Bolt question

My bike is a K4 SV650s.

Like a fool, I managed to shear off one of my rear caliper retaining bolts (the rearmost one - It's the one with the size 14 head and should be set to 23Nm according to Mr. Haynes). Fortunately, I managed to get out the snapped bit and ordered a replacement (plus a spare ). Unfortunately, the bolt hasn't arrived yet and won't be in stock till next week at the earliest.

I really need to use my bike next week and public transport to where I'm going is unreliable and it's important I get there on time- so much so, that I'd probably be prepared to pay hire car prices and hire a small car.

My question is this - I've got a load of stainless steel bolts at home, but they're all with the standard thread, rather than the sort of smooth top for 25mm or so, before the thread starts. Is stainless steel likely to be strong enough; I know it's sometimes more brittle than normal bolts? Are caliper retaining bolts made of anything exotic/particularly strong?

If I do try one and it fails (I'll try to stay off the back brake till I've got a proper bolt), as it's the back of the two points it's secured, I presume the caliper would pivot downwards and catch the back of the inside caliper against the edge (not the surface you normally grip) of the disc. Obviously, I'm not going to hold anyone to what they say should it go pear shaped, but am I right in thinking this wouldn't result in the caliper ripping itself from the brake hose/likely causing a crash?

I'm going to try checking the local breakers for one, but unfortunately, I will need to ride up there to get it with the s/s bolt in place, even if they have one.

Any thoughts/comments?

TIA

Have you tried asking different dealers?

Personally i'd fit the stainless bolt, and just avoid using the rear brake if I needed the transport so much - avoid any chance of it snapping.

Originally Posted by jonboy99

Have you tried asking different dealers?

Personally i'd fit the stainless bolt, and just avoid using the rear brake if I needed the transport so much - avoid any chance of it snapping.

Found a breaker nearby that thinks they have one. I'm going to fit the stainless bolt and ride w/o using the back brake.

I caliper mounting bolts are high tensile, so stainless will be more brittle. As it's a Suzuki I'd be very surprised if you couldn't get the bolt at a breakers.
Even if you do, replace it with a new one as soon as possible.

Originally Posted by Razor

I caliper mounting bolts are high tensile, so stainless will be more brittle. As it's a Suzuki I'd be very surprised if you couldn't get the bolt at a breakers.
Even if you do, replace it with a new one as soon as possible.

Yep - I'm not cancelling the order for the new bolts and will fit one asap. Am I right in thinking (in a theoretical world of "best practice") you're supposed to replace caliper mounting bolts every time you have the calipers off, anyway?

[timwilky]

Not having one of those inferior pointy things I well be wrong but.

Please also check the pitch of the thread. Jap 10mm bolts are not compatable with european ones. as they use a 1.25mm (fine) pitch whereas europeans use a 1.5mm pitch.

Originally Posted by timwilky

Not having one of those inferior pointy things I well be wrong but.

Please also check the pitch of the thread. Jap 10mm bolts are not compatable with european ones. as they use a 1.25mm (fine) pitch whereas europeans use a 1.5mm pitch.

Thanks for the warning; I ended up collecting the bolt in my girlfriend's car, so haven't used the s/s one.

Back brake is moving when I press the lever, but not enough to usefully (although you can notice it) slow the bike. To be fair, the caliper did get banged about a bit being fitted. I'm hoping the slight top up of brake fluid (was nearing the low line, in spite of the garage allegedly doing it 3000 miles back ) coupled with leaving the back brake depressed for a few hours should sort it. Anything else I should check/try (doesn't appear to be a leak in the fluid anywhere/no kinks in the hose)?

[Richie]

Please check what pitch thread it is, I know there not Repeat NOT standard....otherwise you will strip out the thread on it.

sorry .. you know already.... must read thread to the end before posting....

Originally Posted by Richie1743

Please check what pitch thread it is, I know there not Repeat NOT standard....otherwise you will strip out the thread on it.

sorry .. you know already.... must read thread to the end before posting....

No problem Richie; better for 2 people to tell me than none!

[Sid Squid]

Just FYI: It wouldn't be a good idea to fit an alternative bolt in that place as the plain section of the standard bolt is a bearing surface that bears upon the caliper bracket, (it's the pin that allows the caliper to float - the pointy rear brake is a single piston caliper). The peaks of a thread obviously have far less surface area than does a plain section, thus the brake torque would be fed through a much reduced area, and the bracket being much softer material than the bolt it would likely wear rapidly.