You shouldn’t accept ridicule from cyclist who think they know just how important the seat tube is on a bike. For example, did you know that currently the humble seat tube is one of the most design focused areas on a carbon bike (I refer to established brands). Granted the new Cervelo P5x TT bike has done away with it but if you are a UCI compliant cyclist the seat tube is here to stay. Why so important? The biggest gains on UCI compliant road bikes these days comes from a more comfortable bike. Advances in aero tubes, BB stiffness and weight are well developed compared to rider fatigue. This is the no 1 enemy of competitive cycling. Trek’s development of the ISO Speed system in the Domane and Madone 9 is an obvious example of minimising rider fatigue without compromising frame stiffness. The genius of the Madone 9 with it’s internal flexi tube and external aero cover allows relative comfort on a sprinters bike. Another myth is that thin seat stays provide a softer ride. The purpose of the seat stay is to push back (stay) the over-flexing seat tube. It does not allow the chain stays to flex as some think. The new thinking is to design the frame around the seat tube!
The more relative point from a carbon repair perspective is if you find a fracture anywhere on your seat tube, you should seek advice immediately. The seat tube flexes like a bow when stressed. Any flaws or cracks in the tube could compromise the structure of the whole frame. A bit like a house of cards.
The opening date for Carbon Bike Repair South Africa is set for 1st of September 2017. Their advanced training course is now coming to a successful conclusion before we fly them back home. However..there is one final test. Even though they are now qualified in advanced carbon repair and restoration to Level 3, the new team are put to the ultimate test. Their task is to repair and paint restore this Trek Madone which was in 5 separate pieces. Once structural tests are successful and the graphics restored, the repairer will ride it in the next local 100km race.
So if you are ever considering getting your bike repaired in any branch of CBR, be assured that only those ‘living’ persons at Carbon Bike Repair will touch your bike.
When carbon was first introduced into mainstream cycle manufacturing, carbon was seen as a ‘replacement’ for steel because it was stronger then steel (weight was still a problem) and was seen as ‘progress’. There was little consideration for the potential of ‘frame shaping’ into non conventional designs. In addition the poor relationship between alloy and carbon bonds became an issue as it turned out. There were some conceptual carbon bikes but I refer to the mainstream approach at the time. So for a while we generally went backwards in the late 80’s and early 90’s.
There are still companies such as Colnago and smaller brands who continue with carbon lug designs in some models which receive great reviews. Lugged frames allow the tailoring of frame sizes where mono-cock frames rely on mould size variety and stem lengths. Some say with lugs you can tune the ride quality best but I am not convinced.
Today’s bikes have little resemblance to the carbon bikes from 15- 20 years ago. It is such an exciting time to own a carbon bike. There is no doubt when you look at the 3 primary cycling disciplines: road, MTB and TT that road bikes, in particular from 2015 onwards, have evolved in areas such as agility, aerodynamics and comfort while making them still lighter and stiffer. I refer in particular to the higher end models where the competition to provide efficiencies are becoming harder to achieve. TT and MTB’s have carved the way for experimentation to bring new but maturised concepts to the road bike. Some suggest road bikes are starting to look more like a hybrid of mountain and TT bikes.
However – The downside of this development seems to be where the line is drawn between the physical demands on experimental designs and consumer use. It is a mystery why some manufacturers still apply fatigue tests when they know perfectly well that carbon does not weaken with repetition as much as it does by impacts. It is the real-life effects upon the design or structure which seems to be over looked. These oversights make a common appearances in our workshops with alarming consistency. I guess it is the price you pay for progress. Just make sure your insurance policy is comprehensive enough or insure with a bike specialist insurer.
We bang on about quality all the time. We don’t often get an opportunity to share the difference between fake restoration and factory finishes. This Agron18 was not restored to Nitrogen specification and clearly the customer was not happy. As a result it gets sent to CBR to get corrected. We wouldn’t bother coming to work if we can’t AT LEAST replace the correct detail to a restoration project… Attention to detail is the clue to the standard of work under the paint…
I seem to be posting a fair bit of Colnago related stuff. This is not a true reflection on a various brands we work on every day. That said CBR have 2 of only 9 in the UK. Both suffered some sort of damage and require precise restoration.
If you read our blog you will find other examples similar to this fracture repair and restoration. The image is unfortunately inline with the handbars so we get a few per year. This is for a Sigma Sport client.
Many who searched online for a resolution to this issue are in for not-so-good news – It was a bad idea from the start to clear lacquer any naked carbon. Don’t get confused between shiny moulded race car surfaces. These are not painted. Only a well polished high pressure mold can create this clean finish. When carbon was first used in bike manufacturing they understandably wanted to show the material off. The problem with carbon is the waxy resin surface which forms as an outer skin on the frame which cannot hold clear lacquers for very long. A bit like trying to spray onto nylon..There are a few clear coat primers out there but none very effective as far as we know.
The modern way to show carbon weave is to tint the carbon with a darker primer. This provides better grip and you can just about see the grain coming through. My advice is if you like your blistering frame then the best way would be to go this route but please don’t attempt a fresh clear lacquer respray. You are throwing good money after bad.
EXPRESS SERVICE DOWNTUBE REPAIR & RESTORE
A roof rack incident has left this Wilier damaged in a highly detailed section of the downtube. The client required his bike to be repaired within 1 week if possible so he could attend a race in Europe the following week. We managed to repair, test and restore the graphics to original within a few days.
Guess which one? The other is an original finish.