I’ve exhausted all avenues I can think of so I thought I’d ask here as it always seems to be the font of all knowledge.

I’ve got a 1951 Automoto AV125 with some knackered suspension rubbers – here it is –

[url=https://flic.kr/p/t4sZQ5]IMG_2221[/url] by mattbowns, on Flickr

and the knackered bits, this is the ‘good’ side (there are more pics on Flickr)

[url=https://flic.kr/p/s7SG58]IMG_2968[/url] by mattbowns, on Flickr

[url=https://flic.kr/p/sM6upf]IMG_3102[/url] by mattbowns, on Flickr

They are the top out bumpers and have perished with age. They are a simple tube 50mm/2inch OD, 31.8mm/1.250inch ID that’s 25mm/1inch long. After searching for geniune parts (no luck) I’ve been looking for an existing bump stop to use as a starting point. So far I’ve only found these which have the correct OD and length but I@m not sure how I can put a hole through the centre. I have a lathe, mill, pillar drill etc (full framebuilding workshop) at my disposal but I’ve never worked with rubber.

So I’m wondering if any of you lot work in the rubber industry and can advise me either on how to cut a hole through the centre of the part linked to above, where to buy the right kind of rubber as a 50mm diameter ‘bar’ or (*crosses fingers*) where to get something the right shape that I don’t need to do anything to

For things of this nature first name that springs to mind Is porter_Jamie on here

Failing someone coming up with an off the shelter its relatively easy to cast some in silicone rubber but your still going to need a mold
Sometimes

For things of this nature first name that springs to mind Is porter_Jamie on here

Personally I was thinking more along the lines of Ron Jeremy 😀

You could have a go on the lathe or mill. Freezing it is supposed to help. Use co2 from a fire extinguisher/paintball gun. Nice sharp tool. Or just take the stop you found and drill it with a hole saw. Won’t be a particularly smooth edge and the hole will likely finish up under size as the rubber moves out the way if the tool. I suspect that will be good enough for the application. If you want it precise then moulding is an option, maybe in polyurethane. Easy to make a mould on the lathe hand the casting is fairly easy, just a two part mix. You can even 3D print rubber.

Frost.co.uk do rubber moulding kits in different hardnesses might be worth a try.

It looks like a big rubber O-ring.

Similar to itstig’s link these guys provide diy kits but they can also custom make to your specification:

http://www.aceseal.com/custom-rubber-molding.html

Cheers guys. I had thought of moulding something but didn’t know where to start with the hardness, the bike is light but I think these will still take a hell of a beating. I’ll get reading.

My fallback is to get the parts I linked to and pull the metal bits out then modify an old holesaw so the entire edge is sharp (like a circular knife) and use a hydraulic press to force it through with a bit of silicon lube to help it. If that doesn’t work then I could try it in the lathe but I’d read that it needs to be really cold (liquid nitrogen cold) for that to work. The ID isn’t critical or the surface finish inside, I just want to the outside to look vaguely right

Thanks!

I’ve moulded rubber parts from liquid 2 part polyurethane, shore (hardness) 70 for diff mounts / bushes maybe 60 for bumpstops? I bought 500g off ebay.

I’d try the press cutting approach too, though the resulting cut will be tapered as the rubber compresses. Sounds like that might not be a major issue. Does steel pipe exist at a close enough diameter? Probably easier than modifying a hole saw.

Tapered hole shouldn’t be a problem as long as it clears the tube/shaft inside which is 31.8mm (or 1 1/4 inches). I’ve got loads of offcuts of tube and holesaws all in the same common sizes – 32mm/1.25″, next up would be 35mm/1.375″. Using tube or an old holesaw makes no difference to me really, it’s just the holesaw will have a solid back to push against. I’m sure I’ve got a knackered 35mm holesaw so I’ll chuck it up and see how easy it is to get rid of the teeth, if that fails I’ll use an offcut of 853 like a tart

I think I’m going to place an order for those parts, got to be worth a punt for a fiver each

Ive just put some of These on a generator.

link
There threaded but you may be able to push the thread out with a socket and increase the hole size?
then trim them down.

