Creating a custom 1 x 10 speed. Options for 12-32 cassette?

[Ed209]

After reading all the excitement over Aero bikes I've challenged myself to make a sub 7kg, sub £1000 road bike for club run specific route and maybe the odd TT/crit race.

I've so far spent £330 on a used Planet X N2A frame forks and seat post, and will also invest in some of China's finest 50mm clinchers for another £300.

Now on to the groupset. Call me mad but for simplicity's sake (and cost and weight targets) I want to ditch the Front Deraileur and go for a 1 x 10 speed on a 12-32 cassette with 50t chainring. This isn't as bad an idea as it sounds, since on our club run route I currently ride a Cube Litening with 11-25 cassette and 53/39 chainrings; I use less than half of the range offered by this setup on this particular route and could reproduce this range with the 50 x 12-32 proposed. Plus having this range on the same chain ring would be preferential.

Now then, I am open to suggestions on groupset to achieve this. I have no bias towards manufacturers, and will have to buy used. My goal is light and all in for £250. I'm thinking:

-Dura Ace 7800 shifters and RD (but not sure I can get a 12-32 cassette for this).
-SRAM Red 10 speed BB30 crankset
-DA 7800 brakes

OR

-SRAM Red 10 speed everything (again not sure if 12-32 cassette available).

All pretty dependent on what bargains I can find on ebay.

[acliff]

You'd probably need a medium cage ultegra mech or wi fli SRAM mech, or a mountain bike mech.
I believe 7800 RDs have max 28t capacity, possibly up to 29 or 30t.

SRAM red 10 speed with wifli rear mech should work, along with pg1050 11-32 cassette.

£250 seems optimistic, but you could easily swap out various bits for Force or Rival without a huge weight penalty.

[kulivontot]

Shimano tiagra 12-32 was like $18 from Wiggle.com. Seems to work well with sram red.

[ergott]

Those gaps between shifts will suck for road riding. Hard to get the cadence right that way.

Sounds like you have your mind made up, but don't be surprised if you change it after riding it for a while.

So many ways to do budget 10 speed with a double there's no point.

[pushstart]

You should be fine with a short cage rd, there isn't that much chain to wrap with single front ring. I am using a short-cage X9 RD with Apex shifter (and S500 left brake) on my commuter/cx/rain bike. One great thing about SRAM 10sp is that road and mtb components are interchangeable. I wanted extra chain retension with a clutch rear derailleur. Plus road derailleurs won't allow for 36t cogs.

I am using an 11-36 cassette (with 46t ring), so even larger gaps; it really isn't a practical problem, though you might notice.

You want a narrow-wide ring to keep the chain on. The SRAM X-Sync rings are great, since they move the chainline in (you likely will only be able to mount a 50t on outside of spider).

If you are only going to 32t you should be able to use some of the newer road derailleurs. Definitely the wifli ones, but maybe any of them -- just check max cog size. Or MTB derailleur, but the extra tension shouldn't be necessary for road riding -- assuming you have a narrow-wide ring.

[Ed209]

Just the sort of info I was after. Thanks guys.

And yes, a little nervous about how the jumps in a 10speed 12-32 will feel in reality.

[CharlesM]

The better solution...

Go with SRAM Force 1x11

48 tooth chain... 10-42 rear.

You get the same top end as an 53x11 and a lower low end than 39x30... There is nothing you can't do with that combo.

[mattjevans]

Actually if you do the calcs, 50 with 12-32 if almost identical to 46 with 11-28, which means 10 speed red with short cage mech is fine. I run cx1 front ring w 11-28 red/force group 10 speed and I think it's great.

50/12 = 4.16
46/11 = 4.18

50/32 = 1.56
46/28 = 1.64

(Alternatively 44T front if you really need the 50/32 equivalent, slightly lower top end)

[Ed209]

Food for thought.

[mattjevans]

But if you decide on your original plan, it appears that the SRAM 1070 is available in 10 speed 12-32
https://www.sram.com/sram/road/products ... 0-cassette

[steelisreal79]

Interesting thread!
Are the guys currently on a 1x setup running narrow wide chainrings and a "clutched" rear derailler?

Thanks for the response and information!

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[pushstart]

Personally, I am using a clutch RD(X9). I ride off-road a fair bit on that bike and value the silence (less chain slap), not sure I would have chain drops without the clutch though (?). I do know of people that use the narrow/wide without clutch for road.

[steelisreal79]

Thanks for the feed back pushstart. You're not using a narrow wide chainring are you?

I'd be going for a 44T narrow wide chainring and a 11-36 or 11-32 10 speed cassette. I've been looking at the x9 derailler, good value for money!

Thanks again....

Verstuurd vanaf mijn GT-P5210 met Tapatalk

[pushstart]

Sorry if that was unclear. Yes, I am also using a narrow-wide (46t SRAM X-SYNC) with an 11-36 cassette. Range is slightly more than an 11-28 with a 36/46 setup. Obviously bigger gaps, but they are in the low gears so little practical impact on road (where they would be more noticeable).