Modern MTB gearing set-ups for dummies.......

[I like Skol]

I keep thinking that at some point in the near future I am going to 'upgrade' my 20yr old MTB to a modern gear set (been thinking this for nearly 2 years ).

Currently running a 3x8 set up that started life as Shimano XT but over time has drifted down spec as 8spd parts dried up. Thinking about the way I use my current gears and the range of gears available with current cassettes and chainsets I am strongly tempted to ditch the triple for a double. I am also reluctant to go to a 10spd cassette when I have seen suggestions that the 8/9spd chains are more robust than the super narrow 10spd variant. 9spd also means I have standard chains across my 3 bikes and I never find myself wanting more gears on my 8spd MTB.

My main questions are-

• Is 9spd more robust than 10spd so should I try and get 9spd shifters while they are still available in XT?
• Will a 10spd chainset run with a 9spd chain ok or am I destined for rubbing and ghost shifting at the front due to the wider chain? I can only see 10spd XT chainsets (double and triple) available and would prefer to stay with XT.

All help, advice and experience gratefully received.

Skol.

 

[fossyant]

10 speed chainset will be fine with 9 speed chains.

 

[potsy]

Are you two old duffers not running 11 speed yet?

 

[RecordAceFromNew]

I never find myself wanting more gears on my 8spd MTB.

Unless your right shifter is gone, why change from 8 speed? Even if it is gone you can certainly get perfectly decent new ones from Shimano. The thing is 8 speed chains are generally tougher than 9, and 9 more robust than 10 etc. Also you can get great 8 speed cassettes for peanuts (e.g. sram PG850 11-32 is only 275g, while some similar level 9 speed cassettes weigh nearly 400g).

You can use any speed chainset with your existing system, all you need to do is to maintain a similar chainline.

If you want to stick with a high groupset and period, XTR m950 8 speed brifters are amongst the lightest, nicest brifters money can buy (secondhand only obviously), and they can only increase in value over time.

 

[Cubist]

Or go 2x9 using xt m770 secondhand . All the 9 spd shifters are compatible, and loads available via classifieds.

 

[I like Skol]

Unless your right shifter is gone, why change from 8 speed? Even if it is gone you can certainly get perfectly decent new ones from Shimano. The thing is 8 speed chains are generally tougher than 9, and 9 more robust than 10 etc. Also you can get great 8 speed cassettes for peanuts (e.g. sram PG850 11-32 is only 275g, while some similar level 9 speed cassettes weigh nearly 400g).

I fitted 8 speed Alivio Brifters about 18 months ago because my XT units were shot and I've regretted it ever since. The shifters aren't too bad but the brakes are terrible. Not nearly as much power as my old 1990's set with the moving cam cable pull.

Or go 2x9 using xt m770 secondhand . All the 9 spd shifters are compatible, and loads available via classifieds.

This is what I am thinking. A 2x9 set-up will suit my needs perfectly, 9spd XT M770 shifters are still available new and with an M785 28/40T chainset and a 34-11 cassette I will be pretty much where I am now with my 3x8 set up.

All parts need to be new! I am also tempted to try a 1x9 or 10 just to be radical. I reckon I could live wuith a 38T chainring and an 11-36 cassette?

 

[Cubist]

It's your money of course, and I love XT, ..... BUT. You can get SLX 2x10 cranksets from Bike-Discount.de for 125 euros posted. SLX is, thanks to trickle down technology about 40 grammes heavier than XT equivalent!


My full thoughts are this. 10 speed is plenty robust, unless you are a huge fat knacker who stands up all day to mash your bike up cliff-faces. The flat-earthers will bang on about gossamer thin chains but it's been around as a standard for quite a while, and I don't see many "my chain snapped 'cos it's too thin" threads.

The shimano 2x10 range are 38/24 and 40/26. The dedicated front mechs are designed to run those combinations (albeit with a 14 tooth difference max.... I run mine 38 24 'cos I'm old and knackered). Mixing and matching may work, but may also give you chainline issues, rubbing and trimming headaches. Using a 9 speed mech other than an SLX 2x9 front is possible, but you'll have to limit the throw, and bugger with clamping height.

2x10 cranks are cheaper than 9 speed triples when bought from the Germans. OK, cassettes and chains are dearer, as are the shifters, but not by much, and Dynasis 10 spd shifters are all compatible with each groupset, so you could, to bring costs in line, run an XT with Deore shifters and mechs.

