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Discussion Starter · #1 ·
I know offically the hd140 takes a 2.75-2.0 rear shock, but I have heard rumblings and rumors of people running a 2.25rear stroke in 140 (boosting the travel a bit) my question is...
who has done it?
how is the geometry?
any tire buzz?

let me know...
 

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[
I had the 2010 and 2012 HD and ran the following

7.875x2=140 (officially 140 but since the HDR came out Ibis has stated that it was closer to 130mm) I did not like the 140 setting, it was to harsh for me on rougher stuff.

7.785x2.25 w 140 chips = approx 148 no tire buzzing, worked great no change in geo just longer stroke. Felt "poppy" and playfull. I ran this with a 160mm and 170mm fork it was really fun a bit slack and made you want to pop over the hits.

8.5x2.5 = 160mm the plushest and most fun but a bit higher BB with a 160mm fork.

Make sure you check bottom out by letting air out of shock and bounce hard and if your tire contacts the seat stay.
 

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I'm running it right now with a Vector Air (200x57, no travel limiting shims) and 650B wheels. I went that direction because I didn't think I'd like the 14.3" BB of a 8.5x2.5" setup with 650B wheels. It's worked pretty well for me.

Geometry-wise I'm sitting at a 13.8" BB and ~67deg HTA (hard to get a low-error measurement) using a 160mm fork (XF Sweep) and 2.35 Neo-Motos. The 2.25" stroke gives you the exact same static geometry as a 2.0" stroke. If you decide to run more sag with the longer stroke, what would make the bike slightly lower and slacker when sagged. In my mind, the real advantage is that it's easier to tune for the big impacts without giving up small bump sensitivity when you use the longer stroke. It should climb identically to a normal HD140 with the same spring rate.

For tire rub, assuming you're running 650b, it will limit your choices compared to the 2.0" stroke. Neo-Motos clear perfectly. I've tried 2.4" Conti X-Kings, which don't quite clear on hard bottom-out (and leave black witness marks). 2.3 Ardents, which barely cleared the swingarm anyway, were fine with the 2.0" stroke but are a clear no-go with the 2.25". You'd have to be careful with your testing to make sure you get a true bottom-out. If your shock has a hard bumper (as the Vector does), you may not actually be getting full travel when you bounce on it deflated.

If you're running 26", of course, you probably wouldn't have any worry about tire rub.
 

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Discussion Starter · #4 ·
Thanks guys...appreciate the input...
Wld be running 26 so should be fine...
Thinkin a cane creek db air, and keeping the coil I already have for the big park downhill days
Anyone got any links to any relevant threads? Advanced search gives me nothin
 

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Or, with offset bushings and 1/4" of spacers, you could get the same geometry and the same amount of travel (~143mm) from your existing 8.5x2.5 shock and 160mm limbo chips as from the 140mm chips and a 7.785x2.25 shock.
 

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Discussion Starter · #6 ·
Or, with offset bushings and 1/4" of spacers, you could get the same geometry and the same amount of travel (~143mm) from your existing 8.5x2.5 shock and 160mm limbo chips as from the 140mm chips and a 7.785x2.25 shock.
yeah did think about that, but would like to keep the 160 option (and the geometry that goes with it) for down hill days...
 

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I run a 200*51 Factory Tuned (DW) XF RLX as well as a 200*56 XF stock H3. Prior to getting the RLX tuned I'd echo what was said about the 140 mode, the stock Fox CTD never felt quite right. That said the RLX is so much an improvement over the CTD that the difference in travel isn't as noticable, it definitely feels plusher and "more usable". That said the H3 in its full open mode feels pretty endless in travel without giving up pedal efficiency.
 

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Discussion Starter · #8 ·
You guys have got me thinking now...
What about 650 wheels with the longer stroke
Hmmmm with a cane creek db air it could be a quiver killer...
Like my BB low though, how much would offset bushings actually help?
And tire choice...what would be my tire choices?
 

