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Re: 1x11 gearing on a bent

Posted: 6 Feb 2019, 10:21pm
by UpWrong
So, the poor shifting wasn't caused by a worn chain. It was caused by the RD mounting bolt loosening :shock: Anyhow, I now have new chain fitted (old one will be kept for re-use) and the RD bolt torqued to 10Nm along with a washer to stop the bolt protruding on the inside of the chain stay and fouling the chain.

But the shifting between first and second is still poor. The biggest sprocket is holding on to the chain because there isn't enough clearance to the top jockey wheel I think. And there's no B-screw on these shadow derailleurs. I'm going to have to try an 11-34 cassette rather than the 12-36 to see if that improves it. And if it does then may have to think about changing the chainrings from 34/48 to 33/44.

Re: 1x11 gearing on a bent

Posted: 8 Feb 2019, 9:56pm
by UpWrong
I was right, the shifting is much improved with an 11-34 cassette. I think there is something non-standard with the RD mount on the drop out of my Nazca. THe 12-36 cassette should work with the Shadow Deore RD. I also found that an 11-34 cassette did not work with an SRAM X9 RD, even with the B-screw all the way in. Again, that's an in-spec combination.

Still have to sort out the FD shifter and the rear brake. Shouldn't be long now. :)

Re: 1x11 gearing on a bent

Posted: 9 Feb 2019, 12:44pm
by UpWrong
squeaker wrote:
UpWrong wrote:Zach Kaplan's comments on the MD here are that it resulted in a lot of boom flex,
http://www.bentrideronline.com/messageboard/showthread.php?t=144548
Oooh, nice link. Worth looking at the onward FB link for the pix. (I'd never heard of Mitas tyres either!)

Curiosity has got the better of me. I have ordered two Rubena/Mitas Speedo LT Elite 47-406 tyres. They are each 165g lighter than a BA. I'm determined to get my Paseo below 18Kg :evil:

Re: 1x11 gearing on a bent

Posted: 10 Feb 2019, 1:29pm
by nigelnightmare
The Deore Shadow RD M592 9 speed "DOES" have a "B" stop screw.

Mine does.

Looking from the rear there are three(3) screws, on the left you have the High & Low adjustment screws one above the other,
and to the right (the other side of the gear cable) is the "B" stop adjustment screw.

What it doesn't have is a gear cable adjustment.

According to the specs it has a range of 11-34 Min-Max on the cassette, which may explain the difficulty you had with the 36t first gear.
HTH
*EDIT*
I'm surprised you had problems with the Sram X9 as well.
Maybe the hanger is slightly bent!

Re: 1x11 gearing on a bent

Posted: 10 Feb 2019, 8:34pm
by UpWrong
nigelnightmare wrote:The Deore Shadow RD M592 9 speed "DOES" have a "B" stop screw.

Mine does.

Looking from the rear there are three(3) screws, on the left you have the High & Low adjustment screws one above the other,
and to the right (the other side of the gear cable) is the "B" stop adjustment screw.

What it doesn't have is a gear cable adjustment.

According to the specs it has a range of 11-34 Min-Max on the cassette, which may explain the difficulty you had with the 36t first gear.
HTH

Aha, you are right about the B stop screw being present. I never realised. I should have read the installation guide, except there wasn't an installation guide in the box. I think it's ridiculous that Shimano don't include a paper installation sheet in the box. It's not as if they give a simple URL link either.
Anyhow, I now have to make a decision about whether or not to try the 12-36 cassette again, which is in spec according to the technical service instructions I managed to find (but not on the Shimano web site).

Re: 1x11 gearing on a bent

Posted: 18 Feb 2019, 11:21pm
by UpWrong
I reinstalled the 12-36 cassette, adjusted the B-screw and all is fine. I changed the rings on the compact double to 33/44. I am able to start in bottom gear on the big ring ok, and all the gear changes work well. The steps in gears are comfortable. Compared to what I had with the SA CS-RK3 I have basically lost the two ratios at the top of the range, so now have 11 non-overlapping ratios rather than 13. The total gear range is 400% so the whole thing is similar to a 1x11 with a 12-48T cassette, if such a thing existed, with a 44T chainring.

Re: 1x11 gearing on a bent

Posted: 17 Mar 2019, 2:01pm
by UpWrong
After a couple of rides with the 33/44 chainset I realised that I needed lower gearing to be comfortable climbing on some of my usual rides. So I switched the crankset to a 30/42 plus chainguard triple. I was at least able to keep the chain, derailleurs and shifters as they were so it was an easy swap. It's worth mentioning the cranks have been shortened to 148mm.

I did a long ride this morning and the 20.4" bottom gear is about right for me. Any lower and I would struggle to balance. The high of 85.6" with the short cranks is enough not to spin out on the flat (about 24mph@90rpm). The change between the ring sizes is pretty sweet being a jump of about 40% changing up and a drop of 30% changing down. Overall range is 420% which beats an Alfine 11. I did find I could stay in the large ring for stopping and starting, only dropping to the small ring when climbing.

The Alivio shifter means I can see what gear I am in. I had to brake quickly whilst following a car and was able to drop down from 8th to 2nd in three quick clicks for starting off again.

Whilst it might be argued that all I've done is to thrown away the outer ring of a triple, I would say that I have both easier to use and more efficient gearing as a result.

