Custom mtb build geometry

Icyseanfitz

Hey guys, I am going about building myself a new 27.5 bike for xc/trail/enduro from the frame up. I am after ordering a 2016 cube stereo 140 frame in a size 22 (im just over 6 foot but ive heard cube are sized small).
I am now looking at what i can do to make the bike slacker while retaining a steep seat angle. Stock the bikes head angle is 67.5" and its seat angle is 74.5" and it was sold as a full bike with both a 140mm fork and a 150mm fork.

What i am thinking of doing is putting a 2017 160mm rock shox lyrik which should slacken the head angle to around 66.5", it will also raise the BB height but as the bb drop on this bike is quite low at -15.5 that hopefully wont cause too much issues. I was also looking at these offset shock bushings to further slacken to if needed.
My problem is then how to correct the seat angle, I assume the longer fork will reduce it to something like 73.5", is there anything i can do to bring the seat angle back up?

Any advice or ideas?

nordicb

I think Enduro and XC are very different setups. This is more enduro one.
Just my opinion, from XC perspective, 160mm front shock travel is obviously too much, the head tube is too high and angle is too slack for efficient climbing and carrying momentum over obstacles on flats. This head angle will result in long front wheel trail, that will give you stability, but less nimbleness, but perhaps can be addressed slightly with shorter stem... You could probably fix BB position over seat by moving seat if there are enough seat rails.

Not sure... my 2c, I think it won't be an XC weapon...

Mr. Grieves

I'm curious as to why you want to change the geometry from how the frame has been designed?

Would moving the saddle forward or mounting a seatpost with layback rotated 180 degrees help with your seat angle?

Sorry if I'm not being helpful, I'm interested in learning about these things, having never really taken an interest in geometries until recently.

Icyseanfitz

Oh I've no illusions of it being a pure xc weapon, but I need it to be able to get to the top of hills

But from what I've seen with more modern bikes head angles and moderate travel don't equal a bad climbing bike, just look at say the Santa Cruz hightower lt or pole evolink 140, getting great reviews on climbing abilities for bikes >140 travel.

Budget is limited so I'm trying to build something that can climb (hopefully eagle 1x12 will help) and do the likes of bike park Ireland, GAP and some enduro.

Icyseanfitz

Mr. Grieves wrote: »

I'm curious as to why you want to change the geometry from how the frame has been designed?

Would moving the saddle forward or mounting a seatpost with layback rotated 180 degrees help with your seat angle?

Sorry if I'm not being helpful, I'm interested in learning about these things, having never really taken an interest in geometries until recently.

No problem, I want to give the bike 160 as opposed to 150 it was sold with it so that it will be more capable going downhill as well as slackening it so that it's more stable. A lower head angle generally makes a bike stable but less nimble, steeper seat angle increases seated climbing abilities.

nordicb

Since you are getting a larger frame, which, in my mind, is a good thing to do, you will have enough cockpit to move the seat forward. It's the position over BB that matters, less so the angle of the seat tube. Problem arises when seat has not enough of rails to move if far forward enough, which is usually the case.

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nordicb wrote: »

Since you are getting a larger frame, which, in my mind, is a good thing to do, you will have enough cockpit to move the seat forward. It's the position over BB that matters, less so the angle of the seat tube. Problem arises when seat has not enough of rails to move if far forward enough, which is usually the case.

You can get a seatpost mounted extender to bring the saddle more forward. I have one on my track bike, and the saddle at the end of its rails on top.
It is undeniably ugly though. It goes onto the seatpost clamp and the saddle clamps onto it, which brings it forward a couple of inches.
I don't know how it'd work on an mtb, I imagine there might be issues with dropper posts?

Icyseanfitz

I saw a fizik thar saddle with extended rails, might be the way to go

C3PO

Why do you always do things like this Icysean? (I couldn't find a smiley face on my iPad!)
It will almost definitely climb like a pig with a 160mm fork! Stick with what the frame was designed for - 150mm will be enough for just about anything that you will come across here!

Icyseanfitz

i am a gluten for bike build punishment yeah it might be worth sticking a 140/150 on it and do a -1.5 degree with offset bushings or something.

Anyone ridden or heard anything about fox 34 rythem forks? can be got for 300ish

Icyseanfitz

can the travel on a 2016/17 lyrik be reduced to 150 from 160?

Icyseanfitz

well ive the frame on the way, and im just after buying a manitou mattoc pro 2 fork and carbon bar the mattoc 2 seems to review really well in comparison to pikes/34’s, better damper but not quite as stiff, 140,150,160mm adjustment, lots of tweeking options as well. Might get the IRT add on to adjust progressiveness on the fly.

I am now thinking of buying the manitou McLeod rear shock as well, seems to be reviewed fantastic as well as been great value.

Icyseanfitz

Finally got the build finished up rides really well, i assume the head angle is somewhere around the 66 degrees with the offset bushings in the shock. Must just put a nice saddle on it and a set of vaults.