Yet Another Cycling Forum

General Category => Audax => PBP => Topic started by: simonp on 27 February, 2019, 02:38:34 pm

Title: Gearing
Post by: simonp on 27 February, 2019, 02:38:34 pm
I went out on my PBP bike on Sunday for a couple of hours and quickly came to the conclusion that I don't like its gearing for flat-ish routes. I had assumed I wanted the widest possible ratios but what's resulted is a large overlap between big and small chainrings combined with a large jump in ratios in the mid-range at typical Audax pace.

The gearing was 50/34 compact double with an 11-30 cassette. I've ordered a new rear cassette, 12-25, so that I have a higher bottom gear, less overlap, more usable gears, and smaller steps in the middle of the range.

Before:

http://www.gear-calculator.com/?GR=DERS&KB=34,50&RZ=11,12,13,14,15,17,19,21,24,27,30&UF=2150&TF=90&SL=2.6&UN=KMH&DV=speed

After:

http://www.gear-calculator.com/?GR=DERS&KB=34,50&RZ=12,13,14,15,16,17,18,19,21,23,25&UF=2150&TF=90&SL=2.6&UN=KMH&DV=speed

In the first setup the big issue is around the 20-25kph speed range. At 90rpm you go 20.8kph, then 23.2kph, then 26.3kph.

With the second set-up it's 20.8, 21.9, 23.2, 24.7, 26.3.

I hope to try the new ratios this weekend. I might find that on hilly routes I miss the 27 and 30 sprockets.
Title: Re: Gearing
Post by: LittleWheelsandBig on 27 February, 2019, 02:59:44 pm
I find that rolling routes require quite a lot of overlap between chainrings for a comfortable ride, so that I can stay on one chainring for a decent length of time. It can be annoying to keep having to swap rings and double shift at the back for short distances and then back again. Fixed riders don't have so many of these problems.


That said, the gearing you've chosen should be more than enough for PBP for you.
Title: Re: Gearing
Post by: simonp on 27 February, 2019, 03:15:23 pm
The overlap of usable gears is from about 25-30kph after; 21-33kph before. However the bike's got Di2 and the synchro-shift makes it much easier to switch seamlessly through the sequence. With the new set-up it's now single-tooth steps on the rear all the way from 21-48kph. With the old arrangement many steps in that range are 2-tooth.

I'll need to check the synchro-shift settings and might customise them a little to avoid hunting between big and little rings at the overlap.
Title: Re: Gearing
Post by: Zed43 on 27 February, 2019, 03:50:15 pm
So far my preferred setup is a 14-32 cassette with 33/41 chainrings (110BCD), this gives nicely spaced (~ 6%) changes around my cruising speed of 25kph. Ideally I would have 25/29/34 at the end of the cassette instead of 25/28/32 but :shrug:

gear calculator (http://ritzelrechner.de/?GR=DERS&KB=33,41&RZ=14,15,16,17,18,19,20,32,22,25,28&UF=2070&TF=90&SL=2.6&UN=KMH&DV=speed)

I intend to set up synchro shifting to move to the small chainring when downshifting when I'm on the 20t cog (and back when upshifting from 17t).
Title: Re: Gearing
Post by: postie on 27 February, 2019, 04:16:57 pm
I have fonud 34x25 low enough for wessex events, welsh events and dare i say it mr corless events.
For pbp i wouldn't expect to get out of the big ring-46t , or less i use a different bike. Then the big ring could be 50 or 53!
Title: Re: Gearing
Post by: zigzag on 27 February, 2019, 04:59:11 pm
i've used 52/42 with 12-27 cassette last time and was happy. gears is not a major consideration for pbp, most setups will work fine (as long as they work properly).
Title: Re: Gearing
Post by: RobD62 on 27 February, 2019, 05:02:03 pm
46 X 32 with 13 - 26 (13;14;15;16;17;18;19;21;23;26)
I work on the principle if I am revving out on 46 X 13 I should be freewheeling and if I cant manage an accent on 32 X 26 I should be walking.  Not too proud to do either!

It still puzzles me why anyone in our game (or any non professional) would want the ubiquitous 11 sprocket that the big manufactures try to trust upon us!

But, I know it is all personal....my everything else bike is 48 X 20 in the winter months and 48 X 19 in the summer....fixed wheel of course.  :)
Title: Re: Gearing
Post by: Ian H on 27 February, 2019, 05:55:52 pm
I shall probably be using a 13-26 with a 48-38-26 triple.  But I doubt I'll use the small ring.
Title: Re: Gearing
Post by: Ivo on 27 February, 2019, 05:56:37 pm
I'll settle for a triple again (as usual). I do prefer some big gears for descending though.
So quite likely the following set up: 30-40-50 front and 12-27 rear (10 speed).
Title: Re: Gearing
Post by: RobD62 on 27 February, 2019, 06:59:06 pm
I shall probably be using a 13-26 with a 48-38-26 triple.  But I doubt I'll use the small ring.

