the science this time. Hence the query about sit bone width.

Apart from my belief that the shoulders of the wings should be tougher, there was nothing I didn't like about the WTB Rocket V Race. Incidentally, the very first Rocket V I had was the top of the range SLT, with titanium rails. When it came to replace it, I found that the Race version was £60 cheaper and only 60 gm heavier! £1/gm seemed an outrageous price to pay, so I didn't. Been happy ever since.
 

Albez

Well-known member
Sep 14, 2018
214
129
United Kingdom
My sit bone is 120mm and just purchased an Ergon saddle in size m/l.. will probs take a few rides to adjust but its gotta be better than the stock focus one that came with the bike. If you're sit bone is 130mm I would go for the larger saddle
 

urastus

⚡The Whippet⚡
May 4, 2020
1,548
995
Tasmania
I've found that 140 or 145 works for me - so I'm guessing I could be the same size? You're right though re styles. I have a rocket on one of my bikes and I really like the kick up at the rear of it. Just eyeballed what I currently have: merida comp cc (came on my ebike) - that's actually the only current one. I knew it would work when I saw it. My other saddles are all old models - some of the names are now the same, but the saddles aren't :rolleyes:. One of the oldies I've always like, it's the firmest too, is on my 2012 trek fuel ex 8. I'm guessing I have the large which is 148mm wide.
 
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steve_sordy

Wedding Crasher
Nov 5, 2018
8,993
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Lincolnshire, UK
I measured my sit bones yesterday at 130 mm. I checked again, but leaning forward to see if it made a difference (been watching videos). It didn't, I still got 130 mm. Just been out to the garage to measure my saddle. The much loved WTB Rocket V Race that I got from Hong Kong a few years ago that I have been using for the last few months measures 130 mm wide!!!! Then I discovered that the saddle comes in different widths, never thought to ask before because I never knew. The previous ones I had must have all been the 145 mm version. I then measured the Focus saddle that had been giving me problem and that was 135 mm. So, less likely to give me problems but still too narrow.

The advice on "sit bone width to saddle width" is to add 20-30 mm to your sit bone width. For me that means a saddle of at least 150 mm. That sounds wide, but it's only 10 mm per side and I'm sure I can deal with that whipping back and forth between my legs!

Just got to buy one now. :)
 

speedkills

Member
May 17, 2020
230
221
Boulder, CO
I don't recall my sit bone width, but I will say after buying my ergon saddle and not getting along with it I decided to just bite the bullet and spend the big bucks for a bi-saddle and then tweak it as needed instead of trying to find the perfect saddle. It's adjustable for front and rear width, plus angle/roundedness. It's a little funny looking but I've never been so happy with a seat. An added bonus I found was that I actually found a couple of different setups with it I really like so if I do get sore if I do more riding than usual I can just take an allen wrench out, move the seat a bit and put the pressure in different areas. I wouldn't advocate it for most as it's like $300 USD, but if you really struggle to find the right seat, or actually like different seats for different ride lengths/styles then it might be worth checking out. Worst case they do have a 30 day return policy. A small bonus is that if you tear it up, you don't need to replace the whole seat, you can replace say just the left padded portion.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,993
9,395
Lincolnshire, UK
I don't recall my sit bone width, but I will say after buying my ergon saddle and not getting along with it I decided to just bite the bullet and spend the big bucks for a bi-saddle and then tweak it as needed instead of trying to find the perfect saddle. It's adjustable for front and rear width, plus angle/roundedness. It's a little funny looking but I've never been so happy with a seat. An added bonus I found was that I actually found a couple of different setups with it I really like so if I do get sore if I do more riding than usual I can just take an allen wrench out, move the seat a bit and put the pressure in different areas. I wouldn't advocate it for most as it's like $300 USD, but if you really struggle to find the right seat, or actually like different seats for different ride lengths/styles then it might be worth checking out. Worst case they do have a 30 day return policy. A small bonus is that if you tear it up, you don't need to replace the whole seat, you can replace say just the left padded portion.
When I read that, I found myself wondering what the date was. Nope its not April 1st!
I believe you though. :)
Its just not something that I ever thought would be a thing. How does anyone make money out it? Even at US$300 a pop!
 

speedkills

Member
May 17, 2020
230
221
Boulder, CO
I don't blame you for thinking that, but yeah, it's totally a real thing.
A7B44E11-F128-4DEB-BC36-8DA36388C5EC.png
 

CavMan

Member
Jun 9, 2020
37
38
Australia
I rode roadies too and spent lots of money on saddles that didn't fit. Eventually got an infinity saddle. Took 3 rides to adapt, never looked back. Ordered one for my new emtb as well. You don't sit as much on an embt, but stock saddles don't suit me.
I prefer the E2, but the E1X is designed for mtb.
Screenshot_20200705-090136_Firefox.jpg
Screenshot_20200705-090221_Firefox.jpg
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,993
9,395
Lincolnshire, UK
WOW! I'd be concerned about trapping something in there.
The thought of bounding down a rocky descent whilst attached to but not actually riding the bike gives me the shivers!
 

