Author Topic: What to do when your rack fails  (Read 12890 times)

onebikeoneworld

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What to do when your rack fails
« on: March 19, 2017, 07:08:31 pm »
I'm flying off to South Africa in a week and decided to clean my bike up. To do a stellar job, I decided to remove my rear rack. I started undoing my bolt on the right hand side, and turned out the mount came straight off my frame. There was a little bit of rust, but it didn't seem anything major. I'm going to be calling SJS for advice tomorrow, but any suggestions that people have would be welcome. Googling around suggests that https://www.sjscycles.co.uk/carriers-racks/14mm-tubus-clamp-set-rack-eyes-for-seat-stay-mounting/ could work as a solution. Are they as sturdy as they claim? If not, would it be a case of welding it back on? I'm not far from Manchester. If I had the time, I could go to somewhere like Bob Jackson Cycles (http://www.bobjacksoncycles.co.uk) who chopped my bike in half to apply S&S, but there's no way they'll get it done in such a short time.

Danneaux

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Re: What to do when your rack fails
« Reply #1 on: March 19, 2017, 07:15:34 pm »
It may well be Bob Jackson could work you in, as rebrazing a rack mount is quick work. If you were near me, I'd do it for you right away.

Lacking that, the Tubus seatstay mounts aren't a bad option -- just make sure they're large enough to fit your stays. If you have a Nomad (I don't recall...), then they need to be able to wrap around 19mm.

The reason they work okay is the bottom mounts bear the bulk of the weight, while the upper ones tend to serve as fore-aft locators. Where you're in a hurry, these should get you going...but a proper repair would be most desirable.

Based on repairs I've done, the biggest component in upper mount failures seems to be loose rack bolts, allowing the rack to fret on the upper mounts, leading to failure. Looking at yours, however, it appears there wasn't full penetration of brass into the joint ("cold joint") -- but that is just going off of one rather dark photo. I'd have to see it in person to say for sure.

The silver lining to this is you found it while prepping the bike, instead of mid-tour. You've got more ready options as a result.

Please let us know how you fare.

All the best,

Dan.
« Last Edit: March 20, 2017, 02:56:03 am by Danneaux »

martinf

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Re: What to do when your rack fails
« Reply #2 on: March 19, 2017, 08:54:55 pm »
I have used Tubus seat-stay clamps with no problems on at least two family bikes, though not for long distance touring. 

I had seat-stay clamps (not Tubus) on my old 700C lightweight, which was used for several long distance cycle camping trips when it was my only bike, again no problems.

And, several years ago, when one of the brazed-on attachments on my old utility bike broke, I used a seat-stay clamp instead. That bike was used for hauling fairly heavy loads, most of it in the rear panniers.

So I reckon seat-stay clamps are quite tough enough to do the job, although they don't look as neat as the braze-ons.



onebikeoneworld

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Re: What to do when your rack fails
« Reply #3 on: March 19, 2017, 11:21:45 pm »
It may well be Bob Jackson could work you in, as rebrazing a rack mount is quick work. If you were near me, I'd do it or you right away.

Lacking that, the Tubus seatstay mounts aren't a bad option -- just make sure they're large enough to fit your stays. If you gave a Nomad (I don't recall...), then they need to be able to wrap around 19mm.

The reason they work okay is the bottom mounts bear the bulk of the weight, while the upper ones tend to serve as fore-aft locators. Where you're in a hurry, these should get you going...but a proper repair would be most desirable.

Based on repairs I've done, the biggest component in upper mount failures seems to be loose rack bolts, allowing the rack to fret on the upper mounts, leading to failure. Looking at yours, however, it appears there wasn't full penetration of brass into the joint ("cold joint") -- but that is just going off of one rather dark photo. I'd have to see in person to saw for sure.

The silver lining to this is you found it while prepping the bike, instead of mid-tour. You've got more ready options as a result.

Please let us know how you fare.

All the best,

Dan.

Thanks for the detailed reply. I have a Thorn Raven Tour, so I guess seatstays are a similar size as on the Nomad but marginally smaller. I'll try and give the nearby frame builders a call and see if they can squeeze me in. Would I be best putting my old mount back on?

bobs

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Re: What to do when your rack fails
« Reply #4 on: March 19, 2017, 11:36:18 pm »
You probably would,  but I would take a set of a tubus brackets as a standby.