Not the lovely titanium fixed bike this time Ian?
Title: Re: Gearing
Post by: SR Steve on 27 February, 2019, 07:14:42 pm
I have fonud 34x25 low enough for wessex events, welsh events and dare i say it mr corless events.
For pbp i wouldn't expect to get out of the big ring-46t , or less i use a different bike. Then the big ring could be 50 or 53!

My legs clearly aren't as strong as postie's because even a 34 x 32 wasn't low enough for me on the steepest climbs of the Mille Pennine last year!

I still have 50/34 and a very worn out 11-32 on one Roubaix and 50/34 with brand new 11-25 on the other, both 10 speed. For PBP I'll go in between with 50/34 and 11-28. It means I can use the shorter cage rear derailleur and should still be able to stay on the big ring virtually all of the time, whilst keeping the 34 ring as an insurance policy for the odd steep ramp and when I'm feeling tired.

On the Shimano 105 10 speed it's only the last two sprockets that are different between the 11-25 and 11-28. They both go 11,12,13,14,15,17,19,21 then 23,25 or 24,28 so the percentage differences are still very good throughout the range and the extra weight is negligible.

I still like my 11 sprocket for those long slightly downhill sections, especially with a tailwind. I don't like pedalling any faster than necessary!
Title: Re: Gearing
Post by: Exit Stage Left on 27 February, 2019, 08:36:24 pm
I can guarantee that no-one else has ever used the gearing I used in 1999. Oddities included a Campagnolo Gran Sport front mech, Sun Tour Accushift rear mech, with Shimano RSX 7 speed STIs. The cassette was 14/28. using a TA locknut sprocket. The chainset was a 182.5 mm Stronglight 107, with 56/42 rings.

2003 was a 180mm Sugino MTB chainset, with 22/32/42 rings and an 11 to 19 8-speed cassette. Shimano XT mechs, with right hand Shimano RSX STI, and a left hand Campag Ergo

2007 was a 175mm Shimano Tiagra 50/34 compact and a 13 to 30 8 speed cassette. Shimano XT mechs, with right hand Shimano RSX STI, and a left hand Campag Ergo

2011 was a 175mm 50/40/30 triple, with a 12 to 27 10 speed cassette. Disappointingly, it was all Shimano 105.
Title: Re: Gearing
Post by: DCLane on 27 February, 2019, 09:12:42 pm
My gearing's way above that; for PBP I ran 53/39 with either an 11-23 or 11-25 cassette. Only on the biggest couple of hills was it a struggle, although the audax bike's 18kg fully kitted.

My LEL it was on a more sensible 52/36 with an 11-28 cassette. On Yad Moss and a couple of other places a 11-30 may have been better but I like the 'bling' Dura-Ace 7800 rear derailleur that's fitted.
Title: Re: Gearing
Post by: wilkyboy on 27 February, 2019, 09:21:57 pm
...my everything else bike is 48 X 20 in the winter months and 48 X 19 in the summer....fixed wheel of course.  :)

I'm trying to get my legs used to 48x17 at the moment with a view to running 18 or 19 on the other side for PBP.  Mixed results so far — less spinny than I'm used to and I don't have the proper strength for the gear yet, but I can ride 200 miles on it without dying  ::-)
Title: Re: Gearing
Post by: simonp on 27 February, 2019, 09:28:18 pm
I have fonud 34x25 low enough for wessex events, welsh events and dare i say it mr corless events.
For pbp i wouldn't expect to get out of the big ring-46t , or less i use a different bike. Then the big ring could be 50 or 53!

47x19 is low enough for PBP.
Title: Re: Gearing
Post by: grams on 27 February, 2019, 09:52:13 pm
I did LEL on 40x11-36 (11 speed) and found the gear range fine. I’ll likely do the same for PBP.

I intend to set up synchro shifting to move to the small chainring when downshifting when I'm on the 20t cog (and back when upshifting from 17t).

Last I checked synchro shifting only let’s you pick which *standard* complements you have and it chooses the shifting strategy for you. Setting it up with non-standard chainrings may require some experimentation.
Title: Re: Gearing
Post by: Ian H on 27 February, 2019, 10:02:10 pm
I shall probably be using a 13-26 with a 48-38-26 triple.  But I doubt I'll use the small ring.

Not the lovely titanium fixed bike this time Ian?

