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Discussion Starter · #1 ·
Hello riders ,
I'm building a full suspension trail bike, and was thinking about building it with the Rohloff speed hub, instead if a "conventional" drive train.
Thing is, more than one bike mechs, have told me that because of the extra weight on the hub, it will bog down the rear suspension.
This makes some sense, anyone with a Rohloff on a FS notice this , or is it complete BS?
 

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Mantis, Paramount, Campy
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I'd say its pretty BS

There are plenty of beefy downhill hubs that when paires with the weight of a cassette and disc rotor have to weigh pretty comperably to a Rohloff hub.
 

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rohloff rich
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The only time I notice the weight of the rear end is when I lift the bike up onto the rack on top of the car. My Rohloff is on an XC rig and I've never felt a difference in the way the rear suspension worked vs. how it worked when I had a standard derailleur drivetrain.
 

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MattSavage
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chain tension??

I don't know anything about those setups. What would you use to maintain chain tension? Can you use a double or triple chainring?
 

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Discussion Starter · #5 ·
rs3o said:
The only time I notice the weight of the rear end is when I lift the bike up onto the rack on top of the car. My Rohloff is on an XC rig and I've never felt a difference in the way the rear suspension worked vs. how it worked when I had a standard derailleur drivetrain.
Thanks
Could you maybe post a picture of the Rohloff actually installed on the bike ?
 

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Derailleurless
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mattsavage said:
I don't know anything about those setups. What would you use to maintain chain tension? Can you use a double or triple chainring?
Rohloff provides a nifty chain tensioner to handle taking up the slack.

You can use a double ring setup, but for it to be meaningful either (a) you'd want a really tiny difference in chainring sizes to, in effect, get "half steps" between the gear ratios, providing a finer selection of gearing but not really increasing overall range, or (b) have a really, really big jump in chainring sizes to truly extend the range of gearing on the top end.

With option (a), you'd need nothing more than a front derailleur.

With option (b), you'd likely need a new tensioner, as the tensioner provided may not have the capacity to absorb that big a difference between chainring sizes. You're somewhat limited in how low the Speedhub can be geared, but you can stretch out the high gearing to whatever extreme you choose.

In either instance, with two rings, you lose your perfect chainline, re-introduce derailleur tuning to the equation, as well as accelerated ring and chain wear -- all major attributes of the Speedhub as compared to conventional drivetrains.

 

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angelic fruitcake said:
...more than one bike mechs, have told me that because of the extra weight on the hub, it will bog down the rear suspension...
I'd ask them if they have ridden one on an FS. This is a common argument in theory, but does not appear to be an issue in practice. The issue is suspended verses unsuspended weight, suspension improves if the ratio of unsuspended weight decreases. The question is, does adding a pound to the unsuspended weight, when the suspended weight is ~200lb, make a noticable difference. Besides, some FR & DH wheels are more than a pound heavier than thier XC counterparts, and the suspension works just fine.

PS: here is a tensioner-less FS setup:
 

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angelic fruitcake said:
Hello riders ,
I'm building a full suspension trail bike, and was thinking about building it with the Rohloff speed hub, instead if a "conventional" drive train.
Thing is, more than one bike mechs, have told me that because of the extra weight on the hub, it will bog down the rear suspension.
This makes some sense, anyone with a Rohloff on a FS notice this , or is it complete BS?
To an extent, I agree with this assumption as the hub does add to unsprung weight, but I'd be lying if I told you I feel a difference. Mind you, I'm not doing side-by-side comparisons of similar bikes with and without Speedhubs, but logically, if suspension performance were truly compromised, downhillers would get rid of the 8" rotors, 150mm thru-axle hubs, 800g rims and 3 pound tires in the rear. So I'm not claiming complete BS, but more like "The Princess and the Pea" BS.

Thomas at Rohloff has indicated in the past that his company has a study showing the Speedhub actually improves rear-end handling on full suspension bikes, but I haven't read it myself and well, heck, I don't even know who commissioned and who wrote the damn thing.

I had to chuckle at the latest review for the disc Speedhub (posted last week) where the author claims he is experiencing increased pinch flats due to the installation of the hub. I don't see how this is possible, and I haven't felt the need to vary my tire pressures due to Speedhub installations. The reviewer also claims a 2.6 pound weight gain from his installation, but somehow sees fit to include his (apparantly new?) disc rotor and caliper in the equation, which isn't really a fair assessment if he was running V brakes before.
 

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I don't do PC
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I want one of these setups bad!, I'm tired of bent der. hangers and replacing worn out parts every season. How does it compare on the low end of the gear ratio?, I currently run an XTR 46/34/24 and a 11-32 cassette. I've read your reviews and it sounds like it works, but will I lose too much low-end gearing for climbing. Thanks
 

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rroeder said:
I want one of these setups bad!, I'm tired of bent der. hangers and replacing worn out parts every season. How does it compare on the low end of the gear ratio?, I currently run an XTR 46/34/24 and a 11-32 cassette. I've read your reviews and it sounds like it works, but will I lose too much low-end gearing for climbing. Thanks
The overall range of the Speedhub is a slight compromise over what you've got now. Your XTR standard setup offers you 557% gearing range, while the Rohloff is limited to 526% -- about the same if you chose to run an 11-30 cassette.

You can run whatever chainring/cog combo you see fit. The lower the ratio, the lower the lowest gear. Just keep in mind that your highest gear will be dragged along with it. So you could run a 43x16 ring/cog combo with a Speedhub and have the same effective low gear as the 24x32, but that would take your highest gear down a half-notch to what would effectively be a 46x11.6T setup -- 5.2% off your top end.

