Have I killed my Nomad frame?

[dsim]

Hello,

I just emailed SJS asking for their advice about this, but since they will be closed until Monday I thought I'd ask here for some quicker advice/reassurance hopefully.

While I was changing my bottle cages I noticed that there was a dent to the right of the cage bosses on the top side of the down tube. They are now pointed to the right (from the perspective of sitting on the saddle and looking down).

There are also very thin lines of corrosion to the left of the bosses which I found later.

I took some photos which I'll try to remember to attach.

I think I must have knocked the bottle cage on the down tube with my left leg when I came off slowly on a very muddy bridleway (unloader) a few weeks ago.

Otherwise I'm not sure how it could have happened. I've been using 1.2 litre bottles while touring, so I don't think it was excessive weight.

How much weaker is the frame?
Is there any way to fix it?

Or will I need to stump up to buy a new frame?

I should add I'm leaving on a world cycle tour in March and got this Thorn specifically because I believed it to be stronger than my other options. I'm surprised that the tube could have deformed this easily.

[PH]

I'm also surprised a tube would distort from a bit of a fall.  However IMO there's no way that the frame isn't still perfectly OK. 
See what Thorn say, but plenty of people are riding far more dented frames than that with no ill effect.

[mickeg]

I do not have a Nomad MK III, so I have not researched that frame.  But on my other bikes including my Nomad Mk II, I think I would have bent or broken a bottle cage before I could have bent a frame like that.

What kind of bottle cages are you using?

The largest bottles I carry are 1 liter.  I suspect that the bottles I use are not sold in the UK, they are considered disposable bottles in North America.  Photo of my bottles, attached.  My cages on that bike are made of aluminum tubing.

If you are trying to use one of those giant cages that are designed to hold a tent or something like that, I could see that happening.

[JohnR]

Double-butted tubing is surprisingly thin walled in the centre part and therefore easy to dent but I don't think that small deformation will have significantly affected the structural strength of the tube. I would, however, touch up the exposed metal with some similar grey car touch-up paint. You'll have to live with a slightly crooked bottle cage unless it's possible to insert some packing.

[Danneaux]

If I may offer a suggestion, some stacked mating spherical washers scavenged from old brake pads can compensate for misalignment. I'd suggest sandwiching the spherical washers between M5 washers so any load bears directly on the smaller bottle bosses rather than the already stressed, dented tubing around them. I've used this method for years to compensate for headlight mounts that are off-center; I believe George (mickeg) does also.

As for the tubing, I don't see a failure in the offing, but it is not wholly unexpected when overstresses occur in the unbutted sections of tubing, as JohnR observed. It is one reason I often used star-shaped reinforcements 'round my bottle bosses in the frames I've built. See...
https://framebuildersupply.com/products/water-bottle-boss-reinforcing-stars-pack-of-10
They're scarce now and go in and out of stock, so I sometimes make them from leftover tubing I re-radius to match tube OD.

This -- and the popularity of larger "cargo cages" -- is a prime reason why gravel bikes that often employ these cages have three bottle mounts to better distribute the stress.

One alternative you may wish to consider is one or the Wolf Tooth B-RAD adapters. The 3- and 4-slot models use not only your two bicycle bottle bosses, but also include slots to accommodate a cable tie, intended to further secure the adapter (and whatever is attached to it) and better distribute stresses beyond those two bosses. See...
https://www.sjscycles.co.uk/bottles-cages/wolf-tooth-brad-mounting-base-3-slot/?geoc=US
...and...
https://www.sjscycles.co.uk/bottles-cages/wolf-tooth-brad-mounting-base-4-slot/?geoc=US

So sorry this happened, as I know it really stings; especially so on a new frame!

Best, Dan.

[martinf]

Shortly after I got my lightweight Reynolds 531 frame bike in 1977 I had the chain unship and get caught between the small chainring and the chainstay, making an unsightly dent in the latter. It annoyed me at the time (new bike), but as it didn't affect the performance of the bike I soon stopped bothering about it.

In the early 1980's after I moved to France I got the dent repaired at the same time as I had the cantilever brake bosses on the front fork repositioned and rebrazed to suite 700C wheels, because it was difficult to get 27" spares locally. I didn't need to alter the rear cantilever bosses.

I think the framebuilder just filled the dent with braze and smoothed it down.

I still have that frame, it was used fairly intensively up until the mid 1990's, including some long cycle-camping tours, and has currently done about 77,000 kms, although it only gets occasional use nowadays. 
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Not sure if it would be economical nowadays, but in the past it was fairly easy to find a framebuilder that would repair a steel frame.

In the mid 1980's I had an old ladies' bike with a twin lateral frame that I used as a low theft-value utility bike. The point where the two small lateral tubes joined with the seat tube started cracking after a few years of hard use (the bike wasn't designed to withstand use by a tall and heavy male). At the time, my local bike shop still did brazing, so I got them to braze an improvised top tube to the frame, they didn't charge very much. This repair was sufficient to keep the bike going for about 10 more years, when I scrapped it in 1998 after some more cracks started appearing. The bike did about 35,500 kms while I had it, but it was already old when I got it.

I replaced this bike with an even older frame, probably from the 1950's or early 1960's. As the original calliper brakes were nearly useless, I got my local bike shop to braze on a set of cantilever bosses, once again they didn't charge much. 25 years on I am still using this bike regularly.

Nowadays I think I would have trouble finding someone to do this kind of work, my local bike shop closed when the owner retired and the chap that did the brazing has also retired.

[mickeg]

If the paint has a crack in it that will allow water to pass to the steel, you might consider some clear coating to seal the crack.  I have used clear nail polish for such things, it is cheap, only takes a minute to apply with the included brush.