Next alternative is a triple 9 speed converted to double and bash. There are plenty of 9 speed triples left, and it's a simple case of removing the 44t outer and replacing it with a bashguard. I did just this, and replaced the middle 32 with a 36 to give a better spread of gears. Chainline issues are a thing of the past (although I did get an SLX double front mech ..... see above)

Chain retention is sorted by way of a Blackspire Stinger, although if you went full new 10 speed you'd be able to use a clutched mech to stop slap.

If you go 1x10 you have the options of up to 36 t cassette. General consensus is that you drop the granny from an XT 2x10. Again, chain retention is a necessity here, as you'll need a chain device, BB mounted or ISCG tabs on your frame to fit one. Therefore to my way of thinking no weight saved, just a bit of simplicity, and I'm an old fat knacker and already have to get off and push up some stuff running a 22-34 bottom gear!

My recommendation would be complete 10 speed in new SLX, bought from ze germans or french sites.
http://www.bike-discount.de/shop/k407/a51795/xt-m785-no-brakes-groupset-2x10-speed-40-28-black.html

SLX cranks.... tell me they don't look gorgeous
http://www.bike-discount.de/shop/k407/a51795/xt-m785-no-brakes-groupset-2x10-speed-40-28-black.html

cheaper here http://www.hibike.de/shop/product/p...-incl-bottom-bracket-FC-M675-RETAIL-pack.html

In fact, forget all of that , get one of these before they sell out. Astonishing value, and even includes a shadow plus clutched mech. Why bugger about?
http://www.merlincycles.com/bike-sh.../shimano-xt-double-transmission-groupset.html
as

 

[RecordAceFromNew]

I fitted 8 speed Alivio Brifters about 18 months ago because my XT units were shot and I've regretted it ever since. The shifters aren't too bad but the brakes are terrible. Not nearly as much power as my old 1990's set with the moving cam cable pull.

If you are talking about the servowave levers I think the feature is no longer available on modern cable levers. If braking power is poor for standard V brakes the reason might well lie elsewhere (cabling/pads/rim clearance etc.).

My full thoughts are this. 10 speed is plenty robust, unless you are a huge fat knacker who stands up all day to mash your bike up cliff-faces. The flat-earthers will bang on about gossamer thin chains but it's been around as a standard for quite a while, and I don't see many "my chain snapped 'cos it's too thin" threads.

You don’t see many “my chain snapped 'cos it's too thin" threads only because not many chains snap, and that the key user concern with chains is wear rather than breakage (well to those who ride more than talking about their bikes anyway...).

All else being equal, one would be foolhardy to believe 10 speed chains can be as robust/durable as 9 speed, and 9 speed as robust/durable as 8. The reason is as obvious as it is common to find experience in threads confirming it - chain stretch/wear is mainly due to wear on the rivets and “bushings” as Sheldon demonstrated, and the shorter rivets and “bushings” of a narrow chain simply don’t have as much material available to resist the load, and available to be worn away as a thicker chain.

 

[Cubist]

No one is pretending they are as robust, but a chain is a consumable. I ride til stuff wears out and then replace it. I like the weight, looks and sweet shifting of my 2x10 setup. If the chain needs replacing I replace it.

 

[marzjennings]

All else being equal, one would be foolhardy to believe 10 speed chains can be as robust/durable as 9 speed, and 9 speed as robust/durable as 8. The reason is as obvious as it is common to find experience in threads confirming it - chain stretch/wear is mainly due to wear on the rivets and “bushings” as Sheldon demonstrated, and the shorter rivets and “bushings” of a narrow chain simply don’t have as much material available to resist the load, and available to be worn away as a thicker chain.

I've been riding 10 speed (1x10) for about a year and so far with fewer problems than my old 9 speed. And I've seen nothing tangible to say that the new 10 speeds are less robust than 9s except a few folks speculating on something they've not even tested.

Here's a link to 'test' that shows 10's outperforming 9's ... link

 

[RecordAceFromNew]

No one is pretending they are as robust

Good to know you can see one does not have to be a fat knacker who subscribes to flat earth to want to avoid 9/10 speed chains then.

 

[Cubist]

If you want to run 8 speed then crack on old luv.

 

[RecordAceFromNew]

Me? Chains I run range from 1/8" to 10 speed at present. They all have their place.

 

[Cubist]

Then why are you being belligerent?

 

[RecordAceFromNew]

Then why are you being belligerent?

Belligerent? I suspect you are taking what I wrote too personally when they are not meant to be. To me with chains it is horses for courses, but I do have the feeling that the march of the number of rear sprockets to infinity and beyond is oversold, and not necessarily for the benefit of the vast majority of cyclists.