Missing Rear Shock Pivot Bolt

[b3nb123]

I'm trying to fix up an old 2006 Stumpjumper, I bought the frame cheap-ish, including rear shock, front forks, stem and bars, thinking I'll respray it, fit some donor wheels and groupset, period Avid Juicy brakes etc.
However, when I first through wheels on to check it over I noticed the rear shock moved and knocked loads. It turned out that one of the rear shock's pivot bolts had been replaced with a long nut and bolt.
Without this one bolt the whole project is knackered!
I bought a used bolt from a 2020 Specialized, thinking it would be the answer, but although it's the same thread on the end, and the correct thickness for the shock, it's not long enough to reach the threads.
So I need this exact bolt, but 10mm longer on the smooth part. Possibly a similar bolt from elsewhere on a more modern Specialized would be perfect, but I don't live near to a biker shop who might have parts to check for me!

Where else would I find specific engineered bolts like that?

 

[b3nb123]

Oh no, I realise by project isn't retro enough for this forum! Still hope someone can advise!

 

[ishaw]

Try looking up shoulder bolts online with the dimensions you need. Thread pitch is important too.

I did buy a full kit for a specialized a works enduro of 2007 vintage from specialised directly, they were happy to help with getting a kit with the right bolts, but they was around 5 years ago.

 

[madjh]

That is not a M8 bolt? it is easy to find one. And if you want to upgrade, go to aliexpress and buy a Titanium one. They have in all measures by 5mm each (M6x10, M6x15, M6x20 etc all in mm)

https://es.aliexpress.com/item/1005...|x_object_id:1005008952546224|_p_origin_prod:

 

[Cloverleaf]

That is not a M8 bolt? it is easy to find one. And if you want to upgrade, go to aliexpress and buy a Titanium one. They have in all measures by 5mm each (M6x10, M6x15, M6x20 etc all in mm)

https://es.aliexpress.com/item/1005008952546224.html?spm=a2g0o.productlist.main.24.183510175ZUBPa&algo_pvid=bdc3aa95-8740-4c24-bd26-d9ebfea4465c&algo_exp_id=bdc3aa95-8740-4c24-bd26-d9ebfea4465c-23&pdp_ext_f={"order":"1132","eval":"1","fromPage":"search"}&pdp_npi=6@dis!EUR!2.30!2.30!!!2.60!2.60!@211b61a417627971637378681e9e14!12000047350065521!sea!ES!136645574!X!1!0!n_tag:-29919;d:d0d5d0fb;m03_new_user:-29895&curPageLogUid=UZZVRIN7rEvB&utparam-url=scene:search|query_from:|x_object_id:1005008952546224|_p_origin_prod:

Thread looks quite coarse as some of these bespoke bolts are. To the OP; measure the gap from the peak of the first thread to the last one and divide by the number of threads. It'll come out as 1.5 or 1.75, which will be the pitch. M8 x 1.5 is fairly standard coarse thread, M8 x 1.75 will be harder. Go shouldered as standard ones will allow too much play on some bikes if the mounts are very stiff and don't move together enough to effectively clamp the shock bush or pin, dependent on which design you're using.

 

[b3nb123]

Thanks so much everyone! I was panicking the bolt would be bespoke and the bike would never be rideable again, but hopefully it is just an m8. I've got a standard m8 bolt here (albeit without the smooth middle, and with a head too big) and the thread is the same, pretty normal. So hopefully any m8 with the smooth shaft will be 7.9mm too

I'm ordering AliExpress bike bits, I'll stick some bolts on the order!