rack failure / obsolete spec.: on holiday

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latequartet
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rack failure / obsolete spec.: on holiday

Postby latequartet » 24 Jul 2015, 7:46pm

Is there an easy, cheap solution, while away on a family holiday, can get things posted to local bike shop?
Canondale Street rack 2.jpg
The grey bit on top of the rack is a separate item to mount a bike seat onto it.


The rack's failed, Canondale specific it seems, cannot find a replacement that will fit onto the frame, disc brake mounting racks won't work because the spindle has another bit of kit on it (for the FollowMe Tandem, to hitch two bikes together).

The problem is on the back frame there's only a tiny space (2.5mm) below the rear rack fixing point, before you come up against the screws holding the derailluer in place.

The bike's a Canondale Street (10 years old), the rack's failed on one of the frame fixing points, because the amount of metal below the fixing point hole is so thin, 2.5mm.
Canondale Street rack 1.jpg
Amazing they even made such a narrow piece, the other one's lost half of the curve now.
.

We don't want to spend much money ... I spotted a Tubus rack which did seem to be the correct size but over 100 GBP, hoping to spend twenty to thirty
Canondale Street rack 3.jpg
A view of the light / mudguard mounting point, 50mm gap between holes
We are in one location for the next two weeks, so can get something posted. I'd already looked at TorTec and an Avenir was posted out to us.
A towing-daily-road cyclist (without a car) with children and a wife. Cycling close to and on the NCN 6 in Sheffield.

Brucey
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Re: rack failure / obsolete spec.: on holiday

Postby Brucey » 24 Jul 2015, 8:17pm

go to a workshop (where they actually make stuff instead of just using spanners), have them drill three holes in a piece of 2mm steel, drill two holes in the rack end plate, bolt it all together, job done.

Or (even simpler) just drill a fresh hole each side of the rack, a bit higher up, and trim it back a little where you need to, to make it fit. The plate looks big enough for that.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

PH
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Re: rack failure / obsolete spec.: on holiday

Postby PH » 24 Jul 2015, 9:22pm

Yes, it's a simple bodge rather than a need for replacement. That 2.5mm of metal has lasted 10 years, that ought to give you some idea of the stress it's under.

latequartet
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Re: rack failure / obsolete spec.: on holiday

Postby latequartet » 27 Jul 2015, 11:27am

Thanks both, I appreciate your thoughts. Due to age of rack, 9 years, and aluminium / alloy and thinness above fixing holes I'm wary about Brucey's solution since it's used for 15kg son & 5kg bike seat. I have found a newer Cannondale rack that looks nearly identical ... so will try that next, then bodge, if one of 3 bike shops on Isle of Cumbrae will help.
A towing-daily-road cyclist (without a car) with children and a wife. Cycling close to and on the NCN 6 in Sheffield.

Vorpal
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Re: rack failure / obsolete spec.: on holiday

Postby Vorpal » 27 Jul 2015, 11:47am

If you use the newer Cannondale rack, it may be worth reinforcing the mounting, if you can. I think I'd be worried about something like that (for which you have already had a failure) supporting my child.

Is there any chance that your son getting heavier as he grows has caused the failure? If so, the next one might fail, too? I donæt want to worry you, but there's no guarantee that just because the last one went 9 years before breaking that the new one will too. Especially if it was causeed by the gradually incresing weight of your son. Do you know the published weight limit for the rack?
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CREPELLO
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Re: rack failure / obsolete spec.: on holiday

Postby CREPELLO » 27 Jul 2015, 11:51am

I don't entirely understand the problem. I can see that the lower rack mount comes very close to the mech hanger, as you say. Wouldn't any rack work by spacing the rack legs out a bit with washers to clear the mech hanger?

latequartet
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Re: rack failure / obsolete spec.: on holiday

Postby latequartet » 31 Jul 2015, 12:44pm

Thanks all: spacer could work, except it's still tight because of spindle adaptors that protrude for Follow Me Tandem. Will send pics. 25kg is the maximum and child / seat / adapter close to it (21kg).
A towing-daily-road cyclist (without a car) with children and a wife. Cycling close to and on the NCN 6 in Sheffield.

