Shimano 2x10 to 1x11 conversion on a budget

Especially for light weight issues concerning cyclocross / touring bikes & parts.

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ross
Posts: 394
Joined: Mon Mar 14, 2011 10:59 am
Location: Oxfordshire UK

by ross

Hi folks

On my CX bike I'm currently running Ultegra 6700 2x10 with 50/34 and 11-28. I like the fact that it's bombproof and can take some abuse - getting snagged in brambles and down narrow wheel ruts etc. The rear mech is short cage 6700 so max capacity is 30t officially. I'm finding the 34x28 ok offroad but a lot of my riding is on a chalk & flint downs escarpment with short (250ft high) but steep (20-30%) climbs and currently when getting out of the saddle I lose traction on the rear wheel over loose surfaces. i'd like to run a 1:1 ratio to spin up them a bit easier while keeping weight over the rear wheel.... so something like a 34 rear cassette is required and I'm also toying with going 1x11, but the Force1 groupset is £700 over here and no availability, so I found a cheap XT M8000 drivetrain upgrade kit with rear mech, cassette, rapidfire trigger shift https://www.bike-components.de/de/Shima ... it-p49644/

Now, apart from looking a bit messy with the trigger shift under the drop bars, is there any reason why not? The MTB cassette should fit my Fulcrum Racing 5 DB wheels with a 1.85mm spacer, I also frequently use the tops over rough ground and being able to shift from there does have an appeal, as does braking without the whole shift lever moving inwards, which can easily happen on a bumpy, rutted downhill.

I'm currently running Juin Tech R1 cable / hydro brakes so will likely just need some bare drop bar brake levers such as TRP RRL or SRAM S-900?, then lastly I'd like to change over to single front chainring, any good options for Ultegra 6700? Or would it be better to replace the crank altogether?

Any advice or tips welcome. Many thanks

ETA pic of bike :D

Image

JScycle
Posts: 172
Joined: Wed Mar 08, 2017 11:41 pm

by JScycle

Hi,
Just an opinion. Would it be better if you bought a set of cheap 11 speed shifters and a Wolftooth cable actuation adapter meaning you would be able to run your mountain bike derailleur on road shifters.

by Weenie


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bikerjulio
Posts: 1901
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

I had the same dilemma as you. I had been vacationing back in my home territory and riding on the North and South Downs using a 10-speed cross bike with 50/34 and 12-30.

It just wasn't enough to get up the steep pitches. After thinking through various options, I settled on a Deore crankset, 40/26 and FD. Nothing else changed. It actually reduces the chain takeup required too. Worked perfectly for what I needed, at minimal cost and complexity.

Since then, there have been "road" type cranksets introduced with that kind of tooth count. Like these direct swap for Shimano https://www.suginoltd.co.jp/us/products/road/ox.html So, that's another approach, just not quite such low gearing with 44/30 as lowest.

Note that this approach requires a frame using a clamp type FD mount as a braze-on isn't going to get low enough.

Image
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

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maddog 2
Posts: 348
Joined: Wed Feb 25, 2009 7:58 pm
Location: Lancaster, UK

by maddog 2

the XT rapidfire pod won't fit on a drop bar. You won't get the clamp round the bend.

You'd be better of running the road STI with a converter, as JScycle suggests. If you kept your current STI then you'd be 10 speed though, not 11.

If you're happy to stay 10spd then you can get 10spd MTB mechs which can handle 11-36 cassettes (cheaper than 11spd mechs too).

For the front ring, then any 5-bolt 110bcd narrow-wide ring will be fine. Superstar may still do cheap ones.

ross
Posts: 394
Joined: Mon Mar 14, 2011 10:59 am
Location: Oxfordshire UK

by ross

Thanks for the replies chaps, as it's a band on front mech I should be able to lower it just fine. I have been reading up on Shimano HT2 MTB chainsets and have found a 10 speed M985 XTR 44 30 which might do the trick with a spacer or two for the 68mm frame

Bikerjulio - yes very similar terrain, I'm lucky to have direct access to the Ridgeway so I have miles of paths, bridleways and byways to explore which is brilliant

maddog 2 wrote:the XT rapidfire pod won't fit on a drop bar. You won't get the clamp round the bend.


Bugger, that's quite a biggie. Thanks for confirming!


