Mechanics and Fixing Any Questions Answered

Thanks : )

Awesome ta

Tourney isn't great imo, try and find a decent older deore or deore lx as I find them really good on 7 and 8 setups

It’s what I’ve found in the bin, I’m still looking for that friction shifter though. Then I can use whatever wide range cassette I can find. This really is just to try something out, before I commit.

There is a reason it was in the bin ;)

I don't like them. Replaced the tourney rear on cheap bikes my friends have, with the tourneys from Halfords and tho cheap they are flimsy.

Hi smart bike people,

I’m trying to put a new 105 derailleur on my old Roberts steel.

On the new mech, the bracket projection bit has very little purchase on the hanger end tab - a combination of short pins on the mech bracket, and a raised face on the hanger.

Previously the bike had a sram rival mech with a much wider and deeper projection, so this issue never came up.

Is this too sketchy?
Is there a solution that doesn't involve a new hanger?

Thanks for any help!

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Is that direct mount and you need the adapter bit?

https://wheelsmfg.com/blog/standard-mount-vs-direct-mount-derailleur-hangers.html

[Edit]: Nevermind. took me a while to see what you mean

[Edit 2]: Maybe you can find a replacement "b-link" or "Bracket Axle Unit" that has better purchase? Like this one, although that's also a reach extender https://pilo.co.il/s10-adapter-for-shimano-shadow-direct-link-rear-derailleur.html

Thanks! Yeah, it's a little tricky to explain.
Not sure if I've got the right terminology.

Basically this bit here feels wrong.

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Yes, that would be the Bracket Axle Unit and the protrusions not being prominent enough.
Any shadow one should be fine. The sticky out bits on the RD-r8000 one look a bit more beefy from the pics. You might wanna check with a shop?

Part number is Y3E998020

https://www.sjscycles.co.uk/gear-spares/shimano-ultegra-rdr8000-bracket-axle-unit-y3e998020/?geoc=AU

Nice, will have a look.
Thanks Pascalo!

So you think I’m right to be cautious?
That bit needs to withstand a lot of pressure, so does need to be strong?

Well, ideally you have good purchase on any kind of interface, but force wise ordinarily it's just the chain tension created by the spring of the derailleur, me thinks? Of course you could hit a bump or a pothole and the whole thing gets slapped up and down ... Not sure ...

I wouldn't worry about it. It's only there to locate the derailleur whilst you tighten the hanger bolt. There's a chance that if you crash, you will damage something, but that's always the risk with a non-replaceable hanger.

Thanks both!

Which way should a seat post clamp be oriented?
I got steel frame where the gap is the front of the seat tube - should I align the gaps or install clamp on “normal” way (gap on rear)?

The slot in the clamp should always be opposite the slot in the frame. Not many people do this though (I tend to like the slot in the clamp facing forward and will put it that way regardless of where the slot in the frame is) so it seems unlikely to end in fiery death whichever way around you put it.

The slot in the clamp should ideally be offset from the slot in the frame

I can be as prescriptive as the next man, but there's a limit 😀

Ah ok so any degree of offset does as much good as 180 then?

any degree of offset does as much good as 180 then?

180deg is likely to be easiest anyway, so you might as well go for that, but once you're past 30deg you'd be hard pressed to detect a difference.

What's the theory here? In my head, if the slot is offset then you are unnecessarily adding the friction of the clamp / frame surfaces into the equation. If the slots are aligned, then there is a much more direct translation between the torque you put on the screw and the clamping force on the seatpost.

I think there is slippage and friction wherever the slots are.

If all parts were well toleranced then there should be very little, but given that we think barrel nuts are a useful feature, then we should assume there is some movement and therefore friction plays a part in the clamp force. If the slots are opposed, then the clamp and frame surfaces are effectively moving in opposite directions when the screw is tightened.

We need to summon Tester to tell us how everything is rubber and so on.

The Thomson seat clamp instructions say 180 if the post is carbon fibre, 0 if alloy.

That said they spec soft shit bolts so maybe not an authority.

I just put mine on so the slot is facing forward, away from mud splatter.

Or so that anyone behind you can see the logo of whatever bling bling boutique brand it is