I'm taking it easy now I'm an OAP.
Title: Re: Gearing
Post by: quixoticgeek on 27 February, 2019, 10:25:59 pm
So far my preferred setup is a 14-32 cassette with 33/41 chainrings (110BCD), this gives nicely spaced (~ 6%) changes around my cruising speed of 25kph. Ideally I would have 25/29/34 at the end of the cassette instead of 25/28/32 but :shrug:

gear calculator (http://ritzelrechner.de/?GR=DERS&KB=33,41&RZ=14,15,16,17,18,19,20,32,22,25,28&UF=2070&TF=90&SL=2.6&UN=KMH&DV=speed)

I intend to set up synchro shifting to move to the small chainring when downshifting when I'm on the 20t cog (and back when upshifting from 17t).

Are you making the 14-32 from a shimano Junior 14-28, mixed with an 11-32 ? If so why not mix with an 11-34, and get the lower low end?

What 41/33 chainset are you using?

It still puzzles me why anyone in our game (or any non professional) would want the ubiquitous 11 sprocket that the big manufactures try to trust upon us!

It depends. If you have a 50/34, or 59/39, etc... then that 50x11 gear gives you 52kph at 90rpm, but if you have a 46 front ring, then the 11t is only 47.8kph, a 40t gives you only 41.6kph. For many that's too low a top speed. Why run such a small large chain ring? because with modern derailleurs, the max size difference is limited to 16t (10t on mtb), so if you want to have a small enough low gear to spin up hills, you need a small enough little ring. This means that for many, an 11t smallest sprocket is actually entirely sensible, it's the crazy 50/34 chainsets rather than 46/30 that is the issue. But I've had this rant before... a few times...

J

Title: Re: Gearing
Post by: Zed43 on 28 February, 2019, 10:41:16 am
Indeed combining the junior 14-28 with a 11-32. The (ultegra and 105) 11-34 have the last three cogs on a spider (27+30+34) so that would make a mid section of 19-21-24 (27+30+34) instead of 19-20-22-25-28-32. This would actually work out nicely (http://ritzelrechner.de/?GR=DERS&KB=33,41&RZ=14,15,16,17,18,19,20,32,22,25,28&UF=2070&TF=90&SL=2.6&UN=KMH&DV=speed). Assuming Ultegra Di2 does allow the use of the 3rd cog when on the small ring (XT Di2 does not), and you can find a 24t cog.

At this moment I am still using 34/42t (TA Zephyr) rings, but already got myself some WickWërks junior 33/41 rings (https://wickwerks.com/products/junior-road-4133/) when they were on discount  :)
Title: Re: Gearing
Post by: CrazyEnglishTriathlete on 28 February, 2019, 11:52:39 am
I rode 2007, 2011, and 2015 on triples, 50-40-30 with varying combinations of 12 - 25, 11 - 28 or something similar on the back.  I don't recall ever having to use the little chainring.   It is rolling terrain, and so the jump between chainrings on a compact chainset (e.g. dropping from 50 - 34) will have a bigger impact than on a more dramatically hilly route.  If I was riding it on two chainrings I'd go for my current set up of 50 -36 and 11 - 28.
Title: Re: Gearing
Post by: veloboy on 28 February, 2019, 01:36:55 pm
I have used the following ratios in the past:

In 1999 - Ultegra 9 spedd triple with something on the back I cannot remember!
In 2003 - 53/39 with 12-25 (Ultegra 9-speed)
In 2007 & 2011 - 50/36 with 12-25 (Campag Record 10 speed)
in 2015 - 52/36 with 12-25 (Campag Record 11 speed)

The rolling terrain lends itself to close-ratio gears; not many steep gradients at all.
Title: Re: Gearing
Post by: Zed43 on 28 February, 2019, 01:57:59 pm
Slightly off-topic, but how are the hills in PBP? Say compared to the Howardian Hills, Yad Moss and the northern bits of LEL? (yes, I can look at the elevation profile, but for those of you who have done both, what are your subjective impressions?)
Title: Re: Gearing
Post by: Rod Marton on 28 February, 2019, 02:09:50 pm
Slightly off-topic, but how are the hills in PBP? Say compared to the Howardian Hills, Yad Moss and the northern bits of LEL? (yes, I can look at the elevation profile, but for those of you who have done both, what are your subjective impressions?)
Much easier than any of these. PBP is largely long gradual ascents and descents, though there are a few short steep ones, particulrly at the Paris end (though the change of start/finish may have changed this). I don't know of anywhere in the UK which is directly comparable, maybe Oxfordshire/Warwickshire is closest. Anyway, don't worry about them, they aren't difficult.

