fender cracked after installing extender

[gpd211]

I installed the fender extender over the winter. I took the fender off, cleaned it well and allowed it to dry. I used the adhesive supplied with the extender and drilled two holes and put stainless bolts through. The black caps go under the bolt head (like a washer and then cover the bolt). I put locktite on the bolts and didn't tighten them down too much (apparently too tight though). Luckily a new fender is only around $100 (thank god for plastic). Just wanted to give everyone a heads up not to tighten a fastener on the fender too tight.

 

[dog]

Luckily a new fender is only around $100 (thank god for plastic).

Bummer! So is that $100 for a pre-painted silver one?

 

[SuperMek]

There you got it!
Never ever use lock-tite when there is any plastic nearby. It WILL crack!

 

[gpd211]

Bummer! So is that $100 for a pre-painted silver one?

Yep $114.52 for front fender in digital silver

 

[L.B.S.]

Ouch! Sorry to see that happen

My extenda has been gathering dust since before I bought the bike, lol. Have been too lazy to put it on (regret that) but didn't really want to use screws or bolts. Not too trusting of only adhesives either, so I'm probably going the glue+rivet route if my lazy self finds the time.

If mine cracks or splits, I will just bodge up some DIY plastic repair, paint it flat black, and call it a day. Being factory black color up here in Canuckland makes that easier for me anyway.

 

[Ramseysteve]

I went straight to stainless steel rivets. Looks like a slight case of overkill with 6 rivets, but the ones nearest the front ended up very close to the front edge of the extender (I know, measure twice, drill once) - I just didn't fully take into account how the shape of the extender cuts back.

 

[showkey]

There you got it!
Never ever use lock-tite when there is any plastic nearby. It WILL crack!

Think you found the cause.................................

 

[DanH]

It looks to me like the head on those fasteners are something in the neighborhood of 1-1.5 cm in diameter and cause quite a bit of deflection across the curve of the fender. With smaller fasteners you probably won't have that concern.

 

[ziggie]

Those do look big.i went the 8 mm bolt.plus the match the others on the bike at different places.

 

[Spaceteach]

This may have nothing to do with it, but it looks like the fasteners are at least twice as far from the edge of the fender than the instructions call for. One thing I noticed when I installed mine was that the extender seemed to fit flush around the edge, but there was a gap between the extender and fender in the middle. I assumed they did this to accommodate the thickness of the adhesive tape. From the picture, it looks like the fasteners were installed far enough away from the edge to be in that gap which deformed the fender and caused stress cracking.
I may be wrong, but I think the location of the fasteners caused the problem.

Bob

 

[ziggie]

I was just looking at mine and and they are not that high up.that could be the cause.good call.

 

[670cc]

I think I use neoprene washers under the bolts heads of mine. I used self locking nuts. No Locktite. Did apply beads of black silicone RTV as an adhesive and to fill/bridge any gaps in the interface between the fenda and the extenda. No problems so far.

Thanks for the warning, though.

View attachment 341

 

[DanH]

I think I use neoprene washers under the bolts heads of mine. I used self locking nuts. No Locktite. Did apply beads of black silicone RTV as an adhesive and to fill/bridge any gaps in the interface between the fenda and the extenda. No problems so far.

Thanks for the warning, though.

View attachment 341

That is a good looking install.

 

[Blackrider]

I just used some heavy duty silicon caulking. I don't think mine is coming off.

 

[StratTuner]

I went straight to stainless steel rivets. Looks like a slight case of overkill with 6 rivets, but the ones nearest the front ended up very close to the front edge of the extender (I know, measure twice, drill once) - I just didn't fully take into account how the shape of the extender cuts back.

View attachment 3816

Novice here: How do you install rivets?

 

[DanH]

Novice here: How do you install rivets?

Rivet is a generic term for any fastener that holds by deformation as opposed to threads or whatnot so there are lots of methods depending on they type of rivet you choose. The rivets depicted are pop rivets. You can go to you local hardware store and ask for a pop rivet gun and starter pack of assorted rivets and leave about $20 lighter in the wallet. To use it, drill an appropriate sized hole. Insert the appropriate sized rivet in the gun, put the rivet through the hole and squeeze until it clicks and lets go. Rivet installed.

 

[Spaceteach]

If you want to use pop rivets, you can google pop rivet instructions and find step by step instructions. You can also get washers for pop rivets and it would be a good idea to use them in this application since you are riveting two fairly thin pieces of plastic.

Bob

 

[TC3]

I just used waterproof silicone sealant and did the same on my previous bike. Never became loose in 5 winters of riding so am pretty sure the one on the NC is going no where.

 

[DanH]

I just used waterproof silicone sealant and did the same on my previous bike. Never became loose in 5 winters of riding so am pretty sure the one on the NC is going no where.

My fender extender should be in the mail shortly and that was my plan for installation - maybe a couple of self threading screws on the side if it was wiggling loose over time. I shall approach that method with confidence now.

 

[670cc]

When deciding how to mount the Fenda Extenda, try to imagine the consequences of it coming loose if the fastening method failed. It could simply blow off and go winging off to the side of the road, never to be seen again. OR, the lower edge could droop and that "leading" edge could catch the upward spinning tire tread. Would it simply rip the extender off, would it break the fender in the process, could it wedge in and lock the front wheel? Something to consider.

Greg