Touring bicycle frame weight - info gathering

[meic]

So far all I can see is that touring bikes are heavier than Audax bikes and bigger bikes are heavier than smaller ones.

Those are qualitative observations, this thread raises us to the level of quantitative observations.

[PH]

So far all I can see is that touring bikes are heavier than Audax bikes and bigger bikes are heavier than smaller ones.

Those are qualitative observations, this thread raises us to the level of quantitative observations.

I think there's a danger in believing it does - for example on the spreadsheet the 56cm Spa Audax is 1g heavier than the 54cm.
This isn't a criticism, there's always going to be such discrepancies, IMO you'd need far more control to make any realistic quantitative observations.

[Samuel D]

My Spa Audax (the 54 cm model that’s a gram lighter than the 56 cm one) was weighed with bits of the headset attached as noted. Were you expecting a greater weight difference between a 54 cm and 56 cm frame?

By the way, mine was weighed on a calibrated precision balance.

[meic]

IMO you'd need far more control to make any realistic quantitative observations.

That depends on where you are starting from.
The rest of you may have already had a rule of thumb matrix from a Xlarge steel tourer in the top right corner weighing 4Kg to a tiny CF racer in the bottom left weighing (as yet unknown)Kg in the bottom left corner. But I certainly didnt, slowly if this fills out I will develop such a matrix and have an idea of the ball-park figures which I would expect from a frame of a different size, material and type.
At the present I have a tiny scattering of random data points but that is a great improvement over last week. I dont see any other source of this information.

When I built my titanium bike, I was quite disappointed about how its weight at the point of being road usable (9.5Kg*) was quite high compared to a lot of weights being thrown about by others, this thread helps me see how much that is due to the fact that I ride bikes with as large a frame as I can get, ditto for the stems, seatposts.

*It weighs a lot more with mudguards, lights, racks, saddlebag etc.

[meic]

Mid 1980's Raleigh special products lightweights "MTB" Cajun. 531ATB main tubes.

21.5" (ie Large) frame 2415g

Unicrown Forks 1006g*

*with about 1.5" of steerer broken off.

[rickd]

In what context are you seeing all of these failed forks?

IBut some of what I see is really very worrying. CF forks fall into the 'worrying' category.

cheers

That is very interesting. In what you see are carbon forks with alloy steerer more prone to failure compared with full carbon?

[amediasatex]

to a tiny CF racer in the bottom left weighing (as yet unknown)Kg

For reference, a 'normal' CF road bike frame weight is in the ~1-1.2kg area, with forks 400-600g, top end race frames are regularly less than 800g now with forks being ~300g

MTB hardtail CF frames aren't much heavier, race frames under 1kg not unsual, but a sturdy general purpose CF MTB hardtail frame is normally 1.2-1.4kg

I don't think there are many CF tourers kicking about, and CF 'adventure/gravel' frames are likely to be similar to MTB hardtail weights.

So in summary, flipping light when looked at in isolation, but still negligible in terms of overall weight if you were to use one for touring.

In what you see are carbon forks with alloy steerer more prone to failure compared with full carbon?

In my experience yes, I would imagine Brucey and others have seen similar but in fact I'd go so far as to say most of the (non-impact*) CF fork failures I've seen have been on forks with a bonded Alu or steel components (crown/steerer/dropouts).

I think the reason for this is two-fold. Firstly full-carbon forks are often the more expensive models**, more likely to have been built 'properly' and also more likely to be used sympathetically, ie: on a race bike, not banged about in a bike rack or plane cargo hold. Secondly they simply don't have to deal with the issue of bonding dissimilar materials and all the pitfalls and problems that come with that with regards to interfaces and differing failure/degradation modes. They can be by their very nature more integral and the designer/builder has a degree more control over the structure.

*impact related failures are harder to quantify, and it's hard to normalise for the inherent differences in the intended use of the fork, ie: a superlight 300g full-carbon fork is not necessarily designed for the same use as a weightier 600g composite model so it's to some degree expected that one might be more prone to impact damage, in the same way a super thin walled 6-700g steel racing fork differs from 1kg+ touring fork.
**thus thirdly, there's fewer around in the first place.

