Wisper Bike rack cracked

Hi all

 

I have a Wisper 2019. In the last year, the rack frame which came as part of the bike has broken on both sides of the bike.

 

This means the whole rack makes a terrible noise every time I ride over the smallest bump in the road, of which there are many in the UK.

 

I spoke to Wisper who informed me that the rack frame is excluded from the warranty. Really don't understand that, as it comes as part of the bike as standard.

 

I was told it would cost £72.50 to buy a replacement and that there is no stock currently. That was a few months ago, I have sent emails recently asking for an update and now Wisper is ignoring me!

 

I have tried holding the two broken parts together with a clasp but it comes loose. I was told it cant be welded either due to the nature of the metal used.

 

I have attached photos of the broken rack frame. Does anyone have any ideas on what I could do?

 

Many thanks

What's the inner diameter of the tube, and can you pull the break apart far enough to slide a short copper rod inside, bent in the middle to the right angle? Then drill through the tube ends and copper rod after pressing the break together, bolts though and nyloc nuts to secure? I'm sure others will come up with better suggestions.

 

https://www.ebay.co.uk/itm/194501354717

 

 

 

Aluminium rods are also quite easy to bend. Vice > hammer.

 

https://www.ebay.co.uk/itm/284045182877

 

Edited September 24, 20241 yr by guerney

It looks like aluminium, so it has probably failed due to a fatigue crack originating at the inside of the bend.

 

I would add a support hoop from the lower mounting bolts each side up to the rearmost bolt under the battery. Stainless steel strip, about 25 or 30 mm wide, maybe 3mm thick.

Hi all

 

I have a Wisper 2019. In the last year, the rack frame which came as part of the bike has broken on both sides of the bike.

 

This means the whole rack makes a terrible noise every time I ride over the smallest bump in the road, of which there are many in the UK.

 

I spoke to Wisper who informed me that the rack frame is excluded from the warranty. Really don't understand that, as it comes as part of the bike as standard.

 

I was told it would cost £72.50 to buy a replacement and that there is no stock currently. That was a few months ago, I have sent emails recently asking for an update and now Wisper is ignoring me!

 

I have tried holding the two broken parts together with a clasp but it comes loose. I was told it cant be welded either due to the nature of the metal used.

 

I have attached photos of the broken rack frame. Does anyone have any ideas on what I could do?

 

Many thanks

I repaired a motorbike rack that broke when I accidentally tried to drive away with my lock through the rack and wheel. It lasted many years after the repair. I simply bandaged it with fibreglass. It didn't look fantastic, but it was functional. You can always paint it afterwards. You could stuff some inside the tube as well for extra strength.

I would fit a triangular gusset on each external side, much like but larger than the existing pannier bottom clip ones.

These I would cut from aluminium sheet (like this example) fixing them with pop rivets. I would exploit the full 120mm width of the example sheet, the larger basically here the better functionally enabling say four equally spaced pop rivets on each side of the triangle. On completion Hammerite paint to match or to complimentarily contrast.

 

Edit: It would IMO do no harm to bed the gussets onto the tubes with a good polyurethane bonding agent like one of the more available Sikaflex products. Obviously having thoroughly degreased the bonding surfaces immediately before making the joint. Then when "set" make the pop rivet holes and fix the rivets again with a smear of the bonding product. I would have very locally scrapped the paint off the tubes, so the bond is directly to the aluminum tube not the paint, it is a stronger joint made that way and the bonding agent will readily replace the corrosion protection the paint had previously given.

Edited September 25, 20241 yr by Ocsid

I don't think this was ever a warranty issue. You normally only get 1-3 years max for general parts etc and only the main frame and rigid forks go beyond that. I assume this is a bolt on rack to the main frame. As for welding is it heat treated aluminium? It might be possible to weld it if you have the skill and equipment as it may not be heat treated anyway and even if it is, it might still be worth doing. Also what is the clamp in one of the images is the bike being suspended by a repair stand by its rack? If so surely that would be out of normal use. Apologies if its not that I couldn't make out what that clamp was clamped to the rack.

 

As for the repair itself many of my fixes aren't very elegent so would probably use wood inside each tube as tight as possible with glue to keep it in shape, then wrap around some thin metal plate (just thin enough to bend around) glued as well and secure with a couple small hose clips each side before painting over. To be honest though most of my fixes revolve around what I can find at the time.

