Two down hill bike options for next build

I am looking at two used DH bikes for my next build. Thinking possibly of a high powered hub or mid drive and have not fully decided yet. Two that have come up so far.




The iron horse yakusa 2006(in Black) and a chahuba f4 2009 (yellow one ).

Besides no place for a battery inside the frames, anyone have experience with either.

cheers

I'm not calling the yellow one weak, but I feel the iron horse one would flex less between the frame and the seat.

The modern bikes have all but given up the Y frame design, for various types of frame that go back to a triangle. In the case of the iron horse, it splits to let the shock through.

But bottom line, if prices are similar, buy the one in the best condition, or if it matters buy the one easiest to fit your torque plates to. Look for a flat plate with room to bolt on thick steel.

The Yacusa is a much better ride, but the Chumba is a much better frame.

i like to fit an 18 fet controller in frame, and neither does have the space, yet the Yacusa in XL size might.

If I had to chose between them, I would build on the Chumba, because the Yacusa frame is not strong enough for real power.

Thanks dogman

I think I can get the iron horse for much less and trade some for it. The chahuba is lighter and has better suspension for certain, but will most likely be much more money. Both have roughly the same geometry. Will look at at least one of them in the next days and see how beat up they are. The chahuba has a floating rear brake setup which may be a perfect spot for tying in a ebrake/ torque arm and is much more open for mods. Forks are the good ones also.

Mad knows his bikes a lot better than I do. I was just looking again, and it seemed like the yellow bike had a nicer fork. I've loved my bomber forks.

Back end of the yellow one looks better. Either one won't be bad for 3000w of power I'd think.

Thanks guys

I like the chahuba better also. John in cr had the idea of making a moto style seat/battery box for either of them which would be cool and fit possibly a larger controller. I can picture that. Could always hang it off the triple clamps. I have a commuter and want power for this build. Hopefully it is in good shape.

It is comparing oranges and apples. CHUMBA has a reputation with Freeriders for being able to hit hard and fast. Chumba makes every frame in house in small series, their joints are overbuilt and very durable. The suspension is a bit harsh and doesn't soak the small stuff very well, but it is a good jumper built for the big drops.

The Yacusa is a poor man's amateur DH racing bike made in large series. It rides real good but doesn't last and has a reputation for cracks in welded joints. Its handling is closer to modern DH racing bikes, and I would prefer to ride this one on a single track.

Adding weight and power, I first select a frame that is strong enough to build on. Mods and components are coming after, to tune and make it ride as good as it can. That is why I'd prefer the Chumba to build power on, even if I know that a Yacusa will be easier to tune to ride fine.

Thanks MadRhino

I will look at them both. Know from some of my builds that small differences sometimes make for big changes in ride feel. Glad you know and can tell more on the bikes as they are very similar in lengths/angles and hard to tell from the pictures how they ride. With the right trading I may end up with both for two very different builds.

cheers

Got it!


Chumba f4, to be: ...... CHUMBA f4..12KW

Some minor hardware issues, no front derailleur, 8 spd, and the rear wheel is not dished properly for the floater, but all the pivots are good and tight and a very good solid frame with clean / good working suspension and brakes. Need to go with a bit longer seat post and stem for flatland riding. Weight is not too bad either.

Looking at that swingarm, it would be simple to lengthen the wheelbase or build it a new swingarm. The original pic didn't do it justice for how beefy that frame. Now I want one. 8)

It is a nice piece of work. Hate to mess with it, but it can simply be extended. Great swing arm pivot. Does not have drop outs, just through holes (slide outs). Wheelbase is 46.5" unloaded and weighs in at 40 pounds with some heavy stuff on it. If I go "pure dirt ebike" with it, may be good the way it is. Easy to attach to the mid ship gussets at the front - rear shock mount as they are already drilled with mounting holes. Feel much better about it now than when I first started going through it.

If your going to use it offroad mainly i would consider a GNG kit with all the lil upgrades
from LighteningRods, over volt it to 70ish volts and you'll have ample power for the trails
and fantastic hill climbing abilities...just a thought.

KiM

Beautiful bike! I would recommend taking Kim's advice on this one. 3kw is fun on a commuter but on a bike like that, I'd want something light that could get me u the hills without upsetting the balance and handling of that bike.

Whatever you do, have fun and post pics!

Hi Folks

I have a GNG kit now on my commuter. Not considering tagging into the crankset for this one. This DH bike is hopefully getting a much more powerful setup. John in CR put the idea in my head, and I don't think there is a way of turning back now. Shooting for a minimum of 8kw on this build. Will be a while before I get things past the planning / design stage.