Jamze

Well-known member
Jun 30, 2020
391
720
Oxfordshire
kept it in reserve for a couple of years and used the saddle that came with the Whyte (must find out which one that was)

Whyte do sell their saddles separately. I have one sat in my workshop, but it'll be going back on the T-130 when I sell it, sorry! Similar shape to a Charge Spoon IMO. Have you tried one of those?

 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,993
9,395
Lincolnshire, UK
@Jamze I almost bought one of those. I was waiting for the eBay seller to reply with the width when I came across the WTB Rocket. It is not exactly the same as the WTB Rocket V that I had earlier but it looks very similar and I could get it in 150 mm width. Maybe I am assuming too much that because the name "Rocket" is the same, it's an updated version of the old Rocket V. Hope so!


I bought it with the help of £50 CRC voucher I still have another £40 to spend. That £90 had been slowly building up from birthday, Xmas, Father's Day etc It's like free money! :)
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,993
9,395
Lincolnshire, UK
Yesterday's ride was a bit odd. By now I knew that my 130 mm spaced sit bones were perched right on the edges of my 130 mm wide saddle. I think I could feel them, but maybe it was just psychological. I was also trying to imagine a saddle that was 20 mm wider whipping back and forth between my legs. Nope, couldn't imagine it!
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,993
9,395
Lincolnshire, UK
My new saddle came today. I bought a WTB Rocket 150mm wide. I'll fit it tomorrow.

The packaging was interesting. If I had seen it before I would have ordered the Volt Wide. On the web page I saw when ordering the Rocket I didn't notice it had thick padding. Let's see how I get on with it. It might be wonderful! :)

WTB Saddles Fit Right.jpg


Top left, I noticed the WTB Fit Right System. Also interesting, see here.
 

Gary

Old Tartan Bollocks
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it's certainly interesting paying a multiple world champion of a cycling discipline where sitting down yeilds a massive loss of performance to market the performance of your "new" saddle fit system.
;)
 

urastus

⚡The Whippet⚡
May 4, 2020
1,548
995
Tasmania
Good luck steve. I'm guessing the width will be good. I also found my partner's saddle which I really like and it's cheap. She is tiny (4'11") so probably close to our size. They vary in price but from ebay or aliexpress around $30 - otherwise up to $80 or $90. They are padded but really firm - it feels good; quite thick padding but firm. Also not too long - more of an mtb saddle. They also have a crazy light CF model with two different sizes. The one in the first link is the one I'm familiar with.
 

urastus

⚡The Whippet⚡
May 4, 2020
1,548
995
Tasmania
:ROFLMAO: This video just came out! Emtb specific. I'm guessing it'll just confirm what you've already learned :). Although I disagree with the upswept back theory - he says needed for ebikes because of steeper climbing. I climb steep - it's really a big feature of where I live. I have the seat nearly all the way forward and still perch on the front when it's really steep. Never noticed the lack of upsweep at the back. That's the merida seat that came with the bike.
 
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speedkills

Member
May 17, 2020
230
221
Boulder, CO
I agree completely there, I'm on a Levo with pretty long seat stays and I need to scoot to the front of the seat long before I'm worried about sliding back on the seat. The acceleration isn't quite that good yet.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,993
9,395
Lincolnshire, UK
it's certainly interesting paying a multiple world champion of a cycling discipline where sitting down yeilds a massive loss of performance to market the performance of your "new" saddle fit system.
;)
I didn't know what you were on about until I went back to the link I posted. All hail the fair Rachel!!!
On my screen Rachel's head is cut off by the top part of the screen where you access the Fit Right System. I didn't watch the video until now. Rachel's appearance is the price she has to pay from being sponsored by WTB (I'm assuming she is sponsored by them, I don't know for sure). If she is really not that interested in their saddles for the reason you give, then I'm sure she gets great value from their tyres and all the other products they make (rims grips, TCS products, clothing , accessories, they even sell a dog bowl!) :)
 

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