 

I personally don't think it would be fair to expect Wisper to replace this rack free of charge. It's obviously quite a high value part and well out of its guarantee period I would of thought.

I agree that after five years this isn't a warranty issue but it's pretty poor that Wisper cannot sell you a replacement rack. It looks like your bike is a Wisper 905 which is a current model. Surely they should have spares?

 

Why can't a gusset be welded over the broken part of the rack?

 

Clearly the lower pannier attachment point has been welded on.

 

I'd be inclined to to the rack off and take it to a welding shop and ask their advice.

 

Also, you might want to stop using the rack as the attachment point for your bike stand.

 

But in the meantime if the only problem you're having is noise, how about wedging a piece of rubber between the broken points of the rack?

Given that the rack is carrying the battery and that this was sold as an ebike, I think it is a bit much that the supplier doesn't treat it as part of the bike. It isn't an ancillary part added on if you bought it as an ebike and the rack carries the battery. It clearly isn't up to the job of carrying the weight if it broke.

 

 

When aluminium is welded, it needs to be heat treated afterwards, otherwise strength in the vicinity of the weld is reduced. Straightforward during production, not so easy after a repair.

 

The most common failure with aluminium parts is fatigue, and that always starts at a stress concentration, for example a place where the cross section changes abruptly. Combine that with high load, and failure is only a matter of time.

 

Zoom in and look at the far side, you can see the crack starts right at the edge of the mounting tab weld, which is right next to the bend that is heavily loaded over every bump as the battery weight acts on it.

 

 

Welding a gusset on might give a short term fix, but it is likely to break again at the edge of the gusset weld. A gusset fixed by rivets will fail at a rivet hole.

 

A gusset fixed in a way not involving welds or holes will be successful!

Edited September 26, 20241 yr by matthewslack

Good morning,

 

We are waiting for those particular racks to arrive, unfortunately we ran out of stock recently, we have two racks that are very similar, the ones we have in stock won't fit older bikes. It may be another 6 weeks before they arrive in the UK. It is possible that we may have one on a bike that's coming back from the National Motor Museum, Beaulieu, I will get the guys to see if it's back yet. We have very little call for them but it is a part we should have, sorry for the inconvenience.

 

Our frames and racks all go through two heat treating processes, so we dont see many breakages, but it can happen.

 

All the best, David

Thanks everyone for your suggestions. I an not very savvy with the type of fixes suggested so I doubt I am able to carry them out. The clamp someone asked about it is a fix I tried - a washing machine hose clamp that I hoped would keep the frames bound together along with some tape, but it only lasted a day and then comes loose

 

I will probably have to wait until the stock comes back into Wisper so I can change the whole thing.

 

I dont know how I could use rubber to stop the banging noise but I guess it would help. I will look into the fibreglass suggestion.

Perhaps just get some 2 part epoxy metal putty, there are a number of brands jb-weld is well known, mix up a load, its like blu-tak/plasticine Id roll a sausage and poke it into the tubes, perhaps with a nail or screw.

 

prep the rack tubes with sandpaper and degreasing alcohol or solvent, And add a wrap of putty around the break and its connecting parts, you can sculpt it like clay and you can sand it down for an ultra smooth paintable surface..

 

just wear gloves, and if you muck up, scrape it off n start again, if it starts to cure (very unlikely it can taake an hour or so to start.. just mix up another dollop

It would probably take you longer to replace the rack than repairing it. You would have to remove the controller box or the controller from the old rack and transfer it to the new rack.

To repair the broken tube you may need to insert a bent round aluminium rod to line up both sides of the break and give it support then epoxy both sides of the broken tube to the inserted rod. I reckon fibreglass would work well too.

Good afternoon,

 

We can supply the rack from the National Motor Museum this week. Please drop me a line so we can sort out paperwork. David@wisperbikes.com it’s brand new, unmarked and unused.

 

All the best, David

I love you know if a 48v battery would fit in that rack. Just asking for a friend..

Edited September 29, 20241 yr by Wayners

I love you know it a 48v battery would fit in that rack. Just asking for a friend..

 

Not that we can supply, the best we can do is 36V 750Wh.

 

All the best, David

Given that the rack is carrying the battery and that this was sold as an ebike, I think it is a bit much that the supplier doesn't treat it as part of the bike. It isn't an ancillary part added on if you bought it as an ebike and the rack carries the battery. It clearly isn't up to the job of carrying the weight if it broke.

