GolfGTIforum.co.uk
General => General discussion => Topic started by: Khare on 02 August 2011, 21:45
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Right, got my kart chassis today (will post pics soon) and I've stripped it almost fully. I'm going to be replacing various bolts as the previous owner has put bolts with different heads on certain areas and ideally I'd like them all to match. As I'm a heavy driver and won't be needing ballast I'm going to be putting the kart on a diet (I already am on one). I'm looking at replacing 12 M8 x 25mm bolts that hold the rear axle down in place, demon tweeks wants over £15 excluding delivery on these and after having a quick look around it seems £13-£16 is the normal price. I have two questions.
Are 12 aluminium bolts in M8 thread strong enough to hold an axle on with an 85kg driver and the stress of racing?
And if so, is there any website you guys know where I can buy them cheap? (colour red preferably)
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http://www.pro-bolt.com/Products/M8_125mm
http://www.racebolts.com/index.php?main_page=index&cPath=675_676_679
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http://www.pro-bolt.com/Products/M8_125mm
http://www.racebolts.com/index.php?main_page=index&cPath=675_676_679
Second link is expensive :sad:
First link wants £96 for 12 gold bolts! :laugh:
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Soorrrrryyyy!!!
Screwfix is is then!
:rolleyes:
:grin:
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Yeah it looks that way, although I found some purple ones nice and cheap, however my question on strength remains :smiley:
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strange, but wouldnt it be best asking kart questions on a kart forum :undecided:
just a left field thought like :smiley:
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Yup, true...But I would have thought a car forum would also know about bolts :smiley:
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12 aluminium bolts I would have thought would be alright but I would rather some 8.8 or 10.9 mild/stainless steel bolts for piece of mind
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strange, but wouldnt it be best asking kart questions on a kart forum :undecided:
just a left field thought like :smiley:
Audi et al....
:lipsrsealed:
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Torque ratings:
http://www.engineersedge.com/torque_table_sae.htm
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12 aluminium bolts I would have thought would be alright but I would rather some 8.8 or 10.9 mild/stainless steel bolts for piece of mind
That's what I thought :undecided:
These are the ones I found http://www.ebay.co.uk/itm/Anodised-Aluminum-M8-X-25-mm-Bolts-6-Pack-/250858167189?pt=UK_Motorcycle_Parts&hash=item3a684fdb95#ht_500wt_1156 (http://www.ebay.co.uk/itm/Anodised-Aluminum-M8-X-25-mm-Bolts-6-Pack-/250858167189?pt=UK_Motorcycle_Parts&hash=item3a684fdb95#ht_500wt_1156)
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Specific:
http://www.pro-bolt.com/Products/kart_kits
http://www.ebay.co.uk/itm/Stainless-Steel-Bolts-Nuts-Washers-x-200-Go-Kart-/360197269427?pt=UK_Cars_Parts_Vehicles_Other_Vehicle_Parts_Accessories_ET&hash=item53dd6e27b3
£11.99
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12 aluminium bolts I would have thought would be alright but I would rather some 8.8 or 10.9 mild/stainless steel bolts for piece of mind
beat me to it...Why aluminium? And why are you after cheap ones when they're holding a go-kart together?
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Yup, true...But I would have thought a car forum would also know about bolts :smiley:
each application could be different, so info from source would be the best option :smiley:
12 aluminium bolts I would have thought would be alright but I would rather some 8.8 or 10.9 mild/stainless steel bolts for piece of mind
beat me to it...Why aluminium? And why are you after cheap ones when they're holding a go-kart together?
Nail on the head :grin:
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load bearing, use high tensile steel bolts, with K nuts. anything else use high tensile Alloy nuts and bolts from a reputable source, do not use alloy bolts where there is a shearing force present...
http://www.tridentracing.co.uk/index.htm
Thom
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Is a rear axel to chassis bolt classed as a non stress area?
I dont think it is. Id go for stainless and if they have to be red then paint them afterwards
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Zip ties are even lighter, it's only your safety after all?
Nick
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load bearing, use high tensile steel bolts, with K nuts. anything else use high tensile Alloy nuts and bolts from a reputable source, do not use alloy bolts where there is a shearing force present...
http://www.tridentracing.co.uk/index.htm
Thom
Cheers Tom, just what I was looking for.
Can't use a K nut as the bolt doesn't go through the bearing hanger, however I will be using K nuts for the wheels.
Is a rear axel to chassis bolt classed as a non stress area?
I dont think it is. Id go for stainless and if they have to be red then paint them afterwards
Yeah I think that's what I'll do, get some tough ss bolts and paint.
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Zip ties are even lighter, it's only your safety after all?
Nick
Bwaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaah
that is all
:smiley:
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ali dosent fair to well with metal fatiuge. useing ali bolts to hold something on thats going to be subjected to repead rapid load cycels is an excelent idea.
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aluminium pfffff
if you want to save weight get titanium
http://oscommerce.tibolts.co.uk/index.php
They aren't cheap but the way forward, I replaced all the bolts on my mountain bike with ti bolts :cool:
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Just to please me, have you actually weighed these 12 bolts to find out how much they weigh? And then how much you would save by using aluminium or titanium bolts?
The gain might be insignificant compared to just having a big sh!t before you race.
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Just use steel bolts and look in your yellow pages for Engineering factors. There are loads of these sorts of places dotted around the country (ie All thread) and they will be a lot cheeper than the prices you have put up so far.
