Triple chain set advice please

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Tigerbiten
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Joined: 29 Jun 2009, 6:49am

Re: Triple chain set advice please

Postby Tigerbiten » 29 Feb 2020, 5:39pm

slowster wrote:When cruising on the flat(ish) mid-ride, what gear are you in? More specifically, which chainring and roughly where on the cassette (bigger sprockets, middle sprockets or smaller sprockets)? The answer to that question should give you a good indication of whether 52/42 and your current cassette is optimal for you.

I agree with this.
Workout what gear you're happy in on a flat road around an hour into a ride.
With a triple it's easy, it wants to be middle ring/middle cassette.
A double is slightly more tricky.
If you're not to bothered about top speed then big ring/middle cassette works.
You may well find that dropping your big chainring 52 -> 48 shifts your flatland gears to a better place on the cassette.
Then you need to work out what size step you're happy with.
I also like close ratio gears at the top end, so 13-14-15 works for me.
I'd be more inclined to open the bottom end from 21-23-26 to 21-24-28.
That way the biggest step is at the bottom of the gears not the top.

Luck ......... :D

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531colin
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Location: North Yorkshire

Re: Triple chain set advice please

Postby 531colin » 1 Mar 2020, 1:36pm

OP is 70. I'm 72.
My current approach is to fit the lowest gears I conveniently can; I don't think there is such a thing as too low a gear.
There is a long thread about how I got my desired intermediate ratios for 9 speed https://forum.cyclinguk.org/viewtopic.php?f=5&t=54328&hilit=nightmare&start=15; my post of 11 Aug 2011 (11.28 am) sets out my preferred sprockets for 8 speed (12 to 34) and I combine that with a chainset with the smallest practical middle and small rings, 34 and 24 respectively. (for 8 or 9 speed you can use an MTB rear mech. to give capacity for a 34T sprocket with road STIs)
I don't like too big a jump in the middle of the cassette where I'm likely to be trying to make progress, but other than that I'm not too fussy exactly where my "favourite" gears lie....on the flat I'm usually on the "big" ring (not very big!) and somewhere in the middle of the cassette.
I have never yet come across a septuagenarian who needs the same 52 tooth chainring as a world class professional racing cyclist, but the low gears are indispensable.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Triple chain set advice please

Postby Brucey » 1 Mar 2020, 3:09pm

One of the reasons why I suggested a different cassette is that it is probably a part that needs changing anyway (unlike the chainset probably?) and retaining a 13-26 cassette is (IMHO) going to constrain whatever gearing you are likely to have in some way or other. Whereas losing the 14T sprocket and gaining a 30T is not.

Having ascertained that the sky will not fall on your head with a cassette which is largely similar but has more useful sprockets in it, I'd then look at the chainset.

A 110/74 triple is not an expensive thing and can be fitted with much smaller chainrings as needs be. I'd probably think about a 46 or 48T big ring and a 26 or 28T small ring to start with, with a middle ring to suit, and see how it goes.

http://ritzelrechner.de/?GR=DERS&KB=30,42,52&RZ=13,15,17,19,21,23,26,30&UF=2170&TF=90&SL=2.6&UN=MPH&DV=gearInches&GR2=DERS&KB2=26,38,48&RZ2=13,30,15,17,19,21,23,26&UF2=2170

as it happens 38,48 big rings (compared above both with a 13-30 cassette) almost duplicate the intermediate ratios you are used to with the 42-52 pairing, except using different sprockets.

FWIW on a triple setup for touring, I'd favour having good 'tapping along' ratios accessible on the big ring; for example 48/19 would be one I'd use a lot, and could have a good chainline too, with the cassette envisaged.

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

De Sisti
Posts: 1072
Joined: 17 Jun 2007, 6:03pm

Re: Triple chain set advice please

Postby De Sisti » 1 Mar 2020, 8:17pm

Brucey wrote:A 110/74 triple is not an expensive thing and can be fitted with much smaller chainrings as needs be. I'd probably think about a 46 or 48T big ring and a 26 or 28T small ring to start with, with a middle ring to suit, and see how it goes.

My three bikes have triple chainsets from Spa Cycles. For a few extra quid you can specify the rings
you desire. For the bike I'm riding now I have asked for the following:
46/34/24. Works fine for me with a customised 9s cassette: 13/14/15/17/19/21/24/27/30
The other two bikes have the following rings: 48/34/26 and 50/34/26.

bgnukem
Posts: 605
Joined: 20 Dec 2010, 5:21pm

Re: Triple chain set advice please

Postby bgnukem » 3 Mar 2020, 5:25pm

The Spa triples are very versatile and affordable. Got them on 3 of my bikes.

