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High Alpine Adventure
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Discussion Starter · #1 ·
I have a question for all you folks that ride a Rush. I've been following some of the folks over on the 650b Forum that say the Rush feels pretty good as a B6er. Now if that is the case the front wheel will lift the front end about 3/4" and will slacken the 69degree HT angle a bit.

I have also read of the folks who just remove the swingarm brace and go "Full 650b". In this case there is no real change in Geometry other than a rise in the BB Height (not a bad thing).

What I'm thinking is this, going "Full 650b" and using a Max 130. It would seem to me that the change in Geo would be about like doing a B6'er but you would have the added advantage of having 5" of travel up front and an even higher BB.

So here's my questions;

  • Has anyone put a Max 130 on a Rush and how did it feel?
  • Anyone think removing the Swingarm Brace really causes that much additional rear end flex (also a question for those that have a pre-2007 Rush)?
  • Am I crazy?
 

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I've put a 130 max on my Rush and took it straight back off again, a ride up and down the road and the bike just felt terrible with the front end wanting to flop about all over the place.

Mine is a 2005 Rush so pre-brace, Ive not ridden a post 2007 bike so dont know the differance between the two, however I do feel that the back of my bike could do with some stiffening. I currently run a Hope Pro2 with a bolt up axle to try and stiffen the back of mine a bit.
 

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mnt bike laws of physics
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Agreed, there will be some people who will post that like it, but I like a bike that steers precisely.
I raised the rear (with a longer shock) and have a 650b up front. My HA is now 69.5 with the 110SL. Putting the 130PBR was super sweet for bumps - steering sucked. My HA was about 68.
IMO, the 69.5 HA makes for a perfect ride with the 650b wheel which adds some trail to the geometry over the 26" wheel.
 

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I just had my first ride on my new 2008 Rush SL 5Z (brace removed) yesterday. My old bike was a 2007 Rush 5 (no brace).

I noticed no appreciable difference in the swingarm stiffness with the 2008 vs. the 2007, granted I removed the brace on the 2008 to allow me to run my 650b wheelset front and rear.

I can't comment on the 130mm Max fork as I'm running the 110m on both bikes.
 

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High Alpine Adventure
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Discussion Starter · #5 · (Edited)
yogiprophet said:
IMO, the 69.5 HA makes for a perfect ride with the 650b wheel which adds some trail to the geometry over the 26" wheel.
You're making some sense there Yogi. I can see the trail of the fork changing a bit to be a little more stable because of the larger wheel.

What did you do to the rear end to gain some travel?

I'm still thinking 130 Max. I mean the bike I'm considering replacing it with is a Spez Enduro SL, so the front end slack doesn't concern me too much. The Geo on it is 68 degrees fully extended (Spez Geo Link)
I've read John's 650b thread and he seems to think the B6er Geo works for him, but that's the point, everyone has a little different feel they are looking for.

I guess the best for me might be to go stock 110 650b and then try a larger fork to see how it feels. That's the nice thing about the Leftys are they are real easy to change. :thumbsup:
 

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High Alpine Adventure
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Discussion Starter · #6 · (Edited)
Well I did a "back to back" test this weekend of the 2007 Carbon Rush with both the 110 SL and 130 Max. I'll try to give an objective account of what is admittedly a subjective issue.

First off, I realize the Rush is "designed" as a Marthon XC platform designed around 110mm. Any attempt to move away from that design poses some challenges. I have my reasons for attempting these changes which eventually I'll get into.

As for the box stock Rush, it came with flat bars and was decidedly more XC than Marathon in it's setup. I swapped out the flat bars for a wider 3/4" Salsa Pro-Moto Riser which really helped me feel a little more comfortable on the bike. However, I was still biased too far over the front for my liking.

Don't get me wrong. I race XC and understand the reasoning behind an XC geometry. Being able to pull up on the bars provides needed leverage and power. But what I am attempting to build here is more of a "Marathon Trail Bike".

In 110mm guise the bike has a real solid predictable feel to the handling. It is precise and well mannered. However, the weight bias is toward the front and the capability to handle rough terrain felt a little limited.

