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If you add more stack and reach you will find that front wheel grip will suffer. Can’t increase those without increasing rear center to account for the shift of COG
My bike (Nicolai G1) geo:
HA: ~62.5º
SA: ~78º
R: 510mm
WB: 1349mm
CS: 474mm
FC:RC 1.85
Handlebar height: 113cm (used to run 107cm for years)
I've run this same bike with 442mm, 453mm and 462mm chainstays.
My current setup offers the most front end grip and is the easier to corner. I would love to try 500mm chainstays and see how the bike would handle with FC:RC 1.75.
I have found that the longer the chainstays the more stack you can run and still have loads of front end grip. Long chainstays also allow me to climb steep stuff without the front lifting and without needing to shift your weight forward.
So I think longer sizes need longer chainstays and 450mm isn't enough. Also BB heights should be higher in general especially as bikes have gotten longer. Also seat tube angles should be steeper on the larger sizes and not the other way around.
The Be More Bikes guy aparantly is making an enduro bike with a 520mm reach and 503-533 chainstays, built around his weird stem. Might want to hit him up to see if he needs test riders.
I know that the front wheel grip would not be as high, but I still feel I could ride the bike better despite that given a better body position. I'm designing my own bikes, currently, and I'm working on a high single pivot enduro with a 500mm reach, 640ish stack, 20mm bb drop, 445mm static stays, 20mm of rear ward growth, 63.5 degree head angle 180mm fork. This is going to be a race bike for myself, so I am going with longer chainstays than I usually prefer for casual riding to maximize my cornering grip. Same thing with the DH bike I'm working on, 445 static, but almost 30mm of rear ward movement. Trail bikes though, I like them a bit shorter, 435 with a 480ish reach, for a more playful ride. Horses for courses you know? I know my preferences aren't everyone's, but as a community we shouldn't have too narrow a view of what makes a good bike. It's why some people refuse to ride anything other than a basic horst link bike like they're objectively the best, but there isn't an objectively best suspension platform.
His enduro bike, the one that was stolen, has 445 reach with those chainstays and a 180mm head tube. It's the trail bike that has that reach with super short chainstays.
I read that the Enduro had a 520mm reach too, might have been reported wrong where I read it.
I'm kind of surprised that someone hasn't tried making a brand that has a highly adjustable frame in a few sizes (maybe a few years ago, not in today's economy). Something like what GG was doing with headset adjustment for reach (say +/-5mm) andhead angle (whatever +/- angle sets exist), as well as a suspension link adjustment for progression/rear length (another +/- 2-5mm). Then you could have 3-4 sizes but still cover a wide range of rider size and use cases.
Geometron?
My last bike was a Large Megatower v1 with cascade link and long cs position resulting in ~1.75 fc/rc and that gave a lot of confidence when cornering. I ended up choosing to ride that bike at bike parks more than the large RAAW Yalla! that I also had at the time because it felt easier to ride. I had a -10mm headset installed and long cs setting on a large which gives something like 1.85 fc/rc.
Now riding a medium frameworks enduro with 1.80 Fc/rc and I can’t help but think I still prefer the Megatower haha.
Also tried to keep bar height above the ground (approx. 110.5cm to center of bar) similar between each of these bikes but not sure if that’s super relevant given the varying bb heights and fork travel so may need to reconsider that as an appropriate metric.
i have modified my stumpy evo to go from a 1.85 to a 1.75 (approximate, will measure later...) and the difference is huge. I would not have kept this bike if I wasn't able to get it to turn the way I wanted it to. Its amazing that I was able to bolt on the XL seat stay to give me a 453 CS measurement. Honestly I just got lucky this was an available solution, otherwise I would be on a Madonna V3 (a better bike, but it would have cost me a lot of $$$ to switch frames.) I can see how you could like it more than a DH bike, I feel like my stevo feels like a DH bike with the fcrc more balanced. I can really ride the piss out of the thing, and since I can ride it more balanced I feel so much more dynamic and in control. I wish everyone could like their bike's handling this much!
I was quoting the geo from the Vital interview.
Nicolai/Geometron G1 has all the adjustability you need, version 2024 even more so.
being tall (6'2") has its challenges.... it sure is inspiring reading all the stoke from balanced rides!! Still trying to figure out how to pull it off. Right now its between Forbidden 1.78 (too short or slightly too long between S3 and S4) and a slightly small Raaw Madonna V3 XL rear mated to L front for 1.8.
I CRAVE for a more balanced feeling and more weight over the front. Higher stack too.
Depending on your wheel setup on the forbidden you can go +/-10 on the RC
You can go +/- 5 RC on the raaw as well.
From September I'm gonna be able to play around with geo and balance etc. Should I go the route of multiple rear ends, maintaining the distance between axle and chainstay/seatstay pivot, or modular dropouts? I could go crazy with it and do modular BB mounting?
