S2C gearing

[Mick F]

Can't give a toss about percentages ...................
The OP wants 45" and 65" with a two ratio SA.

3sp SA would give .............
43.9" - 58.6" - 77.9"
47.1" - 62.7" - 83.4"

Pioneer:
I know Ivybridge quite well. I have often ridden over there from Gunny via Yelverton and Meavy and over Cadover Bridge and Wotter to Ivybridge and home via Ermington, Yealmpton, Brixton, Liara Bridge, Plymouth, Saltash, Callington ........... and home.

Good 50miles.

[[XAP]Bob]

33% ~= 38%

Quote from a lecture at uni:
For a Gaussian distribution this term is (1-root 2), which is about 0.4, which is nearly a half so we'll round it up to 1.

Oh that's probability so we can assume that all such errors will probably cancel each other out

To be fair, I said 33 was almost 38 - I was trying to be kind and not pick you up on the 33-38 difference

It wasn't probability (dull lecturer) but was the denominator of an equation... so 1 was a more accurate approximation than 0

[pioneer]

Mick F, the climb up from the dip after Yelverton towards Cadover is a right stinker isn't it? I did a ride in the summer down to Coypool and up the Plym Valley cycleroute to Dousland, then a loop of Burrator and up out of Sheepstor towards Cadover. That hill is a walker', for me anyway. Suffolk, Essex and Norfolk is brilliant cycling country but it's much harder down here.

I was also in Evans recently. Not impressed at all. Thought the whole place was drab and uninspiring. If I was a newbie looking for advice and to buy, I would probably have gone elsewhere.

[Mick F]

Yes, that hill is a stinker, there's no doubt. I reckon it's one of the toughest around here.
Done it few times over the years.
People don't realise how hard it is to cycle round here. I tell everyone on here, but until you actually ride the hills regularly, you can't really appreciate it. 20miles round here is perhaps 40miles of cycling for other people in other areas.

Evans?
Perhaps I agree, but it's the only show in town. Been in there a few times, and bought very little.
I wish SJS or Spa would relocate to Plymouth.

[John_S]

Hi pioneer,

My apologies first of all because I can’t really add anything to help regarding your original request & question about ratios because I’m not that technically minded but you’ve already got messages from people much more knowledgeable than me.

However I just wanted to ask you about why you want to put this Sturmey Archer 2 speed hub on your Genesis Day One? I saw that MickF has asked about this and you’ve said that you want to start using the bike more but the hills in Devon are a bit of a killer. Therefore I’m guessing that the original bike that you bought was the single speed version of the Day One so you’re wanting to change from the SS set up to give you an option to help with your local hills?

The reason I ask and am curious is because I have a Genesis Day One Alfine 8 (2014) model. I’m currently having some issues with the Shimano Alfine 8 hub but following help & advice on this forum I have a plan to work through trying to solve my problems. This will involve firstly replacing the cassette joint & potentially gear cable as well but if that doesn’t solve the issues it’ll potentially be a bigger hub overhaul job. If at the end of that path my problems still aren’t solved then maybe worst case scenario it could be a replacement Alfine hub that I need. If that does turn out to be the case I’ll weigh up the pros & cons of the like-for-like replacement of the Alfine hub versus some other options. That’s why your post has caught my attention because prior to your message I wasn’t aware of the SA 2 speed hub.

Therefore if worst case scenario I get to the point of needing a new Alfine hub I’ll also consider the following options:-

* Single speed ;
* One of the twin rear sprockets, such as the ones that I think White Industries do ( http://www.whiteind.com/new-page/ ) and I think come in either 16/18t, 17/19t or 20/22t but although obviously you’ve not got the option or changing gears mid ride but it does perhaps give you an option of changing your gear ratio ever so slightly according to either where you’re riding or the conditions at the particular time of the year ;
* Or getting the SA 2 speed hub that you’ve mentioned.

I live in Norfolk so I’ll hold my hands up to the fact that my commute is probably relatively pan flat compared to your rides in Devon and so I’ve got nothing to complain about. However I’m not getting any younger at all and my knees are rubbish these days so I might end up sticking with an Alfine 8 because on the small bumps that do count as hills around here my knees do appreciate being able to change gear plus on the days in the middle of winter at the end of a tiring day at work when your cycling home into a gale being able to use easier gears is a bonus.

Your post has definitely got me interested in the SA option and I see that it has a gear ratio of 138% whereas I think that the Alfine 8 has a ratio of 307% so there’s a big difference.

If you get your hands on the SA 2 speed I hope that it works for you and gets you back out on your Day One tackling the Devon roads.

John

[mjr]

I live in Norfolk so I’ll hold my hands up to the fact that my commute is probably relatively pan flat

Whenever I read that, I always think that someone must have dented their pans pretty badly I know it ain't Dartmoor but most of it isn't so flat either.

That said, why aren't you considering other hub gears as well as the S2C? With an Alfine 8 currently, you've already got the control cable run and I think avoiding that is part of the attraction of the S2C for single-speeders.

[John_S]

Hi mjr,

I suppose you are right in that it isn't completely flat but I guess it's all in the eye of the beholder and subjective according to what you're comparing it against.

For example I used to live in Suffolk which seems in places to be a bit more undulating and up & down than Norfolk and on average a comparable ride of similar length in Suffolk compared to Norfolk will have more climbing involved. Likewise whilst either on holiday or visiting friends & family I'd say that Devon & Cornwall are hillier than either Norfolk or Suffolk. Again for comparison when going up to Yorkshire or Northumberland they are hillier than at home in Norfolk but on the journey there going through Lincolnshire that's much flatter than Norfolk.

Still I guess it all depends on what you're used to and what you're comparing it to. However I do totally accept that Norfolk isn't pan flat and my average commute depending on which route I take includes at least two or three short sharp hills which seem to have a nasty gradient but then they're not too long so I guess that although we have some hills with some sharp inclines they wouldn't be as long as elsewhere.

Also good point about considering other IGH options as well. My current bike is the first one that I've had with an IGH and it came with it in the first place and so looking around at alternative options is something I've never really had to consider or think about.

However I'm just keeping my fingers crossed and hoping that in my case a replacement CJ & maybe a new gear cable as well is going to solve my current Alfine 8 problems which will make any need for a replacement unnecessary.

John