Getting back to gearing, I'd just use whatever you have on the bike and are comfortable with. The challenge is the distance, not the gradients.
Title: Re: Gearing
Post by: wilkyboy on 28 February, 2019, 03:30:39 pm
Slightly off-topic, but how are the hills in PBP? Say compared to the Howardian Hills, Yad Moss and the northern bits of LEL? (yes, I can look at the elevation profile, but for those of you who have done both, what are your subjective impressions?)
Much easier than any of these. PBP is largely long gradual ascents and descents, though there are a few short steep ones, particulrly at the Paris end (though the change of start/finish may have changed this). I don't know of anywhere in the UK which is directly comparable, maybe Oxfordshire/Warwickshire is closest. Anyway, don't worry about them, they aren't difficult.

Getting back to gearing, I'd just use whatever you have on the bike and are comfortable with. The challenge is the distance, not the gradients.

The three toughest climbs, from memory, were the steep grade up to the centre of Brest, which is on the route again; the long ascent back to Mortagne-au-Perche, which just seemed to get steeper and steeper, and went on forever after 1000km, which is on the route again; and the climb back through the forest to Paris, which is NOT on the route this year.  None of the three required "mountain" gears and the first and last could be walked in under five minutes if you really had no legs left.

And Yad Moss from either side is a much tougher prospect than Le Roc.

Really it's the constant rolling that's hardest — for most of the ride you're either going up or going down, there's not a lot of flat for most of it, IIRC.
Title: Re: Gearing
Post by: Exit Stage Left on 28 February, 2019, 04:01:42 pm
This is the climb through the woods that you won't be doing. A picture from an article by the assistant editor of Cycling Plus. My mate David Robinson and I supplied the photos. This is one of Dave's
https://www.cyclingplus.com/articles/i-rode-it-paul-robson-at-the-2015-paris-brest-paris-randonee/


(https://images.immediate.co.uk/volatile/sites/8/2019/02/Screen-Shot-2019-02-05-at-10.02.47-c909236.png?quality=90&resize=940,626)

We met Paul at Loudeac, where he asked us if we could do some stills.
https://www.youtube.com/watch?v=JJwcKk6-lmQ

Title: Re: Gearing
Post by: RobD62 on 28 February, 2019, 04:44:19 pm
Not the lovely titanium fixed bike this time Ian?
[/quote]

I'm taking it easy now I'm an OAP.
[/quote]

Not behaving like one thankfully...As a club mate of mine says..Growing up is optional, growing older is obligatory.  At nearly 80 he is proud he is not acting his age.

Looking forward to seeing you at BTS 400.  I enjoyed it so much I am coming back for more!  :)
Title: Re: Gearing
Post by: RobD62 on 28 February, 2019, 04:50:20 pm
It depends. If you have a 50/34, or 59/39, etc... then that 50x11 gear gives you 52kph at 90rpm, but if you have a 46 front ring, then the 11t is only 47.8kph, a 40t gives you only 41.6kph. For many that's too low a top speed. Why run such a small large chain ring? because with modern derailleurs, the max size difference is limited to 16t (10t on mtb), so if you want to have a small enough low gear to spin up hills, you need a small enough little ring. This means that for many, an 11t smallest sprocket is actually entirely sensible, it's the crazy 50/34 chainsets rather than 46/30 that is the issue. But I've had this rant before... a few times...

J

I am happy to be doing 95-100 rpm on 46X13 and tucking for that bit extra speed on a decent.
But gear ratios are a personal thing... No rant required  :)
Title: Re: Gearing
Post by: marcusjb on 28 February, 2019, 05:36:06 pm
But gear ratios are a personal thing...

Well, indeed.  Some people can push big gears, some people can't, some people spin, some mash.  Find what works for you and get on with it. 

I suspect I am turning very small gears compared to many, but with bits of lung chopped out, I need to be able to gently work my way up the hills at my own pace.  I'd very rarely be able to even turn my top gear of 48/11.

Ultimately, I am sure 'incorrect selection of gear ratios' doesn't come up often as a reason for DNF on PBP (even for fixed, unless you make a massive, late change to your qualification gear).  However, one thing in my own experiences, you'll rarely wish for higher gears towards the latter stages of any 1000km+ ride....
Title: Re: Gearing
Post by: Exit Stage Left on 28 February, 2019, 06:09:09 pm


Ultimately, I am sure 'incorrect selection of gear ratios' doesn't come up often as a reason for DNF on PBP (even for fixed, unless you make a massive, late change to your qualification gear).  However, one thing in my own experiences, you'll rarely wish for higher gears towards the latter stages of any 1000km+ ride....