If you can get me the critical dimensions, I could 3D print you some replacements…

Merchant Banker – Doesn’t look to me like there’s enough rubber on those for it to work but it’s another option

Daffy – Very interested in this thanks, what’s the choice on materials like? I’ll drop you an email with a more accurate description of the part

Have you looked at exaust hangers?

They are thick rubber doughnuts that would be about the right size (maybe you would need to stack two together).

Something like this

Your local exhaust place should have a selection.

Alternatively, you can get heavy wall, non-reinforced rubber hose, in roughly the right diameter, cut to short lengths length as ‘stuffing box’ hose from the likes of T. Norris. (May have to nest one size within another to get the thickness you want.)

They would be quite expensive but you could get them made from an o-ring/seal supplier.

Can’t remember the company off the top of my head (I have their details at work) but I have used a company in the past that supplied us with machined rubber seals for an ink supply system. They were made of Viton with a shore hardness of 70, I think.

I’ll try to remember to dig their details out tomorrow if that would be any use?

Martins Rubber Company in Southampton are specialists in making rubber things – they might be able to help.

I have no involvement with the company except that I was friends with one of the directors years ago.

I would think that somebody like this company or this one should be able to help.

Thanks for all the leads, I’ll work my way through them.

Stumpy – if you can dig the details out that would be great but don’t worry if it’s too much hassle

Thanks again
Matt

18BikesMatt – Member

Thanks for all the leads, I’ll work my way through them.

Stumpy – if you can dig the details out that would be great but don’t worry if it’s too much hassle

The company I was thinking of is Barnwell.

http://www.barnwell.co.uk/

I was dealing with a woman called Samantha Poole, but I think she was our local sales contact so probably best to just send them an online enquiry or call the sales team via the number on the website.
I always found them very good to deal with.

To make your own on a lathe you’d be better off using a polyurethane, commonly used in aftermarket car suspension bushes to replace rubber. It can be frozen in a domestic freezer and then machined with a very sharp tool.
This company were very helpful to me when I wanted to make some bicycle suspension fork elastomer springs a while ago:
http://www.powerflex.co.uk/road-series/products/Washers-2788/1.html
I managed to speak to someone who was a keen mountain biker. Contact me for their details.
PS: that is a very cool old bike. Villers engine? Will you have to carry round a measuring cylinder to add oil to the petrol?

Daffy – I’ve just sent you an email, got my fingers crossed you can help.

Just to clarify a bit, I’ve removed the better one from the casting and it definitely looks (to me) that it was originally a straight piece of tube as both the internal and external walls are bulging outwards. I’d like to end up with something as original looking as possible so want to try to recreate that so I’d rather not have any gaps/joins from using two parts and also ideally have a surface finish on the outside that looks like an original moulding. The ID and ends don’t matter as they can’t be seen.

I had thought of using poly bushes as I’d assumed they would be easier to machine than natural rubber but I couldn’t find any in black (see above) as it seems most people want to shout that they have them so they’re bright orange/red/yellow/blue

I’m going to work through things in order of easyness so it’s Daffy’s offer first, if that doesn’t work I’ll try pushing a holesaw through the part I linked to then it’s onto the other options. It’s a shame these aren’t available in bigger sizes as they would have been really easy to mod.

Crogthomas – the engine is a Villiers, but as the bike is French the engine was made under license by Automoto (who were owner by Peugeot at the time) so there are a few changes from a British 10D. The main bearings are much bigger and metric sized plus the flywheel is attached differently. I will have to carry oil to mix in the tank, the bike should have a little can mounted behind the engine but mine is missing. I’m planning to ride it back to where it was made (Saint Etienne) and oil will be a major concern in the planning

Thanks again,
Matt

Dunno if these websites would be worth a look:

http://store.resuspension.com/home.php?cat=328&sort=orderby&sort_direction=0&page=1

http://www.avindustrialproducts.co.uk/buffers-bumpstops.htm?gclid=COGFocu70MUCFUjlwgod4RsAvQ

Have a look at part number RB520-300-215 here (expand the ‘Outer Diameter Sizes:19.0mm to 75.0mm’ section).

