Greetings all. anyone know of a slack headtube frame that fits 650b in the rear triangle? I am thinking of trying to replicate the Diamondback Mason 29er, but obviously in 650b. I have a Surly Instigator frame that I might try something with, but wouldn't mind something more appropriate if it exists. Seems most of the hardtails have headtube angles north of 70 degrees.
And yes, this would just be a "because it is there" type project.
These pics show the wheel location with the swinger dropouts almost all the way forward. There is lots of room to go back if one needed more tire clearance.
Cheers,
KP
Last edited by Kirk Pacenti; 12-13-2012 at 12:24 PM.
“Those that say it can’t be done should get out of the way of those doing it.”
These pics show the wheel location with the swinger dropouts almost all the way forward. There is lots of room to go back if one needed more tire clearance.
A Works angled headset can reduce the HTA on a frame with straight 1-1/8 HT up to 1.5*. Up to 2* for tapered HT. There is also a slightly more expensive and more complicated "Angleset" from Cane Creek.
This is the 1.5* Works on a 69* Jamis 650B2:
Old enough to know better. And old enough not to care. Best age to be.
A Works angled headset can reduce the HTA on a frame with straight 1-1/8 HT up to 1.5*. Up to 2* for tapered HT. There is also a slightly more expensive and more complicated "Angleset" from Cane Creek.
This is the 1.5* Works on a 69* Jamis 650B2:
I had pondered the angleset from cane creek, but it didn't appear to work with a straight 1-1/8 HT. I'll have to investigate this A Works deal further.
I had pondered the angleset from cane creek, but it didn't appear to work with a straight 1-1/8 HT. I'll have to investigate this A Works deal further.
Skidad from this forum and a bunch of folks in the AM forum recommended the Works over the CC.
What these head sets do is angle your steerer within the HT in order achieve skacker (or steeper angle). So the steerer moves a few mm closer to the rider on top and further away on the bottom (or vice versa). The Works design takes into account HT length so the top cap ( which has external cup) has to be installed to line up with the bottom cup, which is either zero stack or EC depending your HT. The CC has spherical gimbals which interface with the bearings which make the HT length irrelevant. The trade off is that some folks couldn't get the gimbals to stop creaking and others didn't think they felt solid. So I went with Works and am very satisfied.
Both Works and CC have HS which fit 1-1/8" straight steerers 44mm id.
Last edited by dwt; 12-15-2012 at 01:59 PM.
Old enough to know better. And old enough not to care. Best age to be.
Hey Kirk. Do you know if that forks set at 100mm or 120mm? Would love to talk to the owner about this bike and get his thoughts on it.
Cheers.
He's been playing with 100-140 set ups. Sam says he loves the bike and the wheel size. PM me and I will give you his email address. Fwiw, I just ordered a Chameleon for myself after seeing his bike.
Cheers,
KP
“Those that say it can’t be done should get out of the way of those doing it.”
I keep looking at the Carver Ti 420 for a B9er or full 650b. The geo chart on the site has numbers that are based on a 100mm 29er fork sagged at 480mm A-C. As a 29er with a 100mm plus fork the bottom bracket is high for technical rocky riding.
Website also says with 650b 2.35 tires the bb height is at 12.24" I called and asked what was the fork A-C used for that number. Reply was a 120mm X fusion Velvet sagged to 479mm A-C. (guesstimate) Plus, minimum chain stay length is 415mm or 16.3". A 650b 2.35 should fit without issue at that CS length.
I am thinking this could be the perfect conversion for a hard tail 650b with a 140 to 150mm fork. With a longer travel fork I think the average bottom bracket height would be reasonable. The sagged A-C for a 150 WB Loop 650b fork vs the X fusion is about 35mm difference. Not exactly sure where that would put the BB, but guessing over 12.5" w/fork sagged 20mm.
As a 29 front with a 120 fork and a 650b rear, both on 2.35 Hans Dampfs. The difference in wheel radius is 19mm between the 27.5 and 29 with the same tires. I have guesstimated the sagged BB would end up around 12.7" with a sagged 120mm fork.
This could be one of the best frames available if you want to experiment with wheel sizes due to the numbers. You have your pick of almost any drop outs/hub axles you want to run from Paragon. Short chain stays. 31.6 seat post and standard BB. HT angle is set to work with multiple combinations. Reasonable price for a Ti frame etc. The only thing it is lacking is ISCG tabs. But with the new clutch derailleurs, they become less important on this type of bike.
Would love to try it on a Surly Instigator though. I had one of those as a 26er with a 130mm Manitou Minute fork up front and it rocked big time!
TONS of options!
Any feel for what the BB drop (or height) was with the 130mm fork?
It appears that I can get close to what Kona has in play with their new Explosiv with the Surly, albeit with a higher BB. While my math skills are working well enough to figure out the Headtube angles, I am having a hard time trying to figure out the change to BB. I would imagine that with a 130mm fork, the BB drop would have been close to zero (in line with the wheel axles). If it was a fun ride like that, I think I will go forward.
All of my experience with the Instigator, and the surly documentation, is with he frame and a 100mm fork, putting the BB at about a 1 in drop. with 26" wheels. That puts the Instigator BB close to 12", but with 650b the BB rises to 12.75", and by eliminating any drop due to a longer fork, the BB goes over 13.5".
Never had a hardtail before but I'm looking at these 2 possibilities now
Aluminum vs steel, Kona accepts 12x142 dropouts (very nice), I like the higher BB on the SC which would be about 1" higher with 650 wheels, frame only list price is $250 less for the Kona, lots of other dimensions are nearly identical and both have ISCG tabs and can take a tapered fork.
Is the 12.1" BB of the Kona gonna be an issue here in the New England rocks is my big question/concern. Total HT newbie here but want to give it a whirl.
Tough choice, I wouldn't let the 142 sway you on the hard tail.If the kona rides like my Honza it's a nice ride.The SC looks like it would work in a lot of different formats xc,AM Hardtail.Im going for the SC since its available and I have 26 stuff to get it going till I get some 650b wheels.Dont think the kona is available yet.If you get the kona look at getting a 140mm 34 to get the BB right for your trails if the frame will take it and still warranty.
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Originally Posted by zombinate
