easy fix for caliper upgrade.

[andyvanderpandy]

all this drilling, tapping and sleeving malarky has gone on too long!

i just came across these here bolts of a suki bandit, theyre used to hold the front and back discks on. theyre 8mm and have the correct 1.25 pitch for most calipers and best of all they have a 10mm shoulder!

ive not tried them on the bike yet, but i cant see why they wont work!

[Scott221]

You're on about using these for calipers? They're not long enough mate.

[andyvanderpandy]

are you sure? ive only taken some rough mesurements, but i thought they were just ok length wise

[will#224]

If you want the right bolt just ring pro bolt and they will supply you the correct bolts.

[RedexRobB]

They look long enough to me, maybe im wrong, fit em on and let us know

[tk400]

They could shear off. the cross sectional area reduction from 10 mm to 8 mm is huge. I assume they are an 8mm thread with a 10mm shoulder I would tend to say that the diameter in the caliper bolt bore is a safe bet from the manufacturer and if thats the case their goes your safety margin for shear stress.

Could you imagine the catastrophy of a bolt shearing on your front brakes.

Am I missing something here ? it is early morning.....

[RedexRobB]

so what your saying is, its better to have the 8mm bolts with the 1mm sleeve? I see ya point tho, although i may not understand the technical bit of it

[andyvanderpandy]

you obviously no more about this than i! my chain of thought was its a bolt that holds a disc carrier to the wheel, so surely these have to be at least as strong as the bolts used to hold a caliper?

[RedexRobB]

thats also what i thought, but the actual practical technics of it i guess could be quite different?

[tk400]

you obviously no more about this than i! my chain of thought was its a bolt that holds a disc carrier to the wheel, so surely these have to be at least as strong as the bolts used to hold a caliper?

there are more bolts holding the center on and less impact loading and I may be mistaken but I think they shear load the shoulder and not the thread......
I thought the original ZXR400 calipers had 10mm metric fine bolts?
So what mI am comparing is the 10mm bolt shear area vs the 8mm bolt shear area not the shoulder.

Also of note when dealing with bolts in critical areas is the tensile strength of the bolt. A high tensile bolt can be up to 3 times higher in shear strength to a standard bolt.

My point is. Unless you are going to redo the calcs, Be careful and us the stock ones. the shear stress comparison between two 10mm high tensile bolts and two 8mm standard bolts is massive almost 6 times.

cheers

[Ballsout Racing]

So if I understand this, 8mm bolts are 6 times more likely to shear than 10mm bolts? But gsxr k1 thou calipers use 8mm bolts and the ZXR400 uses 10mm !!!! So, the ZXR400 10mm bolts are way over engineered?? No?? I mean if 8mm is enough to stop a thou, they must be more than enough for a 400!!

[tk400]

yes 2 x 10mm bolts of high tensile strength are 6 times higher in shear load capacity than 2 x 8mm bolts of low tensile strength...Just based on shear area and tensile strength.

As for comparing it to another machine......Have you tested the tensile strength of 1000 cc bolts maybe they are high tensile and the zxr400 may be low tensile.
Also most larger bikes have larger radius disks creating a larger braking moment ( leverage) and therefore less shear load for the same braking force.

I mean its all simple physics, are you suggesting that we don't bother with engineering principles and everyone should just base thier desings on what others do.......I seem to remember a few bridges in that category.......look up "tacoma bridge" on google ...LOL.....


cheers

[masterofinsanity]

are we missing the whole point of this thread? i'm sure Andy was pointing out he has found some bolts to fit upgraded calipers ie gsxr 6 pots to the zxr400.or have i got it wrong?

[RedexRobB]

yeah your right baz, but were also trying to establish weather its actually a good idea to use the bolts as they might not be fit for purpose.

[zxrjohn14]

i'd say these little beauties would be strong enough..........have you ever tried drilling a disc bolt out when you've sheered the head?.......they're fookin tough stuff!! i made a sleeve to fit an 8mm bolt through on mine and they're was no problem, and the bolts i used were nothing to do with a bike, let alone brakes.
when i fitted gsxr calipers to my race bike my thoughts where the same as ballsout racing, if they stand a bike with 120 odd bhp bike with 170kg of weight, they'll stand a 140kg, 75bhp one.
nice find them, andyvanderpandy, i'd use them.