How small a granny gear can you get on the Vendetta

[Charles.Plager]

Hi,

This question is both relevant to other forum questions as well as general interest (to me, at least). I know from this forum that you can get a triple onto the Vendetta. How small (in teeth) a granny can one get onto the bike? Changing crankset and bottom bracket are fair game. Shims, etc, too.

Thanks,
Charles

 

[charlesw]

Charles,
AFAIK, the smallest

Charles,

AFAIK, the smallest is a 30t via the Shimano Ultegra/Dura-Ace 130/92 BCD triple cranksets. And with that, the 30t inner ring has tabs that hang down below the bolt holes to prevent chain-suck if it were to derail around the BB. To use with the Vendetta -- making room to spin around the V's BB chainstay clamps -- the tabs have to be cut-off with a dremel or similar.

The issue is that the chainstays on the V come up and clamp around the outer bearing cups of the BB. This limits clearance for an inner ring.

Only Shimano makes triple cranksets with a 92mm inner BCD.

 

[Charles.Plager]

Hi Charles,
I wonder if one

Hi Charles,

I wonder if one could get a custom granny gear made that would fit that has less teeth.

Cheers,
Charles

 

[Charles.Plager]

Hi,
I looked at the granny 92

Hi,

I looked at the granny 92 BCD gears and it doesn't look like much room to make a smaller ring that can still attach.

So I believe the question now becomes: Are there any other triples that one can get on? I'm assuming one could do something ridiculous like put on a bottom bracket with a JIS square taper that clears the bottom bracket supports? Are there any higher end bottom brackets that would do this as well?

Thanks,
Charles

 

[fthills]

Good Q.

This is a Q , that exercised me a fair bit whilst building my V. In my experiments with triple chainring setups using standard measurement BCD like 74mm for a 5 arm spider and 64 mm for a 4 arm these will not fit and clear the clamps as charlesw described in a triple setup. This limits how small a granny gear that can be fitted from commercially available granny gears.

TA specialties make a 28 tooth ring that will fit 92 BCD but as charlesw described in his post the ultegra is a proprietary 94 BCD.

With the eye of faith I think a 28 tooth ring could be made to fit the ultegra spider but I haven't put pen to paper and calculated the dimensions to confirm this.

But even if you could I'm not sure that going down to a 28 would make a practical difference on the road vs a 30.
I 'd say that for your legs to feel the difference a step down to 25 would be my starting point.
Something custom made opens all sorts of possibilities . You could for example instead have a triple but on a longer crankshaft so the inner ring sits just slightly further out from the BB clamps , but then the FD may not have the reach for the outer ring. Or perhaps a double setup could be made where the granny gear sits in the chain line position of the middle ring.

In practice it might be easier to find / make a big cassette ring at the back. SRAM make a 36 tooth cassette ring but with a long cage dérailleur you could go bigger custom made. If memory serves me correctly you tube has videos of cassettes ,chainrings , derailleurs made by enthusiasts at home........
I was genuinely surprised and very pleased during my recent series of brevets that in spite of my earlier worries! a 30 granny ring served me really well, For the whole trip. Normally on my RWD recumbent I use a 23 granny .and use it........ frequently.
Thats not to say I wouldn't fit something something smaller than a 30 on the V. if I could.
Where the terrain is consistently above an 8% grade or at night when you've been on the bike for more than 24 hrs already it would be nice to just spin my way to the top when you're facing a big hill whose summit you can't see because its so dark.Thing is when I get to that point I get off the bike and walk .

There is also another possibility that might be of interest, adopted by many an enthusiast who do heavy loaded touring to all parts of the world........ Rohloff hub .........

 

[David Callow]

Refer back to Schlumpf subject

Hi Charles, This was why I was interested in the Schlumpf drive fitment. To get the same range on a triple FD you'd need a 56T large ring and a 22 tooth small ring!!
So, if the Schlumpf will fit - problem solved. It ain't cheap though! Price for Schlumpf in the U.K is £400 (which I make to be about $644 at current exchange rates). Regards, Dave.

 

[charlesw]

David, 

 

The thing about

David,



The thing about the Vendetta is that it needs the BB to have outer BB bearing cups for the chainstays to clamp onto.



Does Schlumpf have outer BB cups?

 

[David Callow]

Hmm!

Hi Charles,
Whoops, I thought the chainstays were clamped onto the boom! The Schlumpf does have cones which are available in varying widths. I think these are about the same external diameter as bearing cups. Guess we'd need feedback from John Tolhurst and haberstock-mobility (the company that now manufactures Schlumpf Drives).