What brands will sell you chainstays or seat stays from different sizes as stand alone items? I tried buying an XL seat stay for my large Yalla! and RAAW would not sell one to me.
I would be full 29. I think im solid with the porportions... its the lower stack plus too small of reach on L but XL to me is getting pretty massive. Decently long reach(+20 from what I'm on now) and massive wheelbase(Longer than my DH bike). It could be solid. I need to straddle one someday to see.
The solid proportions on the Raaw are with XL rear with the +5 chainstay. It is awesome they have the adjustability.
Dang, really?! Thats what I was going to try to do for a Madonna V3. They seemed like they would sell one in email... kind of vague about it though so sent a very clear email back asking and havent heard back yet... hoping its possible....!
"Hi there,
My email back is specifically about purchase of different size. We shall see...
Haha dang you got a better response than I did.
Hopefully they will let you do it.
“Hi Jeff,
I think you just have to purchase it separately. Maybe don’t tell them what size front triangle you have?
I bought my cl stumpy Evo seat stay from a speci shop. They just ordered it as a replacement part.
If the Raaw option is available that sounds like the way to go (and I might have to copy you on that!!)
The Madonna V3 you can already +-5mm RC with the different axle kits.
So you can run a 455 RC on the size Large with a different axle (instead of the standard 450), you'd only need the. XL rear triangle to run a 460 RC.
V3 Large with 455 RC gives you a 1.83 ratio which I would say is pretty balanced for a bike like that. Flat corners won't be amazing but itll work amazing in the steps.
All frame sizes come with the rear wheel axle in the mid position. For S and M size frames that’s 445 mm, L is 450 mm, and XL and XXL frames are 455 mm. From there, the chainstay length can be adjusted to 5 mm shorter or longer with separate rear wheel axle kits.
One variable we haven’t discussed here is the ratio as it relates to mx vs. full 29. I have a feeling 1.8-1.8? Is ok with 29, but it seems like MX likes that 1.7-1.7? ratio.
Anyone have experience with this?
I am fairly sure I prefer longer stays than what most brands offer currently. Of course, that’s because I ride XXL’s and am 6’5” with long legs. I can’t say I know for sure, because I have never been able to try a bike with front:rear ratios like the M L sizes have.
I think proportional Is the way to go, or at least a lot closer to proportional than we currently have.
Sure, some people need or want shorter or longer, even at the same body height. But, offering (nearly) proportional ratios of front to rear length for a certain bike would allow you to choose a bike that matches your preferences, regardless of your size.
As a tall rider, I also want taller stack. Just to get my bars level with my saddle (common for smaller bike sizes) on my S6 Stumpy Evo I have 35mm spacers, a riser stem and 70mm riser bars.
Again, while some people want their bars high, and others low, starting with proportional scaling gives individual riders the choice. Currently small riders can’t get a really low position, and tall riders can never get a very high handlebar.
Proportional scaling for stack gets really hard with 29 inch wheels on the small side, even on xc bikes running 100mm forks. Having your saddle level with your bars isn't a great indicator of fit either, since it doesn't say anything about your hip handle and hip impingement while pedaling. I'm on the taller side, 6'1 32 inch inseam, and I have always ridden with my saddle higher than my bars because I really like an aggressive seated position on the bike, chest low and forward. Recently, I've been really bringing up my stack height, currently on 35mm of spacers, 3° rise 40mm stem, and 35mm rise bars on an over forked L Norco Sight, and it's been an adjustment for me to ride seated since it's so much higher than it used to be, but my saddle is still about an inch above my bars. My descending is way better now and I feel stronger. Next step is getting some higher rise bars, 40-50 mm, and actually going narrower, from 800mm to 780 or so. There's a good chance I'll go to a 50mm stem again too, to bring the bar a bit forward.
I'm lucky since I have a lot of options to raise myself up, but smaller riders aren't. There are a lot of bikes I work on where the rider has bars that sit well above their saddle slammed to the head tube with a flat bar (riders 5'5 and shorter) and they just don't have nearly as much room to move around on the bike. We focus a lot on the tall side of the spectrum when talking about geo, but not nearly as much for the shorties.
Some complaints about geometry are due to a lack of understanding of packaging constraints. I’m still curious about how these bike designers honestly feel about the compromises between sizes…
My Kavenz has a 1.8 front center/rear center ratio. I’ve also ridden the same bike set up with a 1.93 ratio. The handling characteristics between the two setups is stark. Not as noticeable when it’s super steep but the 1.8 ratio corners way better. Front wheel grip is massively better in flatter corners. The 1.8 ratio setup is also more forgiving of body position and easier to ride fast. I’m firmly in the long chainstay gang at this point.
My bike has a 460mm reach, 718mm stack, 525mm chainstays, 1334mm wheelbase, ~1.55 front center/rear center ratio. AMA
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