Author Topic: Chain glider advice  (Read 1234 times)

PH

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Re: Chain glider advice
« Reply #15 on: January 04, 2021, 02:59:06 PM »
Does the efficiency, or noise, of a chainglider vary with chain tension? It's hard to imagine how it wouldn't and my experience with a Rohloff, and other hub gears, is that they run noticeably smoother with a slack chain.

The short answer is no to both your question and your further perfectly logical supposition.
Thanks Andre, I'm going to have to file this one away in the box labelled things I don't understand.
I had hoped that as I got older I'd start emptying it, but it just looks like I'll need a bigger box.

Matt2matt2002

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Re: Chain glider advice
« Reply #16 on: January 04, 2021, 06:31:48 PM »
Does the efficiency, or noise, of a chainglider vary with chain tension? It's hard to imagine how it wouldn't and my experience with a Rohloff, and other hub gears, is that they run noticeably smoother with a slack chain.

The short answer is no to both your question and your further perfectly logical supposition.
Thanks Andre, I'm going to have to file this one away in the box labelled things I don't understand.
I had hoped that as I got older I'd start emptying it, but it just looks like I'll need a bigger box.

Ha ha. That made me smile. A nice smile. It rang a few bells.
Don't worry about not understanding.
Go with the flow - and good experienced advice here.
Ride the wave. With a bigger box.😉
And I can confirm Andre's comments, as a Chainglider user of some years.
Never drink and drive. You may hit a bump  and spill your drink

ourclarioncall

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Re: Chain glider advice
« Reply #17 on: January 06, 2021, 09:36:41 PM »
Great reading gents

As you all will notice Im a bit of a conversation starter . I light the fire and invite your firewood . Then I come back after a while to find to warm my hands 😄

Having 5 kids, I get pulled away

ourclarioncall

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Re: Chain glider advice
« Reply #18 on: April 08, 2021, 12:00:23 AM »
Quote
Does the chainglider only fit certain combinations and Certain brands?
Yes, I'll second what Andre said and and home in on one more caveat:

Choose your crankset's BCD/PCD (bolt circle) carefully when you order your bike. I am running a Deore crankset with 104mm BCD. Unfortunately, Surly stainless chainrings are not available in tooth sizes larger than 36t in a 104mm BCD and I am running a 36x17 combo. As was recently mentioned here, suitably thin steel BMX chainrings are available in larger sizes but tend to run toward non-stainless.

Needless to say I want a Chainglider too, but so far have been out of luck unless I change both bottom bracket (an expensive Phil Wood unit), chainring, crankset and sprocket to something closely equivalent to the ratio I have that will fit the Chainglider.  Hebie might introduce additional sizes in the future. Alternatively, Surly may expand its range of 104mm BCD chainring sizes. I hope so. That way I would only have to buy a new sprocket and chainring to fit one of the existing Chainglider sizes/front-rear combinations.

Best,

Dan.

So, if I want a chainglider , on a Nomad mk3, and I go with the advised 38 x 16 gearing ... then I have to get these 4 things to work together for compatibility ?

BOTTOM BRACKET
CHAINRING
CRANKSET
SPROCKET

For CHAINRING  there is a surly 38T https://www.sjscycles.co.uk/chainrings/surly-110mm-bcd-5-arm-stainless-steel-chainring-silver-38t/ which I hear is thinner than Thorns and compatible with the chainglider

If Im correct so far, what SPROCKET would work with this ? This ? https://www.sjscycles.co.uk/sprockets/13-rohloff-speedhub-50014-hub-gear-reversible-splined-sprocket-steel/
« Last Edit: April 08, 2021, 12:11:40 AM by ourclarioncall »

JohnR

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Re: Chain glider advice
« Reply #19 on: April 08, 2021, 08:56:35 AM »
The standard Rohloff sprocket will be fine. What matters is the width across the teeth. Thorn's reversible aluminium chainring https://www.sjscycles.co.uk/chainrings/34-thorn-110mm-bcd-5-arm-reversible-single-chainring-332-inch-black is mainly about 5mm thick but is thinner at the teeth to fit a standard single speed chain (8 speed chains will also fit).

However, what you need to look out for is matching the cranks to the chainrings. The Surly chainring is 110 BCD (Bolt Circle Diameter see https://www.qbp.com/diagrams/tech_content/crank/bcd.html ) so you will need matching cranks. You also need to decide on the crank length. 170mm is a good starting place but, if you have a bike that you are comfortable with then check the distance between the centre of the crank and the centre of the pedal spindle. Cranks and bottom bracket will need to be compatible and the bike should use an eccentric bottom bracket for aducting the chain tension.

Finally, for now, it is advisible to use use a gear inch calculator such as https://www.sheldonbrown.com/gear-calc.html to compare the gearing of any bike you have with what you propose to order. 38T / 16T is, however, a good starting place as the rear chainglider part for a Rohloff can handle sprockets between 15T and 17T so you can change the gearing by about 6% up or down although this is only about half a gear step on the Rohloff hub.

ourclarioncall

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Re: Chain glider advice
« Reply #20 on: April 08, 2021, 02:42:31 PM »
Thanks JohnR

Hows this one?

https://www.sjscycles.co.uk/cranks/sjsc-110-pcd-alloy-singledouble-crankset-170mm/

If that is okay , then what about a bottom bracket? Im clueless

ourclarioncall

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Re: Chain glider advice
« Reply #21 on: April 08, 2021, 02:46:21 PM »
JohnR

Just to clarify , are you saying the Thorn chainring you linked will or will not be compatible with the chainglider?



