 You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
Bear with me.. I'm trying to solve a geo problem..
I 'm building a Genius frameset for my wife, HMX version so lighter than her curent HMF/alloy Spark, however to keep things lighter I'll be building with a 34 SC which is 120, not 150.
So, using an EC56 angleset that buys me ~12mm over a ZS56 headset but If I use it in 'reverse' orientation, what kind of stack/bb height changes can I expect?
120+12 vs 150 is what 1 degrees steeper, Presumably shortening the wheelbase and steepening the head angle will raise the BB
even steepening things by 1 more degree and we're still in her current Spark head angle range.. the lower BB height with reduced travel forks is the bigger concern, does the EC56 with steeper 1-1.5 solve my problems and keep the BB height comparable to a stock bike with a 150 fork?
cheers
It'll make a trivial difference to BB height, a couple of mm. Honestly the solution to your problem is a fork the correct length or a frame that suits the fork. You're only talking 250g or so of difference between say a SC 34 and a Pike, that's really not worth mucking about.
Totally fair point, but I already have the 34 SC.and its all that's needed out front compared to the other forks I have..
250g is still half a pound and you should see the color on this frame..its really lovely.
I wouldn't turn up my nose at saving 250g off any of my bikes, but not if it meant smashing my feet off rocks forever. I think you basically have to decide whether or not she can live with the BB height. Shorter cranks would be easier and more effective than anglesets mind
yep, she has a dicky knee so will be running 165mm cranks. Fortunately the genius already has a 20+mm higher bb than the Spark so i think it might end up being pretty close to the same HA, BB etc
looks like i could make an non angleset ec56 with one of these.
http://www.last-bikes-shop.com/epages/62262325.sf/en_GB/?ObjectPath=/Shops/62262325/Products/001884
Or, suck up the weight and go regular 34 in the right length..
The BB height will be 10mm or so lower with no ec headset, which sounds liveable and that falls to 0 at full compression so I reckon don't worry about it. Bang in a regular -1.5/2 slackset and try it. The lower BB and steepened seat angle probably work well. Ramp the progression on the shock to max to hold up the travel more in line with the front and go ride.
return fork and get the correct sized one.
That is not going to ride nicely. Scott actually fit a 140mm fork to the entry level genius and that doesn’t feel great, so even with an angleset a 120mm fork will feel horribly unbalanced. Over-forking a bike a little bit generally works, but under-forking can only be bad in my opinion.
A Niner Slacker Puck raises the headtube by 15mm so might buy you enough extra BB clearance (at the expense of 1/2 degree slacker). You could probably combine it with the Angleset to bring it up further..
You could also use a 29" wheel on the front if it'll fit (if it's the 650b version)?
I think I'd be worried about the bike feeling unbalanced with such a difference in rear / front travel?
Thanks for the input. Might be a case of trial and error. If it doesn't work with the SC then I'll drop in a regular 34.
Fwiw, I run my genius tuned with a 140mm 36 and it's super.