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Speed balanced geo....Transition

HAB

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,006
Seattle
kidwoo said:
You've ridden the whole package, I haven't. I just have a hard time believing that the climbing aspect of these bikes isn't compromised when we're talking JUST about steering itself.
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That whole deal is basically what my German monstrosity is going for (super steep STA, slack HTA, long reach), and I've ridden it with both a 40 and a 44mm offset fork. 26" wheels in both cases, and same axle-crown/everything else. 40mm stem, 800mm bars.

I'm definitely not going to claim that the shorter offset fork is totally better climbing, but it's at least not way worse. Kinda summarizes my thoughts on climbing on that thing as a whole. It's no XC race bike, but it sucks way less than I thought it might. That's not the point though, it's about going back down, and I like how it does that part.
 
slyfink

slyfink

Turbo Monkey
Sep 16, 2008
9,331
5,087
Ottawa, Canada
What I don't understand is that when I ran a 650b fork with (presumably) greater offset on my 26" bike, the bike felt floppier at low speeds. Now y'all are telling me that shorter offset will result in floppier low speed handling? Does not compute (with my experience).

My fork (a 2014 26" Pike) had to be sent back for warranty work. My mechanic lent me a 2015 650b Float 34. I think they were both 160mm (at least my Pike was). So I'm pretty sure the only difference between the two was the offset. And the 34 was floppier at low speeds. How is it possible that you guys are saying less offset = floppier low speed? If it brings the wheel back under you, wouldn't it make the bike tend to be more "nervous" in steering?
 
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kidwoo

kidwoo

Artisanal Tweet Curator
Aug 25, 2003
42,146
13,340
Squirtin ketchup n' mustard on charred flesh
slyfink said:
What I don't understand is that when I ran a 650b fork with (presumably) greater offset on my 26" bike, the bike felt floppier at low speeds. Now all of your are telling me that shorter offset will result in floppier low speed handling? Does not compute (with my experience).

My fork (a 2014 26" Pike) had to be sent back for warranty work. My mechanic lent me a 2015 650b Float 34. I think they were both 160mm (at least my Pike was). So I'm pretty sure the only difference between the two offset. And the 34 was floppier at low speeds. How is it possible that you guys are saying less offset = floppier low speed? If it brings the wheel back under you, wouldn't it make the bike tend to be more "nervous" in steering?
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Maybe floppier is a bad word. Slower responding? Less snappy? For every calm and stable at the fast end, it's pretty impossible to not go sluggish and slow and low speed end.


Lower offset/greater trail forks with everything else equal are just more calm. They deflect less because there's less leverage on the fork from bumping into the side of things and you get an effectively slower arc when steered.

But that's why they're more stable at speed. They're calmer. But that calmness also causes some sluggishness at low speeds where you want things to be responsive without the magic of high velocity that you'd have descending.

One way to look at it is the extremes. Imagine a fork with a 2ft offset, wheel way out in front of the fork centerline. at 45 degrees, that wheel is by nature further along in the steering arc because it's sticking out so damn much. So you get moar steering effect with less speed because it's already sitting where the no offset fork would have to roll to. Does that make sense?

Something you might have been feeling with the 27.5 fork is an additional 10-15mm AC slacking the bike out a little.

Most of the reason earlier 29ers sucked so hard was that they didn't increase the offset from 26er forks so they handled like pigs. Then everyone just steepened up the bikes which just went down dipshit alley.

But the trailbikes I've had with multiple forks and all 26" wheels, they've been much easier to steer uphill, slow with 65deg headangles going uphill with 27.5 forks on them. I'm talking really really close AC measurements with a 170mm 26 fork vs. a 160mm 27.5 fork where there really isn't much of a difference other than offset.
 
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Gary

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,649
5,562
UK
kidwoo said:
One way to look at it is the extremes. Imagine a fork with a 2ft offset, wheel way out in front of the fork centerline. at 45 degrees, that wheel is by nature further along in the steering arc because it's sticking out so damn much. So you get moar steering effect with less speed because it's already sitting where the no offset fork would have to roll to. Does that make sense?
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Crystal! :drag:

You should definitely consider combining bongshed designz and market the whole new steering system with this guy:

https://www.kickstarter.com/projects/1457425032/pedi-scope-the-periscope-for-your-bicycle?ref=nav_search

PROFIT
 
troy

troy

Turbo Monkey
Dec 3, 2008
1,008
742
So it has basically a dh bike geo. Now let me guess... "it climbs like a goat!!1!!11one!!1eleven!"? LOL
 
slyfink

slyfink

Turbo Monkey
Sep 16, 2008
9,331
5,087
Ottawa, Canada
So... given that I just got a Patrol, and given that this video just popped up indicating that the rest of the Transition line-up will be getting the SBG treatment (https://www.pinkbike.com/news/transition-giddy-up-20-video-bikes.html), I've been thinking about this and trying to figure it all out again.

It's honestly mystifying to me that more offset results in less trail, and therefore "calmer" handling. And so I looked for diagrams that showed one fork with two offset #s superimposed and found this: https://www.pinkbike.com/news/To-The-Point-Rake-and-Trail.html. Which seems to contradict Transition... they are essentially saying slacken the head angle for better high-speed stability, and lets offset the fuck out of our fork to reduce trail and make it quicker handling at low speeds. But from what I gather, Transition is saying that bikes are now really slack, and maybe a bit prone to under-steer as a result. Lowering offset (more trail) makes it "twitchier", which would correct the under-steer, in a sense "balancing" the slacker head angles.

In the end, all I'm trying to do is figure out what to do to reduce something I felt on the trail on my new bike. I found a couple of times that my front wheel was washing out in medium-speed tight-radius chunky turns. I think this is text-book under-steer. I think there's five things I can do to fix this: 1) lower my stem by one spacer; 2) increase sag in my suspension (it's at about 25% now - which seems more than enough); 3) lower tire pressure (it's already as low as I'll go to avoid damage in high speed descents); 4) lessen LSC in fork (though it feels pretty balanced now); and 5) get a fork with less offset, resulting in more trail, twitchier handling, thus correcting the under-steer (this is sort of a stupid option IMO, kind of expensive). I guess I could also throw an angleset in there, increasing HTA, which would also increase trail. Is there an order I should take these things on?
 
djjohnr

djjohnr

Turbo Monkey
Apr 21, 2002
3,017
1,719
Northern California
Hmmm....unless I'm missing something:

- More trail = more stability, less agility
- Slacker HTA = more trail
- Less offset = more trail

They claim the quicker handling is from shortening the wheelbase (by reducing offset).

As far as your front wheel issue, assuming you're otherwise currently happy with your bar level, tire pressure and suspension setup I'd either lower your stem or slacken the head angle; I normally opt for the latter, I prefer bar height to be more of a feel thing.
 
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