2 x 9 Gearing

[phlowhoot]

Hello,
I am getting back into mountain bike racing after a long hiatus. I am primarily a road racer. I just bought a Scalpel 2 and was thinking of going to 2 x 9 gearing.

I would really appreciated suggestions on:

1. Gearing
2. What front derailleur to use
3. Pros and cons of 2 x 9

I live and race in Oregon.

[HAL 9000]

42 x 29 with a 11-43 cassette

[Dan Gerous]

A 11-43 cassette HAL 9000? Now that must climb anything!

Now, I don't know much about Oregon terrain but if you are a road racer, you shouldn't have any problem with the 2x9, people that need triples are either on heavy bikes and/or don't ride/train as much as most racers IMO, but on a go fast XC bike, which the Scalpel is, 2x9 just makes sense.

I also use 29/42 and a 11-34 cassette and it gets me up anything I can climb with the common 22/32/44. I don't see any cons personally but many pros. Front shifts are much slower and clunkier than rear shifts so a 2x9 usually means less front shifts, more rear ones. And rear shifts can handle shifting under power much better than front shifts. With the 42 big ring, you can stay on it most of the time and dropping to the 29 only on very long/steep climbs or slow technical sections. Sure you lose a few low-end gears compared to a triple but it actually helps sometimes because you don't want to have a too slow cadence when climbing so if you are out of gear, you just pedal and go faster...

It also apparently cuts the chainsuck risks but I cant say, never had too much trouble on 2x9 or 3x9 unless my drivetrains are really dirty.

You also save a bit of weight on the crank but I saved more by going with a road derailleur, it works just as well as a mountain unit but it's much lighter. I use a Dura-Ace 7700, it's the last 9-speed Dura-Ace so the cage is a bit wider than 10-speeds. This allows you to use more gear combos without having to trim the front derailleur, not a big issue with Grip Shifts but it can be helpful with triggers. Mine in 31.8 clamp style weighs 86gr, almost half of what a XTR weighs and currently, XTR are the lightest front derailleurs available. Anyway, weight is not the first reason to go 2x9, a better gear range and better shifts are much more important if you ask me.

[bikegizmofan]

I have a Scalpel with the BB30 2x9 29/42 and a 11-34 cassette. I think it is the perfect setup. The only time I switch it back to a 3x9 is for one race that has a lot of long steep climbs (leadville 100). On that ride I want to have the granny gear, but the rest of the year the 2x9 is great. Highly recommend it.

[grimes_joseph]

what do you guys think about 2x9 with 11-34 on a f29er??? my f29 1 is on order with cdale and i have a si alloy crank with 3x9 setup currently, but also have a 2x9 spider, rings, etc. its 29-44 so maybe i'd spend more time in the small ring... i've heard that the 29er is like riding two teeth smaller in the back... so basically, dan, could you get along on your scalpel with 29-42 and 11-32?? thanks a bunch guys

jg

[HAL 9000]

A 11-43 cassette HAL 9000? Now that must climb anything!

[Dan Gerous]

My old F1000 had a 24 front small ring and a 12-27 cassette and I was fine, it's about the same as 29 x 32 so yeah, I could deal with it, 2 teeth is not that much, I use the 29 x 34 very rarely as it is, the only places I can think of that is already hard on the 29 x 34 was on the Mont Sainte-Anne World Cup course where I raced once, there was a long and very steep climb with switchbacks that was following other long and steep climbs, a little muddy at the same time... But like those who ride singlespeeds, always riding with taller gears will train you to use it and it would probably become okay even if it's hard at first... When we know we have easier gears, we tend to just go for the easy choice even though we could probably stick with a harder gear or two...

They're probably not good exemples since they are among the best XC riders in the world but on the same course at Sainte-Anne at this year's World Cup, Julien Absalon and Geoff Kabush were riding 32/44 rings, they didn't walk and finished 1st and 2nd...

[sstokke]

I've been sold on the 2x9 setup for my team rush. It has the si cranks, with standard 22/32/44 setup. First let me say I know very little about the 2x9 setup, but I've been told my best option is to move to a 94/58 bcd spider and a 42t & 29t setup. I believe I'm have 104/64bcd at the moment. I had my local dealer call C'dale for a 94/58 spider, but apparently they won't have any available until sometime in December. So, does anybody happen to have one I could purchase???

Any other insight would be appreciated as well.

[splangy]

I've been sold on the 2x9 setup for my team rush. It has the si cranks, with standard 22/32/44 setup. First let me say I know very little about the 2x9 setup, but I've been told my best option is to move to a 94/58 bcd spider and a 42t & 29t setup. I believe I'm have 104/64bcd at the moment. I had my local dealer call C'dale for a 94/58 spider, but apparently they won't have any available until sometime in December. So, does anybody happen to have one I could purchase???

Any other insight would be appreciated as well.

What brand of rings did you use for 29/42t rings and where did you get them?

[rvmdmechanic]

22/36t front, standard in the back (11-34) is a winner. Especially if you bash-guard the front, protect your stuff and keep you rollin over the big logs. (currently on a 22/32 front, but it's too easy so come spring, it's going to a 36.

[dypeterc]

has anyone run 2x9 using an xtr crankset? in particular the M960 cranks with their funky 146/102mm bcd.

