- This topic has 17 replies, 6 voices, and was last updated 12 years ago by perthmtb.
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2 x 9 woes
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perthmtbFree MemberPosted 12 years ago
Sorry to interrupt the Beyonce forum with a question about bikes, but…
Converted my bog standard 22/32/44 SLX to 22/36/bash at the w/e and I’ve got all sorts of issues.
First off, when in the 22 chainring, the chain rubs on the 36 chainring when I use any of the top (smallest)four sprockets on the cassette.
Then, when I’m using the 36 chainring (steel Deore M510), the chain rubs on the FD cage when using the bottom (largest)two sprockets.
I know these are the least used combinations, but I’d kinda like to have the choice of using the whole cassette with either chainring to minimise front shifts. Also, I see from Shimano tech docs that they don’t really support the 22/36 combination, except with their SLX double, but I thought lots of guys here were running 22/36 combinations?
So, anyone else have this problem – and what did you do about it? Thanks.
TandemJeremyFree MemberPosted 12 years agoMine is set up to be rub free for everything on the 36 but only use 1-5 ish rub free on the granny ring. You really should not need the top few gears in granny ring.
so using cable tension set teh position of the cage on the 36 to give the best rub free performance and only use the bottom half of the casette in granny.
CaptainMainwaringFree MemberPosted 12 years agoDidn’t have too much problem when I changed from triple to double but did put an SLX crankset on.
You have to accept that you won’t have all the cassette available from either ring – the chainline is just wrong. With careful adjustment of the front mech I can get all but the top 2 from the 22t and all but the bottom 1 from the 36t.
As well as fiddling with the lateral adjustment the front mech needs to come up a little IIRC
perthmtbFree MemberPosted 12 years agoHi TJ, thanks for the post. I’m using an SLX Triple FD, and while the cage is wide enough to accomodate the whole 9 gears on a 32T chainring, where the chain runs with a 36T is narrower. So, adjust as much as I like, it rubs at one end of the travel or the other. I even tried raising the FD up the seat tube a bit, but then the chain rubs on the bottom of the cage when on the 22T chainring! Maybe I should fork out for the M665 double specific SLX FD – this should be designed to have all the correct clearances for a 22/36 combination – right?
TandemJeremyFree MemberPosted 12 years agojust acept the minimum rub that can adjust it for – or use a grip shift so you can trim the mech – or a thumbie friction shifter. I actually have a slightly wider 7 sp mech on mine so can get it adjusted rub free -but at a cost of clunky shifting
perthmtbFree MemberPosted 12 years agoHi CM – did you get the M665 double specific SLX? I’m wondering if the 36T chainring on that is ‘different’ somehow, to give extra clearance for the chain when on the 22T? Don’t mind buying the M665 36T chainring if that’ll solve my problem, but would like to know that its going to solve the problem before I spend the money…
perthmtbFree MemberPosted 12 years agoHi TJ – interesting point – I’ve got a couple of old deore FDs in the shed, maybe I’ll measure them to see if they’re wider at the point where the chain runs on a 36T.Otherwise, looks like I might be buying the M665 double specific FD – anyone had experience of this?
perthmtbFree MemberPosted 12 years agoBack from the shed – unfortunately the deore FD clearance is identical to the SLX. However, did raise the FD up a tad, not too much to affect shifting but enough so that I can now get eight of the nine sprockets without rub on the 36T – which I can live with.
So, remaining issue is only being able to use half the sprockets with the 22T before the chain starts to rub on the 36T chainwheel.
I’m really curious if the smart guys at Shimano have done something special with the M665 double specific 36T chainring to solve this problem. Anyone using this chainring, and can share their experiences?
CaptainMainwaringFree MemberPosted 12 years agoPMTB – yup I bought the whole SLX double and bash crankset when my previous BB died. At £99 fitted it did not make sense to do anything else.
Just wondering if the double specific SLX has a slightly different chainline with the two rings set slightly further out. Might be worth trying a spacer?
ScamperFree MemberPosted 12 years agoI changed to a OE double and bash SLX chainset and just accept the chain rub as “character”. Using the original tripple SLX mech with the H screwed in to stop shifting onto bash, although its angle can’t be altered du to the way its direct bolted onto the frame.
perthmtbFree MemberPosted 12 years agoHi CM – yes I wondered about chainline too. The Shimano site says the chainline of the triple SLX is 50mm, and the double is 46.8, which means the two rings of the double are basically in exactly the same place as the two inner rings of the triple. That’s not to say you cant push it out a bit with extra spacers during installation, as you suggest. And I think this would help the rubbing problem. Trouble is I’ve got a push fit BB and it looks like I’d probably ruin the cups getting them out!