Re: 1x11 gearing on a bent

Posted: 27 Jun 2019, 8:40pm
by UpWrong
I’ve been pretty happy with the 2x9 set up, however the lure of a 2x11 is hard to resist. Prices seem to have fallen and I realise I could use the 33/44 compact double, FD and front shifter I have. So would only need a rear shifter, RD, cassette and chains. Reckon I can buy those for £160. Hence mulling it over.

I think an 11 speed 11-40 cassette has nice spacing and a switch up from 30/42 to 33/44 at the front will give me more top end whilst preserving the current low (on a 9 spd 12-36). The gear changing ought to improve with Dynasys cable pull as well. The XT shifter has a gear indicator so hopefully I wouldn’t get lost in all those cogs.

OTOH, I’d be losing the chainring guard which bothers me from a safety point of view. I don’t want to get sued for ripping someone open with a chainring. Can probably buy a separate one though. And how much do I really need those higher gears?

It might be that the gains are pretty marginal. Won’t know unless I try it of course!!

Re: 1x11 gearing on a bent

Posted: 27 Jun 2019, 11:05pm
by Brucey
one of the things that puts me off is that the cassettes still wear out and cost a fair bit more to replace than (say) 9s ones. In fact they wear out faster if you use a smaller chainring/sprocket to get the same (most-used) gear ratios, maybe slightly slower if you go ahead as planned.

BTW I don't quite understand why you don't just use a wider range chainset with the 9s cluster...?

cheers

Re: 1x11 gearing on a bent

Posted: 28 Jun 2019, 1:13am
by Tigerbiten
UpWrong wrote:OTOH, I’d be losing the chainring guard which bothers me from a safety point of view. I don’t want to get sued for ripping someone open with a chainring. Can probably buy a separate one though. And how much do I really need those higher gears?

If you've the room on the crank, the easiest way to add a chain guard to a double is to turn it into a triple but the outer chainring has the teeth removed.
Each extra tooth adds 2 mm to the chainring diameter.
So a 48t without teeth should work as a chain guard for a 44t chainring.
That's how I've seen it done.

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

Re: 1x11 gearing on a bent

Posted: 28 Jun 2019, 7:57pm
by UpWrong
Brucey wrote:one of the things that puts me off is that the cassettes still wear out and cost a fair bit more to replace than (say) 9s ones. In fact they wear out faster if you use a smaller chainring/sprocket to get the same (most-used) gear ratios, maybe slightly slower if you go ahead as planned.

BTW I don't quite understand why you don't just use a wider range chainset with the 9s cluster...?

cheers

Interesting point about running costs with increased wear.

I have thought about a wider range chainset, but I don't like " cadence shock". I can handle 30 to 42 (40%), not sure about 50%. A 28-42 double with an 11-34T cassette would provide more range and be at least 100g lighter. (Current Alivio 12-36 weighs 435g.)

I've read the thread on customising 10-Speed cassettes (https://forum.cyclinguk.org/viewtopic.php?f=5&t=130603) and that has got me thinking about using an expander to convert an 11-36 into a 13-40 and then using my 33-44 true compact double. Similar range to what I have now but lighter and more efficient. Much cheaper than the 11-speed option. Will play around with gear calculators.

Re: 1x11 gearing on a bent

Posted: 30 Jun 2019, 3:59pm
by UpWrong
After spending way too much time on this I've decided to go from a 2x9 to a 2x10. I will keep the chainset (a triple converted to a 30-42 double plus guard) and change the cassette from a 9-speed 12-36 to a 10 speed 11-36. That way I retain the same bottom gear (20.4"), slightly raise the top gear (from 85.6" to 93.4"), improve the gear spacing a little (only one change of more than 16%), improve the shifting (move to XT Dynasys) and probably save a bit of weight (100g-150g). Cost of shifter, RD, cassette and 3 chains of around £120.

Re: 1x11 gearing on a bent

Posted: 2 Jul 2019, 12:43pm
by UpWrong
I have a problem with the XT m781 shadow RD ordered from CRC. It didn’t come with the bracket axle link for a normal hanger. Very naughty of them not to say so in the description:
https://www.chainreactioncycles.com/shimano-xt-m781-shadow-10-speed-rear-mech/rp-prod83163

I need to decide whether to buy the proper part (around £18 RRP) or buy a Wolf Tooth Goatlink (£20) and go with the expander sprocket idea after all.

Re: 1x11 gearing on a bent

Posted: 5 Jul 2019, 10:59am
by nigelnightmare
UpWrong wrote:I have a problem with the XT m781 shadow RD ordered from CRC. It didn’t come with the bracket axle link for a normal hanger. Very naughty of them not to say so in the description:
https://www.chainreactioncycles.com/shimano-xt-m781-shadow-10-speed-rear-mech/rp-prod83163

I need to decide whether to buy the proper part (around £18 RRP) or buy a Wolf Tooth Goatlink (£20) and go with the expander sprocket idea after all.


It says DIRECT MOUNT in the description.
Which means it doesn't have the bracket.

Unlike the Deore M6000 shadow+ which states "direct mount compatible" which does but can be reomoved for direct mounting.

Re: 1x11 gearing on a bent

Posted: 5 Jul 2019, 11:56am
by UpWrong
You are right but does anybody have a direct mount frame? I had never heard of it before.

I am still trying to decide which link to buy. Am waiting on the cassette I ordered to see if converting it to a 13-40 is easy or not.