Best Layback Seatpost for Brooks

[reohn2]

I have recently bought a Van Nicholas Yukon and have been looking for the elusive large layback seatpost for my Brooks. I need 8.5cm BB to front of saddle. I have tried the Nitto posts but they haven't quite got enough.

The Velo Orange Gran Cru mentioned above fits the bill perfectly for me and still has some spare:
http://www.freshtripe.co.uk/Freshtripe/ ... posts.html

My only issue now is the post keeps slipping. They are both supposed to be 27.2mm. The post is fine in my Bob Jackson but slips in the Yukon. I have tried carbon paste and now wait for a beefier seat collar to arrive.
Cycling shouldn't be this frustrating!

The answer to the seatpost slip is another seatpost clamp (27.2mm in your case) clamped on the post so that butts upto the one on the frame,I bought mine off Ebay it needed some filing and fettling to suit.

[Mick F]

The REALLY stupid thing is, they make the seat tube angle steep on small frames in order to shorten the top tube.

If the saddle won't go back far enough, surely the frame is too short?
Therefore it's not a seatpost problem, rather it's a geometry problem.

So maybe I was right.
That doesn't help with the OP though, it seems like a layback seatpost is the only answer to counteract the frame design.

[531colin]

The REALLY stupid thing is, they make the seat tube angle steep on small frames in order to shorten the top tube.

If the saddle won't go back far enough, surely the frame is too short?
Therefore it's not a seatpost problem, rather it's a geometry problem.

So maybe I was right.
That doesn't help with the OP though, it seems like a layback seatpost is the only answer to counteract the frame design.

Spot on, Mick. We have to come up with ugly "workarounds" to counteract the brilliance of the "designers"

[The Mechanic]

I think I may have started a revolution. I still have the problem of sourcing a long lay back post. The VO one looks the dogs but no one has it in stock except VO in the states. This will no doubt cost an arm and a leg in postage so might wait Until the Irish outfit have them back in stock. The only other alternative I can see it a mega expensive FSA carbon jobbie.

[Mick F]

Thinking right off the top of my head here ........

If you found a steel seatpost, you could have it bent enough using a pipe-bender to give you enough lay-back. I wouldn't suggest you do this with alu, but it could still be possible with some heat applied by an expert.

How long is your seatpost? Is this possible? It wouldn't need much of a tweak.

[reohn2]

Just been looking at the VO s/post and according to my reckoning its giving about 7mm more layback than the Easton EA50's I use.
I calculated this by enlaging the photo on freshtripe's site which showed the s/post Diameter @ 25mm, drawing a line paralell to the front edge of the clamp shows it 5mm behind the back edge of the post,which is roughly 25% of the s/post diameter, 25% of 27.2mm is 6.8mm.
The EA50's front edge of the clamp is inline with the back edge of the s/post.
I don't know if this is of any help to anyone.

[531colin]

My only issue now is the post keeps slipping. They are both supposed to be 27.2mm. The post is fine in my Bob Jackson but slips in the Yukon. I have tried carbon paste and now wait for a beefier seat collar to arrive.
Cycling shouldn't be this frustrating!

Look what I found while idly browsing....(putting off doing the washing up)...............http://roseversand.com/bike-parts/seat-posts/accessories/accessories/xtreme-wcr-seat-tube-clamp-double-clamp.html?cid=156&detail=10&detail2=12616

[CREPELLO]

Out of interest, just how does a frame builder achieve no toe overlap on a small frame, without resort to the geometry that Mechanics frame has?

By the way, I'm experiencing overlap on my three main road going bikes (all largish frames - Dawes, Hewitt and Mercian), since I've put my shoe cleats further back, hence shoes further forwards. I'm finding the new cleat position more efficient (in leg movement) and less stressful on my legs, feet and knees.

[horizon]

On another thread I suggested that the stem raiser was the best innovation of the last few years. I might have said the VK adaptor instead.

I swapped my 57cm Super Galaxy (recommended by the bike shop as the best size) for my present 59cm Horizon simply in order to achieve a longer set back of the saddle. These are not small bikes and I am not short at 5' 10". Nor was it a problem of the Brooks - I have always wanted to sit further back than the saddle allowed on every single bike I have owned. The VK adaptor was recommended on here I think and it transformed my cycling - I was comfortable for the first time ever.

