Seat post query: offset or zero offset?

[SatNavSaysStraightOn]

I know this is going to sound mad to some but I thought I would check before I purchase...

I have been out over the last few days on my new hard-tail mtb. The size of the bike is fine, the reach is good but I have started with a slight issue with my popliteal muscle in my right leg (behind the knee) caused by not being able to straighten the leg enough (the left leg probably has the same issue but I can't feel it due to a dog ripping out the nerve in same area...)

Anyhow the seat post is as high as it can go and the seat is as far forward as it can go... I have slightly longer legs and prefer to pedal with my feet more 'under me' than they are currently.

The post is an odd size (30.9mm and currently 350mm length) which has reduced but not completely eliminated the options. I have located some possible seat posts that meet these requirements, some have 25mm offset and a couple have zero offset which would allow me to put the seat slightly further forward whilst going slightly higher (and also allow me to fit the saddle bag which I can't currently do because there is not enough room, seat is too far forward).

So my question is would going to a seat post with a zero offset help? Or have I missed something fundamental?

I have tried the seat at the right height carefully on level ground and I appear to only need an extra 1.5cm in height, but the saddle does seem to far back or my feet to far forward compared to what I am used to.

 

[Pale Rider]

Not quite answering your question, but a seatpost shim would allow you to fit a wider choice of post.

So if you've found a post that's ideal for you, but the wrong diameter, a shim might do it.

http://www.winstanleysbikes.co.uk/category/423/Seat_Post_Shims

 

[SatNavSaysStraightOn]

Not quite answering your question, but a seatpost shim would allow you to fit a wider choice of post.

So if you've found a post that's ideal for you, but the wrong diameter, a shim might do it.

http://www.winstanleysbikes.co.uk/category/423/Seat_Post_Shims

OK - that widen's the field a touch more! now you have me thinking again... too early in the year for that
thank you

 

[cyberknight]

You can buy an extender that can reduce or add to offset of the seat post by clamping where your seat would go then attatching the seat to the top of it and also increases saddle height by maybe 3 cm a s well, fecked if i can find one atm as my google fu sucks.
had one from sjs cycles for a while when i was trying to get a too big bike to fit but sold it , might be worth ringing them ?

 

[cyberknight]

EDIT
Found it ..
http://www.sjscycles.co.uk/vk-saddle-adaptor-prod1249/

 

[SatNavSaysStraightOn]

EDIT
Found it ..
http://www.sjscycles.co.uk/vk-saddle-adaptor-prod1249/

thank you - it was looking great until I got to the line

Fits on 99% of all single bolt micro adjust seatposts

and guess what this bike has? a 2 bolt system...

 

[Pale Rider]

thank you - it was looking great until I got to the line

and guess what this bike has? a 2 bolt system...

Thought it might - most mountain bikes have two bolts.

I suppose there's nothing to stop you buying a micro-adjust post, and shim if needed, and the bracket, but that's probably complicating things - and making them more expensive - than necessary.

 

[RecordAceFromNew]

I suppose there's nothing to stop you buying a micro-adjust post, and shim if needed, and the bracket, but that's probably complicating things - and making them more expensive - than necessary.

+1, especially when that offset thing costs more than this seatpost e.g.!

30.9 are exceedingly common, and long ones like the above are readily available, e.g. many spesh mtbs have them.

The issue of raising another 1.5cm is it will move the saddle back, assuming the same clamp point and 72 degree seat tube angle, by around 0.5cm, but the zero setback should be able to more than negate that.

 

[SatNavSaysStraightOn]

OK - purchase has been made at a "local" bike shop... "local" because we had to ring round and find out who had any 30.9mm seat posts in stock and who had any that where longer than 350mm. Whilst the shop concerned did have a 30.9mm by 375mm post in that they had set aside for me saying it was an inline post, it was actually an offset post (see getting the hang of the terminology now!) which was a touch annoying... anyhow amongst all the 60% off stock there was a single post that was not reduced and low and behold it was 30.9 by 410mm and inline... so I now have a seat post that is 1/3 of what I paid for the bike 2nd hand but I can now go out tomorrow with my OH on the last ride of his annual leave and do what we wanted. He's trying to avoid is road bike at the moment, his lower back is hurting from other issues and he thinks riding the road bike is not going to help and wants to be out on mtbs... I did wrangle a 10% discount for the CTC card I could not produce so that has eased the £££ a touch!
Fingers crossed.

 

[SatNavSaysStraightOn]

quick update - a test ride today on the new seat post has vastly improved the feet position and whilst I only did 11 miles or so, the problems 2 days ago kicked in in less than that and my leg feels fine! So for those who confirmed what I suspected - thank you.

My old seat post has now found its onto my OH's new mtb bike (also a specialized rockhopper but 2006 model) because the seat clamp was not as adjustable on the 2006 model to the 2011 model.

One thing I did notice was how heavy by comparison with the new post, the old post was. Saddle + New post = weight of old post only!

 

[Pale Rider]

quick update - a test ride today on the new seat post has vastly improved the feet position and whilst I only did 11 miles or so, the problems 2 days ago kicked in in less than that and my leg feels fine! So for those who confirmed what I suspected - thank you.

My old seat post has now found its onto my OH's new mtb bike (also a specialized rockhopper but 2006 model) because the seat clamp was not as adjustable on the 2006 model to the 2011 model.

One thing I did notice was how heavy by comparison with the new post, the old post was. Saddle + New post = weight of old post only!

Pleased that's worked.

A seat post on its own is a neater solution than having to use shims and/or special clamps.