Cheers

JohnR

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Re: Chain glider advice
« Reply #22 on: April 08, 2021, 06:14:01 PM »
Hows this one?

https://www.sjscycles.co.uk/cranks/sjsc-110-pcd-alloy-singledouble-crankset-170mm/

If that is okay , then what about a bottom bracket? Im clueless
That crankset is probably OK and would work with a Shimano UN55 bottom bracket cartridge. However, the UN55 has been discontinued but I believe that SJS has found a substitute. Once you have decided on your preferred crank length and BCD / PCD (to suit your choice of sprockets) then Thorn / SJS can recommend suitable crank / bottom bracket combinations.

Just to clarify , are you saying the Thorn chainring you linked will or will not be compatible with the chainglider?

The Thorn chainring will not work with the chainglider as it's too thick. I was just trying to point out that it's thinner where the teeth are. The chainglider encloses the chainring about 1.5cm in from the end of the teeth where the Thorn chainring is its full thickness.

ourclarioncall

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Re: Chain glider advice
« Reply #23 on: April 08, 2021, 06:41:18 PM »
Cheers JohnR

Is this the one you meant thats out of stock ?

https://www.sjscycles.co.uk/bottom-brackets/107-shimano-un55-73mm-shell-english-thread-sealed-cartridge-taper-bottom-bracket/

If so , I see this is 73mm and there is another one that is 68mm that is in stock. Im guessing these are important sizes that I need to be aware of to get my desired setup ?


JohnR

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Re: Chain glider advice
« Reply #24 on: April 08, 2021, 08:58:51 PM »
Yes, 68mm and 73mm are different sizes where the cartridge screws into the BB shell so they aren't interchangeable. There's also another variable: The crank axle length. Thorn recommend 107mm for the Rohloff hub but 110mm is also close enough to give an acceptable chainline for the Rohloff hub (chainline is the offset of the chain from the bike centre-line - it should be parallel).

ourclarioncall

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Re: Chain glider advice
« Reply #25 on: April 08, 2021, 09:27:41 PM »
JohnR

Is the crank axle a separate piece that you buy thats different from the bottom bracket ? Or is the axle a part of the bottom bracket ?
« Last Edit: April 08, 2021, 09:30:44 PM by ourclarioncall »

JohnR

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Re: Chain glider advice
« Reply #26 on: April 08, 2021, 10:15:14 PM »
There's a bewildering choice of bottom bracket designs. Some are listed here https://www.sheldonbrown.com/cribsheet-bottombrackets.html . My Mercury is fitted with a UN55 cartridge (which has the crank axle built into it) which is fitted with square taper cranks. I have another (non-Thorn) bike which uses a GXP crankset which has the axle fixed to the right crank and the axle is independent of the bearing. The Thorn Rohloff bikes use an eccentric bottom bracket https://www.sjscycles.co.uk/bottom-brackets/thorn-raven-twin-mk3-eccentric-bottom-bracket/ which fits within the frame to enable chain tension adjustment.

ourclarioncall

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Re: Chain glider advice
« Reply #27 on: April 09, 2021, 11:30:43 PM »
I see on a thorn mk2 sjs have for sale  https://www.sjscycles.co.uk/bikes/thorn-nomad-mk2-620l-black/ , the have specked a Tange Seiki 73mm English Square Taper Bottom Bracket - 107 mm

They have these for sale https://www.sjscycles.co.uk/bottom-brackets/tange-seiki-ln3922-73-mm-jis-english-square-taper-bottom-bracket-107-mm/

Here is the transmission specs

Transmission:
Thorn 104/64 PCD Triple Crankset MK2 - 175mm
Rohloff Hub 14spd 32h Black DISC 17T SLIM Carrier & Tandem Axle Plate
KMC E1 Rohloff Compatible 1/2 Inch x 3/32 Chain
Thorn 104mm BCD 4 Arm Reversible Single Chainring - 40T
Tange Seiki 73mm English Square Taper Bottom Bracket - 107 mm

Just a hypothetical question for now, but would this Tange Seiki work with the other parts Ive mentioned ?

EDIT: I see the surly chainring is 110mm, does that mean the bottom bracket has to be 110mm ?
« Last Edit: April 10, 2021, 12:33:09 AM by ourclarioncall »

ourclarioncall

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Re: Chain glider advice
« Reply #28 on: April 09, 2021, 11:37:49 PM »
 I from heard from Thorn today that they have no 26 forks left for nomad mk3 builds until March 2022 !!

 so looks like my only choice is a mk2 in 620M or 620L

I do just fit into the height measurement for this frame which Thorn says is the equivalent of a 21 mountain bike frame.

So hmmm 🤔 need to ponder this one

Matt2matt2002

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Re: Chain glider advice
« Reply #29 on: April 10, 2021, 07:52:28 AM »
I from heard from Thorn today that they have no 26 forks left for nomad mk3 builds until March 2022 !!

 so looks like my only choice is a mk2 in 620M or 620L

I do just fit into the height measurement for this frame which Thorn says is the equivalent of a 21 mountain bike frame.

So hmmm 🤔 need to ponder this one

What is your time frame?
Less than a year to wait.
I love a good countdown.
More time to save up for extra goodies. And there will be lots.
The anticipation. Expectation. Marking those weeks and months off on the calendar.

Don't compromise. Get it right first time.
Never drink and drive. You may hit a bump  and spill your drink