My wife's bike is setup 34x16, which is lower than the common 22x34 granny gear most compact derailleur drivetrains run (approximately 22x35 in her case). Her top end gearing sucks at an equivalent 44x13, but she doesn't miss it.

Here's a link to a gearing chart I made that is handy for comparing Speedhub gearing to derailleur gearing. It might take a minute to figure out, but ask me if you have any question about it.

https://gallery.consumerreview.com/webcrossing/images/rohloffratios.jpg
 

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I don't do PC
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Speed?e said:
The overall range of the Speedhub is a slight compromise over what you've got now. Your XTR standard setup offers you 557% gearing range, while the Rohloff is limited to 526% -- about the same if you chose to run an 11-30 cassette.

You can run whatever chainring/cog combo you see fit. The lower the ratio, the lower the lowest gear. Just keep in mind that your highest gear will be dragged along with it. So you could run a 43x16 ring/cog combo with a Speedhub and have the same effective low gear as the 24x32, but that would take your highest gear down a half-notch to what would effectively be a 46x11.6T setup -- 5.2% off your top end.

My wife's bike is setup 34x16, which is lower than the common 22x34 granny gear most compact derailleur drivetrains run (approximately 22x35 in her case). Her top end gearing sucks at an equivalent 44x13, but she doesn't miss it.

Here's a link to a gearing chart I made that is handy for comparing Speedhub gearing to derailleur gearing. It might take a minute to figure out, but ask me if you have any question about it.

https://gallery.consumerreview.com/webcrossing/images/rohloffratios.jpg
Thanks Nate, that sounds like a very slight compromise considering all the benefits. I will be seriously looking at upgrading maybe when santa comes, the additional pound is not an issue for me and the initial cost seems like it will be offset after a few years compared to purchasing and replacing a full drivetrain.

One other question, I ride rocks a lot and bend my hanger on a regular basis, is this a problem with the tensioner? and I'm assuming it will handle 5" travel.
 

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rroeder said:
I ride rocks a lot and bend my hanger on a regular basis, is this a problem with the tensioner? and I'm assuming it will handle 5" travel.
That's going to vary between different suspension designs in terms of chain growth, as well as how tight you run the tensioner.

My 5" travel Hollowpoint hasn't had any trouble, and guys are running these on 8"+ DH bikes, so I don't imagine tensioner capacity is an issue. Tensioner clearance is pretty good compared to a derailleur; if you look at my photos you'll see Rohloff's suggested tensioner setup, to where the chain is cut to such a length that the three tensioner pivot points align.
 

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Discussion Starter · #14 ·
Speed?e said:
The overall range of the Speedhub is a slight compromise over what you've got now. Your XTR standard setup offers you 557% gearing range, while the Rohloff is limited to 526% -- about the same if you chose to run an 11-30 cassette.

You can run whatever chainring/cog combo you see fit. The lower the ratio, the lower the lowest gear. Just keep in mind that your highest gear will be dragged along with it. So you could run a 43x16 ring/cog combo with a Speedhub and have the same effective low gear as the 24x32, but that would take your highest gear down a half-notch to what would effectively be a 46x11.6T setup -- 5.2% off your top end.

My wife's bike is setup 34x16, which is lower than the common 22x34 granny gear most compact derailleur drivetrains run (approximately 22x35 in her case). Her top end gearing sucks at an equivalent 44x13, but she doesn't miss it.

Here's a link to a gearing chart I made that is handy for comparing Speedhub gearing to derailleur gearing. It might take a minute to figure out, but ask me if you have any question about it.

https://gallery.consumerreview.com/webcrossing/images/rohloffratios.jpg
Thanks man, this is so much great information about the speedhub. Sounds like I've got nothing to loose from this setup . Price also doesnt seem so high when compared to how much I spend each year on broken or bent der's , worn out chainrings, etc... It seems the Speedhub's initial cost will cover itself in a year or so.
 

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ditto on weight gain

The reviewer also claims a 2.6 pound weight gain from his installation....

I was carefull in my comparison of weight. I only change out the drivetrain parts, everything else was the same. Before and after weights on the same scale, I didn't even wash the bike, just changed out parts. I saw a 2.14 pound increase. I have the TS model of the speedhub, which is the heaviest model. 2.6 pound increase can not be correct.
 

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nmcculloch said:
I saw a 2.14 pound increase. I have the TS model of the speedhub, which is the heaviest model. 2.6 pound increase can not be correct.
It also depends on the drivetrain being replaced. Swapping out all lightweight XTR, X.0 or hand-selected components is obviously going to result in a greater weight gain then the mix of LX, XT & XTR components I got rid of.
 

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dirtpaws said:
Did you dremel a slanted slot in the dropouts of that Cat?BTW, what did you use for a rear disc adapter?
Filed & dremel'ed the dropout, they were massive so there's lots of room:

The disc mount is a hack - parts from an old woodman adapter, cut, filed and bolted to a hole drilled into the dropout, with a shortened torque arm attached to the canti mount. I made the caliper bolts to line up with a "front" ISO spec, gave me more room for the Rohloff. I just had to use a front caliper.

The thing weighs ~32lb(!!) as it stands.

Cheers,

Tom
 

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The "pines"

dirtpaws said:


Isdoable, ran into you at the "pines" a few weeks back, was riding the cove g-spot bike with the speedhub, Did you go to the chico 24 hour event? raced the xc ride with speedhub and must have "fielded" a lot of questions/answers throughout the event, Great times..
I'll get pics of my rides up sometime~somehow!

Vernon VernDog
Team Dirthigh2, plate #132 pics from the chico event will up soon.
www.chicoracing.com
 
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