Loose seatpost - Spa Aubisque frameset

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PH
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Re: Loose seatpost - Spa Aubisque frameset

Postby PH » 5 Jul 2019, 12:53am

wearwell wrote:
fastpedaller wrote:..... Certainly a Quality control problem somewhere, but I suspect very difficult for Spa to have any control over.

Why? Spa can do the same as anybody else and return faulty goods. It is Spa's quality control at fault and they should simply replace the frame. Packing it with coke cans etc is fine for a cheapo 2nd hand frame but not for something brand new from a shop with any reputation to maintain.

I don't know if Spa frames are made in Taiwan, but the Taiwanese have an excellent reputation for high end engineering and quality control. I have experienced this myself, having spent some time working there. If their customer wasn't happy with the tolerances they were working too, tighter ones could be specified, for a price. In what was my field of industrial fabrics, you can specify what percentage of variation/faults you'll accept, 10% to zero triples the price, yet in most cases there wouldn't be any difference.

wearwell
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Re: Loose seatpost - Spa Aubisque frameset

Postby wearwell » 5 Jul 2019, 9:38am

Brucey wrote:
wearwell wrote: It's not about "perfection" it's about normal practical tolerances and quality control....


yes, and you are assuming that those tolerances are not 'normal' whereas IME they are. ........
The acid test is whether your seat pin moves in normal service or not. ...s
Er - isn't that what the OP was complaining about?
Or having seat tubes loose and impossible to secure and packing it with a bit of coke tin is normal? Why couldn't the shop do that as part of their service?

Brucey
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Re: Loose seatpost - Spa Aubisque frameset

Postby Brucey » 5 Jul 2019, 11:30am

wearwell wrote:
Brucey wrote:
wearwell wrote: It's not about "perfection" it's about normal practical tolerances and quality control....


yes, and you are assuming that those tolerances are not 'normal' whereas IME they are. ........
The acid test is whether your seat pin moves in normal service or not. ...s
Er - isn't that what the OP was complaining about?...


AFAICT the OP has stated that

a) an undersize seat pin needs the clamp to be 'significantly tightened' to grip the seat pin and
b) that there is still some detectable wobble with a seat pin that is closer to the correct nominal size and
c) the next size up seat pin (+0.2mm) won't fit


Maybe I've misread it but this is not the same as

- there is a measurement of the (well lubricated) bolt torque required to clamp a seat pin of the correct size or
- the seat pin moved in service
- that the fit has been compared with seat pins that do and don't move around in service for the OP (or other folk)
- that the permitted tolerances of the frame are known or
- that the frame has been carefully measured and is known to exceed said tolerances

The usual course of events with an OTP frameset is that

a) a (nominally correctly sized) seat pin is fitted
b) it is seen to move in service and
c) possible issues with the clamp and the actual size of the seat pin are eliminated

In this situation if the seat pin is also seen to be a bit of a wobbly fit this is almost certainly part of the problem. However if a little movement is evident, but the frame has not been ridden or compared with other similar frames, to then assume that this is definitely abnormal or a problem of some kind is jumping the gun a bit.

Note that the stresses that are seen around this joint and factors which might influence slippage can vary enormously, with rider weight, seat pin length outside the frame, seat pin length inside the frame, terrain ridden, riding style, materials used, surface finish of the parts, bolt torques employed etc all making a difference. Also note that there is a always a stiffness mismatch between the frame and seat pin, so that, under load, the parts may deform enough to move a little even when they are nominally a good fit. Even that the seat pin has moved (even if it moved because the bolt wasn't tight enough having been OK for years beforehand) this can change the finish inside the frame so that the seat pin will move ever after.

I have encountered situations (which BTW were not with heavy riders, but were most often on MTBs) where no commercially available seat pin could be made to stay put in the frame with a normal clamp. A seat pin that was less than + 0.1mm larger did stay put and this was a good solution. However with the best will in the world, no-one could have predicted whether the original seat pin would definitely move or not beforehand, only that it conceivably might do. IME if you try the seat pin fit of (say) most OTP bikes in a typical dealers then they are more likely to wobble than not, but most of them won't cause problems in service.