[dsim]

If you are trying to use one of those giant cages that are designed to hold a tent or something like that, I could see that happening.

I was using Velo Orange Mojave cages which I think may be the cause based on your suggestion. They are wider than a normal cage and I didn't realise this could happen. I was only using 1.2 litre bottles to not be too wide or heavy for the bosses, but I guess the width was sufficient to damage it nonetheless.

Double-butted tubing is surprisingly thin walled in the centre part and therefore easy to dent but I don't think that small deformation will have significantly affected the structural strength of the tube. I would, however, touch up the exposed metal with some similar grey car touch-up paint. You'll have to live with a slightly crooked bottle cage unless it's possible to insert some packing.

I've got some touch up paint already so I'll do this in the next few days - the bike lives in the house while I'm saving money anyway. I'm going to switch to either a cranktank4 or a frame bag with MSR dromedary type water carriers instead as I don't want to stress the bosses too much and I'm scared of it happening again or worsening if I come off.

the popularity of larger "cargo cages" -- is a prime reason why gravel bikes that often employ these cages have three bottle mounts to better distribute the stress.

One alternative you may wish to consider is one or the Wolf Tooth B-RAD adapters.

It's a shame they aren't reinforced on the nomad mk iii or having three bosses to reduce the stress. I thought they were for better weight carrying ability - but only using 1.2 litre bottles I thought would be alright.

I'm going to move away from the bosses to carry water as mentioned above as I'm a bit scared of this happening again and further damaging the frame. Also they aren't the most efficient use of the space anyway.

Not sure if it would be economical nowadays, but in the past it was fairly easy to find a framebuilder that would repair a steel frame.

I had a look for framebuilders/repairers near me - Bedford, UK - but I can't seem to find any that will repair the tubes. I'll wait to see what SJS says hopefully tomorrow regarding whether it's OK to tour with it.

Do you know any places that might be suitable? The closest I found was Yorkshire I think! I'm now without a car as I sold it to save on insurance and as an additional incentive to cycle more before leaving!

If the paint has a crack in it that will allow water to pass to the steel, you might consider some clear coating to seal the crack.  I have used clear nail polish for such things, it is cheap, only takes a minute to apply with the included brush.

Good call. I'll see what SJS says tomorrow and then seal it up.

[mickeg]

While that Mojave cage does not look very robust at first glance, I can see that when a bottle is in that cage that a side impact to the cage could put a lot of stress on the frame.  The bottle can't easily fall out of that Mojave cage. 
https://velo-orange.com/products/mojave-cage

A side impact to my cages, the bottle would fall out and the cage would bend.  At least that is what has happened in the past.  I have never seen that as an advantage to the cheap metal types of cages I use, but now I do see that as an advantage.

[dsim]

A side impact to my cages, the bottle would fall out and the cage would bend.  At least that is what has happened in the past.  I have never seen that as an advantage to the cheap metal types of cages I use, but now I do see that as an advantage.

Yeah I got it so it would be secure but hadn't realised that was actually disadvantageous in instances like this.

SJS replied and said that's why they suggest the Profile Design Kage cages as they offer some protection for the frame.

It's annoying as I've been quite careful with choosing accessories to protect the frame, except for the cages I had and was in the process of removing anyway. I clearly should have thought about it some more!

[mickeg]

...
It's annoying as I've been quite careful with choosing accessories to protect the frame, except for the cages I had and was in the process of removing anyway. I clearly should have thought about it some more!

This is the first that I have heard of any bottle cage bending a frame tube.  Thus, I do not see it as something that a user should have to think about when building up a bike. 

I do not know how long Velo Orange has been selling that large cage for large bottles, but the three bolt cargo cages are a fairly recent development.  I have seen a few photos of bikepacking bikes fitted with those cargo cages on a frame, but usually those cargo cages were mounted on a fork.

I have considered attaching the three bolt cargo cages on the front fork of my Nomad Mk II, but I would have used  the upper pannier mount, not a bottle cage mount for one of the bolts.  And the pannier mounts are robust enough for a pannier load.  And I have had one fall with my Nomad Mk II with panniers, no damage.

I worked in a bike shop half a century ago, at that time frames did not have brazed on mounts for bottle cages, the cages came with straps that you wrapped around the frame tubes.  But at that time, virtually all frame tubes were the same diameter so that a single set of straps that came with the cage always fit.  Those cages often bent in a crash, not the frame tube.

I put a pair of Reg brand cages, made in Italy half a century ago on my new road bike a few years ago.  Photo attached.  It just occurred to me now that I had not realized that since those cages originally came with frame straps, that it was pure luck that the distance between the two holes were the right distance for my newer road bike frame bottle mounts.  Yes, those cages in the attached photo are ones that I bought in the 1970s that originally came with straps.

My point with this long post is that if you wanted to put a big cage on the frame, I suspect you would be better off with some of the after market three bolt cage mounting systems.  A gal I know wanted to carry more gear on her road bike for credit card touring, she used some aftermarket three bolt mounts attached with two way tape and zip ties to attach them on her fork.  On one, it slipped a bit where the tape slipped but overall it appeared to work quite well for her so she could mount cargo cages on her carbon fork.  Dan mentioned some options, there are several others out there too.

[RonS]

SJS replied and said that's why they suggest the Profile Design Kage cages as they offer some protection for the frame.

I have 2 Profile Design Kages on my Raven. They are about eight years old and still working. There is a shock cord that goes around the cage, presumably to keep bottles from "flying out" or perhaps to satisfy the lawyers. Mine broke after 6 months, and the cages are none the worse for functionality. I regularly carry a 900ml stainless insulated bottle with a full weight of 1.4kg. Photo is from my Japan trip where I was given a bottle of tea, at least 2L maybe larger, and rectangular . The Kage held it with no problem.