Spa Wayfarer with 27.5" wheels

[UpWrong]

Has anyone done this? The smaller rim lowers the BB by 19mm which I guess will cause a problem unless you move to short cranks. I have ordered a 47cm frame which is sized for 160mm cranks anyway, so I'd need to go to 140mm cranks I guess. I'm considering this in order to make room for a suspension seat post which needs slightly over 4" of extension. Thoughts?

[531colin]

Here is a 47cm Wayfarer being ridden by one of my test pilots...



She is five feet tall (and no inches).
The bike is designed for small people; adding an enormous seatpost won't make it into a bike designed for people of "average male height".
If you must have a suspension seatpost I think you would be better off starting from a frame which is designed for somebody of your height but with a low top tube ….such as a "mountain" bike which is designed to have a lot of standover clearance....or even a hybrid type bike with a similar frame shape.

[UpWrong]

Hi Colin, I was afraid you would say that. I'm below average height so I might get away with it. We'll see. I spent a long time looking at MTB and hydrid options but couldn't find anything available without a steep seat tube. I might have gone with a small Genesis Longitude frame if I could have found one.

[slowster]

I would not fit 27.5" wheels or 140mm cranks simply to have more seatpost extending above the seat tube. If it was absolutely essential to have that in order to use a suspension seat post, I would probably copy Vantage and saw off the top of the seat tube, and void the warranty:

https://forum.cyclinguk.org/viewtopic.php?t=131583&start=15#p1380339

[iandusud]

Has anyone done this? The smaller rim lowers the BB by 19mm which I guess will cause a problem unless you move to short cranks. I have ordered a 47cm frame which is sized for 160mm cranks anyway, so I'd need to go to 140mm cranks I guess. I'm considering this in order to make room for a suspension seat post which needs slightly over 4" of extension. Thoughts?

You don't say why you want to fit 650B wheels but if it is with a view to using wider tyres then the BB height will not be as much as 19mm. I believe the Wayfarer is speced with 700Cx32 tyres. If you had in mind to fit 650Bx47 for example then the difference in BB height would be only 4mm, which is insignificant on a touring bike.

[Chris Jeggo]

Have you considered a sprung saddle instead of a suspension seat post? I have fitted a Brooks Flyer to my off-road bike, a hard-tail with suspension forks, and am happy with it.

Chris

[UpWrong]

Have you considered a sprung saddle instead of a suspension seat post? I have fitted a Brooks Flyer to my off-road bike, a hard-tail with suspension forks, and am happy with it.

Chris

That's certainly an option. I was extremely impressed with my Suntour NCX Linkage seat post though.

[UpWrong]

I would not fit 27.5" wheels or 140mm cranks simply to have more seatpost extending above the seat tube. If it was absolutely essential to have that in order to use a suspension seat post, I would probably copy Vantage and saw off the top of the seat tube, and void the warranty:

https://forum.cyclinguk.org/viewtopic.php?t=131583&start=15#p1380339

Would never have thought of that but might be worth considering.

[UpWrong]

I expect I'll stick with 700c wheels. I might find I can fit the NCX seatpost anyway with 37mm tyres, or I might be prepared to trim the seat tube. Thanks for the suggestions.

[531colin]

If its not a rude question, why is a suspension seatpost essential?
I have a bad case of the "princess and the pea delusion" which means I am driven to adjust my saddle height when I change between SPD shoes and SPD boots. The adjustment is less than 5mm, but I just have to do it, I can't leave it and be comfortable. I run about 4 bikes at any one time, and saddle height is adjusted to within 3 millimetres; saddle setback, reach to the bars and bar height are OK plus/minus 5mm. (just as well, as stems come in 10mm increments!).
Cleat placement probably varies a couple of millimetres between different shoes.
I think I would prefer to have a puncture every ride to having my saddle move up and down as I ride!
Off road I find I can ride in contact with the saddle but with no real weight on it (and therefore no jarring), my weight is mainly on the pedals....I am pulling back/up on the bars in order to do this.

[531colin]

Hi Colin, I was afraid you would say that. I'm below average height so I might get away with it. We'll see. I spent a long time looking at MTB and hydrid options but couldn't find anything available without a steep seat tube. I might have gone with a small Genesis Longitude frame if I could have found one.

I've just bought a medium one of those!. I'm interested to find out how the slack angle/long trail steering works out. Keep finding things in the way of building it all up! I looked at Surly, but they are all a bit steep in the seat tube angle for me. I guess if you are fixed on a suspension post then you don't have much opportunity to vary the post layback to compensate for a steep seat tube?

[531colin]

I would not fit 27.5" wheels or 140mm cranks simply to have more seatpost extending above the seat tube. If it was absolutely essential to have that in order to use a suspension seat post, I would probably copy Vantage and saw off the top of the seat tube, and void the warranty:

https://forum.cyclinguk.org/viewtopic.php?t=131583&start=15#p1380339

I'll have to read that, I have no recollection of it whatsoever!

[Nigel]

Other option is whether different sprung seat posts fit ?

We have bikes with different USE sprung posts on them. Quickly measuring bikes in the garage, the current Vybe post is 4.25in minimum from top of frame to saddle rail. The older types which may be found as new-old-stock, or second hand, are nearer 3.5in.

I put a USE post on my old tourer after moving to the Scottish Borders; the coarser grade of gravel used in road surfacing created a very much rougher ride vibration than that in East Anglia, and my old tourer became unbearable after an hour or so. The sprung post took the buzz out of things. There isn't room for fatter tyres without scraping against the chainstays.


- Nigel

[Bmblbzzz]

So you're thinking of fitting smaller wheels in order to lower the BB and thus the seatpost, in order to fit this sprung seatpost. What I don't follow is the reason for fitting shorter cranks. Your legs aren't going to shrink... so either you're worried about pedal strike, in which case, is the BB really going to drop 20mm? Or the bike is too big anyway, in which case...

[Bmblbzzz]

I'd like to compliment 531 Colin on his Ancient Egyptian camera, which takes photos of people in profile but with their faces full on. Also, his test pilot has a very fine moustache, especially for a woman!