Just thought folks might like to see the first FS 650b bike I've done - this was finished about a month ago for my friend Martin, who is really happy with it. Ventana 650b specific rear end (~435mm chainstays), Notubes 355 rims/DT hubs, lots of fancy XT (brakes, cranks, derailleur) and XTR (shifters, pedals, derailleur) and 4" front and rear suspension provided by Fox (at bottomout with no air in the chamber, the F100 fork crown just barely clears the tops of the knobs on the Neo-Moto). The frame is True Temper OX Platinum and weighs about 6 pounds with the RP23.
The whole bike weighs about 26.5 pounds with the big 2.3 tires, and would probably be close to a pound lighter with the newer 2.0s, but those big guys are just too much fun so he has no immediate plans to swap.
I haven't personally ridden the bike, as it's unfortunately WAY too small for me, but Martin assures me that he notices a significant difference between his old 26" wheels and the 650b setup.
In any case, kudos to Ventana for jumping in with both feet and making this rear end. The lateral stiffness on the quad bearing setup is awesome, IMO, and it's much better than futzing around with a 29er rear end or trying to stuff the wheel into a 26" setup.
It sure is nice to see an XC 650B FS bike. I noticed you shortened up the head tube a bit like a 29er. Well done. Can we get some geometry for that baby?
Here are the basics (all numbers are without sag)
Toptube: 56cm (22") effective
HT: 70.5 degrees, 90mm long
ST: 73.5 degrees, 42cm center-top
BB: 20mm drop
Chainstays: 435mm
Trail: 85mm
If there's something more esoteric you'd like to know, just aks. It's really just a straightforward XC geometry.
-Walt
Originally Posted by Waterat Pat
It sure is nice to see an XC 650B FS bike. I noticed you shortened up the head tube a bit like a 29er. Well done. Can we get some geometry for that baby?
Just thought folks might like to see the first FS 650b bike I've done - this was finished about a month ago for my friend Martin, who is really happy with it. Ventana 650b specific rear end (~435mm chainstays), Notubes 355 rims/DT hubs, lots of fancy XT (brakes, cranks, derailleur) and XTR (shifters, pedals, derailleur) and 4" front and rear suspension provided by Fox (at bottomout with no air in the chamber, the F100 fork crown just barely clears the tops of the knobs on the Neo-Moto). The frame is True Temper OX Platinum and weighs about 6 pounds with the RP23.
The whole bike weighs about 26.5 pounds with the big 2.3 tires, and would probably be close to a pound lighter with the newer 2.0s, but those big guys are just too much fun so he has no immediate plans to swap.
I haven't personally ridden the bike, as it's unfortunately WAY too small for me, but Martin assures me that he notices a significant difference between his old 26" wheels and the 650b setup.
In any case, kudos to Ventana for jumping in with both feet and making this rear end. The lateral stiffness on the quad bearing setup is awesome, IMO, and it's much better than futzing around with a 29er rear end or trying to stuff the wheel into a 26" setup.
-Walt
Awesome bike Walt!
The thing i don't like in Ventana bikes is that the main pivot of the rear end is too low, too close to the BB. A slightly higher pivot would perfectly mate with a Sclumpf Speed Drive, or a Schlumpf Triebwerk or a Truvativ Hammerschmidt.
Walt, what do you think about that? is a higher-main-pivot/Schlumpf (or Hammerschmidt) combo a viable configuration?
I have just such a frame in my shop now, but I screwed up the shock mount position and have to fix it before it sees the light of day. Pivot is about an inch higher than the Ventana standard, for a more rearward/neutral axle path. It's otherwise almost identical geometry to the bike pictured (2cm shorter seat tube being the only difference) - intended to be a travel bike (no derailleurs to worry about when packing) since it's easy to unbolt the rear end and put it into an S&S travel case.
Of course, with this pivot position you cannot use a front derailleur. I may install an ISCG setup to use a Hammerschmidt, or just do a Rohloff.
The unfortunate thing (beyond me realizing *after* powdercoating that the shock mount wasn't right) is that it was for my wife, who has decided full suspension is (in her own words) "for sissies" and no longer wants it. So I'm trying to decide what to do with it now. If anyone is interested in such a bike (at a significant discount), feel free to drop me a line to discuss.
-Walt
PS In general I agree with you on the pivot position on Ventanas, but for lower travel (ie, 4" or less) I've found that the slightly forward axle path doesn't bother me at all. The rear end feels very plush, IMO. I've had rave reviews from customers, as well. Might be a different story for DH or freeride apps, but then again I do a different design for those situations.
Originally Posted by lavolpeeluva
Awesome bike Walt!
The thing i don't like in Ventana bikes is that the main pivot of the rear end is too low, too close to the BB. A slightly higher pivot would perfectly mate with a Sclumpf Speed Drive, or a Schlumpf Triebwerk or a Truvativ Hammerschmidt.
Walt, what do you think about that? is a higher-main-pivot/Schlumpf (or Hammerschmidt) combo a viable configuration?