Retrobike Forum Index

It is currently Thu Oct 01, 2020 1:43 pm

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 10 posts ] 
Author Message
PostPosted: Mon Jun 23, 2014 11:31 pm 
retrobike rider
retrobike rider

Joined: Sun Jan 24, 2010 12:32 pm
Posts: 344
Location: Northants
Anyone tried to cast their own elastomers? Seems like plenty of people have done it to make custom engine mounts and suspension bushes.

Other than the hardness, I'm not sure if all 2 pack polyurethane is the same and whether it is all suitable.
Was going to get some of this for a play unless anyone can suggest something better.

Ten quids worth of material would keep an awful lot of forks going if it works!


Top
 Profile  
 
PostPosted: Tue Jun 24, 2014 10:00 am 
Retro Guru
User avatar

Joined: Tue Jun 25, 2013 10:47 am
Posts: 1197
Now that is interesting!

But I have to say the hardness is very important. We had the discussion about where to get new elastomeres from in the German classic bike forum. And there are some companies around that sell elastomere "sticks" in the correct diameter. You only have to cut them to the right length and boar a hole in case your fork/frame needs it.

BUT.

The they are usually too hard. IIRC the softest are ~70 shore. I for instance would need something about 50 to 60 shore. I weight 85kg.

But if it only about getting the fork to work and look ok: Use something like this:
http://www.ebay.de/itm/like/11138248495 ... ue&viphx=1
These are synthetic wine corks and this is as cheap as it gets ;)


Top
 Profile  
 
PostPosted: Tue Jun 24, 2014 12:16 pm 
retrobike rider
retrobike rider

Joined: Sun Jan 24, 2010 12:32 pm
Posts: 344
Location: Northants
Well, the compound I am thinking of getting is 60A, which from a bit of googling sounds like a medium fork elastomer.
I like the idea of casting as drilling and cutting soft polyurethane is tricky.

Just hunting around for a good mould now.


Top
 Profile  
 
PostPosted: Tue Jun 24, 2014 12:41 pm 
Retro Guru
User avatar

Joined: Tue Jun 25, 2013 10:47 am
Posts: 1197
phill77 wrote:
I like the idea of casting as drilling and cutting soft polyurethane is tricky.


Absolutely. Please report your outcomes :D


Top
 Profile  
 
 Post subject: Re:
PostPosted: Sat Aug 08, 2020 6:14 pm 
Retro Guru

Joined: Wed Apr 03, 2019 4:25 pm
Posts: 330
Did you ever cast any?


Top
 Profile  
 
 Post subject: Re:
PostPosted: Sat Aug 08, 2020 7:41 pm 
Retro Guru

Joined: Wed Apr 03, 2019 4:25 pm
Posts: 330
I got an email from a casting supplier, SmoothOn; in their product line a (shore80 a & shore 90 a) urethane rubber with the name pmc-780dry & pmc-790. They cast amber & light amber. It’s possible these are the same materials as the company supplying suspension fork replacement elastomers.


Top
 Profile  
 
 Post subject: Re:
PostPosted: Sun Aug 09, 2020 12:41 am 
Gold Trader
Gold Trader
User avatar

Joined: Fri Jan 23, 2009 2:30 pm
Posts: 16708
Location: Surrey
Cutting elastomer isn't that tricky. If you buy it with the bore hole in you can slot some wood in it to keep the shape. Better still. If you have a vice tool for clamping rear shock shafts you can use this to help hold the shape even more while cutting.


Top
 Profile  
 
 Post subject: Re:
PostPosted: Sun Aug 09, 2020 12:44 pm 
retrobike rider
retrobike rider
User avatar

Joined: Fri Mar 13, 2009 7:19 pm
Posts: 3463
Location: Leeds, for ages!
I'm not sure how this thread relates now but, I know sod all of casting.

However you can save a load of effort, alchemy and probably money by buying this..


See below...

I bought some to revive a shock post with certain success and rockshox indy with some follow up to do, mine has no bore hole, on below has it ready casted.

Can be bought by selected diameter and as fore shore rate....the stuff below is very much medium. I reckon its red counterpart is to a more firm shore rate.


Attachments:
20200809_123739.jpg
20200809_123739.jpg [ 82.33 KiB | Viewed 353 times ]
Top
 Profile  
 
 Post subject: Re:
PostPosted: Sun Aug 09, 2020 7:49 pm 
Retro Guru
User avatar

Joined: Mon Oct 08, 2007 9:01 am
Posts: 1422
Location: Rhuddlan - North Wales
PM John Deverill (I think!) - sells through eBay too. Does the all sorts of fork kits, good price too considering you don't need to put in effort getting the right grade, cutting it, boring it etc.


Top
 Profile  
 
PostPosted: Sun Aug 09, 2020 9:11 pm 
retrobike rider
retrobike rider

Joined: Sun Jan 24, 2010 12:32 pm
Posts: 344
Location: Northants
Well following up from my original post, I found some plastic caps from work which were the perfect size for Manitou elastomers.
I mixed up some 60 shore 2 pack but got the ratio slightly wrong and they didn't harden/cure completely.
Then family got in the way so I bought some replacement elastomers from Pace which were the right stiffness. However they were too long but rather than cut them I increased the travel of my Manitous with some longer bolts.
Every other fork I have is air spring, so never bothered again and it sounds like the chap on this site who started selling Proflex elastomers has everything covered if required.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 57 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

About Us

Follow Retrobike

Other cool stuff

All content © 2005-2015 Retrobike unless otherwise stated.
Cookies Policy.
bikedeals - the best bike deals in one place
FatCOGS - Fat Chance Owner's Group

Powered by phpBB® Forum Software © phpBB Group