DIY carbon frame repair

Bike N Gear

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Shop Keep
#1
Got bored and decided to attempt to repair a cracked Tarmac frame that’s been hanging here for years. Sold this to a friend who got hit by a car on day 3 of ownership. Insurance bought him a new one.

Figured if this stays together it will make the perfect trainer bike.

Forgot a before picture, but this is after I just started sanding it down.

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Bought a diy carbon repair kit on eBay for $24.

Mixed the ingredients and did 2 wraps of carbon.

diy1.jpg


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Wrapped in electrical tape and let it sit over night.

diytape.jpg



Then sanded a bunch. Could have done better on the sanding, but this was really just a test.

diy3.jpg


diy4.jpg


Hopefully this doesn't blow apart the first time I stand on the trainer.

Surprisingly fun and easy to do.
 

MadisonDan

Well-Known Member
Team MTBNJ Halter's
#2
Got bored and decided to attempt to repair a cracked Tarmac frame that’s been hanging here for years. Sold this to a friend who got hit by a car on day 3 of ownership. Insurance bought him a new one.

Figured if this stays together it will make the perfect trainer bike.

Forgot a before picture, but this is after I just started sanding it down.

View attachment 78905

Bought a diy carbon repair kit on eBay for $24.

Mixed the ingredients and did 2 wraps of carbon.

View attachment 78914

View attachment 78908

Wrapped in electrical tape and let it sit over night.

View attachment 78915


Then sanded a bunch. Could have done better on the sanding, but this was really just a test.

View attachment 78916

View attachment 78917

Hopefully this doesn't blow apart the first time I stand on the trainer.

Surprisingly fun and easy to do.
video please
 

Bike N Gear

Shop: Bike N Gear
Shop Keep
#5
thanks for sharing!

toxic in any way? fumes? gloves? mask?

hand sand? grits used?
No severe toxic warnings. Said drink milk if you accidentally swallow. I kept my mouth closed. No smell at all. Wore gloves because sticky.

Sanded by hand with whatever was laying around. I think with actual effort it could look close to perfect. If I were truly concerned I would have gone thru a progression of grits, but I just grabbed one course and one fine, then called it good enough.
 

Bike N Gear

Shop: Bike N Gear
Shop Keep
#8
Interesting, do you need to align the frame in anyway? Seems your first pic showed a substantial gap.
I had pulled it apart for the photo. Everything was still in alignment before and after. Wheel slides right in and sit straight. I'll be using this on a Cycleops Hammer, so no rear wheel, but plenty of stress if I try to stand and sprint. Maybe I should video this.
 

iman29

Active Member
#9
cool experiment always wondered if carbon repair was legit but I dont think i would ever ride it outside.

look into making a "rocker plate" for under the trainer. there's tons of info out there on youtube etc.. some folks turned this into a business.

Basically it takes the stress of the frame and gives you more of a road feel from what I read. I dont have the room to leave the trainer in one place or i would build one.

good luck looks good.
 

Delish

Well-Known Member
Team MTBNJ Halter's
#11
I would think that hammering on a no-rear-wheel trainer puts as much or more load on a seatstay than riding on the road would. Nice project. Any idea how the wall thickness of the repair compares to what was there before?
 

Magic

Formerly 1sh0t1b33r
Team MTBNJ Halter's
#13
I would think that hammering on a no-rear-wheel trainer puts as much or more load on a seatstay than riding on the road would. Nice project. Any idea how the wall thickness of the repair compares to what was there before?
Agreed. Sean broke his Kona on a trainer I think. I feel like it makes the frame stiff in the areas not usually designed for it. The BB flex looks crazy looking down on my Soma Smoothie the few times I had it on a wheel on trainer.