Paging the metallugists

I need to reinforce the Elefant's front mudguards, and the recommended
way of doing it is to make up some pieces like this:
http://elefantadventurebikes.com/install_guides/forks.brakes/source/reinforcing.template2.html

Looks like it's probably easiest to get the aluminium off eBay, but:
what grade should I look for? And what thickness will cope with that
kind of shaping without cracking at the 90deg bends?

 

I actually know a serious expert in the field, to the point he has
alloys named for him. Unfortunately he's out of the country at the
moment, so I can't ask him.

 

Thin stuff - it won't crack if you bend it once. If it's drilled &
bolted to mount it, use rubber grommets.

--
Krusty
www.MuddyStuff.co.uk
Off-Road Classifieds

'02 MV Senna '03 Tiger 955i '96 Tiger '79 Fantic Hiro 250

 

I don't think I need a serious expert. One of the comedy experts from
round here will do.

 

Well, yes, but: how thin is thin? The last time I molished something
from aluminium it was to make a flat bracket, so thickness wasn't really
an issue.

1mm? Thinner?

It's going to be glued with some E-6000, something like this:
http://elefantadventurebikes.com/install_guides/forks.brakes/source/reinforments.install.html

 

I molished some brackets to hold the RatTig's front mudguard on using
ally flat bar from B&Q, & 90 degree bends were no problem. I'd guess
that was 2mm.

'This web page is not available'.

--
Krusty
www.MuddyStuff.co.uk
Off-Road Classifieds

'02 MV Senna '03 Tiger 955i '96 Tiger '79 Fantic Hiro 250

 

In message

Dr Mazac ?

 

2mm? Blimey.

Did you stick the URL back together?

 

He couldn't. He'd run out of E-6000

 

It didn't need sticking back together in XanaNews. Just refreshed the
error page & it's working now. Looks like a lot of grief just for a bit
of reinforcement.

If it's not visible, I'd just squish a bit of that aluminium body
repair mesh onto the offending piece & glue it.

--
Krusty
www.MuddyStuff.co.uk
Off-Road Classifieds

'02 MV Senna '03 Tiger 955i '96 Tiger '79 Fantic Hiro 250

 

Hmmm, that might work. But this is a known weak-point of the Elefant's
mudguard design (mine have snapped and been "professionally" repaired
once already), so I'd rather go a bit over the top and make sure it
stays fixed.

 

Heh. I was going to comment, but I couldn't really be arsed. I thought
that Pip, WUN or Andy would be along shortly.

P.

 

Is this vibration-caused damage? Thin ally sheet won't resist that for
long. If it's impact damage, then worth a go.

--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

 

I think, strictly-speaking, it's "Italian-design-caused damage". The
original moulding isn't really strong enough for the weight it has to
carry; once it's snapped, the only way to make an effective repair is to
reinforce it.

Looking at the diagram here:
http://www.oemmotorparts.com/oem5.a...EPH-1&O=BODY&F=CA-ELEPH-1_CA&L2=CA-ELEPH-1_CA

I'm reinforcing the "mudguard holder" (part 26 and 27) where it attaches
to the "front mudguard" (part 25) and the front fork (not on this
diagram, but it's where bolts 29 attach.

Someone suggested that I tape all the pieces together, use them to make
a mould, then make myself my own glass or carbon fibre replica, but
given the unmitigated disaster that was my one and only experiment with
glass fibre, I don't think I'll be bothering...

 

Ah, it's a vertical support for the mudguard. If the mudguard doesn't
bolt on anywhere else, I suspect vibration may have played a part in the
failure. Do bolts 30 and 33 go through a lug on the fork leg, or are
they just to join the upright support with the mudguard?

Iiwm, I'd look at glassing up the inside with a couple of layers.
--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

 

It's got USD forks, so they just bolt to the mudguard. I'm reinforcing
the mudguard, too.

*shudder*

 

Bit of bent ally bracketry might well be the way to go, then.

IME, glassfibre repairs around bolt holes are rarely successful,
long-term. Damned stuff don't stick to bike plastics, for a start.

Quick and dirty answer is glassfibre mat and plenty of resin, and
embed expanded mesh in it - and a washer round the hole to spread the
load would work for a year or two. Unless finished well, would look
like what it is, though - and be a bastard to clean down round there
too, so there's always be clag hanging around it making it look even
worse.

 

<narrows eyes, readies bat>

 

IANAM, but I've bodged ally plates into stuff before.

The thickness (thinness, actually) shown here is outside my
experience: looks like the sort of stuff you can cut with scissors,
FFS. I have a remnant of a chunk that was 2mx0.5m before Loz and I
started to use chunks of it, but that's 5.5mm thick. The thinnest
ally I've used recently is ~2.5mm thick and that isn't what I would
call strong.

I've bent the 5.5mm stuff through 90deg, quite easily in a vice with a
nylon hammer - made some rather nice replacement fridge door handles,
as it happens. The thicker the material, the larger the radius of the
bend required: you can't really get a square inside edge in a plate
like that with a hammer and vice and the outside of the bend distorts
at the edges, curling up a bit like a BR sandwich.

If you bend thin stuff with pliers, don't try to bend it right over
the nose of the pliers - start the bend where you want it, then shift
your grip back from the line 0.5mm or so and lever it round. This
avoids stretching the ally in the crease, which thins it and leads to
cracking. Clamping in a vice and gently rounding it over works well.

IWT that 1mm, bonded to the plastic like wot matey did would be good -
reasonably strong (well, stronger than broken plastic, anyway) and
capable of spreading the load of the mountings over a large enough
area to obviate repeated breakage. It won't shape like paper, but
with a bit of application you'll be fine. A large-diameter rubber
mallet will persuade most stuff to bend around and they're available
in most DIY sheds (or Screwfix) for a fiver or so.

HTH

 

Effing 'orrible stuff, it is.

I reckon I can knock up the required bits of aluminium pretty quickly,
once I've worked out what I need in terms of thickness and grade, and
it'll make for a much neater job than spreading resin everywhere.