Putting on the 130 Max resulted in a geometry that was a little more upright. It's interesting how a 3/4" change can really alter the feel of a bike. I felt less weighted towards the front and generally a little more comfortable for the long haul and rugged descents.

That being said, the front end steering did feel a little more vague. I think the weight bias towards the rear floats the front end a bit. It's interesting because while climbing I didn't feel like the front end was pulling up off the ground. I tend to climb real steep stuff on the nose of the saddle and the bike actually felt a little more balanced in this mode. I also felt out of the saddle stabs climbed better because my weight was more centered. But undeniably the steering does feel less precise.

How bad was it? Well I wouldn't say it "sucked", but it was different and if you like the precision of the 110mm realm, it definitely is not the same. But I was OK with it and actually felt it wasn't much worse than my Enduro.

What did feel good is descending. It seems the vagueness of the steering disappears at speed. So the faster descents were fine and I actually felt more comfortable with the added 3/4" of travel. The same is true if the climbing that your doing is a faster paced smooth roll. While the bike is moving it's fairly stable, but as the speed drops the precision of the steering becomes a bit blurred.

Now, let's talk about "Floppiness". I think this is an interesting concept that I'm still trying to understand a bit. I define floppiness as how quickly the front wheel deviates off the line of travel. If the steering is stable it rolls through directional changes with a similar feel on the bars. If the directional change accelerates as you leave the line of travel, the feel on the bars is of the bike flopping over into the new direction.

I did feel some floppiness out on the road. In other words the steering would somewhat quickly shift when leaving the line of travel. It definitely wasn't as stable. In the dirt it wasn't as pronounced because of the undulating nature of a trail.

I may be wrong on this and I welcome any discussion, but I think floppiness is not necessarily directly tied to Head Angle. Wiki explains it as a combination of Front Trail and Head Angle. With a longer fork you increase the Front Trail and this has an impact on floppiness...

The other way of looking at it is floppiness developes when the fork goes from rotating smoothly parrallel to the CG and instead starts to rotate through the CG. If you increase the Front Trail the line of action of the Fork drops down closer to the CG.

Just a theory on my part, but interesting none the less.

So, where am I with this little experiment? I think I'm going to keep the bike setup as a 130/110. I'm use to a Trail Bike feel and I like the geometry and travel capability a little better with the 130 on it. What I'm trying to accomplish is more suited to this setup. Yes the steering is not as precise, but I can deal with that.

Would I discourage anyone else from going this route? I don't think so. Again, I don't think the bike is "horrendous" with a 130 Max on it. It is different and if you are looking for something that is a little more along the lines of a Marathon Trail Bike, it works fine.

Now what will be interesting and this will be the final piece of the puzzle, is this; I believe going to a 650b will actually lengthen the Front Trail. It will be interesting to see if that has any impact on the steering. I would think Floppiness would increase, but then in the Wiki article they say this...

"The rotational inertia of the front wheel will lessen the severity of the wheel flop effect because it results in opposing torque being required to initiate or accelerate changing the direction of the front wheel."

Since a 650b has more rotational inertia than a 26" wheel I wonder what the impact will be?

Give me a month and I should have an answer! :thumbsup:
 

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Floppy...

Nice review DaGoat. I run a 130 Max Carbon on my Rush and it really isn't doom and gloom and the end of the world. I run a short stem and don't really suffer from floppiness :blush: It's a great trail setup and if you're not interested in racing/marathons then it really isn't that much of an issue.

I just ride and don't over-analyze :p

Nice looking Rush BTW.
 

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High Alpine Adventure
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Discussion Starter · #8 ·
Dibbs_ said:
I just ride and don't over-analyze :p .
Yeah Dibbs, I hear ya, in the end it's all about having fun. I am trying to help give people some perspective, since many don't have the resources or the gumption to try it.

I had a 130Max PBR on the 29er so it was pretty easy to play around with it. It will be interesting to get the 650b's on it and see how it feels.

I'm running a 120mmX5degree quill. What do you have set up?

