SpecialK Posted July 23, 2013 Share I bought a second hand carbon road bike with an integrated seat post (not the most intelligent thing to do), and when I took the bike for an initial spin, everything felt fine. In the meantime, I have started to develop a niggling pain on the inside of my right knee during long rides, so today I took the bike for a professional fitting. Surprise, surprise: the saddle is too low - along with one or two other things that need to be changed on the bike which aren't an issue. So my problem now is that I need to gain 16mm in saddle height, but the seatpost has been cut too low. When lifting the seatpost cap to its desired height, the fastening mechanism barely catches on the inside, so there is not enough stability for the saddle. A 27.2 seatpost does fit, but that would mean cutting into the frame to install a clamp and I loathe to go this route as I like the look of the ISP and hate the thought of taking a blade to the frame. Does anyone know of a person that would take on a carbon repair like this in South Africa? I have searched on the internet but could only locate people either in the USA, the UK or Australia. Link to comment Share on other sites More sharing options...
Bike Mob Posted July 23, 2013 Share firstly what frame is it? Link to comment Share on other sites More sharing options...
Bike Mob Posted July 23, 2013 Share you need something like this http://www.chainreactioncycles.com/Models.aspx?ModelID=59624 Link to comment Share on other sites More sharing options...
SpecialK Posted July 23, 2013 Share It's a Karbona Zodiac Frame: http://www.karbona.c.../b-1-4-24-1.jpg I think the main problem is the cross section of the seatpost, i have attached a pic of the bit that has been cut off by the guy who originally bought it (apologies if the quality is not that great). Link to comment Share on other sites More sharing options...
Captain Fastbastard Mayhem Posted July 23, 2013 Share Should be a reasonably simple fix by a carbon repair guy. Link to comment Share on other sites More sharing options...
SpecialK Posted July 23, 2013 Share Should be, but I am looking for this magic "carbon repair guy" Link to comment Share on other sites More sharing options...
la.ct Posted July 23, 2013 Share I actually just had the same problem. All I did was buy a seat clamp working for me and has extra length. Link to comment Share on other sites More sharing options...
gummibear Posted July 23, 2013 Share Macarbi Racing do carbon repairs. Andy 0827860940 Steve 0824626860 http://www.macarbi.com/home Edited July 23, 2013 by gummibear Link to comment Share on other sites More sharing options...
Big H* Posted July 23, 2013 Share Fit the seat post and epoxy the sawn off part on the IS as a faux piece increasing the mass of your ride. The saw line can be filled with body putty, sanded and repainted in black, luckily an easy colour. That sawn of part is not load bearing I assume?????? Edited July 23, 2013 by Big H* Link to comment Share on other sites More sharing options...
gummibear Posted July 23, 2013 Share That sawn of part is not load bearing I assume?????? It is part of the ISP seat post so it is load bearing? Link to comment Share on other sites More sharing options...
SpecialK Posted July 23, 2013 Share Macarbi Racing do carbon repairs. Andy 0827860940 Steve 0824626860 http://www.macarbi.com/home I'll give them a call tomorrow, see if they can help... Link to comment Share on other sites More sharing options...
SpecialK Posted July 23, 2013 Share Fit the seat post and epoxy the sawn off part on the IS as a faux piece increasing the mass of your ride. The saw line can be filled with body putty, sanded and repainted in black, luckily an easy colour. That sawn of part is not load bearing I assume?????? Its not that simple, apparently. As soon as its not fitted exactly 100% and is out by a fraction of a millimetre, then the cap doesn't go on properly. We tried adding the spacer back, but with no luck, as the clamp on the inside of the cap is right on the joint line which is the weak point of the whole construction. I apparently have 3 options:1. try find a carbon guy to lengthen2. epoxy the cap onto the seat post but then no-one will EVER change the height of the saddle3. retrofit a seat post Link to comment Share on other sites More sharing options...
gummibear Posted July 23, 2013 Share Its not that simple, apparently. As soon as its not fitted exactly 100% and is out by a fraction of a millimetre, then the cap doesn't go on properly. We tried adding the spacer back, but with no luck, as the clamp on the inside of the cap is right on the joint line which is the weak point of the whole construction. I apparently have 3 options:1. try find a carbon guy to lengthen2. epoxy the cap onto the seat post but then no-one will EVER change the height of the saddle3. retrofit a seat post I'd go with #1 and if it doesn't work you can revert to #3 Link to comment Share on other sites More sharing options...
Johan Bornman Posted July 23, 2013 Share I think this is a reasonably easy repair. I've done similar jobs on carbon steerers with great success. The trick is to make a lug that fits inside. In this case, a single round(ish) lug will do. Aluminium is best. The lug should fit tight but have flutes along its length so that the epoxy can flow through. Expoxy works best with a 2mm layer and nice deep flutes, maybe even criss-crossed, will do the trick. Once the expoxy has made a structural bond it will take just a bit of finishing on the outside, with a few drops of fresh resin, to smooth the outside off so that it doesn't interfere with the clamp. They beauty of a lug is that it will give you plenty of warning should it fail, whereas a direct bond not. Link to comment Share on other sites More sharing options...
SpecialK Posted July 23, 2013 Share I'd go with #1 and if it doesn't work you can revert to #3 Option 4:Took everything apart, might be able to get away with a longer bolt and a few washers to lower the fixing point further down into the seatpost. Fingers crossed Link to comment Share on other sites More sharing options...
gummibear Posted July 23, 2013 Share Option 4:Took everything apart, might be able to get away with a longer bolt and a few washers to lower the fixing point further down into the seatpost. Fingers crossed Link to comment Share on other sites More sharing options...
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