Rise H30 and H15 Geometry

[ionut.holbia]

Hi all,

I am interested in buying the Rise H30 and install myself an 150mm travel fork.
When I checked the geometry numbers on the Orbea website I saw that the only change in geometry between the H30 and H15 is higher BB, haft of degree in head and seat angle.
What is interesting to me is that when you put the geometry numbers of the H30 in a bike geometry calculator and change the travel to 150 a lot of other numbers change like the reach decreases by almost 10mm.
Do they use any offset bushing on the stock bikes with 150mm travel to keep the same reach numbers?

 

[mark.ai]

I don’t think they change the headset in any way.

10mm change to reach sounds wrong, as most of the 10mm change in fork height will be vertical.

Note that changing sag can have the same or more effect. E.g. 25% sag on 140mm fork is 35mm, and 30% sag on 150mm fork is 45mm.

 

[mark.ai]

Lowering your handlebar riser height by 10mm should pretty much account for the cockpit change. Or change the stem spacers from the standard 20mm to 10mm.

 

[thewrx]

its pretty conservative geo's stock, wouldn't think it would make much of difference; but I would match my rear travel with front, and adjust geo with headset cup or other ways.

 

[R081N]

I got the H30 (marzocchi bomber) and when I measure it's 150mm, despite the spec chart saying that it's 140

 

[Shjay]

The H30 & M20 both come with 140mm forks, which gives a 336mm BB height & 66 head angle, I am running my M20 at 160mm & keeping rear at 140! Most of the bikes I have owned & built have all had more travel on front than rear, Ibis, Transition. Evil & Santa Cruz all do this with their bikes!!

 

[ebsocalmtb]

Hi all,

I am interested in buying the Rise H30 and install myself an 150mm travel fork.
When I checked the geometry numbers on the Orbea website I saw that the only change in geometry between the H30 and H15 is higher BB, haft of degree in head and seat angle.
What is interesting to me is that when you put the geometry numbers of the H30 in a bike geometry calculator and change the travel to 150 a lot of other numbers change like the reach decreases by almost 10mm.
Do they use any offset bushing on the stock bikes with 150mm travel to keep the same reach numbers?

You are correct that more then just the bb, head tube and seat angle change. Essentially, all of the numbers change slightly, including stack, horizontal tt. Orbea is actually a bit loose with their geo chart. Not as bad as some brands, but the numbers that they post are approximated numbers and a few are rounded liberally... not uncommon in this industry, actually most brands do this.

For example, Orbea lists all of the models to essentially have the same geometry out of the box. This is despite the fact that the all of the forks that they use across the range, have different axle to crown measurements, yet you do not see adjustments to the geo chart for these models:

2022 Fox 36 @ 150mm = 561mm A2C = https://www.ridefox.com/fox17/img/help/page1090-TDOX/2021_Fox_36_29in_USER_SPEC_RevB.jpg
2022 Fox 34 @ 140mm = 554mm A2C - https://www.ridefox.com/fox17/img/help/page1163-9N2F/2022-34-29in-User-Spec.jpg
2022 Marzocchi Bomber Z2 @ 140mm = 561mm A2C https://www.ridefox.com/fox17/img/help/page1163-9N2F/2022-AWL-29in-User-Spec.jpg

I don’t think they change the headset in any way.

10mm change to reach sounds wrong, as most of the 10mm change in fork height will be vertical.

Note that changing sag can have the same or more effect. E.g. 25% sag on 140mm fork is 35mm, and 30% sag on 150mm fork is 45mm.

Any increase in bar height will result in reduced reach. Whether that is done through a longer fork, or headset spacers, or handlebar rise. Some of the adjustments will have a greater impact to the balance of the bike, or weight distribution then others. For example, 10mm more axle to crown will not have the exact same impact as 10mm of spacers or 10mm of additional bar rise. That being said, generally, the impact to your weight distribution is very close to the same. The thing to keep in mind is the difference between adding 10mm fork length, which impacts both the seat tube angle and shortens the reach, vs spacers under the stem which is just going to shorten the reach. Either way, less weight on the front, more on the back. Removing spacers under the stem as @mark.ai suggests is a good way to partially correct the geometry changes... that is if you have spacers you can remove.

I got the H30 (marzocchi bomber) and when I measure it's 150mm, despite the spec chart saying that it's 140

Fox forks (as well as rockshox now) do not generally bottom out with the O ring at the top of stanchion (Said another way, bottoming the fork doesn't mean the o-ring is resting against the bottom of the crown). That's not to say that you can't bottom with the wrong setup without enough progression. In that case, you're bottoming out the air spring and crashing into the bottom out bumpers that are in the bottom of the lowers. This is not something that you want to do generally, although a few times certainly won't hurt anything.

I digress, any fox/rockshox fork that is XXX travel, will have about XXX+10mm of stanchion showing +/-. This means that your 140mm marzocchi bomber has about 150mm of stanchion showing, and yet, is still 140mm of usable travel.

 

[hind-corners]

I have been wondering about this. My Z2 measures also close to 150mm(148mm). I also have Fox34 150mm which measures 153mm. This is with same pressure. If the ”bottom” is not real bottom, how do we know when we reach it?

 

[ebsocalmtb]

I have been wondering about this. My Z2 measures also close to 150mm(148mm). I also have Fox34 150mm which measures 153mm. This is with same pressure. If the ”bottom” is not real bottom, how do we know when we reach it?

You know that when the o-ring is within 7-10mm of the crown, that you've bottomed the fork. If you did that without a huge clunk, bang or huge knock into your hands through the handlebars, then you likely have the right amount of volume reducers and progression in the fork.

This starts to go into a greater tuning and subjective rider feel conversation. However, from my pov, when I do something gnarly, screw up a line, land nose heavy from a jump or just generally load the front of the bike in an oh-shit moment... I expect to bottom the fork. If I am riding well, super smooth, not riding super steeps and/or huge jumps, then I'd expect my average every day suspension settings to leave ~10mm of travel on the table.

Everyone has their own preferences and theories on if you should bottom your fork/shock every single ride, so only you can make that choice. However if you are bottoming or near bottoming out the fork and you aren't feeling it... then you're likely in the right spot.

The truth is that a handful off mm of suspension travel won't change how your bike rides/feels, neither will a handful of mm/degress in the geo chart. That's why it's understandable that bike mfg's aren't going overboard on the geo charts and why some people that are designing bikes sorta cringe when the public is laser focused on exact travel or exact geo.

I'll send you down another rabbit hole... if you're twisted up about the exact travel that your fork has, and knowing if you've used it all and bottomed... whatever you do, don't start reading about how total shock/frame travel is measured. Let's just say that very few, almost none of the bikes on the market have exactly the amount of travel listed, but rather it's approximated. Or if it's not approximated, what length of travel are we talking about, wheel travel along it's axle path, or vertical travel?