Cool project 🙂

This might be something that my brother could help with.

Have a look at part number RB520-300-215 here (expand the ‘Outer Diameter Sizes:19.0mm to 75.0mm’ section).

Thank you tillydog, I don’t think I’m going to get closer off the shelf (50mm OD, 30mm ID, 21.5mm length) so that is my new 2nd place option. I wonder how easy it would be to open up the ID by such a small amount. Hmmmmmm. It might actually be easier with the next one up that’s 23mm ID, then do my original plan with the holesaw

It might stretch… 😉

FWIW, I would expect trying to machine / saw rubber to be a royal PITA.

Might be worth giving them a ring to see if they have something closer, or can make you what you want. (I’m not connected with them, btw.)

It’s been a while but I’ve finally got them sorted. I ended up ordering from the guys Tillydog linked to, although they don’t have the one linked to anymore so I went with part number RB520-230-500 instead. Here’s the bush as delivered with one of the old ones

Chucked one up in the lathe just to see how a brand new holesaw would cut it and was pleasantly surprised. Had to take it slow to prevent it heating up too much and going soft

I then made a ‘knife-lathe’ to cut it to length

And after a few spins it was done

I had to add a chamfer onto one end for the bottom washer to sit correctly (didn’t get a pic of that). Here they are in place with the old ones in front

Just need to work out what glue/epoxy to use to hold it together

Thanks for the help people, especially TillyDog,
Matt

Are you going to leave it with all that lovely patina. It looks fantastic just rebuild the motor and bouncy bits and enjoy

Are you going to leave it with all that lovely patina. It looks fantastic just rebuild the motor and bouncy bits and enjoy

+1, it looks wonderful with that barn find patina.

Glad you like the look, it’s why I bought it and I’m definitely leaving the patina as is, there are a few places where I’m doing more work in order to keep it looking as it does. For example, the rear mudguard is cracked at one of the rack mounting points. I’ve drilled the ends of the cracks and will epoxy a stainless sheet inside the guard to reinforce it but externally it will still look cracked.

The engine has already been rebuilt, front suspensions stripped and the links nickel plated (again to look more in keeping than full chrome), brake pads relined, wheels trued and new tyres fitted. I’m basically waiting to finish the rear suspension off to get it back on it’s wheels

I’m doing a write up of the ‘restoration’ here – Automoto AV125 blog if you want to keep up with the work.

Bit late now but Draganfly might be worth a look as lot of old Ariels have similar setups

I’m doing a write up of the ‘restoration’ here – Automoto AV125 blog if you want to keep up with the work.

Can you check the blog link? Doesn’t work for me.

Can’t edit the post, should be http://www.automotoav125.blogspot.co.uk/

*Crosses fingers*

Excellent blog. It’s a joy to see the care with which you are preserving the care worn patina. When I restored my ’32 Mortis Major Six, I tried wherever I could to preserve the originality. The interior is wholly original, tears in the seats, threadbare carpets and cracked and faded varnish on the dash. The instruments are slightly rusty too. You can go to any bike or car show and weep when you see what has been lost. Keeping it real does it for me. Good work, looking forward to some updates and something of your ride to France.

Thanks McMoonter, got any pics of the Morris? I love a well worn leather interior

Not sure if people care but I’ve just done another blog post, you can read it here (assuming I’ve got the link right this time. If people care enough I’ll start a new thread with a less ambiguous title that I can update every time I post

Matt

I’ve only got a few scanned pics from photographs of the Morris rebuild.

My dad was an engineering student at St Andrews. His father have him the car as a project in the late fifties. He partially dismantled it, then left if fir at least twenty five more years before he moved it here. It sat for at least another fifteen years before I made a start on restoring it. I didn’t even know if I had all the parts.

https://picasaweb.google.com/113038090087066024057/1932MorrisMajorSix

Love the pics mcmoonter, hate the idea of assembling something with no idea if it’s all there though!

Just done another blog post about the rear suspensions and mudguard if anyone cares – http://automotoav125.blogspot.co.uk/