Any question answered...

For a bike light: What sort of lubricant should be going on connectors like these to slow corrosion?

Copper grease?
Silicon grease?
Vaseline?
GT85?

Can I run Niner BioCentric II or any other eccentric BB with GXP on my GT frame? My intention is 1. To avoid the bottom pinch bolt mechanism 2. To create space in the BB shell possibly to run Alfine Di2 cables

I don't know the shell specs but can measure; from a very basic measurement the outer diameter is close to 60mm ..

For a bike light: What sort of lubricant should be going on connectors like these to slow corrosion?

Copper grease?
Silicon grease?
Vaseline?
GT85?

None of those, use silicone grease

:-)

Grand. Thanks dan.

What kind of wheel obeys I = m*r^2 yet gives such a simple result as "double"?

For an ideal wheel (all mass concentrated at periphery) of
radius = r
mass = m
rolling at a forward
velocity = v
moment of inertia
I=mr²
and angular momentum
L=Iω
Angular velocity relates to forward velocity and radius
ω=v/r

Now apply an arbitrary braking
torque = τ
for a
time = t

such that
L=τt
bringing ω to zero

The
force = F
at the periphery needed to generate the torque is given by
Fr=τ

Now rearrange

L=mrv
&
L=Frt
so
Frt=mrv
and dividing each side by r gives
Ft=mv
in other words, the impulse which can be extracted from a spinning wheel is maximised at the same value as the translational momentum for the ideal condition of concentrating the whole mass of the wheel at its periphery, independent of the radius.

This gives a maximal impulse available from a wheel of exactly double the translational momentum mv; all practical wheels will provide a smaller impulse than this.

PS: I haven't been in a maths class for 30 years, so I won't be too upset if somebody proves me wrong :-)

^ It's exactly the same result as i get by a slightly different thought process.

Planet X carbon framed bike with Ultegra for £1k. Good deal?
Also considering a Ribble with Ultegra, but they come in quite a bit more, like £1.6k-£1.8k.

^With an Ultegra groupset costing about £550 on average, it's hard to argue with £450 for the rest of the bike!

Planet X carbon framed bike with Ultegra for £1k. Good deal?
Also considering a Ribble with Ultegra, but they come in quite a bit more, like £1.6k-£1.8k.

Very good deal, even though it's the outgoing 10-speed Ultegra rather than the new 6800 series. My brother bought one. Only really 'cheap' component is the crankset, and even then it's a very creditable Shimano item (it's debranded Tiagra, basically), which I'd take over most cheap FSA stuff. I don't think you'll find a better road bike for a grand.

My Focus with 6600 Ultegra cost me over £1200, discounted from £1600, and that was five years ago.

Planet X carbon framed bike with Ultegra for £1k. Good deal?
Also considering a Ribble with Ultegra, but they come in quite a bit more, like £1.6k-£1.8k.

I think it's a good deal, bear in mind it's not full ultegra though. Brakes and cranks aren't ultegra. Also, the pics and the actual spec are a bit different, if I remember correctly?

Also, the pics and the actual spec are a bit different, if I remember correctly?

Only difference I noticed on my brother's one was that the saddle it arrived with was a Concor Team rather than a Ponza.

Only difference I noticed on my brother's one was that the saddle it arrived with was a Concor Team rather than a Ponza.

Nice! My housemate was looking at getting one and when we sat down and looked through the spec as written, I thought I remembered it being different to that pictured...

Just had another look - spec says FSA Team 30 wheelset, pics are Shimano R500.

They might have tweaked the spec a bit since last autumn then - my brother's was specced with, and arrived with, the R500 wheels.

Do have a look at the Canyon site too though, their Roadlite AL is a great bike for the money if it's in stock.

PX for 1k is definitely a good deal. What wheels does it come with? Even with a pair of (bombproof) R500's would be good!

^ It's saying it comes with FSA Team 30s which PX are selling on their own for £240... I find that hard to believe but the blurb on wiggle for the same wheels says they're handmade with sapim aero spokes - no longer available though. The new version of them on wiggle seems to go for £220ish.

Oh and PX say they weigh 1670g a pair. Is that good for the money, seems like it's about 300g lighter than R500s?

Weight is about par for the money. Ultegra are nicer (IMO) though. FSA stuff is famously overpriced when sold separately.

Looking at the sram force 22 group as I've seen it come as standard on the boardman cxr 9.0

Will I be able to use the standard shifters with mechanical discs or do I need a disc specific lever?

I've got the Apex levers and BB5's on the Mrs bike working pretty well, they just need adjusting frequently.

She's ~50kg mind you.

I'm 100kg+

You see that being an issue?

Before I open a new chains packaging I need to make sure it will wrap around a 50t chainring and 32t lowest rear sprocket, chainstay is 43.5cm (50/34 chain set and 12/32 cassette . How many links am I likely to need?

I'm 100kg+

You see that being an issue?

They need adjusting as the pads wear- you are going to wear them a bit faster I would think.

When and why did Tunnocks remove the jam like stuff that used to be inside the marshmallow of a teacake?

Part of the Scottish nationalism movement, you can still get the jammy ones North of the border

Before I open a new chains packaging I need to make sure it will wrap around a 50t chainring and 32t lowest rear sprocket, chainstay is 43.5cm (50/34 chain set and 12/32 cassette . How many links am I likely to need?

Use a quick link and set the chain length with the chain on 50/32 with the derailleur arm at about 45 degrees. If the derailleur doesn't have enough movement to tension the chain on 34/12 remove more links. Remember that you shouldn't be using the 50 with the 32, so it doesn't matter too much if this combination doesn't work.

PS: I presume you have got a long arm derailleur, I doubt that any short arm one will cover this range.

PPS: Are you climbing walls?