HeartCoppi

what a fantastic bike. So many things to remark on. The shifters are exactly like the ones I have on the zullini but for the colour. Its the first I see another set. This guys frame is freeking spotless. the seat post lug detail is hot. I dig the pump, I am itching to have chrome pump like that. and man, I must learn to wrap tape like that, its a great job. Interesting that he's using Modolo levers! I know your waiting for a comment about the deltas but I'm not sure what to formulate. I wonder if they are home jobs. Anyway I like the more classic look. This dude should loose the pedals though! Is this on ebay at the moment?

ordered and paid for new straps today from WI state side. now waiting for USPS to knock. when I've polished and put on good tape and a new saddle, I should have her studio photographed....its that nice!!!

maybe just one more. Thoroughbred (... its a beautiful word) .

The drive side of my new bike. PS: no sandwiches required for the moment .HeartCoppi2010-03-04 13:09:44

Thats a really nice pic. really nice. ahem...nice pot

Had the same problem. I had it coming from the back of the saddle itself were the rails were housed. Had to laugh out loud at the "its driving me nuts". If its still new, take it back.

weight?

Follow this lead, because by the time you've bought all materials to do a can job you'll have spent R500 I reckon. But check the dale out first. My feeling is: 'you get what you pay for'

Whats your location?

Capricorn has given you a great recipe. But it will always be a second rate job using cans. Have it sprayed proper. It may cost a little. But you know what, by the time you've made a huge mess and damaged your health and spent 50% of that on a 50% job, I don't think you'll go that route twice. IMO. The detail will be so much better and so then is the enjoyment.

Mmm, does look odd and dangerously close to the edge

OK, paint stripper is fine on an alu frame. Just brush on in thick globs and wait 15 minutes. It will blister and flake off. NOT OK for carbon frames. If sanding after, go 1200 and finer until nice and smooth. NEVER NEVER sand away the welds. Rattle cans are so K@K! There is no UV resistance and the colour will fade fairly quickly especially the clear coat. This will turn yellow eventually. It will also scratch easily. Expect to spend on about a total of 7-8cans.

Q1: what material is the frame?

never seen this before. then I saw your thread and 30min later this: well its a lead anyway. http://capetown.gumtree.co.za/c-ViewAdLargeImage?AdId=188292830&back=-3&ImageIndex=1 I take it that they are sold as a set, but dont know about the number of gearsHeartCoppi2010-02-25 13:21:14

I use six white beetles. Great fun but not considered as a great beam. Just for super visibility by others.

Early morning rider, lazy after lunch

Jeepers, I know the feeling. The stones are well cemented in to the hard scab. So trying to dislodge the stones means painfully lifting scab which isn't ready to come off yet. Ouch! What to do: Generally nothing. Heres my vague recollection of what I can remember from biology and my experience from several encounters with mother earth: The epidermis has 4 or 5 layers. The outer layer is constantly replaced by the deeper layers. So it will gradually push forward and eject the debris. If deeper it will have to be extracted with a tweezer. Your MD will do this. No need for hospitalization. Infection is a different matter that would require some form of medication.HeartCoppi2010-02-21 03:42:33

...with regards the headset. What was the experience of the owner regarding the headset: was it very loose requiring regular tightening? was it over tightened? was there play in the headset i.e did the fork 'wiggle'? did the owner change forks? (good question regarding the pot hole ( high vertical impact))

is it plugged in?

It would be great if you (JB) got hold of this frame again and were allowed to dissect it.

It is certain that there are various definitions of 'compression' What is to be considered is the extent of compression. There is a vast difference in the degree of compression between a press fit and an interference fit. In an interference fit, there is a considered overlap of diameters, such that the shroud has to be heated to expand to slip over the inner diameter. On cooling, the shroud shrinks again and exerts high compression on the inner piece. Aluminium is a soft and ductile material. The head tube is also very thin walled. The head set race is hard and strong and several times thicker. On pressing the head set race into the aluminium flange cup, the flange presumable rides up over a broken sharp edge or champer on the entry face of the race. The aluminium is slightly displaced outwards on full seating of the race. (Possibly measurable with a micrometer) How much compression can the thin ductile aluminium ring really exert on a robust steel inner race? Some, but not much !! very very little (compressive force) Previous poster suggests that the aluminium failed first, eliminated critical compression and created a positioned relief for the failure of the race. I maintain that there is no existence of any significant nor critical compression, considering the proportions and materials here. Therefore the aluminium has virtually no influence on the mechanical life of the race. But the integrity of the race has huge force on the tensioned shroud. There was a key statement in the paragraph above for Capricorn: "The aluminium is slightly displaced outwards on full seating of the race. (Possibly measurable with a micrometer)" This explains the burst appearance of the vertical crack in the head tube. Meaning that the aluminium circumference was experiencing stretch when it failed. This also implies that it is a tear and not a crack. I would also like to refer to the most critical info given by JB in his opening post: the cracks coincide exactly in position. When the steel race cracked first it did open and close slightly under continued use creating an immediately adjacent stress vector on the tensioned aluminium further stretching the aluminium sporadically till it fatigued and "tore". Because the circumference is stretched while the race is still inserted, the gap appears severe. There is a possibility that the aluminium may 'close' if the race is removed, but it will not return perfectly because it has a relative low elastic coefficient. It would be interesting to see if the steel ring opens when removed. ha...If you think it will, we have a problem, because it wont. It already could open with the existence of the tear and the total absence of compression, and wouldn't have to be removed for this to occur. Finally the tear turns and follows the circumferential and vibrating plane of the race: as the forces from the road travel through the fork and crown and transverse through into the race and the aluminium it is in contact with. NOTE: This would occur whether there was any welding, or none what so ever(as I propose) around the based of the head set flange cup form. Failures are evidence or indicators of localized stress and do not unnecessarily arise or propagate to non stress zones, but continue to follow the cause. Sorry if I missed something. HeartCoppi2010-02-18 16:33:11

The alu frames I've looked at closely have a hole cut into the head tube where the top tube and down tube meet the head tube. Clearly the top tube and down tube do not fit into these holes for assembly. The holes are smaller than the diameter of the top or down tube. I believe they are there for two reasons: (1) when welding the saddle shaped weld around the outside to join the head tube to the top tube and the head tube to the down tube, there will that final instant where the weld closes onto the weld start point. By now there is already significant heat. The hot air inside the tube needs to escape as the weld closes and heat increases the pressure. It increases the risk of weld defect and reworking the weld because of pressure blowing out the melting pool. This is always more pronounced when working in smaller and lighter dimensions. This is on the assumption that the other end of the top and down tube is closed. It is possible that even Argon purging is taking place. (2) another reason probably is to have an access point to shake out any debris that may get trapped during manufacturing. It really irritating when theres something making a noise in the tubes in a premium frame. Just to be clear, I was not referring to welding cup flanges to the head tube. ...which brings me to another concern. The assumption is that: step1 weld cup flanges to top and bottom of head tube...step2 weld over those welds when doing the saddle welds to join the top tube and down tube to the head tube. Sorry if I missed something. Bit of guessing because not firsthand visual

Wrong forum