latequartet
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Re: rack failure / obsolete spec.: on holiday

Postby latequartet » 31 Jul 2015, 4:35pm

Here's the rack mounting adjacent to two derailleur mounting points and the FollowMe adaptor protruding from the spindle, plus the broken side.
Image Attachments
WP_20150731_003.jpg
WP_20150731_001.jpg
A towing-daily-road cyclist (without a car) with children and a wife. Cycling close to and on the NCN 6 in Sheffield.

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CREPELLO
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Re: rack failure / obsolete spec.: on holiday

Postby CREPELLO » 31 Jul 2015, 9:19pm

Spacers should work fine on that set up. Either washers or the spacers that come V barke pads. Any LBS should have a few spare from worn out pads.

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CREPELLO
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Re: rack failure / obsolete spec.: on holiday

Postby CREPELLO » 31 Jul 2015, 9:24pm

But I've got to say that I don't think you need a new rack. You just need to get a good shop/workshop to drill out a couple of new holes further up the alu plate, then cut off and file excess. A very simple job. I would still use spacers though to allow for more metal around the drilled holes.

That rear light might obstruct the mudguard, in which case, use longer bolts and......more spacers to put the light further out.

latequartet
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Re: rack failure / obsolete spec.: on holiday

Postby latequartet » 1 Aug 2015, 10:14pm

Thanks again, all, we've asked around and someone in the village has the know how / tools / time to help us; will let you know the end.
A towing-daily-road cyclist (without a car) with children and a wife. Cycling close to and on the NCN 6 in Sheffield.

wenty
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Re: rack failure / obsolete spec.: on holiday

Postby wenty » 2 Aug 2015, 6:24am

Hope you got it sorted out. I had a couple of Blackburn racks break under that childseat adapter. No drama but a few of the struts failed and when I investigated the new creaking sound...Couldn't find a "normal" rack to replace them (weight limits seemed too low or they advised against clamping things to them) so I ended up getting a Dutch bike rack which was rated up to about 40kg and came with the right "window" to attach the childseat and so didn't need the adapter any more.

TonyR
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Re: rack failure / obsolete spec.: on holiday

Postby TonyR » 2 Aug 2015, 8:17am

Vorpal wrote:Is there any chance that your son getting heavier as he grows has caused the failure? If so, the next one might fail, too? I donæt want to worry you, but there's no guarantee that just because the last one went 9 years before breaking that the new one will too. Especially if it was causeed by the gradually incresing weight of your son. Do you know the published weight limit for the rack?


It's an odd failure if I'm seeing it correctly because it's the underside of the fixing that has failed implying an upwards, not a downwards, force has broken it.

I would just go for a "mech hanger" approach and bolt a new bit of metal with a mounting hole in the right place to what's left of the old mounting plate.

latequartet
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Re: rack failure / obsolete spec.: on holiday

Postby latequartet » 2 Aug 2015, 8:55am

Yes Wenty and all concerned about weight bearing abilities of this sort of rack; we planned this as last season with this rack for that reason. It gets used most days with weight on it.

TonyR very interested by your question. Thinking about it I think the way we stowed the bike on the first train journey of the holiday--hung up with FollowMe still on--put pressure from the steel FollowMe pressing against the underside of the rack's rear strut. In future will be taking FollowMe off on Cross Country Voyagers where there's never enough height to allow bike+FollowMe to hang freely. Glad you wondered about this.

[Edited for grammar / clarity.]
A towing-daily-road cyclist (without a car) with children and a wife. Cycling close to and on the NCN 6 in Sheffield.

Brucey
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Re: rack failure / obsolete spec.: on holiday

Postby Brucey » 2 Aug 2015, 9:06am

very few riders pedal so smoothly that there is never any tendency for a rear carrier to sway; this being the case, rack mounts can fatigue in bending. Probably that has been an element in this failure.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~