Also, I failed to note above that I gained a 1/4" of BB clearence. Went from 12.5" to 12.75". I'm thinking the 650b's should add at least another 1/2" so that will be an improvement as well for BB clearence.

I'm gonna call this little project the "Rush B54"... :thumbsup:
 

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High Alpine Adventure
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Discussion Starter · #9 ·
Well folks... I've been riding around a bit on the Rush 54 and thought I'd provide some more feedback on climbing with a 130 Max. This setup has some interesting characteristics especially in more rugged terrain. As I mentioned above, the steering has lightened some with the added fork length and I believe it has a lot to do with a more rearward weight bias.

There are pros and cons to the 130 Max setup. These center around two aspects of the steering; the lighter feel and the "floppiness" we discussed. The pros are that the bike climbs technical terrain a bit better in that I can loft the front wheel up onto ledges and through rocky sections a little easier. Basically a slight pull and crank throw and you're up and over. The other positive aspect is that the somewhat floppy feel actually allows me to adjust my line quicker. The bike really reacts to changes in direction and I'm noticing that I can adjust to the terrain on a moments notice.

These "pros" have some "con" to them though. The bike is not as stable steering so when you do launch the front end to clear stuff, you have to be focused on controlling its response when it sets back down. I've found myself a couple times manualing up onto a techy ledge only to gain a foothold and have the bike flop into a new direction throwing me off balance. Gotta be careful with exagerating the steering inputs when the front end is light.

So I'd put it this way; the steering is not as stable, but is actually more responsive if not over responsive because of the increased floppiness of the setup.. The feeling on the bars is a bit vague and not as connected with the trail because of a more rearward weight bias.

Anyway, I've got the 650b wheelset being built up to put on it and test out. Should have it ready in a week or so. I plan to try it out with the 130 Max and then go back to the 110 Speed to see how both of those feel with the B Wheelset.

Right now in the project, I'm begiining to think that maybe Lloyd has the right idea with a 120 Ultra...

http://forums.mtbr.com/showthread.php?p=7583666#poststop

And I know some will question whether 10mm of fork travel is going to make much difference. I've been surprised by the impact of an additional 20mm, so I'd say yea it will be different from the stock 110, but we'll see how it all sorts out... :thumbsup:
 

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High Alpine Adventure
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Discussion Starter · #10 ·
Well, like all good things in the whirld of 650b, it sometimes takes a little bit of work. Finally got my wheelset built by Dan Swinton at Bikeworks in Albq, NM. I bought a set of AC 650BXC from Bikebling and for the price you actually get the new 2011 version. Just so you know.

I wanted to swap a Lefty Front Hub and a DT Swiss Rear Hub for the AC Hubs. The reason was to run a Lefty I needed the front done and I wanted to run the RWS 10mm rear axel and that is only an option on the DT Swiss. Now I thought it would be a simple swap, but turns out the hub flange diameters are different between the AC's and the DT/Lefty.

So we had to find spokes, and yeah, that can be a challenge. But Dan got 'er done and I couldn't be happier with the result. Cost a bit more than I was expecting, but I think it will work out well. Stiff and fairly light.

Now the issue is waiting for the Schwalbe 650b Tires. Seems they have redesigned those this year to make them "Tubeless Ready" and they won't be in stock until mid-February. All old stock is sold out. So I'm in the queue, but not quite ready to test yet.

Stay tuned.... :thumbsup:
 

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High Alpine Adventure
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Discussion Starter · #11 ·
More 130 Max Thoughts...

I've been riding around for some time now on the 130 Max and I wanted to give folks some more feedback. I've decided that the 130 Max is not what I would call ideal. At first I liked the more trail oriented riding position and the extra travel on the descents. I was willing to live with the quickness and vagueness of the steering during the climbs.

However, after riding it for some time, that trait is starting to bug me. I find I lose my line at times on the climbs because the front end is so loose and I'm not sure I'm a fan at this point.

I'm going to keep the 130 Max on there for now so I can test it with the 650b wheelset, but as Yogi and others have pointed out, the 650b's will increase the trail and make the floppiness even worse.

I plan to test it a bit when I get the wheels ready and will then probably go back to the 110mm fork.