Since it's hard to find wide ratio cassettes without small sprockets any bigger than 11 or 12 teeth, I've been varying the chainring sizes on my bikes to vary the overall gearing while sticking with the same rear ratios (12-28, 7 sprockets). Ideally I'd go for bigger sprockets but it's hard to find 13- or 14-up cassettes....

The Spa chainsets allow any size from 24T up for the small ring and 34T up for the middle/outer which is low enough for pretty much anyone.

mercalia
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Re: Triple chain set advice please

Postby mercalia » 3 Mar 2020, 6:57pm

A question you need to ask your self. do you use the 52 very much and do you use the small ring a lot? if the latter think about a more radical triple at the front. I find a 46/36/26 copes well ( with my needs )

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

Re: Triple chain set advice please

Postby slowster » 3 Mar 2020, 7:45pm

bgnukem wrote:Since it's hard to find wide ratio cassettes without small sprockets any bigger than 11 or 12 teeth, I've been varying the chainring sizes on my bikes to vary the overall gearing while sticking with the same rear ratios (12-28, 7 sprockets). Ideally I'd go for bigger sprockets but it's hard to find 13- or 14-up cassettes.

Assuming you have a 7 speed freehub (and so cannot fit 8, 9 or 10 speed cassettes), you can currently still buy 13-28 and 14-32 7 speed cassettes from SJS.

Another option, which I have not tried myself but which Brucey and others have suggested on this forum, is to replace the smallest two sprockets of a 9 speed cassette with a 13t or 14t outermost sprocket to give an 8 speed cassette (with 9 speed spacing) which will apparently fit on a 7 speed freehub. For example, a 12-36 cassette (12/14/16/18/21/24/28/32/36) becomes 14-36 (14/16/18/21/24/28/32/36). Buying the 13t or 14t outermost 9 speed sprocket or cannabilising a cassette with one of those sprockets will probably be a one-off cost, since it's likely that those sprockets will be the one you use the least and so will be able to reuse it on subsequent cassettes.

Brucey
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Re: Triple chain set advice please

Postby Brucey » 3 Mar 2020, 8:24pm

in fact all that is necessary is that the new 'top sprocket' is the integral spacer type; it can be the second smallest from the cassette if needs be. However a drop of Loctite on the lockring isn't a bad idea in this case, because there are not always serrations (which engage with the lockring) on this sprocket.

Some conversions are easy; for example

CS-M580 9s

11-32 is normally 11-12-14-16-18-21-24-28-32 and simply becomes 12-14-16-18-21-24-28-32
11-34 is normally 11-13-15-17-20-23-26-30-34 and simply becomes 13-15-17-20-23-26-30-34

CS-HG200 9s

11-32 is normally 11-13-15-17-19-21-24-28-32 and simply becomes 13-15-17-19-21-24-28-32
11-34 is normally 11-13-15-17-20-23-26-30-34 and simply becomes 13-15-17-20-23-26-30-34
11-36 is normally 11-13-15-17-20-23-26-30-36 and simply becomes 13-15-17-20-23-26-30-36

in all the examples above the new smallest sprocket is simply the original second smallest sprocket (built-in spacer type), and there are no fresh parts to buy.

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

slowster
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Re: Triple chain set advice please

Postby slowster » 4 Mar 2020, 10:23am

Brucey wrote:in fact all that is necessary is that the new 'top sprocket' is the integral spacer type; it can be the second smallest from the cassette if needs be. However a drop of Loctite on the lockring isn't a bad idea in this case, because there are not always serrations (which engage with the lockring) on this sprocket.

Some conversions are easy; for example

CS-M580 9s

11-32 is normally 11-12-14-16-18-21-24-28-32 and simply becomes 12-14-16-18-21-24-28-32
11-34 is normally 11-13-15-17-20-23-26-30-34 and simply becomes 13-15-17-20-23-26-30-34

CS-HG200 9s

11-32 is normally 11-13-15-17-19-21-24-28-32 and simply becomes 13-15-17-19-21-24-28-32
11-34 is normally 11-13-15-17-20-23-26-30-34 and simply becomes 13-15-17-20-23-26-30-34
11-36 is normally 11-13-15-17-20-23-26-30-36 and simply becomes 13-15-17-20-23-26-30-36

in all the examples above the new smallest sprocket is simply the original second smallest sprocket (built-in spacer type), and there are no fresh parts to buy.

cheers


Thank you for explaining that in more detail Brucey. I was thinking about trying an 8 from 9 cassette using a 12-36 cassette to create a 14-36, but I see that converting an 11-36 cassette into 13-36 offers arguably just as good a set of ratios and is likely to be both cheaper and easier (no need to grind or drill out the rivets which the EV for the 12-36 indicates would be necessary to remove the non-serrated 14t and fit an outermost 14t).

