Cycling UK Forum

PeterJ wrote: ↑28 Sep 2022, 2:40pm My largest rear cog has 32 teeth. My smallest chain ring has 28 teeth. The rear set-up is Shimano Deore.

Is it just a matter of replacing the largest rear cog? How many teeth should I go for if I want to twirl my way up hills?

Thank you.

Don't just focus on your lowest gear, I'd look at your overall gears and how you use them.
I assume you have a 28/38/48 triple in front and an 11-32 cassette with ? sprockets on the back.

How often do you use your top gear, do you like to pedal downhill at +30 mph or start to freewheel at ~25 mph.
If you don't use it that often then starting the cassette at a 12t sprocket may give you a better/more even range of gears.
eg:- going from a 11-32 to a 12-36 with a 9 speed cassette.
But you may need a mech extender to use a 36t big sprocket which may make your overall gear shifts less crisp.
But that depends on the number of sprockets you have.

Shimano is always conservative on derailleur capacities.
So it's normally ok to exceed them by a couple of teeth.

So another option is to put your bike in small/small and measure the gap between the chain and the bottom of the front derailleur cage.
The chain moves down by 2mm per chainring tooth reduction.
With 5mm or so you can reduce the inner ring by 2 teeth for something a 26/38/48 triple.
Plus 10mm then middle by 2 and inner by 4 for a 24/36/48 triple, that will give you another gear down without altering your back cassette.
And I've run a 22/36/48 front triple but than was right at the limit of what the derailleur could cope with so not really recommended.
But as you open up the difference between ring the shift may well be less crisp, especially under load.

Luck ...........

Watch "Most People Don't Know How Bikes Work" by Veritasium -> https://www.youtube.com/watch?v=9cNmUNH ... Veritasium
Then come back and answer the question.

Luck ...........

I fully agree with the report on the Alston campsite.
I've also found a couple more sites of similar "Quality" on my travels.

I've been flooded out a couple of times due to thunder storm.
I've also had the tent blown down a couple of times due the storm force winds sifting direction during the night. Pitched with feet to the wind and woke up with the wind side on to the tent.
Not the site owners fault, but still a bad experience.

End of a long day and looking for a wild pitch. You find one that looks reasonable then find out why it's not.
Tent out of the pannier/trailer, tent straight back into the pannier/ trailer, then set off again to go and look for somewhere with less midges.
What looks like a nice flat grassy spot is the middle of a boggy patch.
There's solid rock under the grass and the pegs won't go in or loose sand/gravel and the pegs won't stay in.
You guessed wrong on how much flat space there is and the tent just don't quite fit. But you put it up anyway and then spend a rough night with the tent flapping badly in the wind.

Luck .........

Luck .............

Try wiping some soft soap/washing up liquid around the bead and the inside of the rim.
This helps the bead slide into place on the rim without leaving a residue that can attack the rubber.
If there are still flat spots when at full pressure then going 25%-30% over pressure tend to fix them.
If you do go over pressure remember to let them down to you're normal pressure.

Luck .........

Mine would always clip in easily.
But the wear pattern on both the pedals and cleats caused them to jam and not unclip when twisted.

Luck ...........

I think around 12 years while I had also worn out 2 pairs of sandals and 1 pair of pedals.
The pedals had got so worn that the cleats where starting to pull out.
The Velcro on the 2nd pair of sandals had got so weak such that they didn't stay closed.
And the bolts on the cleats where so worn so I'd needed to drill them out to get the cleats off the sandals.
So I replaced all 3 at the same time.

Luck ...........

531colin wrote: ↑10 Sep 2022, 6:58pm What does "pick up" mean here, please?
It can't mean "lift" ...as in lift the chain to start making the change to the big ring, because if you can change under pedal pressure then that pressure holds the chain right at the bottom of the teeth.

The front derailleur cage doesn't just move sideways, it also moves up as the parallelogram rotates on the top pivots.
I've set my front derailleur up so the bottom of the cannel is lined up just below the bottom of the chain.
As the cage moves out and up, the bottom of the channel helps "lift" the chain off the smaller chainrings teeth making it easier for the big chainring to catch and engage with the chain.
With no ramps and pins on the 55t big ring, it's the only way I can get a clean shift off my 38t inner ring.
I've tried a road double with a flat inner plate and it takes a lot more force to get a clean shift vs a shaped triple derailleur.

YMMV ........

I think a 54t chainring is the largest chainring with ramps and pins.
My 55t large chainring is without and looking around I've not found one in that size or bigger with.

Luck ...........

Looking at the photo of the Moulton, the mech is a lot further back around the chainrings compared to a "standard" mech position.
This is probably why it can cope with the bigger than "standard" chainrings.
But it also means that any lifting ramps on mech will be at a slight angle to the chain.
Therefore there may be more sideways force needed to lift the chain between rings.
Hence the accelerated wear pattern.

Just a thought ...........

The advantage of the banana bags is that they help keep your CoG low and forward.
So less tipping forces when going around high speed corners.
Plus the length helps if your tent poles when folded aren't the shortest possible.

I cannot use a pannier on the left hand side of my trike as it's gets in the way of my carry freedom trailer hitch.
So I've gone asymmetrical.
A small banana bag and pannier on the right and a medium banana bag on left.
That combo works for most shopping trips.
Plus I've 100 litres in the trailer if needed.

I can cycle to the sound of three bags flapping ........

You could always mod a front derailleur to help it work better.
I remember this page -> http://abundantadventures.com/mtfaq/fro ... .mods.html from way back when quads were almost a viable option for ultra low gears.

Now I get a quad by using a Schlumpf HSD to double my double, chainrings are 38/55/95/137.5.

Luck ...........

According to the docs I've just read ......
The FD-R773-2 will fit a 52t chainring and has a 22t capacity.
The FD-R773-0 will fit a 50t chainring and has a 20t capacity.
The FD-4703 has the same capacity as the FD-R773-0.
So the FD-R773-2 will give you a couple more teeth leeway.

As for the price difference, at a guess different generation/quality level of each model comes to mind.

Luck ...........

There's a ridge on the inside of the rim that helps to hold the tyre bead in place under high pressure.

Luck .........

As a guess it's been "cold set" from it's original spacings to the wider ones.

At the back this will let you fit cassettes with more sprockets.
But if it has been done, you may need to check the back dropouts is still symmetrical across the centre line of the bike.
If they're not symmetrical then ideally you'd want to re-dish the wheel to match the asymmetry.

The front so you could fit disk brake hubs.
But the original forks are probably not strong enough to withstand the disk brake forces.
So very iffy if original forks.

Luck .......

All big and most small campsites have electrical hook ups for caravans/campervans and "posh" camping.
As long as one is free and you're willing to pay the extra charge then you can charge your bike off one overnight.
You will need the "blue waterproof" plug which is the standard for outside power in the UK.
Main downside of this plug is it's fairly bulky.
Then either run the power cord into your tent and charge in there.
Or fit a waterproof cover over the bikes and charge there.
I've seen both ways done on my travels.

Luck ...........