New frame. Steep seat angle. Unrideable.

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NATURAL ANKLING
Posts: 13780
Joined: 24 Oct 2012, 10:43pm
Location: English Riviera

Re: New frame. Steep seat angle. Unrideable.

Post by NATURAL ANKLING »

Hi,
With an app "angle pro" I just measured 72.4 & 73.7, not sure how good the internal device on phones is?
You can zero it on the top tube (if you have a horizontal) without needing it to be level to start with.

Like Brucey suggests its difficult to get an accurate reading.
Unless you have a calibrated level on a surface marking out table it will always be out by some.
My experience with spirit levels is to use a long one / a long edge that the spirit level is touched on / fixed to, then offer it up to the part you wish to measure.

And always turn the spirit level around for an average, eg - favours left turn around and it should favour right by same amount, if its a good un then it will be the same eg - it will read left and left turned around / spot on.

Brucey's method with plumb line is the best by far and more reliable bike to bike, the angles are immaterial if you can get the saddle and bars correct, if you cannot and cant get saddle or reach right by swapping parts then frame is wrong for you.

For me all that is important is the the top tube is 22.5 - 24 ", my road bike is 22" back in the day when we worried less, with a 110 mm stem the saddle is only 5-6 mm off max offset back, I have an inch going forward, my thighs are almost touching the saddle rail clamp for my norm 60mm setback.
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
JohnW
Posts: 6667
Joined: 6 Jan 2007, 9:12pm
Location: Yorkshire

Re: New frame. Steep seat angle. Unrideable.

Post by JohnW »

I used a draughtsman's adjustable set square. There's no problem with accuracy of the implement, the hard part is assuring that the edges on top-tube and seat-tube are positioned correctly.

I actually read the seat angle at 76.5º, which agrees with srb88's measurement. (I said above "just over 76º" because realistically I didn't want to claim 100% accuracy!)

You can think me very silly if you wish, but only this morning have I checked the frame-builder's worksheet. The frame angles quoted are
74º x 72º. The seat angle was quoted to me by the assistant who measured me and told me at the time that 74º was correct for me............which from my existing frames I knew at the time it was. As far as I can measure the head angle actually is 72º.

Now the seat angle is 2.5º different from their quotation and my order - I collected the frame in 2007 - why didn't I check it then, when I was sorting through seat-pins and saddles? It never occurred to me - I'd been through it before on other frames, and that was just how things were..........although I do remember wondering at the time why it was proving so difficult to solve. The quality of the frame seems very good indeed and it does ride really well..............but the frame was still wrong.

I would suggest to the OP consult his worksheet, and if another angle is quoted, ask the frame-builder why. I'm not going to question the frame-builder now of course, but is it the same frame-builder and if so has he been doing this for 12 years? (I know that I'd said "about 15 years" in my post above, but I hadn't checked). If so, how many other customers have been having this same trouble? I can hardly believe it! - why didn't I think of that? The OP has said "unrideable" - and I can well imagine that!
David9694
Posts: 908
Joined: 10 Feb 2018, 8:42am

Re: New frame. Steep seat angle. Unrideable.

Post by David9694 »

srb88 wrote:Bit of an essay, but advice and perspective would be much appreciated. Eek, anyway. Thanks for reading, if you made it to the end.


What’s the latest on this?
Spa Audax Ti Ultegra; Genesis Equilibrium 853; Raleigh Record Ace 1983; “Raleigh Competition”, “Raleigh Gran Sport 1982”; “Allegro Special”, Bob Jackson tourer, Ridley alu step-through with Swytch front wheel; gravel bike from an MB Dronfield 531 frame.
JohnW
Posts: 6667
Joined: 6 Jan 2007, 9:12pm
Location: Yorkshire

Re: New frame. Steep seat angle. Unrideable.

Post by JohnW »

David9694 wrote:
srb88 wrote:Bit of an essay, but advice and perspective would be much appreciated. Eek, anyway. Thanks for reading, if you made it to the end.


What’s the latest on this?


Yes srb88 - have you resolved the matter - has it all been sorted? The seat tube angle that you report, and which also applies to my frame, despite 74º on the worksheet, is ridiculous.
JohnW
Posts: 6667
Joined: 6 Jan 2007, 9:12pm
Location: Yorkshire

Re: New frame. Steep seat angle. Unrideable.

Post by JohnW »

I'm quite intrigued to learn what's happened about this one. It's quite a fundamental point - someone goes to an expert dealer/framebuilder and comes away, unwittingly at first, with something that sounds not fit for purpose.

This could affect any one of us - anyone who trusts the state-of-the-art expert.

Has the frambuilder seen the thread on the forum, recognised themselves, and threatened to sue if the victim continues.................?
JohnW
Posts: 6667
Joined: 6 Jan 2007, 9:12pm
Location: Yorkshire

Re: New frame. Steep seat angle. Unrideable.

Post by JohnW »

We still don't know how this resolved itself - do you feel like up dating us srb88?
NetworkMan
Posts: 727
Joined: 25 Aug 2014, 11:13am
Location: South Devon

Re: New frame. Steep seat angle. Unrideable.

Post by NetworkMan »

JohnW wrote:We still don't know how this resolved itself - do you feel like up dating us srb88?

I think I may have missed this thread. If it's the builder I suspect they don't give any geometry on their website even though you can place on-line orders there.
Perhaps the OP bought himself a Spa leather saddle.
What a firm; they sell bikes with sane geometry, tell you what that geometry is and even sell leather saddles that help sort out he wonky geometry of others (mine's a bit hard too but getting better)! :)

I suppose the moral is:-
Don't buy a bike or frame without first trying it out (Tony Oliver used to have test bikes I think), or if not, seeing the frame geometry and understanding what it's telling you.
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