Securing a tandem- M5 fine thread bolt

Hi,

I have a tandem that came with a roof rack. The roof rack doesn’t fit my aero bars.

The solution previously suggested was a Thule t bolt. This  has turned up- awesome.

However, the bolt is an M5 with a non normal pitch. It’s the same thread as a bike tube thread- fine Pitch?

Any suggestions for how to get 3 M5 fine pitch full nuts? Or even better an M5 fine pitch nylock nut?

Bike shop- nope

D T department at the school I work at- told me to go to b and q

Science department- nope

A proper hardware shop, if you still have any nearby? The Thule t-bolts are presumably fine thread since they are normally used with plastic pivoting clamps (a bit like quick release levers) with a metal pivot pin.

A hardware store. A proper one.

Or Ebay – nuts and bolts and fasteners are pennies.

BAPP are excellent if you have one nearby, If not there will be an equivalent.

https://www.bapp.co.uk/contact

Are you sure that the bolt is M5?

I thought that the Thule stuff was M6 x 0.75mm pitch (metric ‘fine’ pitch vs ‘normal’ M6 1mm pitch).

Maybe easiest to buy as Thule spares.

If you know what you need, GWR, Spalding Fasteners or Kayfast (All have proper shops if you’re local to them, but usually cheaper to buy through their ebay stores for small quantities mail order). I’ve had good service from all of them many many times.:

Spalding

GWR

Kayfast

I really doubt that it’s the sort of thing you can pick up in a non-specialist shop (engineers’ merchant, etc.).

Thanks!

I’m not sure it’s M5, the bolt is 5mm across.

Is that M5?

put an adjustable spanner on the threads and snug the jaws up, remove then measure the gap between them

as above theres loads of bolt suppliers on line, postage is always the killer so i tend to buy a couple of spares too

edit yes m5 is 5mm across.

Im a bit confused.  Standard m5 is 5mm across the threads but a valve stem locknut is a standard M6 thread – certainly not M5 and it threads fine on an M6 bolt

Edit:  double checked – valve stem thread IS finer – even tho the locknut runs fine down a standard m6.

ebay is my go-to source for random bolts, a quick google suggests its a m6x 0.75mm – so maybe you need to double-check before you buy?

https://www.roofbox.co.uk/scripts/rbvehsel4_tab.php/all-products/50236_m6_x_40mm_t_track_bolt/Qx@w,6M4PHS,ZGenkQvENtVOsv

https://www.ebay.co.uk/itm/295216877034?itmmeta=01J35VE4GXFJRD969HJVEAFZV5&hash=item44bc4c0dea:g:zC8AAOSwKb9jMa5-&itmprp=enc%3AAQAJAAAA4LbrG3%2FRe06FmOWX6WWe5%2BU1WYg2ZqkYIp0%2BNw6z3T%2FgsGw6JRrw2M0lRDlE2kYr20DT1D%2FRzOs59eYi%2FxB518ldNWc9QQ68oblPUf11UsO7tYdDRau1nEQl18SMcbNa6uua6TrRspohCi9XiHRuHb8gY2ZtKC6XfaFtG36tk3CYopymNAmWsuCSjsnSa2XzqUZhRIBMivd8DwGa1Kt2ZREwu1oyOAKu8RfRyuYcnlam4vYcjCiJFOtoSC1ELAuYPePd9UmH25YsGt5K%2F7lXyCMVaZSEOpZ7c%2BVF5MoAvvAr%7Ctkp%3ABFBM0Mi4u5lk

Accu will likely have what you need. Usually a good enough supply of non standard bolts etc there.

Bolt news

Bolt is 5.8mm across so M6?

@snotrag thanks for the suggestions of BAAP- metric fine starts at M8 so they said they couldn’t help.

@5lab Thanks that is exactly the bolt I am looking for 2 nuts for.

M6 metric  fine thread

At least I know what it’s called now

yes likely M6