Advice on bike gearing

[Murakami]

Quick update to close this out, and say thank you to all for the help.

I popped to a local bike store who supply Shimano components (amongst others) and they informed me that with this Tourney freewheel setup it wasn't possible to get anything below 14T due to the size of the internal bearing. Which tied in with what I saw on Shimano's own website. They don't do a Tourney freewheel gearset with less than 14T.

So instead I changed the front chainring. Removed the Prowheel 42-34-24 and replaced it with a Shimano 48-38-28.
The 38T centre ring is where I spend all my time hacking around the city and in traffic, never needing to move to the 48T in variable speed stop/start city traffic.
The 48T has given me what I wanted on a more open straight spin away from traffic - a much more comfortable cadence at a nice cruising speed. (Blew out my knee when a teen, and whilst it gave me jip on and off through the years it's been a persistent and painful weak link over the last 3 years, hence the need for a comfy cadence).

On a related note - have many on here knowledge of Prowheel components? I wasn't impressed by the quality of the chainrings when I went to count them, and now that it's off the bike it's even more apparent how suspect the quality is. What's the perceived reputation like on their components?

They're an Aliexpress/Amazon type manufacturers of cheap bike parts.

[Allspace]

That's great you got sorted and interesting to know about the Tourney parts.
No experience of Prowheel unfortunately but if you are not straining them maybe give it a while before changing them.

[deltona]

Below is a pic of the Prowheel chainrings, so as people can see for themselves.
I'm not saying this is typical, but we bought 2 identical bikes with Prowheel chainrings fitted, and they're both the same.
I just said I'd mention it in case anybody was ordering online and came across the brand.
You can clearly see the huge variation in tooth shape and depth.

[Type17]

The variation in the height and shape of the teeth (and the stamped-in 'gates' and 'lift-pins') on the two bigger rings is intentional - it's knocked-off (badly) from Shimano's (and others') designs. Not saying Pro-wheel is a good brand, just that some of the teeth are meant to be shorter and there are stamped-in shapes, to assist chain-lift when shifting.

Here's an upmarket pair of Shimano chainrings for comparison:

[deltona]

Thanks T17. It does look worse in real life than the photo. Night and day between it and the replacement.
'Knocked-off' is probably an apt description.

[philb]

Glad you got sorted John. That's interesting about the larger bearing on the 14T freewheel. It has room use more balls or larger balls, it'll probably last forever.

on our commuter bike, I think its 8 speed, the drivetrain still looks absolutely mint.

Just a note on your knee, you might not like a 90rpm cadence but it will not harm your knee like too low a cadence.. you should ensure you've the saddle height fairly bang on ( even 5mm too low could make a difference) and some stiff shoes.
my knees play up from time to time and using higher cadence with less torque is what helps.