The new Troy 29er is Amazing!

PB Forum :: Devinci
The new Troy 29er is Amazing!
Author Message
flag freerider11
O+
Posted: Mar 9, 2020 at 6:31 Quote
My understanding is that the shorter offset will slacken things ever so slightly, probably not enough to ever notice, but tucking the front end a little further up underneath also pushes the front end up a bit, does it not?

And not understanding how slackening the HTA with an angleset would steepen the STA? Unless using the angleset the other way around to steepen things? I have 0 experience with angle adjust headsets though so maybe I'm just not understanding how they work...
flag DMal
O+ FL
Posted: Mar 9, 2020 at 6:43 Quote
freerider11 wrote:
Really curious what these mods have done to your STA? I think we may have had this conversation before...

On my Troy with a 150mm 51mm offset fork, I still found the STA to be a little on the slack side. With the 170mm fork, 42mm offset, and an angleset to slacken it even further now, your STA must be super slack. I know you definitely have a priority on descending with this setup (as you should, especially considering where you live!), but man, long steep sustained climbs must be a bit of a chore.

Yeah, I definitely prioritize descending but need a bike that is still fun to pedal around. We have lots of climbing (both technical and non-technical) around here too.

I found the seat angle change to be a non-issue. I can sit and pedal up a sustained climb and don’t get the feeling of the front wheel getting light. And if I get to a steep punch, I move onto the nose of the saddle. My hardtail (Chromag Rootdown) has a very steep seat angle and I maybe need to move onto the nose of my saddle a bit sooner on the Troy, but in contrast the Troy feels roomier on more sustained, gradual climbs whereas the Rootdown can feel cramped. On the Troy, I have the slid the saddle all the way forward, while on the Rootdown, my saddle is slid back.

It might help that I’m riding a large at 5’8” so my seatpost extension is less than for a taller person. Someone taller may end up feeling like they’re hanging off the back of the bike more.

I played around with some numbers, using bikegeo.muha.cc. I started with the stated seat angle for the Troy with 150 mm fork:

150 fork: STA 75.4 deg
160 fork: STA 74.9 deg
170 fork: STA 74.5 deg
170 fork with -1 angleset: 74.8 deg

So I am changing the seat angle within 1 degree over the course of these changes. But for comparison, sliding my saddle forward by 1 cm is equal to about 0.8 degrees of seat angle.
flag DMal
O+ FL
Posted: Mar 9, 2020 at 6:49 Quote
Long of the short, if I lived somewhere with less full-on descending, I’d probably run a 150 fork to take advantage of a steeper seat angle. But things don’t change that much with the 170 fork and sliding the saddle forward.
flag freerider11
O+
Posted: Mar 9, 2020 at 7:02 Quote
Gotcha, thanks for clarifying. Less than a degree in STA change isn't bad. I'm sure the advantages out weigh the negatives. Good job.
flag DMal
O+ FL
Posted: Mar 9, 2020 at 7:10 Quote
freerider11 wrote:
And not understanding how slackening the HTA with an angleset would steepen the STA? Unless using the angleset the other way around to steepen things? I have 0 experience with angle adjust headsets though so maybe I'm just not understanding how they work...

Slackening the head angle by using a Works Components angleset* drops the front end a touch, which pulls the seat angle forward (steeper). This is similar to running a shorter fork in terms of what it does to seat angle.

*The Cane Creek angleset uses an external bottom cup, wheareas the Works headset uses a zero stack bottom cup. As such, the Cane Creek headset does not drop the front end down relative to the stock headset, so the seat angle would likely not be made steeper.
flag freerider11
O+
Posted: Mar 9, 2020 at 7:17 Quote
DMal wrote:
Slackening the head angle by using a Works Components angleset* drops the front end a touch

Did not know this! Good to know.
flag R-M-R
Posted: Mar 9, 2020 at 7:20 Quote
freerider11 wrote:
My understanding is that the shorter offset will slacken things ever so slightly, probably not enough to ever notice, but tucking the front end a little further up underneath also pushes the front end up a bit, does it not?

Yes, in the most literal sense, but we're talking about a change smaller than the tolerance on the head angle, so effectively zero.



freerider11 wrote:
And not understanding how slackening the HTA with an angleset would steepen the STA? Unless using the angleset the other way around to steepen things?

It changes how the fork slots into the frame. Instead of going straight into the middle of the head-tube, it now sits crooked in the head-tube. The fork is laid out closer to horizontal, which allows the front end to drop a bit. The tilts the frame forward, steepening the seat-tube angle. Not a lot, but enough to change the head-tube angle when measured to tenths of a degree.
flag freerider11
O+
Posted: Mar 9, 2020 at 7:24 Quote
Yeah, understood now. Thanks for the explanations guys. Never really considered or thought about angle adjust headsets and how they work. Interesting...
flag R-M-R
Posted: Mar 9, 2020 at 7:31 Quote
Some folks use them to try to turn a bike into something it's not. Some use them to correct goofy stock geometry. There's only one way for people to find out which scenario describes their ideas! Thankfully, it's cheap and reversible. They're a great tool for experimenting with geometry.

They're also a great tool for design teams to prototype new bikes.
flag DMal
O+ FL
Posted: Mar 9, 2020 at 7:46 Quote
I still maintain that I may not have felt the need for an angleset if my bike had a 51 mm offset fork. That said, the short offset fork and slack head angle feels great.

Too bad it would be hard to test my theory. A different fork is a lot more expensive than a headset.
flag R-M-R
Posted: Mar 9, 2020 at 8:10 Quote
It would be an interesting experiment.

You may be looking too closely at front-centre length and not giving enough credit to trail. The difference in trail between your current set-up and the same 170 mm fork with stock head-tube angle with 51 mm offset is roughly 15%, which is a lot. Compared to a stock bike, your current set-up has more low-speed wheel flop and a lot more high-speed stability.

As you noted, it could be expensive to test a different offset and the only thing to gain is satisfied curiousity, since you're happy with the current set-up.
flag Tinshield
O+
Posted: Mar 15, 2020 at 17:46 Quote
So I dropped the Maxxis Forkasters and went back to Bontrager XR4's. The Forkasters are pretty close to the XR4 but the Bonty's have a little bit more bite. Unlike the old ones that had zero clearance, here's what a new 2.4 looks like. Not sure how tall the XR4 2.6 is but it might actually fit.

Bontrager XR4 29 x 2.4 on Devinci Troy

 


Copyright © 2000 - 2024. Pinkbike.com. All rights reserved.
dv42 0.023838
Mobile Version of Website