[bubba888]

did that on my hunter - 44/32 x 11/32, left off the granny and limited the front derailleur and added an n-gear chainstop. it was ok except for the chainline - the hollowgram 2x9 looks like the 94bcd spider moves the chainline inward.

[scarsellone]

Has anyone tried using the 3 ring spider with 2 rings? easier to get rings? How does it affect chain line?

[Kwik]

Has anyone tried using the 3 ring spider with 2 rings? easier to get rings? How does it affect chain line?

Look at topic rebuilding my scalpel, this guy is making 2x9 with a triple crank. 38 ring is biggest ring he could use

[mrwibble]

Can I alter my Truvativ Stylo Crankset to a 44-39T?

[cyclonewrench]

has anyone run 2x9 using an xtr crankset? in particular the M960 cranks with their funky 146/102mm bcd.

I'm actually converting my M960 to this right now. I'm going with a 34t Blackspire Mono Veloce (non-ramped), a Blackspire 42t, then dropping the granny. I'm also ditching the front derailleur completely, so I will have better clearance on extreme cross shifts.

Sounds kind of weird, but considering the ramped chainrings can only effectively use about 2/3 of the rear cassette (without skipping or grinding), I figured I'd get an adequate range out of the mono 34t ring for most of my riding. In the rare occasions I need taller gearing, I simply pull the chain over to the large ring manually.

[Dan Gerous]

I'm actually converting my M960 to this right now. I'm going with a 34t Blackspire Mono Veloce (non-ramped), a Blackspire 42t, then dropping the granny. I'm also ditching the front derailleur completely, so I will have better clearance on extreme cross shifts.

Sounds kind of weird, but considering the ramped chainrings can only effectively use about 2/3 of the rear cassette (without skipping or grinding), I figured I'd get an adequate range out of the mono 34t ring for most of my riding. In the rare occasions I need taller gearing, I simply pull the chain over to the large ring manually.

Beware of dropped chains with no derailleur and no chain retention device... It has happened to me on my commuter with a similar setup... on the road so while mountain biking, the risk is much higher. My commuter now has a N-gear jump stop and a bigger 46T ring on the outside (use as a sort of bash guard, it was cheaper than buying a trueguard)....

Once my drivetrain parts are worn out, I'll probably go 1x10 on my Scalpel.

[dypeterc]

I'm actually converting my M960 to this right now. I'm going with a 34t Blackspire Mono Veloce (non-ramped), a Blackspire 42t, then dropping the granny. I'm also ditching the front derailleur completely, so I will have better clearance on extreme cross shifts.

Sounds kind of weird, but considering the ramped chainrings can only effectively use about 2/3 of the rear cassette (without skipping or grinding), I figured I'd get an adequate range out of the mono 34t ring for most of my riding. In the rare occasions I need taller gearing, I simply pull the chain over to the large ring manually.

i changed my mind re: switching over to 2x9 with an M960 crankset. the q-factor can't be reduced as the spindle length can't be changed. also, due to the odd bcd you can't run anything less that the 44t on the outside chainring or 32t on the middle chainring.

[BlownCivic]

also, due to the odd bcd you can't run anything less that the 44t on the outside chainring or 32t on the middle chainring.

You can if you get Mattias to make you some custom rings.

[tavaenga]

I'm using and loving the standard 29t/44t SI setup on my 2009 Team Scalpel. For those using 29/42, what is your brand of 42t ring? I've seen the Stronglight 42t on Roel's bike. Any others that fit?

I just find I get the occasional chain drop off when in a low gear then I shift from the 44 ring to the 29 ring. Would 42 ring help? My Front der is XTR. Appreciate comments and suggestions thanks!

[Dan Gerous]

I have used a Middleburn 42T and now use an old Shimano 42T that dates back from the days of 8 speed drivetrains. Both work well. TA Specialites also makes rings in almost every sizes and BCD possible.

I have dropped the chain when downshifting once with the Middleburn but it might have been the derailleur's limit screw that wasn't perfect, I think it was during my first ride on the Scalpel. I'd check the limits... I have a Dura-Ace derailleur though... and Grip Shifts so I can control how fast the derailleur throws the chain on the smaller ring. Too strong derailleur springs timed with a bump and the chain can get dropped so I tend to be gentle on the twist when it's rough....

[cyclonewrench]

Beware of dropped chains with no derailleur and no chain retention device... It has happened to me on my commuter with a similar setup... on the road so while mountain biking, the risk is much higher. My commuter now has a N-gear jump stop and a bigger 46T ring on the outside (use as a sort of bash guard, it was cheaper than buying a trueguard)....

Once my drivetrain parts are worn out, I'll probably go 1x10 on my Scalpel.

Edit to the earlier post--I'm running a 44t big ring on the XTR cranks. Is there still a danger of throwing the chain with a rear derailleur? Seems like there would still be an adequate amount of tension to keep a chain on track.

[YB1]

All this 2X9 talk is inspiring me. Maybe I should buy an XX spider and a set of chainrings for my '09 Team Scalpel. Guess these should be available around the end of the year. I'll live with the 9 speed rear cassette so I can stay fully moto with my gripshifters, and run 26/38 on the crankset so I can make it up the steepest climbs.

[Dan Gerous]

The XX Hollowgram spiders may be hard to find for a while...

[tavaenga]

Dan thanks for the reply and I decided firstly I will try a road front derailleur as a possible quick fix, paying attention to the setup. I'll report back later.