My 2 cents at this point... ;)
 

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Ridin' dirty!
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DaGoat said:
I've been riding around for some time now on the 130 Max and I wanted to give folks some more feedback. I've decided that the 130 Max is not what I would call ideal. At first I liked the more trail oriented riding position and the extra travel on the descents. I was willing to live with the quickness and vagueness of the steering during the climbs.

However, after riding it for some time, that trait is starting to bug me. I find I lose my line at times on the climbs because the front end is so loose and I'm not sure I'm a fan at this point.

I'm going to keep the 130 Max on there for now so I can test it with the 650b wheelset, but as Yogi and others have pointed out, the 650b's will increase the trail and make the floppiness even worse.

I plan to test it a bit when I get the wheels ready and will then probably go back to the 110mm fork.

My 2 cents at this point... ;)
That's what I did too.
I just kept my Lefty max carbon uppers and swapped the lowers and the guts.
110 feels so much better and compared to my SPV guts the DLR2 is Cadillac smooth.... :D
 

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High Alpine Adventure
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Discussion Starter · #13 ·
cdalemaniac said:
That's what I did too.
I just kept my Lefty max carbon uppers and swapped the lowers and the guts.
110 feels so much better and compared to my SPV guts the DLR2 is Cadillac smooth.... :D
Yeah and now that Craig will upgrade the cartridge to the 2011 internals, I think I'll probably get my spare Speed 110mm done while I'm waiting. :thumbsup:

Still not sure what the 120 Ultra would feel like though... might be the happy medium and Lloyd seems to like his. Lloyd, ya out there?
 

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High Alpine Adventure
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Discussion Starter · #15 ·
'Bout time!

Yeah, it took a while... a busted crank and waiting on tires, but it's finally done and ready for a race. 12Hrs of Phil's ought to put it through it's paces.... 25lbs 6oz as it sits.

Yogi was right, the larger wheel definitely impacts the trail and therefore the "floppiness". I wouldn't want to run a 130 on this thing as a 650b. I can definitely feel the floppiness even with the 110. So I think I'll leave well enough alone.

It does feel like a different bike though with the larger wheels... and the BB height right at 13 1/4"... tough to describe but give me a few laps and I'll get some thoughts together. It will be interesting to see how it handles Rib Cage and Vertebra.... gonna be fun! :thumbsup:
 

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mnt bike laws of physics
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Sweet lookin' bike.

Damn that looks tight. Are you going to file those tabs a bit Doug?

Have fun riding your new rig this weekend....I wish I was going.
 

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High Alpine Adventure
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Discussion Starter · #17 ·
yogiprophet said:
Damn that looks tight. Are you going to file those tabs a bit Doug?

Have fun riding your new rig this weekend....I wish I was going.
They'll probably get "sanded" down a bit this weekend... There's actually a little more room there than the picture shows because of the angle.... but it is a little tight. I think I'll eventually grind them down.

Yep, Phil's is a blast... I can't wait to get out there on this thing! I'll let ya know how it goes.
 

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Good looking bike, (I have an 09 white/green version) and might entertain 650.

It looks like the rear swingarm brace could be installed on the backside with a little work, I just looked at mine and I am not seeing any problems that some careful grinding and quality machine bolt/nut could not fix.

Is your frame an XL?

Good luck in the race!
 

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High Alpine Adventure
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Discussion Starter · #19 ·
ASI CA said:
It looks like the rear swingarm brace could be installed on the backside with a little work, I just looked at mine and I am not seeing any problems that some careful grinding and quality machine bolt/nut could not fix.

Is your frame an XL?
Hey Asi... no it's a Large. At 6'0" - 34" inseam and a 35-36 arm reach I could probably go with an XL, but I want to keep the bike light so the Large works.

I have the 120mm-5 degree stem and am probably going to put a Bontrager XXX carbon seat post on it (~150grs). I figure ditching the Thomson will be good for a 100grs. and the XXX comes in a 20mm offset version. That should give me just a little better reach to the bars.