I also like the idea of removing the 14t from a 13-26 8 speed cassette and fitting a 30t, since that keeps the 2 tooth intervals in the middle of the cassette (13/15/17/19/21/23/26/30), so I will probably try that if/when 24x26 is not going to be low enough for me on that bike.

bgnukem
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Joined: 20 Dec 2010, 5:21pm

Re: Triple chain set advice please

Postby bgnukem » 4 Mar 2020, 1:54pm

I guess you'd also need a bigger lockring to fit a 13T top sprocket, as opposed to the smaller lockrings for the 11T and 12T top sprockets.

Would it not be possible to use a 'normal' 13T sprocket with a standard 7- or 8-speed spacer behind, rather then requiring a dedicated top sprocket with integral spacer?

Obviously you lose the serrations intended to engage with the lockring, but not sure how much of an issue that is and could be Loctite-d as Brucey suggests....

Recently bought some 13-28 7S cassettes from SJS so they are a good call. Will keep the the top sprockets and lockrings when they are worn out, for future cassettes!

Brucey
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Re: Triple chain set advice please

Postby Brucey » 4 Mar 2020, 4:12pm

bgnukem wrote:I guess you'd also need a bigger lockring to fit a 13T top sprocket, as opposed to the smaller lockrings for the 11T and 12T top sprockets.

normally there is a slight recess in the second smallest sprocket if the smallest is an 11T or 12T one. The smaller lockring normally just sits nicely in this recess. A larger diameter lockring may engage with the serrations which are present on some second smallest sprockets, but it will also engage with fewer threads in the freehub body.

Would it not be possible to use a 'normal' 13T sprocket with a standard 7- or 8-speed spacer behind, rather then requiring a dedicated top sprocket with integral spacer?


Usually not; the reason is that the splines do not extend to the very end of most 7s freehub bodies. However there are exceptions
1) a 7s body that is threaded externally for UG sprockets (NB if it is UG only ) a HG cassette won't fit the spline without modification.)
2) an original 7s HG freehub body.

In either of the above cases you might get away with it, but realistically the lengths have to match +/- ~0.5mm if you want the lockring to hold the sprockets without bottoming out, whilst a flat top sprocket is still engaged sufficiently with the splines on the freehub body. An integral spacer type sprocket is a much safer bet, even if you have a 'long-spline' freehub body.

Before 11T sprockets the splines went full length on HG freehub bodies. However the so-called HG-C body had shorter splines on the same length body, so that an 11T sprocket could be fitted. Subsequent shimano freehub bodies are based on the HG-C pattern, in ever increasing lengths, so none have full-length splines.

Obviously you lose the serrations intended to engage with the lockring, but not sure how much of an issue that is and could be Loctite-d as Brucey suggests....


it works just fine.

Recently bought some 13-28 7S cassettes from SJS so they are a good call. Will keep the the top sprockets and lockrings when they are worn out, for future cassettes!


good idea.

FWIW there are small variations in exact lengths so it isn't a bad idea to have a 1mm spacer or two on hand just in case you need it.

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

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Triple chain set advice please

Postby Brucey » 4 Mar 2020, 4:38pm

Using the shimano EV techdocs for shimano cassettes is a reliable way of determining whether the second smallest sprocket is an integral spacer type or not. However without careful examination it is often not possible to be certain about other makes of cassette.

For example a sunrace 9s cassette

Image

might be built

11-12-14-16-18-21-24-28-32

In the photo it appears as if the 12T sprocket is the integral spacer type (which is normal in this size) and has serrations which a larger lockring can engage with. I would assume that it has a recess for the 11T sprocket too, into which the original lockring will nestle.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

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

Re: Triple chain set advice please

Postby De Sisti » 5 Mar 2020, 6:47am

mercalia wrote:A question you need to ask your self. do you use the 52 very much and do you use the small ring a lot? if the latter think about a more radical triple at the front. I find a 46/36/26 copes well ( with my needs )

Agree.