Achilles and Knee problems do come up as reasons though. Ultimately that's because people are pushing too big a gear.

There's a tendency to decrease cadence as the ride goes on, and when combined with headwinds, especially uphill, the result is tendonitis.
Title: Re: Gearing
Post by: slugbait on 28 February, 2019, 06:22:40 pm
Indeed combining the junior 14-28 with a 11-32. The (ultegra and 105) 11-34 have the last three cogs on a spider (27+30+34) so that would make a mid section of 19-21-24 (27+30+34) instead of 19-20-22-25-28-32.

[...]

So what is the advantage of this over a 14-32 Miche cassette (https://www.internet-bikes.com/130390-miche-cassette-11sp-light-primato-shimano-14-32t/#)? Or can you make a nice 11-28 cassette out of the discarded halves?
Title: Re: Gearing
Post by: Zed43 on 28 February, 2019, 06:41:17 pm
I prefer the custom 19-20-22-25 over the Miche's  19-21-23-25, but the Miche would work almost as good if your derailleur allows 3rd cog with the small chainring (as I said before the Di2 XT does not).

Given the qualification of the PBP hills I will probably go for the standard 14-28. 32/14 gives ~35kph @ 95rpm (my usual spin, at least until I'm knackered) or 38kph @ 105rpm (that I can sustain for some time when the wattage is not too high). Downhill I tend to accelerate at the top then coast in aero tuck.
Title: Re: Gearing
Post by: Phil W on 28 February, 2019, 06:59:00 pm
In 2015 my front shifter broke about 400m after starting (on the bridge just beyond the velodrome) . So after spinning like a dervish on the granny ring to stay in the groups I reclamped it next morning to the 39t ring. At the back I could use the middle five rings before the chain scraped on the derailleur.  On the way back to Dreux I reclamped the cable to get the big ring (52t)  as it significantly flattens after that all the way back to the finish.

This year my big ring is 46t which I should be able to remain in for longer periods.
Title: Re: Gearing
Post by: simonp on 28 February, 2019, 07:06:41 pm
The difference between 11-25 and 12-25 is losing 11T and gaining 18T. For me this seems to make sense as it gives me a better overlap between the two chain rings. Top speed at 90rpm is still 48kph which seems fine. I expect to sit at around 25kph most of the time.
Title: Re: Gearing
Post by: slugbait on 28 February, 2019, 07:08:00 pm
I prefer the custom 19-20-22-25 over the Miche's  19-21-23-25, but the Miche would work almost as good if your derailleur allows 3rd cog with the small chainring (as I said before the Di2 XT does not).

Given the qualification of the PBP hills I will probably go for the standard 14-28. 32/14 gives ~35kph @ 95rpm (my usual spin, at least until I'm knackered) or 38kph @ 105rpm (that I can sustain for some time when the wattage is not too high). Downhill I tend to accelerate at the top then coast in aero tuck.

Ah, OK. I prefer 19-21-23-25 (in combination with a 50/34 up front). But then again I'm not preparing for PBP (where I might opt for 50/34 combined with 14-25 if they exist).
Title: Re: Gearing
Post by: SR Steve on 01 March, 2019, 01:07:17 am
The difference between 11-25 and 12-25 is losing 11T and gaining 18T. For me this seems to make sense as it gives me a better overlap between the two chain rings. Top speed at 90rpm is still 48kph which seems fine. I expect to sit at around 25kph most of the time.
I would personally rather keep the 11T and miss out the 18T. I've used 12-27 and 12-25 before and occasionally wished I'd had a higher top gear, especially on big descents, not necessarily to pedal constantly, but just the occasional pedal stroke to keep the speed up. I could probably manage with a 25T big sprocket, but I'm used to having a 32T, so I'm going for 28T to make life a bit easier, same as for past PBPs and LELs. My average riding speed was 23.7km/h on the 2015 PBP (20km/h including stops) and maximum speed was 83.5km/h so there must have been a steep hill somewhere!
Title: Re: Gearing
Post by: Pichy on 10 March, 2019, 10:11:52 pm
Slightly off-topic, but how are the hills in PBP? Say compared to the Howardian Hills, Yad Moss and the northern bits of LEL? (yes, I can look at the elevation profile, but for those of you who have done both, what are your subjective impressions?)
Much easier than any of these. PBP is largely long gradual ascents and descents, though there are a few short steep ones, particulrly at the Paris end (though the change of start/finish may have changed this). I don't know of anywhere in the UK which is directly comparable, maybe Oxfordshire/Warwickshire is closest. Anyway, don't worry about them, they aren't difficult.

Getting back to gearing, I'd just use whatever you have on the bike and are comfortable with. The challenge is the distance, not the gradients.

