Rounded Allen hex bolt - lever bracket

luv2ride

Whilst changing over to some flared gravel bars, and following a couple of previous bar changes, I've managed to round off the 5mm Allen bolts on the lever brackets (TRP Hylex). Worst is the right hand side, and now find I need to raise the hoods buts can't get any purchase. Any tips, other than only using high quality hex keys in future?

wongataa

You could try hammering in a suitably sized sacrificial torx bit into the rounded hex hole and use that to try and unscrew the bolt.

figbat

Oversized Torx, as above. Or see if you can cut a slot across it and use a screwdriver. Get some easing fluid in there to give yourself the best chance.

luv2ride

Thanks for the advice. May try the slot option first with a Dremel given there isn't enough space to use a hacksaw. It'd be good to be able to re-tighten in a new position, before investing in replacement bolts. Rode it today anyway, new bars were pretty comfy but think i know where i need to tweak the fit now. Wish I'd done that first

smethley

A tip for the future - don't use ball ended hex keys, whatever the quality, on tight bolts. Smaller mating surface...

luv2ride

Turning into an interesting day after riding the flared bars for the first time. Closer inspection of the stem faceplate after adjusting the angle of the bars shows a clear crack in the alloy, despite careful "opposite cross" tightening with the torque wrench. A lucky spot for me, but can't help thinking the separate twin bolt faceplate pieces are a design weakness...

luv2ride

This is properly turning into a 'mare. Used a combination of Dremel attachments this morning to cut a slot in both lever bracket bolt heads. Managed to cut the slots ok, but my biggest flat head screwdriver's blade couldn't get enough purchase. Decided to drill pilot holes in the bolt centre, and try reverse screw extractor - still no joy, (and broke 2 x drill bits during the process). Just bought and tried some shock freezing / penetrating spray, and a wider blade flat head screwdriver. Still can't turn either of them, and both hex bolts are pretty butchered now. Think an LBS could salvage it? Only thing havent tried is hammering in a sacrificial torx head, as suggested earlier in this thread....didnt get a ride in today as a result

masjer

The bolts are actually recessed nuts (like brake caliper nuts) so they might be difficult to drill out. You could try and use your Dremel to carefully cut through the back of the clamp itself- the nuts should come off easily then.
New clamps and hardware are pricey at £10 each upgradebikes.co.uk/Catalogue/Brakes/Disc/TRP-Hylex

luv2ride

masjer said:

The bolts are actually recessed nuts (like brake caliper nuts) so they might be difficult to drill out. You could try and use your Dremel to carefully cut through the back of the clamp itself- the nuts should come off easily then.
New clamps and hardware are pricey at £10 each upgradebikes.co.uk/Catalogue/Brakes/Disc/TRP-Hylex

Thanks for that. Was an expensive mistake to try using cheap hex keys with ball ends, but if all else fails getting new brackets will be an option...

luv2ride

can't believe it's been 7 months since I posted this, but finally got round to fixing them last weekend, following a combination of a deep-seated fear of making a further terminal mistake, and workload increasing immeasurably during lockdown meaning very little spare time...bike had been rideable so kept using it.

Bought some replacement TRP shifter clamps, as suggested above. Used the Dremel to cut off the bands of the original clamps with the rounded bolts, being careful not to cut into the bars. Got levers in a vice to drill out the bolts. First one was a complete success. With 2nd one, the drill bit can't have been as sharp and didn't drill out as easily. Bolt go so hot it started melting the plastic lever body, burnt thumb in process. Eventually got it drilled out.
New bolts and clamps fitted, bar realigned and hoods tighted, bar re-wrapped. Much better now in the riding position
Bought sharp new Bondhus hex keys to make sure this never happens again, and now will never, ever use the ball end of a hex key to try to undo a stiff hex bolt!
A stressful fix, but all sorted now.