Shaun H
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Posts posted by Shaun H
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Sounds unusual. You may not have screwed the insert in tight enough.
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Im not sure how the coefficient of expansion of carbon compares to aluminium.
Totally different. Carbon is used for the structures of satellites since it has an extremely low coeff of expansion, one side of the satellite can be at -273degC whilst the other is heated by the sun, yet there is barely any distortion.
Adam I recommend getting a water based release agent, you can get spray bottle ones which are super easy to use.
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Fair play, but my reason for saying that was the onza carbon bars are outer carbon construction as opposed to full carbon, and after having a quick look on tarty have realised that the higher range of carbon bars are fully carbon instead. As for stems, I haven't seen a full carbon one released yet so just presumed that companies haven't found a way of making a carbon constructed stem strong enough.
Does anyone have more expierience with carbon? And would anyone have any tips with trying out making a carbon stem?
The reason there are no stems built for heavy use is that there are a lot of issues with getting the fibres aligned in ways which are strong and durable at the steerer and faceplate ends. Handlebars are becoming more common in all mountain, downhill and trials since a simple tube with a few bends is simple to produce and quality control. Stems are on a whole other level due to the complex geometry around the steerer and faceplate and the requirement for hardware to screw into them.
I'd give stems a miss if I were him, there's not much weight to be saved there anyway.
Yeah, it's more a learning experience, using different shapes, sizes etc... He's not doing it to make a quick buck, he just offered to make me up some stuff in exchange for testing (and obviously a bit of cash), so I'll be testing parts out for a while to see if they're any good.
What sort of moulds is he producing for this? Is he using wet lay up, pre-preg or some sort of infusion?
Does anyone have any arguments as to why snail cams wouldn't be suitable in carbon?
I imagine they would delaminate at the edges pretty severely if used for snail cams.
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Nope, he's got all his machines and tools at home.
Can you share the process he's going to be using?
I honestly think he's going to struggle to make any money at the prices people in trials will be prepared to pay. If he's doing it as a learning exercise then fair enough, taking requests is probably a good way to test different shapes etc.
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Unless he's doing it at his workplace on the sly then he's going to be charging a hell of a lot for the low number of units he'll be doing surely?
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The flying frenchie at 2:55 was awesome! Nice video, if a little too laid back.
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FSA Orbit MX on eBay from Merlin Cycles. Mine arrived next day, they have cartridge bearings, they weigh 99g (!!!), they're durable, they last long and at £27 they're great value!
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Just bought a headset rocket (sick of hammer and screwdrivering it) and very nearly bought a headset press, Cyclus or X-tools or something do one for just over £40 which I thought was pretty reasonable.
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Caffeine works well (I'm sure there's studies showing so) if distributed through the day rather than in one massive hit. It's important to stay hydrated, electrolyte and isotonic drinks/foods are highly recommended too.
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Actually, a lot of carbon fibre moldings are done using vacuum bags, which is a lot like a ballon. These frame components would have been done in closed molds though.
Surely vacuum bagging is the opposite to a balloon!? In matched die moulds which these frame parts have been made with they apply high pressure to get the material to conform to the mould surfaces. So they are kind of blown up like balloons.
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You reckon it would be possible for a driveshaft system like that of a rear wheeled car or lorry? No more snapped chains!
It's been done with prototypes running on jump bikes. I wouldn't like to take the weight penalty though.
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You'd trust belt drive?
Works for superchargers?
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Edit: Now found this tube which is a fair bit cheaper than I'd seen before, again - if I'd know about that I probably would have used it instead!: http://www.easycomposites.co.uk/Products/carbon-fibre-tube-roll-wrapped-22-2mm.aspx
That's roll wrapped uni-directional though. Cheap (relatively) but rubbish in torsion, although it'd probably be strong enough for this application. Plus there's no sexy weave
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Could probably do it but might make a mess! Not keen on the super shiny look for CF though or I would have moulded the sleeve 'inside out' (if that makes sense).
How would you have achieved ID tolerance with a female "mould/mandrel"?
Also, did you use a room temperature curing resin system or do you have an appropriate oven?
Trying to get hold of some cheap core material atm but its pricey wherever I look!
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I will not at all be surprised if bike frames are being glued together some time soon.
The potential benefit is very high especially in trials, xc and road.
They already are man, aluminium forks with steel steerers have been bonded together for about 2 decades now, the dropouts on carbon forks are bonded in (and the steerer if it's alloy), as they are on frames plus there's a good few frames about which have aluminium "junctions" bonded to carbon tubing.
Plus anything involving carbon fibre is technically held together by glue (the resin matrix)
I've got a few things I want to try with the spare pre-preg we get from making our chassis, if I get the time to do them I'll post them up.
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Call me old fashioned, but I dont have a great deal of trust in adhesives in a structural situation
I'd stay well away from any modern airliners if I were you then!
We use a 3M adhesive called 9323 B/A on our Formula Student program to bond our wishbones, now THAT is an adhesive!
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Awesome! My only complaint is that you've gone back to your old style of sidehopping "to front".
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Mine's been fine.
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I have to overtighten mine and actually deform them to get them to work.
To this day I still don't understand how they are supposed to clamp effectively.
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Shit, got a wedding to be at on the Saturday
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Mouse - Coolermaster Sentinel Advance
Nice mouse
Mine's blue atm.
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True, it does make sense applying blanket statements to vastly different products.
Well now you're both just being silly
Got most of it I guess, was just confused about how many doubles of Aaron there were and what each was up to
Cutting A Slot In Headtube
in Trials Chat
Posted
Just use the hole saw to do as much of the work as possible, then the dremel to tidy it up a little and finally use a file to get a nice finish round the edges.
With regards to the size, take a look at current frames on the market. You'd hope they've done some calculations to get a rough idea of how much material can be left to hold onto the steerer. Make sure you're not going too close to the headset cups especially.