Chainsets

For discussions about bikes and equipment.
NetworkMan
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Joined: 25 Aug 2014, 11:13am
Location: South Devon

Re: Chainsets

Postby NetworkMan » 26 Aug 2019, 3:52pm

Please, please sir! Please, I claim the mystery prize as I suggested the Spa super compact in post no 3! :(

Freddie
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Joined: 12 Jan 2008, 12:01pm

Re: Chainsets

Postby Freddie » 26 Aug 2019, 9:37pm

Also known as an alpine double, which I recommended in the second post. What is the prize anyway? I suggest upgrade from standard user to mod account for a day with full privileges. :wink:

slowster
Posts: 1915
Joined: 7 Jul 2017, 10:37am

Re: Chainsets

Postby slowster » 26 Aug 2019, 10:50pm

Too late, I've got it now and I'm not giving it back.

Si, is it supposed to sting like that, and how long will it be before the swelling goes down?

Edit. Never mind, I've found the instructions. Why didn't they put a warning on it that it's for external application only?

NetworkMan, do you still want it?

NetworkMan
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Joined: 25 Aug 2014, 11:13am
Location: South Devon

Re: Chainsets

Postby NetworkMan » 27 Aug 2019, 12:29pm

slowster wrote:Too late, I've got it now and I'm not giving it back.

Si, is it supposed to sting like that, and how long will it be before the swelling goes down?

Edit. Never mind, I've found the instructions. Why didn't they put a warning on it that it's for external application only?

NetworkMan, do you still want it?

Probably not and apologies to Freddie for my false claim (though he didn't direct Si to the exact product he needs) :oops:
P.S. Hope you are feeling better now.

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Si
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Re: Chainsets

Postby Si » 27 Aug 2019, 3:29pm

You did remember to lubricate first didn't you??!?!?

slowster
Posts: 1915
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Re: Chainsets

Postby slowster » 27 Aug 2019, 4:52pm

Are you having a laugh? I'm not putting my grease gun in there. Not after what happened the last time.

I'm sure those nurses in A&E were lying when they said they were only taking photographs for training purposes.

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Tigerbiten
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Joined: 29 Jun 2009, 6:49am

Re: Chainsets

Postby Tigerbiten » 27 Aug 2019, 7:17pm

slowster wrote:Are you having a laugh? I'm not putting my grease gun in there. Not after what happened the last time.

I'm sure those nurses in A&E were lying when they said they were only taking photographs for training purposes.

That's where you made the mistake.

Remember:- Tab A must always go into Slot B.

Get it wrong and YMMV ............ :D

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horizon
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Joined: 9 Jan 2007, 11:24am
Location: Cornwall

Re: Chainsets

Postby horizon » 28 Aug 2019, 9:49am

Si wrote:Thanks everyone. I think Slowster wins the mystery prize with the suggestion for the Spa super compact - looks like exactly what i want.


I was out in earnest this week on my Tern folder with its newly mounted Spa double (42/26). I can only say that it has transformed the bike. What was a constant struggle to find the right gear has now given me a delightlful bike where the gears I want are there instantly at my disposal across the whole range. It is quite remarkable the difference it has made.

It is possible that anyone using the bike unloaded on flat urban terrain would now find it a bit under-geared but even that I wonder about. AIUI Tern chose a double for technical reasons and then selected the obvious 50/34. Spa do get some stick on this forum but this simple but inspired product shows why people stay loyal.

