Question, bolt type for rear swing arm 1992 Delta V

[Nico]

I have 2 frames here comparable with a 1992 Delta V1000 model.
From one of the bikes the bolts to attach the spring arm are missing.

I ordered M10 bolts but after trying to mount them I discovered I ordered the wrong parts.

Does any one of you have an idea what type of bolts are used.

I assume these are imperial sized bolts?

Since I am in Europe I shall have to look for them here since shipping costs from the States are ridiculous. ;-)

 

[black lightning 1987]

I'm guessing you are right. I know that in the early years Cannondale used 5/16" - 18 threads on the cantilever studs.

Were the M10 bolts too large in diameter? Guessing that the size is 3/8" - 16. You should be able to find them in the UK if that helps with shipping cost.

 

[Nico]

Here is an image of both allen key bolts.
The clean one is the M10 X 25 mm

They look the same but now I have both.
The M10 has like 9,8 mm wide thread and the UNC has 9,5 mm thread.

I will do some research and see how to get these from a EU supplier.
Since brexit stuff form the UK has become more expensive since they now charge extra taxes. :-(

I am now thinking it is UNC 3/8 - 16 thread
I'll will give an update on the type of bolt and were I got it from when I have solved the 'mystery'.

 

[black lightning 1987]

Did you have one of the originals? 9.5 mm sounds right for a 3/8" bolt. There are only two common thread pitches: UNF (24 threads per inch) and UNC (16 TPI). You should be able to look at them and tell the difference.

I'd be happy to source them and ship to you but as I recall USPS has a minimum charge of something like $15 to Europe.

 

[Nico]

Quick update
I found a company in the Netherlands that sells single stainless UNC bolts.
I have send them a picture of my original bolt and the M10 bolt to see if they can confirm it is a 3/8-16 x 1 1/4 stainless bolt.
If they confim this I will order the bolts and let you know if it is a 3/8-16 x 1 1/4 bolt.

Thanks for the offer to source some bolts for me.

 

[black lightning 1987]

I hope they have what you need.

 

[Nico]

Just received the bolts I ordered and I can confirm these are 3/8-16 x 1 1/4 bolts.
I ordered them as stainless steel and paid € 13,40 for four bolts including shipping.

So I now have a few extra for 'you never know'.

For those in Europe
If you want to order them yourself from this Dutch company, here is a link to the bolt type.

3/8-16 x 1 1/4 rvs - RVS bevestigingsmaterialen webshop | Montagetechniek Patrick Saes

www.montagetechniek.nl

You can order them at this company or, now that you have the correct bolt info, order them from a local/regional company that also sells unified bolts (UNC).
In Europe 99,9999% is metric so you may have to do some online digging to find the right stuff at a reasonable price.

 

[black lightning 1987]

I'm glad you got what you need. Sorry you had to spend that much for them.