Much of the discussion in this thread has been concerning practical solutions to seat pins that are found to persistently move in service; if you can (by whatever means) make the fit practically wobble-free, it is almost certain that you can solve the problem this way. However that is not the same thing as if you have a little wobble evident, that this will definitely be a problem.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

slowster
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Re: Loose seatpost - Spa Aubisque frameset

Postby slowster » 5 Jul 2019, 12:19pm

PH wrote:
slowster wrote:I don't understand why this problem appears to be particular to Spa.

It isn't, throughout the thread you'll see several people have had similar issues and the ways they've resolved them, did you think they were all referring to Spa bikes?

I've just re-read the thread, and the several people to whom you refer appears to be you, i.e. most of the other posts are either about people's varying experience with Spa frames (bohrsatom, Samuel D and Brucey have reported similar experiences, and Horizon's frame was a perfect fit). The posts from others have not been about the same issue with other frames, but about how they've resolved an analogous issue, e.g. using a deliberately purchased undersized seat post or concern about potential wobble of carbon posts in cheap carbon frames.

I actually doubt that Spa's frames are disproportionately likely to exhibit this problem, but various factors mean it is more likely that it will be noticed on a Spa frame and reported on this forum, e.g. this forum has a higher percentage of Spa customers than probably any other forum and more of us are likely to buy a frame and build it up ourselves, whereas a higher percentage of most other brands frames' are sold as complete bikes or are built up by a shop rather than the customer (I suspect that I might find wobble on a lot of the seat posts of those brands' bikes if I actually looked for it, after wiping any grease off the seat post).

As Brucey said on the first page, what really matters is whether the seat post slips, and the response of the manufacturer/retailer in that event. It's not clear if even the OP's post would actually slip in use, and only Samuel D has actually had that problem, and he sought to find a fix for the issue rather than return the frame.

As it happens, I am shortly going to buy a Spa steel frame myself, and by coincidence the seatpost which I have already purchased in preparation for the build is the same one that Samuel D has fitted in his Spa Audax.

PH
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Re: Loose seatpost - Spa Aubisque frameset

Postby PH » 5 Jul 2019, 12:36pm

slowster wrote:
PH wrote:
slowster wrote:I don't understand why this problem appears to be particular to Spa.

It isn't, throughout the thread you'll see several people have had similar issues and the ways they've resolved them, did you think they were all referring to Spa bikes?

I've just re-read the thread, and the several people to whom you refer appears to be you, i.e. most of the other posts are either about people's varying experience with Spa frames (bohrsatom, Samuel D and Brucey have reported similar experiences, and Horizon's frame was a perfect fit). The posts from others have not been about the same issue with other frames, but about how they've resolved an analogous issue, e.g. using a deliberately purchased undersized seat post or concern about potential wobble of carbon posts in cheap carbon frames.

Posters on this thread who have needed non standard solutions to similar issues:
iandriver, AndyA, Samuel D, 531colin, JohnW, Brucey, bohrsatom and myself

Samuel D
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Re: Loose seatpost - Spa Aubisque frameset

Postby Samuel D » 5 Jul 2019, 1:13pm

slowster wrote:As it happens, I am shortly going to buy a Spa steel frame myself, and by coincidence the seatpost which I have already purchased in preparation for the build is the same one that Samuel D has fitted in his Spa Audax.

The Nitto measures 27.2 mm as closely as I can measure with a good vernier calliper.

As for the frame, I’d probably ask Spa if it’s possible not to ream it if I ordered another one. When my frame arrived it had been reamed by someone after it was painted. Furthermore, there was very little material removed (not a full circle or full depth), suggesting to me that perhaps that step wasn’t necessary and was the source of the problem.

Does anyone think this might work? It’s like the model shown by kylecycler earlier but available in a 30.7 mm size – maybe close enough to the 30-odd mm of my frame.

I’ve noticed that my seatpost doesn’t slip or slips so little I didn’t observe it over a period of weeks if I clamp it with the post and frame bone-dry (no grease). However, then water gets in when riding in the rain, especially without mudguards.

I wonder how effective the grease seal is anyway if the seatpost is rocking back and forward. For this reason the shim sounds like an attractive idea, as long as it is deep enough (the full height of a beer can with a 2 mm folded lip at the top to prevent it falling into the frame? One at the back and one at the front, each 10 mm wide?).