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See my post a little further up - all my experiences with a 2.25" stroke are with 650b wheels. You're probably limited to no more than a true 650bx2.3" tire though - thank goodness the Neo-Moto is as good as it is.

Offset bushings with a 650b wheels, 2.25" stroke and 140 limbo chips are a bad idea. Your limiting factor in tire volume is seat tube clearance at bottom out, and there isn't much to spare.
 

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I just built up a HD with 27.5" and a 7.875" x 2.25" shock. Really happy with the setup, no need to shim the rear shock if you run a small rear tire. But as mentioned rear tire clearance is really the limiting factor. Clearance at the lower yoke/chain stay area is very close wit ha 2.25 NN. At bottom out there is about 2mm of clearance between the rear tire and seat tube. A hard bottom would probably cause contact. I haven't measured the bb height yet but it definitely feels noticeably higher compared to my old Mojo C. I am hopeful that Ibis has something in the works that is truly designed for 27.5, but who knows how long before such a bike is released. For now the HD with long shock is a good option if your ok with running a small tire in the back.
 

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Discussion Starter · #11 ·
So tyre choices could be an issue,
so far I am hearing 2.25 nn and neo motos...anyone tried any others with 2.25 in 650? also...Anyone got a bb height with the 2.25 and 650?
Or would it be the same as other 650 conversions...
 

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IMO there are more options than not, there are days when I read these forums and wonder why do folks need 2.4+ tires on everything. I suspect most folks have way more tire than they need. As for options there are cross marks, pretty much all schwalbe a 2.25-2.30, WOlverines, etc... Pretty much tires with low to mid lugs. Where I live Racing Ralph's on wide carbon hoops roll fast and provide great grip. If I went somewhere more rocky idd probably swap to a neo moto or a HD 2.25.
 

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Discussion Starter · #13 ·
IMO there are more options than not, there are days when I read these forums and wonder why do folks need 2.4+ tires on everything. I suspect most folks have way more tire than they need. As for options there are cross marks, pretty much all schwalbe a 2.25-2.30, WOlverines, etc... Pretty much tires with low to mid lugs. Where I live Racing Ralph's on wide carbon hoops roll fast and provide great grip. If I went somewhere more rocky idd probably swap to a neo moto or a HD 2.25.
I tend to agree with you, just worried the 2.25 stroke may complicate things a little...
 

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In that configuration with standard bushings about 13.75". With my RLX and one set of offset bushings is down to just above 13.5".
 

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Fore reference, my 650b HD140 2.25 stroke is at 13.8" with Neo-Motos and 160mm Sweep (551mm a2c). Ramjm's setup is the same except for tires.

You're stuck with an external cup headset, I believe. You may be able to use a ZS49/28.6 lower, but you'd get smaller (less durable) bearings and might have clearance problems between the fork crown and the frame. I believe Hans strongly recommends against it.

You could look for a fork with as low an A2C as possible. With a 150mm fork you could be in the 540mm A2C range. A good rule of thumb is that lowering your front end lowers your BB by 1/3 as much, or every 10mm lower in the front gets you about a 1/8" lower BB. I personally think it would be silly to go less than 150mm on the HD, but YMMV.

I've come to the conclusion that the ~13.8" BB is fine for my tastes. I'd rather get the benefits of a stiff long-travel fork and a nice big front tire and an acceptably-medium rear tire than try to get the bike any lower. You just give up too much handling in other areas trying to lower the BB any further.
 

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Laz nailed it. The one difference in our set up I believe is my Sweep is a DLA version. I can drop the fork 30mm in travel with the corresponding reduction in HTA and BB height if needed. To be honest I prefer the higher HTA in all but the steepest climbs where dropping the front is pretty handy.
 

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So tyre choices could be an issue,
so far I am hearing 2.25 nn and neo motos...anyone tried any others with 2.25 in 650? also...Anyone got a bb height with the 2.25 and 650?
Or would it be the same as other 650 conversions...
Most of the people I know running the conversions are on the Ardent Race 2.25. Not a ton of great tire choices for aggressive riding and minimal rim protection for high speed chunk are the biggest issues.
 
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