Bleeding shock absorber hassles

In communiqué

It is odd. I've fitted non-standard shocks to various bikes over the
years. Hagon supplied me with a custom pair for the Rotarini (250 Morini
length, but much softer springs and IIRC slightly stiffer damping) which
worked surprisingly well.

I grafted a pair of Konis on to the 2C/375 that were meant for something
completely different. They were a tad too long and I had to weld some
pads on to the bottom of the centre stand to make it lift the back wheel
off the deck again. They also worked better than they should have by
rights.

Do Hagon list replacements for it, and if so what length do they reckon
they should be?

--
+-------------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Yamaha WR250Z/Supermoto "Old Gimmer's Hillclimber" |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+-------------------------------------------------------------------+

 

They give a list of different shock lengths for the same application
letter (A). Price £167.50.....

 

You generally have to drop the s/arm a bit, yes, because the old
springs will have got tired and compressed so the old shock will often
be slightly shorter than the new. But only shorter by a few
millimetres, not two full centimetres. Not in my experience, anyway.

 

They're OE shocks. looks, general wear and tear, etc point to that.
And a GN250's seat is only a few inches off the deck anyway. The
exhaust I binned was the OE one, as well.

And, like I said, the Wemoto-supplied 2-1 pattern system is identical
to the OE one it replaced. I actually matched them together - perfect
copy. Except for the finish which is definitely iffy.

 

In communiqué

I've tried to get a good photo of the rear end of a standard GN250, but
most are side (exhaust side) on. It looks to *me* as if the silencer
runs alongside the bottom shock mounting bolt anyway. In which case it
shouldn't be an issue if the hanger is suspending it in the right place.

Time to get your box brownie out I reckon and let the dogs see the
rabbit.

--
+-------------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Yamaha WR250Z/Supermoto "Old Gimmer's Hillclimber" |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+-------------------------------------------------------------------+

 

Yes, you're right: the silencer does run alongside the bottom mount.
But the mount is maybe two-thirds of the way up the silencer, IYSWIM,
and so the curve of the silencer body ensures that there is enough
clearance for the bottom mount *and* the domed securing nut, with the
standard shocks fitted. With the longer shocks, the bottom mount
clouts the silencer even *before* you add the domed nut.

I'll be taking some pictures in a couple of hours, anyway.

 

In communiqué

Part No. 33012. Perhaps that may mean they are 330mm, which would be
another vote for longer than yours.


--
+-------------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Yamaha WR250Z/Supermoto "Old Gimmer's Hillclimber" |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+-------------------------------------------------------------------+

 

Cut out the pies.

 

Even 5mm would make a difference. It's that tight.

 

Sounds like everyone's is longer than TOG's.

<snigger>

 

In communiqué

I see there are some listed on Ebay for £25 quid.

--
+-------------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Yamaha WR250Z/Supermoto "Old Gimmer's Hillclimber" |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+-------------------------------------------------------------------+

 

Trouble with buying second hand shocks from ebay is they tend to be just
as bad as the ones you want to replace.

 

*Ding*

 

True. Though in theory, if just one damper is bent on TOG's he might be
able to cannibalise something usable from all the bits.

He could also send a question to the seller asking the length.

Trouble is he's a perfectionist. If it was me I would be thinking about
a cunning spacer on the silencer mounting bolt after a bit of adjustment
with a broom handle and a none-domed shock nut.

--
+-------------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Yamaha WR250Z/Supermoto "Old Gimmer's Hillclimber" |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+-------------------------------------------------------------------+

 

<snip>

Right, the plot thickens. A bloke in our company has a TU250 which he
paks next to mine. Exactly the same bike, barring some bodywork changes.
Rear shocks are the same. His are OE too, and they measure...

....315mm (or as near as)

These are the pictures of mine. The first is the two shocks side by
side. The second is of the adequate clearance between mount and exhaust,
with the original shocks. And the third is the lack of clearance with
the replacements.

http://www.neil_murray.fastmail.fm/GN250Shock1.jpg

http://www.neil_murray.fastmail.fm/GN250Shock2.jpg

http://www.neil_murray.fastmail.fm/GN250Shock3.jpg

 

I think I may have had this sort of trouble with the replacement shocks
for my 400 4. They were cheap chinky shocks but from David Silver.
I ended up with the bottom nut almost hitting the exhaust after a what
seemed a suspiciously difficult fitting session.
Might explain my uncertainty about the handling too. I've been
suspecting a bent frame because the exhaust bracket nearly touches the
swing arm but now I'm beginning to wonder.

 

If it were mine, I'd definitely be spacing the exhaust out a bit then
hammering a small dent in it too if necessary. It's not like it's some
immaculate, original bike after all.

 

Or simply dont use a domed bolt? That would be enough to clear wouldnt it?
--
Gavin.

Moto Guzzi California Aquila Nera
Suzuki GSXR600K1
Twitter: http://twitter.com/gavin_wilby
Blog: http://www.eekafreek.com

 

Still a bit tight. I wonder if the silencer mounting got pushed in a bit
by the same incident that bent the damper rod.


--
+-------------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Yamaha WR250Z/Supermoto "Old Gimmer's Hillclimber" |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+-------------------------------------------------------------------+

 

Pht, you should see the Guzzi, the clearance is fag paper thin.

--
Gavin.

Moto Guzzi California Aquila Nera
Suzuki GSXR600K1
Twitter: http://twitter.com/gavin_wilby
Blog: http://www.eekafreek.com