Looking for advice . Any top mechanics.

disco1

Hi.


I'm fairly handy with my bikes but am stumped currently.
I have 2019 merida scultaria rim brake bike.

The rear brake is tru the top tube..both inner and full outer.
This outer cable runs in a carbon fiber tube in the top tube..I removed the fork to see the set up.

The big problem is the cable outer rattles in the carbon sheath.
I tried wrapping some insulation tape around cable outer but hasn't worked...tried filling tube with heavy grease...hasn't worked...any ideas on a fix.

Half thinking of trying to remove the carbon sheath and run cable outer tru top tube and dampen it with some foam chunks pushed in the top tube.

Thoughts..cable rattles major hate...wont use this bike if I cannot sort.

Thanks.

Idleater

The only thing to try is to find some frame protector rubber rings and feed them onto the outer casing of the internal cable.

Kevincavan83

I had the same issue with my bike, shop installed a foam insert inside the top tube which reduced rattle a little but still bugs me on sh!te roads. Another fix can be to hold the cable that comes out near the stem end and push the cable from the saddle end so that it sits against the wall of the top tube it will reduce the rattle aswell, must say it's the reason I changed to a different brand of bike

Cee-Jay-Cee

My brake cable which ran bare through the top tube rattled like crazy too, I bought some 2mm ID silicone tubing on ebay and slid it over the section of cable and pushed it into the top tube and its been silent since. You will obviously need to buy silicone tubing with a larger ID to accommodate the brake outer cable too. Plenty of sizes available on ebay.

triggermortis

If the entry hole is large enough, you could pull a couple of cable ties onto the outer and don’t cut the tail off. Spiral them around to make a spring shape and then feed them into the hole. The tail should then try and expand and fill the gap to stop the rattle.
This is just a theory, I’ve never tried it myself

Type 17

disco1 wrote: »

This outer cable runs in a carbon fibre tube in the top tube..I removed the fork to see the set up.

If there's room in the tube, stick a strip of fluffy tape lengthways along the outer cable housing - something like this or this, which is used for keeping electrical looms quiet under car dashboards (works great for this, I've used it during restorations).

Rua_ri

triggermortis wrote: »

If the entry hole is large enough, you could pull a couple of cable ties onto the outer and don’t cut the tail off. Spiral them around to make a spring shape and then feed them into the hole. The tail should then try and expand and fill the gap to stop the rattle.
This is just a theory, I’ve never tried it myself

This is exactly what I did , 4 tie wraps evenly spaced. Worked perfectly for me.
I used to get a lot of cable slap when on rough ground. All silent now. Been in for over a year and no issues.

Rua_ri

If the cable ties can't fit, Shimano came up with their own solution for internal di2 wiring.

Expensive here, but you get the idea.

https://www.evanscycles.com/shimano-di2-cable-tie-set-for-internal-routing-pack-of-20-EV169056

Type 17

The cable ties and Di2 solutions work well, but only where the top tube is empty - it won't work for the OP because his top tube has a guide tube for the cable housing.

PS: The Di2 items only work with Di2 cables (~2.5mm diameter), in case anyone is thinking the'd help with noisy bowden cables (4 or 5mm diameter)