[PH]

My Spa Audax (the 54 cm model that’s a gram lighter than the 56 cm one) was weighed with bits of the headset attached as noted. Were you expecting a greater weight difference between a 54 cm and 56 cm frame?

By the way, mine was weighed on a calibrated precision balance.

My point is, that we don't know the difference because there is no control, so from a comparative perspective it lacks, well information.
I maintain the difference in weight between two bike frames built from the the same material, in the same size, designed for the same purpose is going to be so small as to be insignificant. Others may disagree, but if they wish to examine the evidence it needs to be accurate, frames compared in the same way with he same measure - I've just weighed a known weight (5kg dumbell, not mine, don't ask) on the three scales in my home, kitchen, bathroom and luggage, there's 160g difference between the highest (Luggage) and lowest (Bathroom) and I'm not sure about the kitchen as it only goes up to 5kg.
I'm very fussy about choosing my touring frames, I've been know to set up spreadsheets to compare everything I can find out about the contenders, but I've never given any consideration to the weight. If it's the right frame it'll be the right weight.

[PH]

[
The rest of you may have already had a rule of thumb matrix from a Xlarge steel tourer in the top right corner weighing 4Kg to a tiny CF racer in the bottom left weighing (as yet unknown)Kg in the bottom left corner.

I get that some might be interested in the different weights between different types of bike, it could answer some valid questions, but the question posed this thread is specifically about touring frames.

[elPedro666]

I for one am finding this interesting; the idea of the mental scattergraph is exactly how it works in my minds eye so it's interesting to hear that described!

Whatever the intended aim, I'd suggest that cases of gathering large amounts of information such as this, the interesting conclusions and stand-out observations are rarely the things you're expecting or looking for. Just amass the information and see where it leads...

I'm a trendy consumer. Just look at my wobbly using hovercraft full of eels.

[elPedro666]

, but the question posed this thread is specifically about touring frames.

The pedant in me feels compelled to point out that there was no question posed in the original post, although the OP may have stated it subsequently and it's slipped through my memory - it is more like a sieve than a bucket to be truthful!

I'm a trendy consumer. Just look at my wobbly using hovercraft full of eels.

[pwa]

I for one am finding this interesting; the idea of the mental scattergraph is exactly how it works in my minds eye so it's interesting to hear that described!

Whatever the intended aim, I'd suggest that cases of gathering large amounts of information such as this, the interesting conclusions and stand-out observations are rarely the things you're expecting or looking for. Just amass the information and see where it leads...

I'm a trendy consumer. Just look at my wobbly using hovercraft full of eels.

But few of us have accurate information to give. I have a tourer framest, which is part of a complete bike that I'm very unlikely to disassemble for this discussion, and which I never bothered weighing last time it was naked. I've always imagined it weighs "quite a lot", but not nearly as much as truly heavy bikes.

I'm not particularly light myself and I would be worried if the bike I intended loading up with four panniers weighed too little. I'd suspect flimsiness.

[elPedro666]

For sure, but some will. It may well take a long time to build up a useful spreadsheet but I don't see that as a good reason not to start collecting whatever information is already available.

And next time a bike is stripped for a respray or whatever, maybe it'll cross someone's mind to pop it on some scales. That's just given me a thought - maybe the OP will get lucky and someone who works in a paint shop will be able to turn in a whole load of weights!

I'm a trendy consumer. Just look at my wobbly using hovercraft full of eels.

[Brucey]

That is very interesting. In what you see are carbon forks with alloy steerer more prone to failure compared with full carbon?

as amediasatex has commented the majority of failures are in bonded joints, between carbon and metal. Usually there are clear signs that the bonding wasn't carried out properly, or that the joint has corroded, etc but often the failed parts exhibit part-composite failure in the fracture face even when the failure is at a bonded joint.

Aluminium steerers are a pretty dumb idea anyway; they corrode and they fatigue, with or without CF fork blades attached. If an Alu steerer fails you are headed for the hospital or mortuary. In theory CF steerers can be made better, in practice it ain't always so.

cheers

[ehelifecycle]

BTW, if that helps, I had a custom bike made by Condor

what frame size please?