Not that I’ve noticed water ingress since fitting the second clamp on the seatpost, but I’ve had hardly any rain on my rides over the last few months.

Samuel D
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Re: Loose seatpost - Spa Aubisque frameset

Postby Samuel D » 5 Jul 2019, 1:42pm

Also sold by SJS Cycles (with a couple of user reviews on that page).

And another intriguing gizmo, though that one definitely wouldn’t fit a Spa Audax.

scottg
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Re: Loose seatpost - Spa Aubisque frameset

Postby scottg » 5 Jul 2019, 2:42pm

wearwell wrote:
fastpedaller wrote:Why? Spa can do the same as anybody else and return faulty goods.


The builder will tell Spa to like it or lump it. Unless you have your own man at the factory to check up,
you can get all sorts of interesting running changes to what you spec. There is no return of goods.
Rodeo Labs, a brand of gravel/packing bikes, had a whole run of frames built with tubes thicker
than specced. They put them on sale at reduced price to clear them out, next run had the correct
tubes.
+++++++++++++++++++++++++++++++++++++
Why not the best, buy Cyclo-Benelux.

slowster
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Re: Loose seatpost - Spa Aubisque frameset

Postby slowster » 5 Jul 2019, 4:22pm

Samuel D wrote:I’d probably ask Spa if it’s possible not to ream it if I ordered another one. When my frame arrived it had been reamed by someone after it was painted. Furthermore, there was very little material removed (not a full circle or full depth), suggesting to me that perhaps that step wasn’t necessary and was the source of the problem.

I assumed that reaming was probably done by the manufacturer, because that would be more time/cost efficient, i.e. reaming every frame as part of the production process, and also because for frame only sales the boxed frame could simply be shipped straight out by the shop without opening it. If so, there would be no hope of making a special request for one frame not to be reamed.

Incidentally, Spa are now stating on their website that their steel frames have an Electrophoretic Deposition coating, something which would be done before painting - the only two frames I've seen with an ED coating (a different brand) were either not reamed or any reaming was done before coating and painting, i.e. the black coating inside the seat tube was unmarked and had obviously not been reamed after the coating process.

One thought that occurs to me is whether carbon fibre assembly paste might be a solution. The paste is used to increase the friction on carbon fibre components etc., but presumably could just as well be used on an alloy post in a steel frame. As I understand it's basically just grease containing tiny particles of plastic which give it a 'gritty' texture - those plastic particles might not only provide extra friction, but (dependending upon the actual particle size and whether the particles deform much under compression) they might also have a similar effect to a very thin shim.

As for the Nitto S83 seatpost, I suspect that like me you have the 250mm version. Given Brucey's comment about wobble reducing abruptly in a Spa Touring frame when the post was inserted around 11cm in (i.e. where there is presumably a transition in the butting and/or that was the limit of any reaming), I wonder if the 300mm version of that post might be a better choice.

Samuel D
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Re: Loose seatpost - Spa Aubisque frameset

Postby Samuel D » 6 Jul 2019, 9:16am

slowster wrote:As for the Nitto S83 seatpost, I suspect that like me you have the 250mm version.

Correct. Given the choice, I’d go 300 mm next time.

slowster
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Re: Loose seatpost - Spa Aubisque frameset

Postby slowster » 24 Aug 2019, 10:39pm

Tony Oliver had quite a bit to say on this issue in his book 'Touring Bikes'. In short, he considered that seat posts being used then for lugged and brazed frames were often too narrow, and even though 27.2 was the norm for most quality frames, he maintained that 27.4 should often be used instead.

The reason for this was that most 531, 753 and 653 seat tubes had internal diameters of 27.5mm, in which 27.4mm posts will be a perfect fit when the seat cluster is silver brazed. However, higher temperature brass brazing instead distorts the tube enough to make the internal diameter smaller, and it is then reamed with a 27.2mm reamer. He comments "That is fine but the fit is only second-rate and inevitably water creeps into the gap".

He includes a table of the various different Columbus, Reynolds, Tange and Vitus seat tubes' wall thicknesses, internal diameters, and two recommended seat post sizes for each tube - one for brass brazed and the other for "silver brazed to the highest standards". The sizes for silver brazed are all 0.2mm larger than the corresponding size for brass brazed, e.g. 27.4 vs 27.2 or 27.2 vs 27.0 etc.

