I don't want to bore anyone so look away now if threads are dull for you. If you want to learn a lot about them in 30 seconds then read on.........

I know a bit about fasteners, I have worked as applications engineer for the Germans most of my professional life and spec fasteners every day to automotive,aero engine and defence. Ever heard of Helicoil? the genuine article? that is one of the products that the company I worked for produced. They are often mistaken as a thread repair solution, In fact 99.9% of them go into Aero engines and other high tech applications from new to allow for greater tightening torque and so clamping forces to be applied, but back to the point.

Addressing one point raised, 3 turns of an ISO metric coarse 80 H6 (Standard M8 to most) @ 1.25mm pitch would be 3.75mm deep and would fail. Often in motorcycles particularly in Aly engine casings you will find ISO Metric fine. Reason for this is that you can acheive a higher clamping load from a lower tightening torque because it has more threads over a given length having a pitch of 1mm for m8 for example.

Its therefore not the case that 3 turns is max strength for a bolt in steel or otherwise. It depends on the substrate, class of thread fit. H6 for example, grade of bolt 8.8 10.9 12.9 and so on ....these are tensile ratings not bolt sizes and most fastenings on a bike/car are 8.8..in ordinary stress areas.......a 12.9 grade 8mm will strip a 6% SC aly casting at 3xD after peak proof load is passed whereas a 8.8 grade 8mm will break itself at 3xD at a lower torque and leave the Aly in tact at 6% silicon content.

Number of threads engaged drastically effects the load on EVERY one of the pitches.

Put a 10KN tensile load (nothing to do with torque)on a 12.9 10mm with 3 threads engaged and although the bolt can take it at 3 or 4 full threads, a 0.04% carbon steel (mild steel to most folk) nut or tapped hole in a similar steel component cannot. Increase the depth of engagement by a factor of 3 and reduce load on each pitch by a much higher figure. (determined by many factors) which cannot be covered here.


There are hundreds of factors in play. including the Cr3 coating on the bolts in this case which produce a 410 hour salt spray resistance to red rust but also reduce the friction C/E and therefore influence the torque required to obtain a given clamping load. Cr3 Trivalent Chrome FYI is the shiny stuff your bolts are coated with. You will recall a few years back when nuts and bolts were yellow? that was Cr6 with yellow passivation AKA hexavalent Chromium and was outlawed a few years back as it is a cancer causing agent.

I need to establish what the torque value is supposed to be before I can determine if they are long enough. I understand the economics of drilling and tapping thru holes. Particularly on this application as the threads have probably been cold formed as is ofted the case on Aly castings of this nature, typically this requires a longer lead on the tool than you would find on a "tap" which is a rare thing in mass production.

In summary
The bolts in my yokes are OK if they are capable of imparting the designed clamping force without compromising the material they are screwed into.

Anyone got a workshop manual with the figure in?

Al.

Thanks
There is no way the dealer did it, I know that for sure as they all have the factory Torque marks on them. Under engineering is worse than over engineering, As i have said, they may be capable, but they look terrible.

Thanks for checking yours.

Al.

hey Al.. a think you an Kev are gonna be like sandpaper pals....:067: but hey Kevs got it the gither on here,, an nodoubt another gurus a good thing.. but when the arguing starts...man its time tae get out o the kitchen...:confused2: ma bolts in that picture go right thru.. a think ye know by now the Yam centre ye got yer bike fae is not a yam centre,,its a bike shop wi a yam name on it wi the back shop full a wee boys wi dirty overalls on,, smoking fags an texting...what they called again....asbo`s aye teir workin off their hours that the judge thru at them an guess whit...on your bike....seriously,, atink ad take the bike back tae REputal dealer an cause havoc....man yer payin fur the real thing an a safe bike.. so why not get wit ye paid fur... take it back. an ye`l feel :brave::099:

Lucky you.

I posted 'rules of thumb', emphasising that that is what they were, to point out that threads are generally stronger than most people think they are. The reason I did this, rather than launch into some detailed thesis on the merits of VDI2230 is twofold:

a) because your OP gave the impression you didn't know anything about threaded fasteners. "Terribly bad engineering practice", "Clear that they have the wrong bolts in them" and all that jazz.

b) it is extremely boring.

Now it turns out you do know all about bolts, or at least enough to attempt to baffle everyone with bull****, and you've revised your opinion to "they may be capable, but they look horrible".

I'm not really sure what your point is? Are you going to spend your free time analysing every single threaded fastener on the bike because it was 'built by Italians'?

