Help Carbon repair - where?

danny

Maximum Pace
Feb 29, 2008
160
50
58
Chofu-shi, Tokyo
www.cyclism.jp
#1
Need carbon repair. Does anyone have any suggestions who can do this quickly? Say within one week?

By my own fault I tightened my seat-post (ISP) topper just a bit too tight and crack my integrated seat post. I know better than this. Found out just a few mins into a ride. Crack is from the top of the ISP about 3 cm long. Repair does not need to be cosmetically perfect as it will be covered by a the ISP topper.

Thanks!
Danny
 

TCC

Tokyo Cycling Club
Jun 30, 2013
2,362
1,291
133
#2
1. Ouch (and lol).

2. Are you mates with Hiro Natsume on Strava? Apparently he managed to fix his cracked BMC with carbon repair tape, so if you want to do it yourself, maybe speak to him about how he went about it. He is a monster on a bike, and if what he did worked, and now manages to hold up to his daily abuse, then it will be fine for your seat post. Unless that batch of Perestoika Glasnost Ultra-Swole Biotech steroids that you ordered finally turned up, and you now weigh 300kg.

3. I don't know of any places that do carbon repair (which I think is the key point here), but you can do it yourself for sure. There are loads of Youtube vids of people doing it...

4. Photos please, so we can all have a good wince.
 

TCC

Tokyo Cycling Club
Jun 30, 2013
2,362
1,291
133
#4
Amazon, Ebay, etc. Also try Monotaro.

Don't limit your searches to cycling either; search carbon fibre fishing rod repairs too.

Sorry I don't have anything specific for you; will see what I can come up with later today.
 

TCC

Tokyo Cycling Club
Jun 30, 2013
2,362
1,291
133
#7
Quality link! It is always encouraging when places offering bike related stuff have their main business as automobile; they tend to actually know what they are doing.
 
May 22, 2007
3,608
1,440
143
Kawasaki
halffastcycling.com
#12
Both totally awesome repairs!
It's very unnerving when you brake and the bike stops dead because the front tyre is up solid against your frame. Meanwhile your weight shifts forward several unexpected centimetres.

I should note that I got a new frame/helmet/everything out of the other guy's insurance - that was the GSAstuto Rastabike that spontaneously jumps into rivers with flat tubs.
 
#13
Yes, as per @kimm, I recommend Amanda.

I have been twice to him to carbon patch a frame that I cracked the top tube on two occasions (my fault both times) - he does very nice work, and reasonable prices. I took my bike to him, spoke politely and it was fixed within 1 week (in fact quicker I think....if you say when you need it by he will probably fit around your needs). I paid him 20,000 yen or slightly less both times - which given no normal bike shop will go near a carbon repair for you was fine by me. (manufacturer will always tell you to replace a cracked frame since they don't want any liability issues)

Don't be put off by his place being some small looking house/workshop buried in some back streets off Tabata Shinmachi in Kita-ku, as per the webiste link from @kimm, this guy is the pioneer of carbon frames in Japan - you will see rims, frames in his workshop that he is building. He is a very interesting older guy that knows his stuff. I was recommended to try him by Nalsima when I asked them about repairing my cracked frame - they said he was the only place they knew I could try.

His address is:
114-0012
東京都 北区
田端新町1-11-18

He is open Fri, Sat, Sun 10:30-6:00pm

You can call him on 03 3809 2477, I spoke Japanese with him, which I suspect you will need to do.

As I said, a great find of a place in Tokyo like something out of the past with someone who knows and loves what he does.
Be nice to him and I am sure you will get a great piece of work done (also he won't try to sell or do anything you don't need)

ok, enough said.
 

timefleas

Maximum Pace
Nov 30, 2013
107
45
58
#14
Calfee is pretty much the world standard for carbon frame repairs, but sadly no representatives in Japan. However, you can buy carbon repair kits locally at advanced do it yourself shops (some Tokyu Hands used to have them, for example), or online such as those available from Carbonmods (UK), and could probably easily assemble your own kit here, as the things that you need are pretty common (the different carbon wraps, the resin, the shrinking seals, and so forth)--the good thing about kits is that of course they come with instructions, but even then, there are many online sources for this as well. I wasn't in a hurry, got a kit, and repaired a hole in the seat stay near the BB enclosure on my Orbea Orca--it is now stronger than new, looks perfect, and cost me about $50--plus I have enough left overs from the kit that I could make another ten repairs if need be. Highly recommended it you know your way around model kits, and things like that. I always take the route that gives me complete control of every aspect of the bike I ride--ever since my brother repaired my bike way back when I was 6 or 7, and found myself flying down a steep hill with no brakes....
 

timefleas

Maximum Pace
Nov 30, 2013
107
45
58
#16
Minimum 2, max 5--depends on the amount of structural integrity involved--where the carbon itself is thickest (around frame joints), then of course more fiber is required there, and where it is relatively thin (on tubes) then two or three is probably OK. Usually a thicker weave on the first application--sand--then one or more finer weaves on top of that. You also want to balance strength, so if one seat stay needs the fix, but the other side is fine, some folks will apply the same treatment to both sides in order to have balanced strength at the end of the project, on both seat stays.
 
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Gunjira

Maximum Pace
Oct 2, 2009
1,003
176
83
Tokyo
#17
I think this should be an easy patch, based on fixing my cracked carbon top tube under tutelage of GSAstuto's Tim. Two years and still going strong.

Because the topper goes around the outside, I would:
Order some 3k or UD carbon weave - I found it cheapest via mail order from http://www.news-carbon.com/

Also get some resin, the longer the curing time, the better.
As well as some aceton (nail polish)
A couple of sausage shape balloons
Some sheets of semi-fine sanding paper.

Remove the bb and tape the dt hole shut.

Start filing away the clearcoat on the inside of the ISP. I bet there isn't a lot inside if any at all

Rinse and clean the area with acetone.

Apply a layer of tape around the outside of the post with 1-2cm above the edge to temporarily affix the carbon weave during the next step.

Cut a slice of weave of the right length, it shouldn't overlap but should reach down to the end of the crack and some. On top, if it sticks out, a bit so you hold it in place with the tape, that should help.

Mix up some reasin, apply with a brush so the layer is soaked with it and sticks to the seatpost. Don't use too generously because filing it down will make you curse.

Blow up the balloon inside the frame with some sticking out to force the carbon and reason tightly against the existing carbon. After tying it shut, you can compress the top balloon part sticking out some more with tape, so there is even more pressure inside. You might practice this step as a dry run in advance.

Curing inside the ISP might take some time because it will be difficult to direct any heat there. Probably you just have to let it sit overnite.

Pop the balloon, File down all the carbon and tape sticking out of the ISP, and then all the balloon remnants and reasin inside eavenly until you reach the new carbon layer you just applied.

Repeat 2-3 times. For the last time, you don't need to do any filing for cleaning up inside, if you are not weight conscious.

In the outside, if you don't mind that the crack is still visible, I would just mask and apply some clearcoat spray there and file it done eavenly with very fine sanding paper.

Clean up and enjoy.
~5000yen costs and ~6hrs work, 4 days total because of the curing time.