Mechanics and Fixing Any Questions Answered

Re

Unlikely but if caliper not designed for it, or pistons not all the way back due to...
hydrolock, too much fluid in master
cracked in half piston, the inside part of the piston which used to be one with the outside part, has broken company and is now jamming the whole thing, so you can't push them back (most white piston'd shimano's of the last 10 years).
New pistons wrong, rotor too thick or pad too thick or combination of all three

It's a Hope E4 caliper with the new stainless pistons replacing the old phenolic ones. Plenty of clearance on the caliper, Hope says it's compatible with 2.3 rotors. Pads are pretty new standard sintered ones. I had it working ok before, just the new pistons are so smooth that balancing them is proving tricky using the Hope "hold the pads back with a screwdriver" method

And it's been bled with a bleed block, and Hopes easy bleed cup so it's not overfilled.

the budget hack was a business card folded over the rotor if you have one of those lying about. Or even just some folded paper. might be worth trying before buying a new tool.

back when i used discs I found it easiest to align the caliper by moving it with my hands but over a white background which helped to see the gap between rotor and pad

Yeah might give that go. I've aligned the caliper without the pads and eyeballed it, that's central. It's the pistons advancing too far then not retracting back enough and rubbing I'm struggling with

So I just received an FXE frameset from Dolan and noticed it had burrs where both the top tube and down tube meet the head tube, which I can file down pretty easily but also the end of the headtube looks kind of rough, mostly just paint I think, how usual is this for modern frames? (I was expecting it to be mostly ready to go) can just clean this up with wet and dry or will I need to properly face the ends? Any advice would be welcome, hopefully the pictures are clear enough. Cheers.

3 Attachments

That does look poorly finished but shouldn't be a problem, especially if you do what you said, nothing should be touching those surfaces. I had a mielec arrive that had a dent from shipping in the top of an integrated headset like that, bent it out and am still running it on the original bearings many years later.

First ride on the Winspace today; thanks for all the pointers (smartest one would have been to tell me to throw the integrated bars in the bin). Need to take a spacer out but it's close.

1 Attachment

Thanks, good to hear, bit annoying its needed in the first place, reckon this is within normal QC or worth the bother of contacting Dolan? I’d probably rather just fix it tbh but it might be worth seeing what they say. Cheers!

It should be finished better, so feel free to see if you can blag a freebie but I'd just get on with fixing it and riding it.

Yeah ima just get riding it, cheers.

Looks fine to me. You can tidy up edges of the breather holes in the headtube and the bottom of the headtube if you want, but it'll make no difference whatsoever to how it rides, and the breather holes are invisible anyway once it's built up.

If its flat mount then make sure your mount is proper mega flat and faced properly, hopes' run a very close tolerance at best of time, and when they are new they will mostly rub the rotor for a minute or so after every brake application, this is normal with them and will either go away or cause you to go insane.
Was talking to the hope peeps on a stand recently and the road flat mount calipers they've had some issues with rub, new piston style (like a steel sleeve pressed inside the alloy caliper?) helps reduce that though not seen many new ones to really know.

A bit of white paper on floor under bike is all I often use when bike in a workstand, helps be able to just look down through the caliper and set it on the fly. I tend to do it with wheel gently spinning and just kind of freehand it until it shuts up, then road test, then check it again, repeat until disc perfection is reached.

I have a set of those skinny stainless alignment tools, not found many caliper situations that they work particularly well for though.

Yeah I've got these E4s and also some RX4s, which were a nause to get setup right. I've got no trouble aligning a caliper, it's the piston balancing that's not easy with these new pistons. There seems like a fine line between seal hysteresis and the piston actually sliding through the seal itself. Anyway, I fashioned a pad spacer out of a tin can lid earlier, which seemed to put me on the right side of then being able to balance them again using the screwdriver technique. Seems much better. And like you say, Hope's tend to start working once you actually ride them for a bit

Just need to source the correct rivnut? anything else I'm missing?

Use aluminium ones, stainless while they may seem a better option are much harder to set

ensure you buy open ended ones and not closed end.

drilling size is 7.1mm if needed

https://tinyurl.com/2w4v56c7

perfect info, ta

Ask for a new frame.

Had the same before and although they didnt send me a new one, got a full refund plus 30% off my next purchase.

anyone done a repair job on a deore m770 XT shifter before?

mine isn't shifting down / releasing cable tension.

if i push this little bit in manually then it does work.. anyone more experienced than I reckon it's a relatively easy fix? flushed all the crap and old grease out already.

Can't remember which shifter that is but frequently fix shifters that have stopped ratcheting up or down due to the little clicker (up or down, sometimes both!) sticking due to old grease/time/temperature.
Flush with kroil/gt85/brake cleaner etc, use a dental pick to stimulate the little clicker/spring, don't go all the way to its limit of travel or risk breaking the spring as then its scrap. Just flick it back and forth about 20 times until it moves well enough on its own, then use a pick to stick a blob of nice green shimano type grease on it.

Get it all the time when folk drag 90s/00's hybrids that have been sat in a shed for 20 years. A few days soaking and a bit of flicking/new grease, often work fine again for many years.

This little metal part fell out when I took it apart, think it’s part of the return spring for the shift down ratchet cos this is the bit that refuses to work now 🥲.

Dead, I’m guessing (without a replacement of this part anyway)

1 Attachment

Does anyone have experience of CODA quill stems failing/being known as death traps? Found this example here, pic below: https://www.lfgss.com/comments/15180272/

Today I removed the ally handlebars from a CAAD 3 I bought and the edge of the stem clamp has cut a little groove in them - Cinelli Eubios with a reinforced/thick clamp area. I was going to file the edges of the stem a little and carry on. Or should I consign both to a shelf and replace? Both parts are pretty ugly, but they're original and the right fit so I'm loathe to get shot

2 Attachments

little groove

Wouldn't risk it myself, even if I didn't plan to ride in anger

Pic of the groove would be interesting

Over or under tightened, alu fatigue.

That's what I'll suspect.

The stem on the blue bike looks like the clamp halves are bottomed out against each other which could suggest overtightening or a mismatch in diameters.

I see though that your bars are marked as being 26.0mm so should be the correct fit if the stems are 26.0. It seems particularly unlikely that the stem is available in 2 clamp sizes and that you and the owner of the blue bike both have mismatches in the opposite way.

Could your groove be corrosion? The faceplate bolts look a bit crusty so could the bike have seen some prolonged turbo use with sweat collecting in the join between stem and bars?