 

[John Tolhurst]

Hi All, 
just to clarify what

Hi All,
just to clarify what has been stated earlier, the Vendetta is built to carry road bike components. I have no plans to make it compatible with everything else ...

 

[David Callow]

Compatibility

Hi John, I understand your position. It would be a nightmare to make it fit with every component and accessory out there.

However, if I can get the internal diameter of the chainstay clamps and their width, that would be useful. The rest would be up to Schlumpf/Haberstock and the engineer in Scotland.
Regards, Dave.

 

[John Tolhurst]

The chainstay rings clamp on

The chainstay rings clamp on the outboard bearing units, which are 44mm OD. The clamps are 100 mm wide and are spaced 69 apart and have a total width of 2*10 + 69 = 89mm.

 

[David Callow]

Just checking!

Hi John, So, if I've got this correctly the dimensions are like this:- (with the chainstay clamps going down onto the 44mm bearings)?

 

[John Tolhurst]

Yes. 
A typo: The clamps are

Yes.
A typo: The clamps are 100 mm wide, should "The clamps are 10 mm wide".

If you delete your 100mm dimension line your sketch is correct.

 

[tmctguer]

It would be a tremendous

It would be a tremendous service to customers if Cruzbike installation instructions would include the type of info depicted in this thread (along with thread type). It took me a few days of searching the website and forum to find this info and when shopping for a bottom bracket, most of these measurements are needed prior to making a purchase.

 

[soldierblue]

I just bought a Vendetta V20 recently, and I was told at the time of purchase (by Cruzbike support) that a triple FD would not work, and that I would have to use a compact crank. I’m surprised to see discussions like these where people are able to get Ultegra triple cranks to work with their Vendettas. I see though that the thread is almost 3 years old. Has something changed since then? Is the V20 indeed only able to handle compact cranks (which - if true - is a pity, as I need the small granny on the hills and a big chainring on the flats. 50/34 just doesn’t cut it anymore).

I actually have an 11/40 on the RD, but even with 34/40, I have difficulty scaling some hills.

 

[snilard]

I just bought a Vendetta V20 recently, and I was told at the time of purchase (by Cruzbike support) that a triple FD would not work, and that I would have to use a compact crank. I’m surprised to see discussions like these where people are able to get Ultegra triple cranks to work with their Vendettas. I see though that the thread is almost 3 years old. Has something changed since then? Is the V20 indeed only able to handle compact cranks (which - if true - is a pity, as I need the small granny on the hills and a big chainring on the flats. 50/34 just doesn’t cut it anymore).

I actually have an 11/40 on the RD, but even with 34/40, I have difficulty scaling some hills.

I think that Ultegra triple can be fitted to V20 but you have modify inner ring. It has to be Ultegra because it has unique BCD of inner ring.
If 34/40 is not enought for you, you can buy 42 tooth cog. But I think that you just need to master MBB style of riding. Sit up and use your core and hands to get more power on steep hills. I have 150 mm compact crankset and 13-40 cassete and I can ride any hill where I don't loose traction of front wheel. And you can walk hills what you cannot ride, Vendetta is easy to walk with compared to other recumbents.

 

[ReklinedRider]

Standard cranksets (130BCD) work just fine (for two chain rings)

 

[John Dorlon]

Is the V20 indeed only able to handle compact cranks (which - if true - is a pity, as I need the small granny on the hills and a big chainring on the flats. 50/34 just doesn’t cut it anymore).

Soldierblue, the inner 30T ring of an Ultegra triple has "tabs" inside of the mounting holes that go too far in towards the center of the ring to be mounted on a Vendetta. But you can cut them off and it works fine. At least it did on the Vendetta 2.0. I'm not 100% certain but I'd bet that it will still work on the V20. Cruzbike used to cut them off (they did for me) but I guess at some point decided to stop doing that.

Here's an image of the small ring. Just cut off that inside part and you're good to go. http://maddogcycles.com/merchant/481/images/large/CR6775.jpg

 

[Robert Holler]

You can get as low a gear as you can maintain speed on before falling over, but in my experience any gearing - no matter the chainring/cassette combo - under 1:1 is too low and at that point the bike becomes hard to handle and you simply have to get stronger. Or walk.

 

[mzweili]

You can get as low a gear as you can maintain speed on before falling over,

I experienced the same on my Silvio, I changed the triple for a double.
If you still want to give it a try, my triple crankset Shimano 30/39/50 hangs on the wall in my shop and is available