#12 - Karate Monkey and Front Derailleurs

New Karate Monkeyâ„¢ Nuts for 2007
If you still need more tire clearance, we now have New Monkey Nuts. These are included with all 2007 or newer Karate Monkey framesets that have a headtube/downtube gusset. While the old Monkey Nuts held the wheel back 5mm, the new Monkey Nuts will position your wheel 14mm back from the front of the dropouts and are a simple non-permanent fix if you have a tire/derailleur overlap problem. They are designed to be secured onto the frame and left there, that's it. Simply sandwich the dropout with the Monkey Nuts, slide the Monkey Nuts all the way forward in the dropouts and cinch the bolt as shown in the diagram.

For setting up geared Karate Monkey bikes, we've always recommended using "traditional swing style, bottom pull" front derailleurs. When we first designed the Karate Monkey frameset in 2002, there was an array of front ders on the market that worked great and allowed adequate rear tire clearance. Since then, Shimano has come up with a new "dual pull" derailleur that is both "top pull" and "bottom pull" all in one derailleur. While this may be good for bike shops because they only have to stock one derailleur that fits the use of many, these "dual pull" front ders are hideously large and don't give you proper rear tire clearance. Now it seems Shimano wants to flood the market with this "dual" der. Changing the design of the KM to accomodate this bulky derailleur, however, would make the KM's handling suffer, so that simply isn't an option.

What front derailleur you need for your geared Karate Monkey:

Other ways to add rear tire clearance are by using a button head cable pinch bolt instead of the stock cap head bolt (see photo), or by using the included Monkey Nuts on the rear hub to keep the wheel 5mm back in the dropouts. If you can avoid using Monkey Nuts, do so. They are only there for oddball situations.

This photo above is a Karate Monkey frame with the wheel all the way forward in the rear dropouts, NO Monkey Nuts were used, a Shimano Deore LX M571 traditional swing style, bottom pull, 28.6mm clamp front derailleur with a button head cable pinch bolt and full-sized Kenda Klaw 29" x 2.1" tire. Plenty of clearance, Clarence.

This photo shows the same Kenda Klaw 29 x 2.1” tire, NO Monkey Nuts, new M571 Shimano derailleur, traditional swing style, bottom pull with 31.8mm clamp and 28.6mm reducing shim, stock cable pinch bolt. Still plenty of room.

If you absolutely insist on using any traditional swing style Shimano or SRAM dual pull derailleur or topswing style derailleurs, you will be required to use the Monkey Nuts included with your frame to pull the wheel back 5mm in the dropouts.

Notice the Shimano XT M761 traditional style dual pull derailleur without Monkey Nuts does not offer any clearance

Traditional style dual pull Shimano XT M761 derailleur with required Monkey Nuts

Dual pull SRAM X Gen, Kenda Klaw 2.1” tire with required Monkey Nuts

Shimano topswing style, Kenda Klaw 2.1” tire and NO Monkey nuts offers minimal clearance

As we mentioned above if you can avoid using Monkey Nuts to provide front derailleur clearance with the rear tire, do it. It means one less thing to fiddle with when removing/installing your rear wheel, and you'll get the geometry of the frame as it was designed when the wheel is fully forward in the dropouts.

From 1.27.05 blog post

I'm sure a few of you fellow 29" riding freaks have already heard about WTB's new 29" x 2.3" tire that is currently available. We've been anxiously awaiting it and it looks pretty cool so far. Since I mounted a bunch of different front derailleurs on the Karate Monkey to see what works and what doesn't on SPEW# 12, I mounted this tire up to see how it fit.
For the record, this is exactly what is used on this bike:
* Salsa Delgado X rim
* WTB Exiwolf 2.3" tire
* 20" Karate Monkey frame
* Shimano LX M571 front derailleur with button head cable pinch bolt
* Shimano LX M572 crank
* Shimano LX ES51 73x121mm bottom bracket

As you can see here the tire rubs on the derailleur at both the derailleur cage and the pinch bolt. So this next image below is the exact same components with a Shimano LX ES51 73x126mm bottom bracket to move the crank out 2-3mm and Monkey Nuts to pull the wheel back 5mm. As you can see, it works just fine now. So when using this tire on the back of a geared Karate Monkey, use the longer BB, a button head cable pinch bolt and Monkey Nuts.