The three toughest climbs, from memory, were the steep grade up to the centre of Brest, (don't remember that) which is on the route again; the long ascent back to Mortagne-au-Perche, (or that) which just seemed to get steeper and steeper, and went on forever after 1000km, which is on the route again; and the climb back through the forest to Paris, (now that...) which is NOT on the route this year.  None of the three required "mountain" gears and the first and last could be walked in under five minutes if you really had no legs left. On that basis, it sounds like this year's parcour is flat. ;D

And Yad Moss from either side is a much tougher prospect than Le Roc.

Really it's the constant rolling that's hardest — for most of the ride you're either going up or going down, there's not a lot of flat for most of it, IIRC.
Title: Re: Gearing
Post by: Ian H on 11 March, 2019, 11:05:28 am


Really it's the constant rolling that's hardest — for most of the ride you're either going up or going down, there's not a lot of flat for most of it, IIRC.

Seemed pretty flat to a Devon resident.

I think I was the lowest-geared of the fixed crowd last time, at 43x17.  But that's still a 67" bottom (& top of course) gear; it got me up all the hills without grovelling.
Title: Re: Gearing
Post by: simonp on 11 March, 2019, 11:23:11 am


Really it's the constant rolling that's hardest — for most of the ride you're either going up or going down, there's not a lot of flat for most of it, IIRC.

Seemed pretty flat to a Devon resident.

I think I was the lowest-geared of the fixed crowd last time, at 43x17.  But that's still a 67" bottom (& top of course) gear; it got me up all the hills without grovelling.

I have used 47x19 both times (69"). I would normally use around 65" on UK routes. PBP lacks any steep gradients that would require walking.

Title: Re: Gearing
Post by: LittleWheelsandBig on 11 March, 2019, 11:25:43 am
Most parts of the world seem flat to a Devonian cyclist...
Title: Re: Gearing
Post by: quixoticgeek on 11 March, 2019, 12:15:07 pm
Most parts of the world seem flat to a Devonian cyclist...

The world is made of mountains to a Dutch cyclist...

J
Title: Re: Gearing
Post by: citoyen on 11 March, 2019, 01:02:57 pm
However the bike's got Di2 and the synchro-shift makes it much easier to switch seamlessly through the sequence.

I’d like Synchro Shift on my bike but it would require a battery upgrade. Do you reckon it would be worthwhile?
Title: Re: Gearing
Post by: citoyen on 11 March, 2019, 01:04:15 pm
It still puzzles me why anyone in our game (or any non professional) would want the ubiquitous 11 sprocket that the big manufactures try to trust upon us!

I have no need for an 11-tooth sprocket but off-the-shelf cassettes are a lot cheaper than custom ones...
Title: Re: Gearing
Post by: rob on 11 March, 2019, 01:19:10 pm


Really it's the constant rolling that's hardest — for most of the ride you're either going up or going down, there's not a lot of flat for most of it, IIRC.

Seemed pretty flat to a Devon resident.

I think I was the lowest-geared of the fixed crowd last time, at 43x17.  But that's still a 67" bottom (& top of course) gear; it got me up all the hills without grovelling.

I have used 47x19 both times (69"). I would normally use around 65" on UK routes. PBP lacks any steep gradients that would require walking.

I'm taking 79" again.   Not a spinner.

Pichy was still giving me a kicking when I tried to keep up with him on the 2nd day.
Title: Re: Gearing
Post by: simonp on 11 March, 2019, 03:34:06 pm
However the bike's got Di2 and the synchro-shift makes it much easier to switch seamlessly through the sequence.

I’d like Synchro Shift on my bike but it would require a battery upgrade. Do you reckon it would be worthwhile?

If all you need is a battery I’d do it. It’s nice not to have to think about it and in the dark when you forget which chainring you’re in especially.
Title: Re: Gearing
Post by: bludger on 11 March, 2019, 03:50:32 pm
I did the Kent Invicta Grimpeur on Sunday and was very, very glad for my 34-32 combo for the top of York's Hill! Might have been able to grind it in 34-30 but 34-28 would have required getting off and pushing.
Title: Re: Gearing
Post by: Zed43 on 11 March, 2019, 07:04:27 pm
I have no need for an 11-tooth sprocket but off-the-shelf cassettes are a lot cheaper than custom ones...

Miche has quite a range of cassettes starting with a "sensible" starting cog (even a 18t!) and in addition Malcolm has several custom configurations (https://thecycleclinic.co.uk/products/miche-11-speed-primato-custom-cassettes-for-shimano-sram#)  available for £65.