Just a thought but have you looked at your engine mounts as I managed to take over half a kilo of material out of a friends kart engine mount recently (and could have taken more out if wanted). Admittedly I had access to a milling machine at the time but they dont need the spars that connect the front to the rear of the mount and that can be removed with a hacksaw lol. Bits like this are far more likely to lose weight than replaing bolts with ali versions adn there are plenty of other plaes weight can be safely removed from that will get you some nice added lightness.
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Just to please me, have you actually weighed these 12 bolts to find out how much they weigh? And then how much you would save by using aluminium or titanium bolts?
The gain might be insignificant compared to just having a big sh!t before you race.
:grin: :grin: :grin: :grin: :grin: :grin: :grin: :grin: :grin: :grin: :grin: :grin: :grin: :grin:
thanks jonnie, you just cheered me up after a crap day :afro:
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Ive always used Mr Fastner http://www.mr-fastner.com/ i used to use them all the time when i had bikes. :smiley:
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But if Andres drops a log, AND replaces the bolts with lightweight items, hell be faster than a cat, with a red hot poker up its arse!
Thom
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Just use steel bolts and look in your yellow pages for Engineering factors. There are loads of these sorts of places dotted around the country (ie All thread) and they will be a lot cheeper than the prices you have put up so far.
Just a thought but have you looked at your engine mounts as I managed to take over half a kilo of material out of a friends kart engine mount recently (and could have taken more out if wanted). Admittedly I had access to a milling machine at the time but they dont need the spars that connect the front to the rear of the mount and that can be removed with a hacksaw lol. Bits like this are far more likely to lose weight than replaing bolts with ali versions adn there are plenty of other plaes weight can be safely removed from that will get you some nice added lightness.
I would have thought the scrutineers wouldn't let me race if the engine mounts have been modified, they'd class it as unsafe. I haven't weighted the bolts, but I will do so tonight.
Jonathan - :grin: :grin: :grin: :grin:
But if Andres drops a log, AND replaces the bolts with lightweight items, hell be faster than a cat, with a red hot poker up its arse!
Thom
Damn right!
Think I'll go for average bolts and just drop my arse before every race then :laugh:
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17g per bolt including the required washer.
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stick £15 in the forum charity pot and I'll send you 15 off M8 x 25 x1.25 steel bolts.......
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stick £15 in the forum charity pot and I'll send you 15 off M8 x 25 x1.25 steel bolts.......
Flanged head BTW
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Bought some stainless steel A2 304 grade bolts and washers last night.
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Bought some stainless steel A2 304 grade bolts and washers last night.
Fail of the highest order :grin:. Well done for asking other peoples advice and failing to follow any of it. Mr T would have words with you :wink:. Shall we see some of the benefits?
1: Slightly heavier than steel items
2: In my experience much more expensive than steel items, guess you couldnt break the fear of leaving the internet and using a phone lol
3: The corrosion protection is completely unecessary on a kart, if your not stripping them often enough to keep them clean then you will doubtless run into issues elsewhere
4: Damn sight more dificult to drill for lockwiring (assuming your taking that precaution, its very wise on blind threaded holes)
I would have thought the scrutineers wouldn't let me race if the engine mounts have been modified, they'd class it as unsafe.
Have you checked the regs? Thats not me saying I know what they say, just suggesting you check is all.
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stainless steel bolts are excelent at ratteling themselves loose. hence you've Got to use nylock bolts, tab washers, locking washers or threadlock and idealy wire them.
surely there is more weight to be stolen out of the seat, fairings / pods and off the wheel rims. if your that keen about lightwight getthe shassi remade out of thinner wall higher spec tube
won't make a lot of differance at the end of the day as karting is a midgets game
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stainless steel bolts are excelent at ratteling themselves loose. hence you've Got to use nylock bolts, tab washers, locking washers or threadlock and idealy wire them.
surely there is more weight to be stolen out of the seat, fairings / pods and off the wheel rims. if your that keen about lightwight getthe shassi remade out of thinner wall higher spec tube
won't make a lot of differance at the end of the day as karting is a midgets game
Bolts don't go entirely through the bearing cage, so I'll be using threadlock and washers. Weight will be saved elsewhere too, however there's not much I can shave off due to the MSA being pretty strict on what can and can't be done. Wheels are magnesium, which is the lightest permitted material on the wheels. Floortray is aluminium, ideally I'd like it carbon fibre but they're £300+ so that's something I won't bother with. Chassis is 32mm, can't be modified and I'll be sticking to it as it's a highly rated chassis especially for heavier drivers and in the wet.
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the 1st rule of motorsport.
all rules and regulations that you can get away with ignoreing should, must and will be ignored.
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surely there is more weight to be stolen out of the seat, fairings / pods and off the wheel rims. if your that keen about lightwight getthe shassi remade out of thinner wall higher spec tube
Not a lot you can gain in any of those areas other than the bodywork if allowed and especially not the chassis, they are the suspension so are designed to respond in certain ways. As an example of this, me and a friend ran his new kart up at Hooten park and got straight into the 41 second bracket until the rear bumper fell off (previous owner had bodged it), losing us over 2 seconds a lap due to loss of front end bite and a massive gain in rear grip which took all day to get back out of the setup and ourselves. These are not particularly stressed parts and lost over half a kilo in the process of losing it and its mounting bobbins which illustrates why chassis are left as they are with only tweeks made to the torsion bars if fitted.
Out of interest, are you thinking you wont make your class lower weight limit Khare? If thats the case, you better be one hell of a driver but I suspect you know that already lol.
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I'm heavy enough to race in the rotax 177 but the problem with 177 is that because its a limited class it always has less people, hence why I'll be joining senior Max. I'll be one of the heaviest drivers there.