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bikerjulio
Posts: 1901
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

OP on the spacer issue. Shimano provides 3 x 2.5 mm with an MTB style crank. I used 1 on the DS and 2 on the NDS and chainline was identical to the road setup.

@mad. I'd agree that there is a nice simplicity to a 1x setup, but the whole point of this switch is also to get usefully lower gearing. If limited to a 34T in front, it would need a 40T big sprocket to get as low as my 26 T ring x 30T solution.

A cassette more like this perhaps? http://www.chainreactioncycles.com/ca/en/sunrace-mx3-10-speed-shimano-sram-cassette/rp-prod149194?gs=1&utm_source=google&utm_term=&utm_campaign=Chain+Reaction-CA-PLA-PLA-All-DT-SE-Shopping+QLB+Generic&utm_medium=base&utm_content=mkwid|scygkztcL_dc|pcrid|45501330212|pkw||pmt||prd|544233CA

But then I'm not sure the MTB RD will work with road shifters.

Perhaps a hanger extension and use the existing RD? Even simpler. http://fitwerx.com/wolf-tooth-roadlink-derailleur-hanger-extender-review/ Will work fine on a 1x drivetrain because on a 11-40 cassette chain takeup required is 29T - ie no problem.

This the cheapest solution for sure. All that's changed is chainring, cassette, and extender. Every thing else could stay.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

Marin
Posts: 2819
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

Cheap-as-chips Sram 10-speed MTB derailleurs will work up to 11-36, sometimes even more. You can drive one with a SRAM TT barend shifter, 10s or 11s will both work with the 10s changer, just match the shifter to the cassette. Much better than a trigger on a drop bar.

Or go with a mid-cage Shimano derailleur and a road link or a knockoff -> https://www.aliexpress.com/item/MTB-Mou ... f40ca23311

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maddog 2
Posts: 348
Joined: Wed Feb 25, 2009 7:58 pm
Location: Lancaster, UK

by maddog 2

MTB RD won't work with road STI unless you use a converter

Yes, you can buy a wider 10spd cassette than the std Shimano - like the Sunrace 11-40 and 11-42 - but even with a MTB 10spd mech you can experience capacity issues on the biggest sprockets. People get round this by using either a goatlink, or a RadR cage, or screwing the b-screw right in, and there is some success in this. But that's with a MTB RD. Any road RD will struggle bigtime with a 11-42. Only the goatlink has a chance of working I suspect.

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bikerjulio
Posts: 1901
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

Any road RD will struggle bigtime with a 11-42


I'd agree with you there, but 11-40 stands a chance of being OK with the extender. There's really three issues to discuss:

1. Clearance to the big sprocket. Assuming that the RD will normally clear a 30T sprocket, then a 40T has a 20 mm greater radius. The extender link provides 22 mm, so should be enough to clear.

2. Takeup. A short cage RD will handle a total chain wrap of 32T. So on a 1X setup a 11-40 needs 29T, so no problem there.

3. RD "following" the cassette. This is where a road RD on an extender is not going to be optimal, as the sprocket clearance is presumably going to increase more than ideal as the RD travels down the cassette. Things will work though, i'm not sure how well. Presumably it's shifting precision that will go off.

I'm only talking theory here. If OP was interested in this approach then more research on users experiences with the extender link might be useful.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

Jowwy
Posts: 65
Joined: Thu Jun 09, 2016 6:47 pm

by Jowwy

I used a woolftooth road link on my sram etap wifi rd for riding I'm the alps this year.

Crankset set-up was a 46/34 sram red
Rear cassette was a sun race 11/40 c/w woolftooth......this set-up shifted seamlessly with the etap and got this 18st monster up all the climbs, even the col d'telegraphe

ooo
Posts: 538
Joined: Sat May 21, 2016 12:59 pm

by ooo

Short cage low gears: 40/42 cassette with Single vs 28/32/36 cassette with Triple without big chainring

Code: Select all

rings    cs   low gear capacity  rear shifts following front shift
   34 × 11-42   0.81    31 (SS)
   34 × 11-40   0.85    29 (SS)
39-30 × 11-36   0.83    34 (SS)  1
39-26 × 11-32   0.81    34 (SS)  2
39-24 × 11-28   0.86    32 (SS)  3
'

by Weenie


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