Fender Extender

[Yamazer-92]

Just had a new front mudguard / fender arrive in post today, I want to refit my fender extender but don't really want to be drilling into a brand new mudguard as I believe that is the reason for the old mudguard to have huge cracks at the rear. Is there any one who has used some sort of glue / sealant instead and not had to drill holes? If so where can I buy some from?

[Freck]

The Pyramid ones now come with self adhesive fixings, no drilling required - look here:


http://www.ebay.co.uk/itm/121634442150?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


Steve

[john 087]

like you i didnt want to drill. i used b&q heavy duty glue and jamed a rag between the wheel and extender over night,it hasent movent since i did it.

[Fazerider]

I used black silicone sealant when I did mine in 1998... it seems to be holding OK.

[fazersharp]

You all seem to be ok with glue and silicone but I would not trust it, because if it comes off its going to follow the tyre travel and go under and jam between your fender and tyre.
Can you do the same as the hugger is fixed with a bolt through a rubber tophat grommet and a metal bush so that no metal touches the plastic and the metal bush is something to tighten up against and not the plastic fender     

[darrsi]

Just drill the holes, it'll be fine.
Worthy piece of kit too, keeps the downpipes much cleaner than without.

[chunk166]

Number plate tape from Halfrauds should hold it in place

[darrsi]

I'll warn you now, it's a bit disturbing when you run over gravel with a warm tyre, 'cos it sounds like your front end is disintegrating with the extender on. 

[Yamazer-92]

I have had an extender on for a couple of years, but like I said I removed my old fender recently due to it unfortunately getting paint damage from brake fluid. When I removed the fender from the forks and then removed the fender extender, there was a 6 inch crack along the rear middle of my fender and spider web cracks around all 3 holes. The fender extender was actually holding all this together so tightly it was only visible as a 2cm split and some slight spider web cracking, but on removal the actual damage was very severe. Anyway thats why I dont fancy drilling again.


I went to halfords and got some "serious glue" which was a bit of a pain as it was hard to clamp the curved surfaces and it took ages to set and go tacky, but it's all solid now and I am very pleased with it. It's fully waterproof etc. I can't see it coming off in a hurry as others have done similar and never had problems, I think it would be just as likely for the screwed in fender to crack to the point of totally snapping off. I'll let you know how it goes and yeah I agree darrsi they are well worth fitting to your bike for anyone who is thinking about getting one.

[Grant]

I've just done exactly the same this last weekend.
I didn't want to drill the front mudguard/fender either as this is introdicing a point of weakenss and will be the initiation points for cracks to propegate from over time with vibration.
I used a solvent free two part epoxy adhesive, that is water proof and sets in 5 minutes.
Sanding the two mating surfaces with something like 320 grit and then cleaning with meths provides a good, grease free contact area for the surfaces to bond with the adhesive.
It's ablsolutley solid and looks a very neat job.

[fazersharp]

what about melting holes with a hot nail perhaps that would reduce the likelihood of stress cracks further down the line

[Grant]

Any hole introduced to a structure - whether drilled, bored, reamed, burned or melted is a point of weakness and a stress raiser unfortunatley.
Some locations make that effect much worse, such as at the end of beam/cantileaver that is subject to movement at the extremities from the pivot/mounting point, especialy high speed oscillation (vibration) like at the end of the mudguard/fender.
Melting would seem better than drilling (and reaming for better surface finish to reduce risk of cracking), but the brittleness and hardening of the plastic from the heat would more than likely make the situation worse and speed up the cracking process - engineering is always a compromise.

[clayt74]

I fitted mine 3 years ago using black silicone sealant. I roughed up both mating surfaces with very course sand paper, cleaned both faces with some IPA and covered with sealant. I made sure of a nice continuous bead all around the edges and let cure for 48hrs using a couple of clamps to hold together. It is still absolutely rock solid!! And I use the bike all year round.
I wouldn't over think it.

[Frosties]

The thing I find weird about this topic is that typically to STOP a crack continuing in plastic, perspex etc you would drill a hole at the end of the crack. Got mine to fit and will start with a 1mm drill and work my way up. Just my 2p worth.

[Grant]

You are right Frosties - stop drilling is a proven method, but its only temporary.
We use that method on aircraft all the time but at some point the item has to be replaced as the crack finds another route from the stop drilled hole and continues to failure.  Granted the stresses on airframes are more severe, but the same effects are in force on the mudguard/fender.
In this case though I think clayt74 is right - probably overthinking this.....its just a couple of bits of plastic in the end 

[Frosties]

You are right Frosties - stop drilling is a proven method, but its only temporary.
We use that method on aircraft all the time but at some point the item has to be replaced as the crack finds another route from the stop drilled hole and continues to failure.  Granted the stresses on airframes are more severe, but the same effects are in force on the mudguard/fender.
In this case though I think clayt74 is right - probably overthinking this.....its just a couple of bits of plastic in the end 

Think you're right Grant - sod it, might just rough it up and use the silicone then