As for the brace, I never thought about putting it on the back side. You're right, a little precision with a dramel and you could probably bevel the front side a bit for clearance and establish flats on the back side to mount the brace.

I'm not sure what it would buy ya though. As mine has the 10mm rear axle it is pretty stiff, but they must have thought the brace was good for something and who are we to argue with Pro-Engineer!

As for the clearence to the tabs, I didn't have any issues this weekend with rocks or anything getting caught between the tire and the tabs. If it was muddy it might be an issue.

The only thing I did find out is when you bottom out the shock the tire does touch ever so lightly on the back of the seat tube. But it is so light it doesn't cause the tire to even deform. I did hear something back there on some of the big air associated with Rib Cage and Vertebra, but it didn't do anything to the bike and I only noticed it when I looked at the back of the tube and saw a very light rub mark.

I might see what needs to be done to reduce the shock travel by about 10mm. That should fix it.
 

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High Alpine Adventure
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Discussion Starter · #20 · (Edited)
The Ultimate Phil's Whirld Weapon!

Well.... what can I say. I now know why they call the 650b the "Goldilocks Wheelset". It truly does display the characteristics of a 26" wheel and a 29er. The thing that is cool is it takes the best of both and puts them together into a unique package without any of the bad characteristics. It isn't so much a "compromise" as it is a perfect storm!

I've been riding 29ers for quite sometime and although I love the feel on undulating terrain, I aways felt that the big wheel worked me too hard on the long sustained climbs and that the handling was a handful in the really technical terrain trying to swing that big hoop around.

I had read other peoples' experience with the 27.5er and was fortunate to have ridden for a couple miles on a friends Blur LT 650b a while back. I was convinced enough to give it a go and I selected the Dale Rush specifically because it could fit the b-Wheels. The other things that sold me on the platform was the rigidity of the single pivot rear triangle and the solid head and downtube design all in a really light weight package. If it was good enough for Tinker, I'm in!

So I found a bike and this winter started building it, specifically targeting it to Phil's Whirld and the 12Hrs of Mesa Verde. I won't get too deep into what Phil's is like, but trust me when I say it has a bit of everything and at 17 miles is quite the challenge. A HT Carbon 29er like my Orbea Alma is a handful in the whoops and rough stuff. My Racer-X 29er is smoother, but it just doesn't have the handling for navigating through the fast corners up on "Lemon Head" or the tight rock gardens on sections like "Tuffy's Rim". So I just felt the 650b might be a good way to go.

I wasn't disappointed. Although I didn't crack my personal best out there, the b-Rush Bike was the most comfortable rig I have ever attacked Phil's on. It really shined on all sections of that track.

So what's so great about it? It handles like a 26er when it comes to maneuvering through tight rock sections. The front end is light enough to pop easily up onto a ledge and with the shallower angle of attack it does roll easier over stuff. As easy as a 29er? Pretty simiar but obviously not as smooth. But what you gain in agility I will gladly trade off some smoothness.

It corners with the traction of a 29er, but again maybe not quite as hooked up. However, it also doesn't widen your apex and in the tight highspeed middle-ring corners that Phil's is so famous for, I'll take a little less traction and a tighter turning radius!

So how about climbing? Got the added traction from the longer contact patch and the lighter wheel was much easier to spin compared to my 29er. It builds momentum in a similar manner, but is a lot snappier when it comes to having to hammer up a tech section.

Bottom line is the 650b has a lot of the great characteristics of both the 26er and the 29er and none of the nasty side effects. It truly is the Goldilocks Wheelset... I ate the porridge and will never look back!

Mark my words, with the racing community beginning to take hold of the 650b, the manufacturers are going to have a hard time keeping the b-Wheel down. And believe me they are trying. They don't want to see these different wheel sizes because it messes with their profit margins.... they do try to keep things homogenized! But I look at wheel sizes like bike sizes.... ride the size that fits you, not what the manuffacturers think you need.

I talked to the Factory Trek guys there at Phil's and they have NO PLANS to market a 650b bike. Then right after that the Rep told me he wanted to take one of Travis's 69er's and throw a 650b in the back....

They'll come around! :thumbsup:
 
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