Danneaux

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Re: What to do when your rack fails
« Reply #5 on: March 20, 2017, 12:08:52 am »
Quote
I have a Thorn Raven Tour, so I guess seatstays are a similar size as on the Nomad but marginally smaller.
<nods> Yep, 16mm OD as opposed to 19mm for the Nomad.
Quote
Would I be best putting my old mount back on?
The old mount should be fully reusable; I'd suggest taking it with the bike to the framebuilder's. I'd use some all-thread through the existing mount to locate and align the broken mount on the seatstay for brazing. Rebrazing will toast off the powdercoat in the area of the repair, so be prepared to shoot it with some paint After. One of the blessings of a matte black Thorn...easy to touch up almost invisibly with spray paint. Depending on the maker, I've found exact matches labeled matte, semi-flat, and even satin. If you need spot repairs, spraying into the can lid and then using a 0000 brush for touchups works nicely as well.

All the best,

Dan.
« Last Edit: March 20, 2017, 02:54:16 am by Danneaux »

mickeg

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Re: What to do when your rack fails
« Reply #6 on: March 20, 2017, 12:53:31 am »
Another option that is more a temporary measure is that there are some seatpost clamps that have built in rack mount fittings for those that have bikes without rack mounts.  But a permanent solution such as Dan suggests would of course be best.

This is an example of what I mean.
https://www.amazon.com/XLC-Seatpost-Clamp-Rack-Mounts/dp/B00OZZXONQ

The one above if it is the one I think it is is Aluminum and has a lip in the top of it that is intended to side on top of your seat tube and is used as a clamp to tighten the seatpost.  But if you filed off that lip and got the right size that could clamp onto the seatpost, that might work since most Thorns have a welded or brazed on seatpost binder bolt.

Here is another one.
https://www.amazon.com/Sunlite-Alloy-Seat-Clamp-Mount/dp/B00X0JQ0A2

Andre Jute

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Re: What to do when your rack fails
« Reply #7 on: March 20, 2017, 12:54:34 am »
I found Bob Jackson very reasonable and nice people. Since you have an account with them already from previous work, perhaps in an emergency like yours they will fit you in. It can do no harm asking.

rualexander

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Re: What to do when your rack fails
« Reply #8 on: March 20, 2017, 08:42:32 am »
Similar to mickeg's suggestion there is the Carradice seatpost clamp for Bagman racks that might do the job. Maybe SJSC would send you one out as a goodwill gesture, given that it's their braze-on that has failed.

https://www.sjscycles.co.uk/luggage/carradice-bagman-2-seat-post-collar/

lewis noble

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Re: What to do when your rack fails
« Reply #9 on: March 20, 2017, 09:25:21 am »
I have used devices very similar to the tubus mount, on a bike with no rack mounts on the stays at all.  They worked well, though with commuting rather than touring loads.

I cut up some old inner tube to size, and wrapped that round the stay before fitting, which I think enabled the mount to grip and secure better. Still working on the bike in daughter's daily commuting use.

Good luck!!
 

onebikeoneworld

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Re: What to do when your rack fails
« Reply #10 on: March 20, 2017, 05:40:23 pm »
Bob Jackson, and Dave at SJS, came through with flying colours. I spoke to Dave this morning, he called up Bob Jackson and the repair got approved under warranty. Spectacular customer service from Dave and SJS as always. As far as Bob Jackson, I turned up at 1pm and picked it up at 2pm with 2 new eyes installed. The only slight hitch is that it takes them 4 weeks to do a paint job, and so the exposed steel is going to get painted by me as a temporary measure. I'm going to get it done properly when I'm back in the UK at the end of the year.

For those interested in why it failed...when the guys at Bob Jackson looked at the frame they said that he could immediately tell it was a manufacturing issue. There had not been enough brass applied and so the eyelet was only being held on on the edge. I'm just happy it hadn't fallen off in 6 years so far. The reason it came off this time was that the bolt was in tightly so when it was undone it generated enough torque to rip the eyelet straight off.

onebikeoneworld

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Re: What to do when your rack fails
« Reply #11 on: March 20, 2017, 07:07:54 pm »
I forgot to include a picture of the job. Now it just needs a lick of paint.


bobs

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Re: What to do when your rack fails
« Reply #12 on: March 20, 2017, 07:34:53 pm »
Looks very much like a job well done.

geocycle

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Re: What to do when your rack fails
« Reply #13 on: March 20, 2017, 08:18:36 pm »
Fantastic service and a good outcome. Well done SJS and BJ.
 

mickeg

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Re: What to do when your rack fails
« Reply #14 on: March 20, 2017, 10:01:48 pm »
I have used black nail polish as a touch up for where there is chafing on my black bike racks.  That is convenient because there is a brush built into the lid.  That might not look too bad on the frame. 

But, if you do an ugly paint job on the frame, that makes it less likely it will be stolen.
« Last Edit: March 20, 2017, 10:08:15 pm by mickeg »