Reading this thread, I have just used a plumbline on my MTB (no VK adaptor) and my knee is further forward than the pedal spindle in the horizontal position. Later today the saddle will be swapped over (VK included) for a weekend trip. I don't know enough about physiology (spelling it is hard enough) to know which part of the human frame is to blame - it could be thigh length as Colin suggests or maybe even pelvic size. But whatever it is, it is significant and affects a number of cyclists but not everyone. The VK adaptor seems to be the answer in the absence of a custom built frame.

I don't know of any downside in terms of the resultant change in the geometry. The larger frame doesn't automatically result in a longer top tube either so I will look up some frame angles. The only real drawback of the VK I know of is possibly its weight, though on a touring bike this isn't significant and in terms of riding position/comfort pales into utter insignificance.

While most people seem on here seem to know about the VK, no-one else appears to have tried one. Later today I will do some more tests with the plumbline to check for accuracy but just riding the bike tells me most of what I need to know.

All I can say is: you are not alone and the VK is the answer and no, I don't have shares in the company.

(I am just editing to add that I don't believe the problem lies in the reach of the stem - this is a saddle position issue.)

[horizon]

For efficiency, the front of your saddle should be above, or slightly behind, your bottom bracket

Mick, are you sure about this? Even in its most forward position, the saddle hardly achieves this and any normal lay back of the saddle will result in the nose of the saddle being further back than the BB by about 2" (on my MTB I have checked and it is now about 4").

[horizon]

Brooks seem to have very short rails compaired to some saddles.

I compared several saddles at home as it has been mentioned before but didn't find any difference. If you do have a saddle with longer rails (which I am sure is possible) then it would reinforce the argument that a saddle could usefully and properly go back further without detriment and that the VK adaptor is therefore (apart from weight) an appropriate solution. Although I would not have wanted to jettison the Brooks, I would have grabbed at a saddle with longer rails (or a different seatpost). But it was the VK that won the day and saved the Brooks.

[horizon]

(A last post on this before I go for some lunch.)

A key determinant of saddle position is obviously height (i.e. the saddle goes further back as it goes higher because of the angle of the seat tube). I always had my saddle at maximum reasonable height (am known for it in the family!) and this wasn't sufficient to solve the problem. However it may be worth looking at in some situations. I also just wanted to reiterate that my bikes are not, in a conventional sense anyway, too small. One MTB was carefully selected at a local LBS, my currrent one previously belonged to a man about 2" taller and, as I said earlier, I rejected the advice of another LBS and went for larger frame. The only other point to mention is that all my bikes are Dawes: are their top tubes shorter? Would a racing geometry allied with a higher stem produce a better result? Perhaps, but as I said, the VK came along and fitted the bill.

[531colin]

The REALLY stupid thing is, they make the seat tube angle steep on small frames in order to shorten the top tube.
However, this short top tube is entirely spurious, because, as we have seen, all that happens is the rider goes looking for a long layback seat post. They call themselves designers, they make me want to spit.
The correct way to shorten a frame is to use a shallow head angle, with a long fork offset to bring the trail back to something sensible. both shallow head angles and long fork offset move the front wheel away from the riders toes, one occasion when the laws of physics conspire to help us! If that is not enough, there is nothing else for it except to use a smaller wheel.
Spa are prototyping touring frames I have designed. Just 3 sizes, so nothing really tiny, 51, 54 and 57 cm with 6 or 7 cm top tube slope. All sizes use 71deg head and 54mm fork offset. Its not hard.

I hope that made my views on bike "designers" clear.
However, we are now discussing how to get the saddle far enough back. From the point of view of frame design, that comes down to seat tube angle. In my view, a touring bike wants a seat tube angle of 72deg (or less, for a custom build for somebody who knows what they want). However, my favourite "designers" are in love with "the look" of the racing bike. I looked at Dawes website, the geometry of the 2009 Super Galaxy, for no particular reason. The seat tube angle varies from 74 deg (74 for fun's sake) on the smallest frame, to an almost respectable 72.5 deg on the biggest. VK adapters, anybody?

[Mick F]

For efficiency, the front of your saddle should be above, or slightly behind, your bottom bracket

Mick, are you sure about this?

Yes.
Perhaps slightly behind is better than above.

Efficiency, is the word.

[Mackerel]

Hi Colin,

Spa don't currently show geometry figures for the new frame. Any idea what the seat tube angle, headtube and standover heights are on the 54cm?
http://www.spacycles.co.uk/products.php?plid=m1b17s21p2307&z=2753

Jason