I might even go as far to say that this has changed my view of triples and that Chris Juden's point on another thread about doubles being technically better might be worth following up. :mrgreen:

I've been looking at comments about gearing on this forum for twelve years now and it seems it's the same old story: bikes are over-geared (for the most part) due to the influence of marketing and racing. Well, Spa (no shares in the company) have quietly helped to put that right.
When the pestilence strikes from the East, go far and breathe the cold air deeply. Ignore the sage, stay not indoors. Ho Ri Zon 12th Century Chinese philosopher

Brucey
Posts: 42901
Joined: 4 Jan 2012, 6:25pm

Re: Chainsets

Postby Brucey » 28 Aug 2019, 10:04am

er, haven't you essentially just fitted a triple chainset with one chainring missing....?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

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horizon
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Location: Cornwall

Re: Chainsets

Postby horizon » 28 Aug 2019, 10:45am

Brucey wrote:er, haven't you essentially just fitted a triple chainset with one chainring missing....?

cheers


Yes, but for the life of me I don't understand why it is missing. :D
When the pestilence strikes from the East, go far and breathe the cold air deeply. Ignore the sage, stay not indoors. Ho Ri Zon 12th Century Chinese philosopher

pwa
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Re: Chainsets

Postby pwa » 28 Aug 2019, 3:46pm

My Missus has a Spa double (triple with biggest ring missing) because her STI levers were for double, so fitting a full triple chainset would have required we spent even more dosh. Effectively she has the gears she would have had with a triple, except that she lacks the biggest ring for powering down fast descents. But she never powered down fast descents anyway, so that is an absence that she hardly even notices.

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Tigerbiten
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Re: Chainsets

Postby Tigerbiten » 28 Aug 2019, 7:52pm

horizon wrote:
Brucey wrote:er, haven't you essentially just fitted a triple chainset with one chainring missing....?

cheers


Yes, but for the life of me I don't understand why it is missing. :D

Do the maths .....

When I started riding riding a road triple was 53-39-30 with a cassette started at 14t.
Now the cassettes start at 11t which is very close to 20% smaller.
So if you shrink the triple by roughly 20%, you get 42-31-24.
So a 42-26 alpine double and an 11 block basically gives the same range of the old road triple with a wide 14 block.

The trouble with gears is that until you experiment and find find the ideal setup that suits you, you muddle along with a "standard" setup and you don't know what you're missing.

YMMV ........ :D

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horizon
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Location: Cornwall

Re: Chainsets

Postby horizon » 28 Aug 2019, 9:28pm

Tigerbiten: thanks for that. But what I don't understand is (a) why Tern didn't just stick a triple on (the indicator on the shifter gives three positions), (b) why I didn't just stick a triple on and (c) as it happens, why don't Spa just stick a triple on? I don't understand the limiting factor - I presume there is one.
When the pestilence strikes from the East, go far and breathe the cold air deeply. Ignore the sage, stay not indoors. Ho Ri Zon 12th Century Chinese philosopher

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Chainsets

Postby Brucey » 28 Aug 2019, 9:59pm

Tigerbiten wrote:
Do the maths .....



the Tern has small wheels doesn't it? A bigger chainring would be quite a useful thing, wouldn' t it?

For the life of me I can't understand why folk are fixated on using 11T sprockets, just because they come on most cassettes these days. Most people's gearing thoughts start with what size chainring will give them the top gear they want with an 11T sprocket.... duh...

IME even with brand new parts, using an 11T sprocket is noticably rough-running and obviously pretty inefficient.


BITD (before cassettes of any kind were commonplace) it was possible to fit smaller sprockets; they were made specially for Moultons etc, down to 10T. We didn't all rush out and fit those freewheels to bigger wheeled bikes, complete with smaller chainrings, just to give the same gears, but with smaller sprockets/chainrings did we???? Ask yourself why not; I think the reason is that it is an incredibly stupid idea, its just a recipe for faster wear, less efficency, and rougher running. So why are folk doing this now? It is just daft.

IME it is not that difficult to make a cassette with a 13, 14 or 15T smallest sprocket and to use that instead.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

fastpedaller
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Location: Norfolk

Re: Chainsets

Postby fastpedaller » 28 Aug 2019, 10:31pm

Indeed. Didn't Renolds (or maybe someone else) show that the efficiency dropped off considerably once the sprocket had less than 19 teeth?