He also comments on the difficulty of getting 27.4 seat posts, despite manufacturers listing the size in their catalogue.

Reading the posts on this thread it seems that not much progress has been made since the book was published in 1990.

Also, it seems the quality of the fit of 27.2 seat posts in Reynolds 531 or 725 tubing depends upon the tube being distorted sufficiently by the temperatures of brass brazing and TIG welding respectively to reduce the seat tube's effective internal diameter. In contrast such distortion will not occur with low temperature silver brazing by a skilled framebuilder, with the result therefore that a 27.2mm reamer would be too small and a 27.2 seat post would be a looser fit in such a frame than in a brass brazed frame.

That makes me wonder if the underlying cause of the loose seat posts in Spa's frames might be that the welders are increasingly so skilled and their technique so good that they are unintentionally/unknowingly not causing sufficient heat distortion to reduce the tube's diameter enough for a 27.2 seat post to fit properly.

fatboy
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Re: Loose seatpost - Spa Aubisque frameset

Postby fatboy » 25 Aug 2019, 8:50am

I've read this thread with interest particularly the bit about external butting; I've wondered why in certain loghts I can see this on my 725 Spa Tourer!

My audax seat post slipped a bit when I started with the frame which was irritating ( I guessed that I had a post at the low end of tolerance and the seat tube the other way). I can't clearly recall how I fixed it but I think that I wiped off the grease and tried a different grease and then tightened the clamp up tight (I don't have a torque wrench but I may have over tightened it). After that it's been fine. The other 2 Spa 725 frames that I've built have been fine. I can't remember if the post wobbled a bit befor tightening.

I suspect that you may not actually have a problem just something that doesn't feel right!
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly

gxaustin
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Re: Loose seatpost - Spa Aubisque frameset

Postby gxaustin » 25 Aug 2019, 9:48am

I had a frame where the seat post wobbled a bit. I could see there was a gap but didn't measure it. The saddle used to slip after a while too. I tightened the clamp up really tight and it still slipped. so I used carbon paste (with the bits in) and solved it. However, the torque on the clamp screw bothered me so I took the clamp apart. The screw went into a steel insert in the alloy clamp - and the screw was tightened sufficiently to bottom against it. I found a screw 2mm shorter and the problem was solved.

NetworkMan
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Re: Loose seatpost - Spa Aubisque frameset

Postby NetworkMan » 25 Aug 2019, 12:11pm

I bought my Spa steel touring frame in October 2014 as did fastpedaller upthread. We both have an on-one setpost, almost certainly the same one. I'd thought that there might be an issue with later frames being oversized but I just measured my seatpost and it's more like 27.3 than 27.2 so it would be interesting to see what fastpedaller's measures. I don't recall there being an issue fitting the seatpost so it certainly wasn't too tight. No slip that I can tell but I'm only 60 kg.

I then went on to measure an old Kalloy post not in use - about 27.2 and the Planet-X Superlight on the Spa Ti Audax - more like 27.1. Both posts in bikes were measured without removing and all three were not uniform, perhaps +-0.03 mm. but not easy to be sure with my Aldi digital calliper. BTW it still suddenly jumps by 0.2" - about 5.08 mm - we discussed this a few years ago on here - apparently it's not uncommon and it's obvious when it's just done it.

Oh, and like slowster I read up Tony Oliver's book - very informative if you can find a copy. Mind you they seemed to be about £20+ on Amazon marketplace when I last looked.

fastpedaller
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Re: Loose seatpost - Spa Aubisque frameset

Postby fastpedaller » 25 Aug 2019, 4:38pm

Mine's an On-One Twelfy sports, and (ignoring the white 'measurement marking areas') is anything bbetween 27.14 and 27.18mm. Measured with my Lidl vernier which seems to be accurate/repeatable. Unfortunately my micrometer only goes up to 25mm. otherwise I would have a 'second source of measurement'. Just out of curiosity (because of the thread), having noticed no problem when I built the bike, a couple of days ago i tried to 'waggle' the seatpost, and despite it being a nice 'just about sliding with some grease' fit, there is no lateral movement. Couldn't really be better....... sorry, but I'm sure that doesn't make the OP feel better.