Also, the Shimano 14-28 is on sale (https://www.bike-discount.de/en/buy/shimano-ultegra-cs-6800-11-speed-cassette-14-28-806817) at the moment for 45 euro.
Title: Re: Gearing
Post by: zigzag on 11 March, 2019, 07:10:42 pm
I did the Kent Invicta Grimpeur on Sunday and was very, very glad for my 34-32 combo for the top of York's Hill! Might have been able to grind it in 34-30 but 34-28 would have required getting off and pushing.
that's fine, however nothing to do with pbp..
Title: Gearing
Post by: citoyen on 11 March, 2019, 07:54:03 pm
I have no need for an 11-tooth sprocket but off-the-shelf cassettes are a lot cheaper than custom ones...

Miche has quite a range of cassettes starting with a "sensible" starting cog (even a 18t!) and in addition Malcolm has several custom configurations (https://thecycleclinic.co.uk/products/miche-11-speed-primato-custom-cassettes-for-shimano-sram#)  available for £65.

Also, the Shimano 14-28 is on sale (https://www.bike-discount.de/en/buy/shimano-ultegra-cs-6800-11-speed-cassette-14-28-806817) at the moment for 45 euro.

Interesting, thanks! A custom 14-32 would probably be my ideal, and it’s listed as a possible combo. The standard 14-28 would also be an attractive option at that price - and, more to the point, would give me plenty low enough gearing for PBP. (Current configuration is 50/34 x 11-28 and that’s fine for most rides, even moderately hilly ones - it’s only occasionally I find myself looking for a lower gear, though I did the invicta grimpeur on this set-up a couple of years ago and didn’t need to get off and walk on Yorks :smug: )
Title: Re: Gearing
Post by: grams on 11 March, 2019, 08:49:16 pm
I’d like Synchro Shift on my bike but it would require a battery upgrade. Do you reckon it would be worthwhile?

It's nice but the shift between rings is still pretty clunky plus I usually find myself manually shifting the rear derailleur to something else straight after the synchro shift.

In other words, it's nice that it forces you to shift the front derailleur at the right time but it's still a long way from seamless sequential shifting.
Title: Re: Gearing
Post by: jiberjaber on 11 March, 2019, 10:32:18 pm
I’d like Synchro Shift on my bike but it would require a battery upgrade. Do you reckon it would be worthwhile?

It's nice but the shift between rings is still pretty clunky plus I usually find myself manually shifting the rear derailleur to something else straight after the synchro shift.

In other words, it's nice that it forces you to shift the front derailleur at the right time but it's still a long way from seamless sequential shifting.

I agree - it could do with being quicker moving - sometimes it's a bit slow and need some pre-thought on the downshift.  I just run in normal shit at the moment, might switch back at some point though having a cassette (the 11-34) that's not on the drop down when configuring means I have to do some mental juggling to get the right down/up shift points on the front.
Title: Re: Gearing
Post by: citoyen on 11 March, 2019, 10:42:29 pm
Hmmm, sounds like it’s possibly not a nice enough feature to justify splurging £120 on a new battery... maybe I’ll just leave it until the battery needs replacing anyway.
Title: Re: Gearing
Post by: simonp on 11 March, 2019, 11:03:05 pm
I’d like Synchro Shift on my bike but it would require a battery upgrade. Do you reckon it would be worthwhile?

It's nice but the shift between rings is still pretty clunky plus I usually find myself manually shifting the rear derailleur to something else straight after the synchro shift.

In other words, it's nice that it forces you to shift the front derailleur at the right time but it's still a long way from seamless sequential shifting.

If you don't like the default gear it shifts to when switching rings you can change it.

Accelerating a full tilt and changing up through the gears has just worked seamlessly for me.

Title: Re: Gearing
Post by: FifeingEejit on 11 March, 2019, 11:17:57 pm
I’d like Synchro Shift on my bike but it would require a battery upgrade. Do you reckon it would be worthwhile?

It's nice but the shift between rings is still pretty clunky plus I usually find myself manually shifting the rear derailleur to something else straight after the synchro shift.

In other words, it's nice that it forces you to shift the front derailleur at the right time but it's still a long way from seamless sequential shifting.

If you inevitably have to change gear, and the pattern is always the same you can get the PC hooked up and adjust to suit.

I used Synchro for a bit, but never really got on with not knowing when it was going to change on the front, though had I persevered maybe I'd have got the hang of it.

This thread has now got me thinking about gearing... what sort of size and steepness are the rollers? I have a selection of 11-30T cassettes, and do sometimes find myself between gears on the flat.
Like am I going to run out of legs on the way up one and then wish I had the 30T on the way back up??
Title: Re: Gearing
Post by: bludger on 11 March, 2019, 11:20:31 pm
I did the Kent Invicta Grimpeur on Sunday and was very, very glad for my 34-32 combo for the top of York's Hill! Might have been able to grind it in 34-30 but 34-28 would have required getting off and pushing.
that's fine, however nothing to do with pbp..

Whoops wrong gearing thread :facepalm:

I'd definitely stick with the same combo for PBP anyway, for those bits when you're going doolally from fatigue and you start hearing funny noises.
Title: Re: Gearing
Post by: grams on 11 March, 2019, 11:51:59 pm
If you inevitably have to change gear, and the pattern is always the same you can get the PC hooked up and adjust to suit.

I haven't figured out if it's actually wrong or just me being fidgetty. I need to do some experimentation.

Quote
I used Synchro for a bit, but never really got on with not knowing when it was going to change on the front, though had I persevered maybe I'd have got the hang of it.

I have the mountain bike Junction A (SC-MT800) which beeps on the last normal shift before the front derailleur shifts. This seems like an essential feature, but I don't think the road junction A even can beep.
Title: Re: Gearing
Post by: simonp on 12 March, 2019, 01:35:46 am
Get the wireless nodule and pair it with your Garmin. The garmin beeps when next shift is front and also at the end of the entire gear range. You can also then configure and update firmware over Bluetooth - I’ve been doing this with my phone.  I’ve adjusted the shifting to work better for sequential changes (I hope) with the new gearing. Not tried it yet.

Title: Re: Gearing
Post by: simonp on 25 March, 2019, 11:42:05 am
Went on a flat ride with the new gearing - much easier to keep to a comfortable cadence at cruising pace. Needed to adjust the synchro-shift though as there is too big a jump from small to big ring with the default changeover. I moved it by one sprocket.

Went on a 200k ride on Saturday with plenty hills. Below 30rpm on a big climb at 150km when tired wasn't so good. I think the narrow gearing will be perfect for PBP but for my 300k qualifier and probably the 400 - Brevet Cymru - I will be back on the wide range cassette.

Title: Re: Gearing
Post by: yellabelly on 08 May, 2019, 11:52:10 pm
Is anyone else using 1x? I plan to with a 42 elliptical at the front paired with possibly 11-30 back. This work well on my 600 although I think I may need 40 tooth for some of the hills on PBP.
Title: Re: Gearing
Post by: zigzag on 09 May, 2019, 09:22:44 am
Is anyone else using 1x? I plan to with a 42 elliptical at the front paired with possibly 11-30 back. This work well on my 600 although I think I may need 40 tooth for some of the hills on PBP.

i rode pbp 2011 on 1x (before it was a "thing"), used 42t chainring and 11-34 cassette, worked fine, finished in 60h11m.
Title: Re: Gearing
Post by: PeterM on 09 May, 2019, 09:55:19 am
Is anyone else using 1x?

I'll be using a single-ring setup as I have on pretty much every event for the last 3 years: 36-tooth elliptical chainring, 11-42 11-speed block. (I spin, obviously.)

Title: Re: Gearing
Post by: grams on 09 May, 2019, 10:05:30 am
Me, earlier:

I did LEL on 40x11-36 (11 speed) and found the gear range fine. I’ll likely do the same for PBP.

The bike has had an 11-42 on it for most qualifiers, so it's more likely to be that.
Title: Re: Gearing
Post by: Phil W on 09 May, 2019, 05:34:42 pm
I ran 39 X 11-28 last time as my front shifter broke 400 metres into the ride. I did reclamp the cable as we neared Dreux to give me my 52t front ring till the finish. It was fine but now I run bar end shifters I'm expecting a full choice from my triple this year.
Title: Re: Gearing
Post by: cygnet on 10 May, 2019, 12:17:03 pm
I ran 39 X 11-28 last time as my front shifter broke 400 metres into the ride. I did reclamp the cable as we neared Dreux to give me my 52t front ring till the finish. It was fine but now I run bar end shifters I'm expecting a full choice from my triple this year.

I had nearly the opposite - 53 x 11-28  ;D
Title: Re: Gearing
Post by: wilkyboy on 15 May, 2019, 03:14:32 pm
Is anyone else using 1x?

Yes.  1x1  :facepalm:  ::-)
Title: Re: Gearing
Post by: rob on 15 May, 2019, 03:16:15 pm
Is anyone else using 1x?

Yes.  1x1  :facepalm:  ::-)

The whole way ?

Madness.
Title: Re: Gearing
Post by: simonp on 15 May, 2019, 04:52:08 pm
Is anyone else using 1x?

Yes.  1x1  :facepalm:  ::-)

The whole way ?

Madness.

I concur.