36 on the rear, is it possible?

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RussellS
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Joined: Wed Feb 03, 2010 1:31 am

by RussellS

If you are using a 110mm bcd crankset with 5 arms, then you can use a TA or Stronglight 33 tooth inner chainring. 33 front ring with either a 32 or 34 rear cog should be low enough to get up any hills. No need for a middle of the road 36 inner ring. A 32 or 34 cassette will have more useful middle cogs than the 36 cassette you are looking at. A 50-33 crankset with an 11-32 cassette would work well with all components and get close enough to the gearing you think you want.

964Cup
Posts: 195
Joined: Tue Dec 18, 2012 1:31 am

by 964Cup

Running pro-compact on the front makes no sense, unless you have no cadence at all. 50x11 spins out at just under 70km/h (at a 120 cadence). At which point there's no point pedalling if you're descending, as the aero gains from levelling your feet and tucking in exceed your likely power output, and if you can sprint to that speed on the level you should think about trying out for a pro continental team. Peak sprint speeds in the Tour this year were in the mid to high 70s.

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eric
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by eric

the 33t ring does not work on all cranks. If the mounting ears are long they will contact the chain side plates. The crank i tried fitting it to was one of those.

I agree that a 33t or 34t small ring makes sense for the OP since he wants low gearing, and 50x11 is high enough.

natiedean24
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by natiedean24

Triples are awesome! Don't let anyone say otherwise.


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stevehollx
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Joined: Tue Sep 19, 2017 5:50 pm

by stevehollx

Bumping an old thread with my experience with this.

I just tried putting a 11-36T on the read of my Rival 22 11-speed setup with a SRAM 2x10 GX Type 2.1 rear derailleur. It did not work. Downshifting from the 36T to 32T does not work without double shifting, and to correct that problem, shifting of all the lower gears gets indexed incorrectly. This is with a verified straight hanger and the B tension screw set to spec (and other extreme settings also attempted).

I assume trying a SRAM X9 would be the same poor result for me that I see with the GX Type 2.1.

I am going to try a rival 22 with a longer b-tension screw with this cassette, otherwise will abandon and go back to Rival 22 in the rear with a 11-32T.

yinya
Posts: 229
Joined: Tue Aug 07, 2007 9:06 pm

by yinya

I run 11-36 on my rival 22 mid cage without issues. Bought road link but didn't need it. Someone else was saying depends a lot on frame geometry


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fa63
Posts: 2533
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Location: Atlanta, GA, US

by fa63

yinya wrote:I run 11-36 on my rival 22 mid cage without issues. Bought road link but didn't need it. Someone else was saying depends a lot on frame geometry



Not really frame geometry, but the dropout geometry.

I can also run a 11-36 on an Ultegra 6800 mid-cage RD (officially rated to 32 tooth max) with no issues on my particular bike.

I also imagine the new Ultegra 8000 mid-cage RD, which is officially rated to 34 tooth max, would work even better.

alcatraz
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Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Three things to consider

1. Derailleur cage length = pick up chain slack. Calculate your big+big and subtract your small+small gear. Something like 52+36 - 36+11= 41t in slack. Don't trust small/mid/long terminology. Longer measured in millimeters will take care of more slack.

2. Position of the upper pulley along with your bike derailler hanger will determine how big of a cog the derailleur can clear. If it can't clear you may try using the "road link".

3. Remember that the chain needs to go over the teeth of the largest cog to shift which means derailleur needs to clear it by a few millimeters. I'd say at least 4-5 mm gap to even consider using it regularly. As you switch to the second cog the derailleur minimizes that gap and if it's too small you hear a rattle. This occurs when you switch to the largest cog aswell.

-

I saw somewhere that older 105 derailleurs had longer cages than current long cage derailleurs. It's interesting how that works. It's not so black and white.

If you get an XD freehub you could do the ultimate mod (i havent tried this) and use a 10-42t cassette, long cage derailleur, together with a crank limited by a certain tooth difference. Say 14t. It means you can put a 36/50t crank there or a 34/48. The range would be immense.

It's also possible to get a crank with removable spider like the specialized/s-works. This way you can (even with a short cage derailleur) put an mtb spider with smaller chainrings on and be ready for the hills. (need a chain for each setup)

I'm thinking of doing this myself as I'd like to try different gearing other than the ones the industry is trying to offer us. Also i'd have a very light crank without buying several models and I could put on a power meter.

With my current short cage sram red derailleur I can only clear an 18t chainring tooth difference (with an 11-28t cassette = max). My dream would be to run 28/46t chainrings or 26/44t on an mtb spider. When I want I can put back my 34/50 on another spider.

/a

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