Personally I'll be out riding mine and not worrying about the pinch bolts. It's more fun. I'd recommend you do the same :D

Jeasus, I'm a sad individual. I even dragged out an old revision guide from my days studying Engineering & Geometric Drawing, just to make sure I understood it right. Of course the Chemsitry was staight forward.

Nowthen. You are not going to enjoy this bike at all if you carry on pulling things to bits. There are more than enough people around who will spend a lot of time pulling the bikes to bits, saying how much they hate them, they rust, they rattle, wind blast, I get wet when it rians etc etc.
Then there are the people who accept that there are finaincial reasons why bikes are builts and spec'd in the way they are, these people (I would like to think as myself as one of them), are happy to get out there and enjoy the ride. It's a bike, not a 747, technical tollerences are one thing, but it has to relate to the application.

Some people have even been off the road for long periods, yet they come back and get a second one - To these people, I raise my hat (if I had one), and no - I don't want to see his ass again.

If you want detailed technical discussions on the merits of bolts, I can think of two or three people who might be able to engage with you. But most of us just like to ride bikes.

I just have a rummage in the big jar of 'bolts that have come from somewhere' and find one that fits. Then use that.
Apart from that time when I used cable ties to hold on a rear caliper on my TR1, but don't worry, notice the plural, I used two for safety.

Al, as GULGO says, you can spend ages going through the bike with a toothcomb and finding the faults it has. They're there, but it's more fun just to find them out as you go along. By all mean do pre-emptive maintenance before winter and apply grease and ACF50 to everything you can get at, make sure the loom isn't snagging under the seat on the frame, and that your reg/rect connector is packed in grease and securely fitted, then ride the arse off the thing, that's what it's there for. By 10,000 miles you'll find the rear shock is shot, and if you're over 5' 10" you'll probably get windblast buffeting going on, but **** it, I haven't found a single exciting bike that doesn't have some issues that need sorting. Some call it character, make of it what you will.

LOL

None taken:icon_mrgreen:

I suppose I have over analysed the bike a bit, I suppose this is because it was delivered with issues like the missing tool kit and paint defects in the tank. AND I had time to do this as riding it much has been difficult whilst my ribs continue to mend. So I don't feel too bad about it!

As has been said, its a motorbike not a Jet turbine engine.

Tell you what, I will take a chill pill and ride the thing and worry about it if it falls to bits.




Al.

Correct me if I am wrong but aren't
 

The engine and box of gears Italian, and MBK build the rest of the XT660 in Picardy - France. So wouldn't this be a French assembly issue rather than an Italian one. Oui monsieur, surely you agree that it just doesn't look as finished as it could.

Nothing wrong with checking your bike over I do it every time I get a new one, as most bikes are put together by the human hand.

It does appear you knew the answer to you own question & were only checking to see if other XTZ riders have the same bolt length.
:pjrflash_Q2CCBE:

built in Italy an france using Jap chinese an austrian parts... they are called a jap bike but ridden by many cultures, and they are a cheap mode o transport compared to a honda transalp or a KTM.. fur th esame year o bike,, yed be payin well over the odds.. were o were could ye get a 3 yearold bike fur under half price o the new price.... a lot tae take into consideration..... a suppose a old emz wid have still got ye fae A tae B.. or wose still a Zundapp.. or a hate tae say it a CZ with the kickstart that folds down to make a gear lever....

anyway.. we`re only haein a wee bit o banter here... i know yer first post was about,, the build quality o the bike comming out of a dealer.. i still stand by an say take it to a reputable dealere an make noises,, as yer put together out o the crate is shocking,, an a think we`ve all digressed fae there,, an now as see were arguing about what kinda steel the bolts are made fae... its probably chinese junk... but hey ,, its cheap. it goes, its good on gas... it has a few problems.. but they can be ironed out.. they look good.. the get ye fae A tae B in reasonable comfort, :typing[1]: what more can i say,, everyone an their granny has one,, they are like Vauxhall caviliers, after all if yer looking fur a nice motorcycle.. go buy one.. if yer jist looking fur a half decent aul motorbike.. buy a yammy xt.........:Christo_pull_hair:thats wit kin happen when ye start wi the problems.. but ave found out no matter wit bike or car ye have.. the beuty o the internet is theres a forum fur everything.. an they ALL have problems... so i ask masel...why bother... when yer sittin on it riding it, behind they bars wi yer full face crash helmet on,, an ye have Horse vision... whit does it matter wit colour it is,,, whit kind o bike it is... how it looks... as they all go the same..but what a will say.. when ye get off it an throw yer helmet down.. git yer fags out an look at it,, ye`l say.. aye that bikes not bad after all......:blob8: