Shimergo - latest news

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CJ
Posts: 3076
Joined: 15 Jan 2007, 9:55pm

Re: Shimergo - latest news

Postby CJ » 17 Oct 2020, 12:18pm

fatboy wrote:I have made my audax bike Shimergo and was thinking of going 10 speed. I was wondering if the GRX would do triple since its capacity is close to Sora triple?

No reason why the GRX-400 shouldn't. It's now shifting the same 11-36 10-speed cassette on my tourer but with a 40,20 double. That's as much difference total as almost any triple but without the unnecessary middle-ring / stumbling-block. And it wraps ALL the chain. No 'flottant' combos, not even little and little.

I don't know why Shimano rates this mech at only 41T total (ie chain-wrap) capacity. With 107mm between pulley centres (and the same size pulleys) it actually has a longer cage than 96mm on the Deore XT SGS mech, that's rated 43T. And here it is happily handling 45T on my tourer - as one might expect from those measurements.

GRX doesn't look so useful for 11-speeders however. The 810 mech claim not to handle bigger sprockets than 34T and with only 40T wrap capacity. Of course these may also be underestimates, but since nobody gives me free stuff to test anymore, I can't shed any light upon that.

The 812 mech meanwhile, is strictly for single rings, because it achieves its tempting 42T sprocket capacity by offsetting the guide pulley from the cage pivot - so it moves further down as the cage rotates anti-clockwise, as you shift down the cassette. Accordingly this pulley will bob upwards and NOT clear a sprocket that big, if the cage arbitrarily rotates clockwise instead, as it will if you shift to a smaller ring up front.

So my advice is stick to 10-speed, fit a GRX-400 (also buy a pair of Deore XT sealed-bearing pulleys to upgrade the plain originals when they wear out) and be happy!
Chris Juden
One lady owner, never raced or jumped.

Brucey
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Re: Shimergo - latest news

Postby Brucey » 17 Oct 2020, 12:28pm

CJ wrote:
I don't know why Shimano rates this mech at only 41T total (ie chain-wrap) capacity. With 107mm between pulley centres (and the same size pulleys) it actually has a longer cage than 96mm on the Deore XT SGS mech, that's rated 43T. And here it is happily handling 45T on my tourer - as one might expect from those measurements....


I think it is -in the simplest terms- because shimano are no longer really interested in helping anyone to use a set of gears that they have not manufactured and approved in every last detail. Goodness me, if it ever came out that you could get a wider range and better ratios etc using 'unfashionable' mixtures of bits their sky would fall in.... :wink:

FWIW I agree that sticking with 3x10s seems a sensible thing to do. Even more sensible for many users would be to ditch the smallest sprocket, use a shorter freehub body so that the wheel can be built with reduced dish etc. 3x9 is more than enough gears for most folk, and if it comes with lighter/stronger wheels too, what is not to like, exactly...?

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

fatboy
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Location: North Hertfordshire

Re: Shimergo - latest news

Postby fatboy » 17 Oct 2020, 2:41pm

When my chain wears out I may go 10 speed with GRX. Then I would have a bike with 10 speed, 9 speed, 8 speed and 7 speed (if I cheat a bit my 2 bromptons give me 6 speed and 5 speed)!
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly

PeterBL
Posts: 172
Joined: 26 Oct 2010, 1:04pm

Re: Shimergo - latest news

Postby PeterBL » 19 Oct 2020, 11:52am

Brucey wrote:FWIW I agree that sticking with 3x10s seems a sensible thing to do. Even more sensible for many users would be to ditch the smallest sprocket, use a shorter freehub body so that the wheel can be built with reduced dish etc. 3x9 is more than enough gears for most folk, and if it comes with lighter/stronger wheels too, what is not to like, exactly...?

cheers

Which hubs have shorter freehubs? 7-speed?

Brucey
Posts: 41375
Joined: 4 Jan 2012, 6:25pm

Re: Shimergo - latest news

Postby Brucey » 19 Oct 2020, 6:28pm

PeterBL wrote:
Brucey wrote:FWIW I agree that sticking with 3x10s seems a sensible thing to do. Even more sensible for many users would be to ditch the smallest sprocket, use a shorter freehub body so that the wheel can be built with reduced dish etc. 3x9 is more than enough gears for most folk, and if it comes with lighter/stronger wheels too, what is not to like, exactly...?

Which hubs have shorter freehubs? 7-speed?


yes, also 8s hubs where the freehub body has been shortened a little by grinding (this is usually limited by the length of the lockring threads inside the body, and a revised lockring is often required). Note that it is also possible to use a spacer between the lockring and the smallest sprocket too, all without making the smallest sprocket be any further away from the frame than it needs to be.

NB to implement this change in a shimano hub it is necessary to use a shorter cone/locknut assembly on the RH side. This normally requires a little modification or use of parts from a different model of freehub.

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

fredN4
Posts: 60
Joined: 14 Oct 2012, 8:21pm
Location: 30200 France

Re: Shimergo - latest news

Postby fredN4 » 19 Oct 2020, 6:52pm

thanks CJ and all
i have not taken the luxury of reading all the posts, so forgive me.
I have 3 bikes fitted with Campag:
A 9 speed record triple with a 26 inner front ring that gives me all the gears I need, so we leave that as is;
I also have a 10 speed record Ultrashift. I am tempted to fit a Shimano cassette and GRX400 mech. Bottom line please - an infallible idea?
Third bike is fitted with 10 speed older edition Centaur shifters. Will they take the Shimano conversion?
Thanks folks
Last edited by fredN4 on 23 Oct 2020, 7:03pm, edited 1 time in total.

thelawnet
Posts: 2608
Joined: 27 Aug 2010, 12:56am

Re: Shimergo - latest news

Postby thelawnet » 19 Oct 2020, 8:41pm

CJ wrote:
fatboy wrote:I have made my audax bike Shimergo and was thinking of going 10 speed. I was wondering if the GRX would do triple since its capacity is close to Sora triple?

No reason why the GRX-400 shouldn't. It's now shifting the same 11-36 10-speed cassette on my tourer but with a 40,20 double. That's as much difference total as almost any triple but without the unnecessary middle-ring / stumbling-block. And it wraps ALL the chain. No 'flottant' combos, not even little and little.

I don't know why Shimano rates this mech at only 41T total (ie chain-wrap) capacity. With 107mm between pulley centres (and the same size pulleys) it actually has a longer cage than 96mm on the Deore XT SGS mech, that's rated 43T. And here it is happily handling 45T on my tourer - as one might expect from those measurements.

GRX doesn't look so useful for 11-speeders however. The 810 mech claim not to handle bigger sprockets than 34T and with only 40T wrap capacity. Of course these may also be underestimates, but since nobody gives me free stuff to test anymore, I can't shed any light upon that.

The 812 mech meanwhile, is strictly for single rings, because it achieves its tempting 42T sprocket capacity by offsetting the guide pulley from the cage pivot - so it moves further down as the cage rotates anti-clockwise, as you shift down the cassette. Accordingly this pulley will bob upwards and NOT clear a sprocket that big, if the cage arbitrarily rotates clockwise instead, as it will if you shift to a smaller ring up front.

So my advice is stick to 10-speed, fit a GRX-400 (also buy a pair of Deore XT sealed-bearing pulleys to upgrade the plain originals when they wear out) and be happy!


GRX is a recycling exercise. There are new chainsets with new chainline, new BCD and new FDs.

These are a 46/30 double effort ('600', though it matches with '400') , with the same assembly but a subtly different outer ring for 11-speed. Then a 48/31 double with hollow crank arms which is '810' level, because the crank arms are lighter.

Then there is a 1x crankset in solid crank arm 600 level, and hollow crank arm 810 level; which has 42t or 40t single ring. Supposedly these are 1x11-speed, but this is nonsense, and they would be just as good (or bad) for 1x10.

The brifters are recycled from R8020/R7020/4720 series, which are largely identical anyway.

The calipers are 100% identical to the same series of 'road' calipers (which are internally identical apart from plastic pistons on the 4720/rx400 rather than ceramic)

The RDs are three:

* RD-RX400 uses the RD-T6000 pulley cage (same part numbers). Since it's a single-sprung pivot, the cog numbers are likely fairly accurate. RD-T6000 and RD-RX400 match here 11-32 to 11-36. The T6000 part has a 47t capacity and RX400 41t, the latter reflects only the fact that there is only one matched chainset, the 46/30 double, which gives (36-11)+(46-30) = 41t, whereas the actual capacity might be something else
* RD-RX812 in fact uses the RD-M8000-GS pulley cage (82mm), and can be modded with the RD-M8000-SGS pulley cage (100mm). RD-M8000-GS was originally sold for 1x11-42t or 11-40t with 36/26 double. RD-M8000-SGS was sold originally for 1x 11x42t or more typically 11-40t with 40/30/22 triple. After the release of new cassettes, they updated these specs (not the actual RDs) such that both GS and SGS were specced for 1x11-46, 2x11-42, and SGS for 3x11-40t.

There are also third party mods for this RD for a 1x 10/11-50t cassette

https://www.garbaruk.com/rear-derailleu ... speed.html

People also run the RX812 with a 50/34 and 11-34 cassette



* RD-RX810 is a bit different in that it uses 13t pulleys like the new MTB 12-speed stuff, but it's intended for a smallish cassette and compact chainset.


Comparing the 'road' stuff, you have in the same pull ratio:

6800/5800/4700 (11/11/10 speed but with the same pull ratio). These cages are recycled from 6700/6600/5700/5600 using the previous pull ratio. Depending on different specs you might get a 20t front triple (or double) and an 11-32t, or 16t double with 11-34t. The cage is shorter than the RX400 (80mm), but these are obviously more durable in that they lack the clutch mechanism, and are made all from metal, whereas RX400 is substantially plastic.

R8000/R7000 which are similar in construction to the GRX, but without the clutch. The cage is longer than 4700 (100mm). Probably slightly less capacity than RX400.

NickJP
Posts: 300
Joined: 24 Sep 2018, 7:11pm

Re: Shimergo - latest news

Postby NickJP » 22 Oct 2020, 7:24am

PeterBL wrote:
Brucey wrote:FWIW I agree that sticking with 3x10s seems a sensible thing to do. Even more sensible for many users would be to ditch the smallest sprocket, use a shorter freehub body so that the wheel can be built with reduced dish etc. 3x9 is more than enough gears for most folk, and if it comes with lighter/stronger wheels too, what is not to like, exactly...?

cheers

Which hubs have shorter freehubs? 7-speed?

I have one bike running 9-speed components on a 7-speed hub - with 135mm rear spacing and a rear rim with offset spoke holes, this gives me an essentially dishless rear wheel. A 9-speed cassette with the smallest cog removed fits nicely on the 7-speed rear freehub body - I used an 11-32 cassette with the 11t cog removed, giving a 12-32. And on this cassette, when you remove the 11t cog, the 12t cog also has serrations on its outside face to engage with the lockring. I also needed change the 11t lockring that came with the cassette for one intended for use with 12t small cogs, as the 11t lockring is too small a diameter for the 12t cog - a couple of minutes rummaging in the old parts rubbish bin of my local bike shop turned up a couple of 12t lockrings.

Here's the setup in question:
Image

Brucey
Posts: 41375
Joined: 4 Jan 2012, 6:25pm

Re: Shimergo - latest news

Postby Brucey » 22 Oct 2020, 11:42am

nice!

I genuinely don't understand why more people don't do this kind of thing; it isn't very difficult and it is win-win-win all the way.

I have stuck a near-six figure mileage on a rear HP rim which weighs no more than 440g and would be considered 'flimsy' by modern standards. The main reason this rim survived was because the wheel was built dishless.

Well, I say win-win-win all the way...... apart from one thing, which is that 7s freehub bodies are getting less easy to obtain now. I am presently working up a scheme for shortening an 8/9/10s freehub body so that it is useful for "n-1" cassette conversions.

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

MartinC
Posts: 1899
Joined: 10 May 2007, 6:31pm
Location: Bredon

Re: Shimergo - latest news

Postby MartinC » 22 Oct 2020, 12:54pm

Brucey wrote:...I genuinely don't understand why more people don't do this kind of thing; it isn't very difficult and it is win-win-win all the way...


Yes. Even without an OSB rim the dish on a 135mm OLN 7 speed is very much reduced. Wide range cassettes for 8 speed and above always have an 11 tooth spacer that you can discard too. My only concern is that the remaining 7 speed freehubs may disappear (I have another 4 in my stash along with a selection of 7 speed cassettes bought when CRC and Rose were almost giving then away).

If you acquire a 7 speed hub all you need do is buy a decent new axle for maybe £15 respace it and grease and adjust the bearings. It's even more worthwhile for 130mm OLN wheels now that Shimano have increased the dish even more so that you can put a spacer behind the cassette too.

De Sisti
Posts: 1018
Joined: 17 Jun 2007, 6:03pm

Re: Shimergo - latest news

Postby De Sisti » 23 Oct 2020, 6:53am

Which levers are you using?
NickJP wrote:Here's the setup in question:
Image

NickJP
Posts: 300
Joined: 24 Sep 2018, 7:11pm

Re: Shimergo - latest news

Postby NickJP » 23 Oct 2020, 8:41am

De Sisti wrote:Which levers are you using?
NickJP wrote:Here's the setup in question:
If you mean what shifters, I'm using Dura-Ace 7700 barend, which can be switched between 9-speed indexed and friction. RD is a Deore XT M750 9-speed.

De Sisti
Posts: 1018
Joined: 17 Jun 2007, 6:03pm

Re: Shimergo - latest news

Postby De Sisti » 23 Oct 2020, 5:02pm

I was expecting some Campag bits in a Shimergo set-up.
Last edited by De Sisti on 23 Oct 2020, 9:27pm, edited 1 time in total.

rjb
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Location: Somerset (originally 60/70's Plymouth)

Re: Shimergo - latest news

Postby rjb » 23 Oct 2020, 5:34pm

NickJP wrote:
De Sisti wrote:Which levers are you using?
NickJP wrote:Here's the setup in question:
If you mean what shifters, I'm using Dura-Ace 7700 barend, which can be switched between 9-speed indexed and friction. RD is a Deore XT M750 9-speed.


Are you using an 8 speed chain. So on this forum say it works ok with 9 speed kit. :?:
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin, Raleigh 20, Falcon K2 MTB dropped bar tourer, Longstaff trike conversion on a Falcon corsa. :D

NickJP
Posts: 300
Joined: 24 Sep 2018, 7:11pm

Re: Shimergo - latest news

Postby NickJP » 24 Oct 2020, 1:43am

rjb wrote:
NickJP wrote:
De Sisti wrote:Which levers are you using?
If you mean what shifters, I'm using Dura-Ace 7700 barend, which can be switched between 9-speed indexed and friction. RD is a Deore XT M750 9-speed.

Are you using an 8 speed chain. So on this forum say it works ok with 9 speed kit. :?:

No, 9-speed chain.