Still, the fact that you can get all but the top two gears when in the 22T, means there must be something ‘different’about the M665 36T – the ramps don’t stick out so far maybe? Maybe worth me giving it a try – certainly less hassle (and cheaper) than replacing my BB in the process of adding a couple more spacers!
PaulDFree MemberPosted 12 years agoPMTB,
The 36T is an alloy ring, whereas the 32T is a composite ring and looks to be fatter.
The 22T is the same Shimano part number for both offerings.
The crankarms are different tho, double has pedal thread inserts.Real cheapo solution to try is to pack the 22T with 0.5mm or 1.0mm washers away from the crankarm and see if that buys you enough clearance for an extra few gears.
It assumes there is frame clearance for the bolt heads.PaulD.
perthmtbFree MemberPosted 12 years agoHi PaulD – nice idea, hadn’t thought of that one! Oh, hang on – maybe increasing the spacing between the two rings isn’t a good idea shifting wise…its already a big jump between 22 & 36…might give it a try anyway!
By the way, the 32T is the same width as my new deore 36T on the inside face where the rubbing is going on – I measured them. The problem is the greater diameter of the 36T pushes it into the zone where the chain is crossing over from the inside ring to the small sprockets.
Only solutions I can see (and thanks to the replies above for getting me to this point)…
1. Live with only being able to use half my sprockets on the granny
2. Add washers to move the granny in
3. Shift the chainline out by using more spacers on the BB install
4. Find a 36T chainring that is narrower.My preferred order would be 4 3 2 1, which is why I’m holding out hope that the double specific M665 36T is narrower than others!
My finger’s poised on the enter key to order the M665 36T – can anyone confirm or refute it’s narrower than all the other Shimano 36T chainrings before I spend the money….please…..pretty please?
CaptainMainwaringFree MemberPosted 12 years agoThe other alternative to spending £30 on one ring is £95 on a complete SLX chainset which gives you 2 new rings, new BB, a bashguard and is guaranteed to work
KahurangiFull MemberPosted 12 years agoHi, I’m a bit late to this, but I’d might as well use my lunch break to see if I can help.
I went from a Std SLX double (22/36, alu alloy big ring) and when that wore out I bought a deore steel 36t ring.
Now, I can’t get hold of the model no. from the deore ring from work but it was a steel, ‘middle’ ring with 36t.
When I compared the SLX alu with the Deore steel, the deore did indeed have a different chainline. IIRC, the deore was ‘fatter’ in effect, so I would have had to space out the small ring as has been suggested here. The section profile of the deore might also be worse, but I’m not sure.
It has caused poorer shifting and more dropped chains when shifting (as the gap between the two rings is smaller).
It also causes more chain rub.
I would change back to an SLX pecific one, but that would be also be worn smooth in a year!
perthmtbFree MemberPosted 12 years agoHi JT – that’s good intel, thanks. Interesting to have it confrimed there are differences between the common or garden deore 36T and the M665 double specific, that make it work better in a 22/36 setup! Guess I should have expected Shimano to re-design the thing so it worked well! Interesting what you say about the wear too. I originally went for the steel deore rather than the alu M665 because I don’t like my oft-used chainrings to be aluminium – but not so sure that was a wise decision now with the problems I’ve been getting!
And CM, I’m tempted – really tempted – to just go the whole hog, but at 85 quid (current CRC price) I’d need to be very sure it would work much better than my current thrown together solution!
PaulDFree MemberPosted 12 years agoPMTB,
I have another suggestion…I have 24T and 26T (silver) steel grannies that you can buy for £7 each.
Both are 4-bolt 64mm BCD.
24T is not Shimano or any known ‘brand’ but stamped WC037 7EK.
26T is a Shimano ring.Interested?
paul.r.davisAThotmail.co.uk
perthmtbFree MemberPosted 12 years agoHi PaulD – thanks for the offer, but I really do need the 22 granny as I run 11-32 on the back. If I sacrificed anything to get my smoooooth shifting back I’d go back to the 32 and forget about the 36!
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