 

 

[ATTACH type=full" alt="59939]59939[/ATTACH]

 

It is outside the warranty period and many small ebikes come with even lighter duty racks which have their battery mounted to. A rack can be overloaded or wrongly used to suspend the bike for repairs etc.

Good morning,

 

Good morning,

 

Why battery is so high and so far away from seat tube if I might ask? It looks like a bad design to me.

It's worked very well on the more than 6,000 806's we have sold, we get very few issues.

 

We will be running the current 806 for at least another 12 month as sales are accelerating on this model with about 1000 sold this year alone.

 

We do have a new model due to launch in the spring of 2025, lots of new features and the same price as the existing 806 Torque. We have decided after much deliberation not to go seat post or down tube but keep the rack as for this kind of wide low step through design it works very well. The extra few KG really dont make much difference to the handling when you consider there is probably 80 to 100KG sitting almost immediately above the battery.

 

Perhaps just get some 2 part epoxy metal putty, there are a number of brands jb-weld is well known, mix up a load, its like blu-tak/plasticine Id roll a sausage and poke it into the tubes, perhaps with a nail or screw.

 

prep the rack tubes with sandpaper and degreasing alcohol or solvent, And add a wrap of putty around the break and its connecting parts, you can sculpt it like clay and you can sand it down for an ultra smooth paintable surface..

 

just wear gloves, and if you muck up, scrape it off n start again, if it starts to cure (very unlikely it can taake an hour or so to start.. just mix up another dollop

Thank you so much for this suggestion. I will give it a try. How do I put a nail or screw into the mix? Where would it need to be placed? And what size?

 

I had no idea changing the rack was such a big job in that the controller would need to come off. I dont think that is something I could do, so yes perhaps a repair would be easier.

Thank you so much for this suggestion. I will give it a try. How do I put a nail or screw into the mix? Where would it need to be placed? And what size?

 

 

 

Just bear in mind this is my initial approach.. often its my 2nd or 3rd that takes..

just clean out the tubes poking a rag with solvent on to degrease best you can for at least an inch each side..

 

them roll a sausage of epoxy fold it in on its self and plug up at leas an inch of tube poking in if necessary to ensure its in and solid..leave a little extra on each too.

 

to re enforce further a 2cm or so length of nail or screw with the head chopped off or bit of steel coal hanger, or the nearest thing on the garage floor in my case , and shove it in about 1/4-1/3 in one side before squishing the two together twisting a cord loop might be needed to squeeze out excess putty and close the gap fully

 

A solid plug of epoxy is probably stronger than the rack so the nail is optional and only needed if you think the 2 ends need help adjoining.

 

just be mindful of closing the gap and releasing before clamped tight, if it breaks open stuff more putty in and re squeeze clamp. Edit this is critical, you want a solid plug of resin not 2 plugs..

 

then once clamped tight smear some round the crack and smooth down for looks..

 

sanding is best done after a few hours and before fully cured as its solid stuff.

Edited October 1, 20241 yr by thelarkbox

OK. So I tried (using this JB Weld Original Cold-Weld 8265-SUK Steel Reinforced Epoxy - Dark Grey (Packaging may vary) : Amazon.co.uk: DIY & Tools )

 

Unfortunately, it didnt work. I let it set for 48 hours and then took the bike out and it immediately just broke apart after just a few minutes.

 

Going to have to just buy a new rack. Sigh.

You used the wrong stuff, you need epoxy putty not glue (and plenty of it) to make a sausage that can fill both tubes completely for at least 15mm and something in the middle like a screw or tube to give additional support.

That bend is highly loaded, and simple bodge repairs are not going to work. The load needs taking away from the corner, which can be done using a fairly large triangular support plate.

 

If you have the tools then you could try this.

 

I would use aluminium sheet, 2mm thick is probably sufficient. A triangle, mounted on the existing rack mounting bolt, with its top edge roughly horizontal, and the other two edges with a wide margin bent around the rack tube to support it. Ideally bent all the way round with a flange sitting flat on the main part of the triangle, then secured with rivets. Rivets close to the rack tube will squeeze it all nice and tight.

 

You can buy small amounts of suitable aluminium off Ebay for a few £, and it will be the easy to bend fairly soft variety.