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6mm of chainstay length make any discernible difference?

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6mm of chainstay length make any discernible difference?
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flag bicyclebicyclebike
Posted: Mar 20, 2021 at 19:52 Quote
hi.

I was wondering if 6mm of chainstay length would make any discernible difference as far as "playfulness" is concerned?
flag Snake-Plisskin
Posted: Mar 21, 2021 at 14:46 Quote
Yes. 16.9” is perfect. 17.1” is harder to get the front wheel up.
flag R-M-R
Posted: Mar 21, 2021 at 16:25 Quote
There are many more factors in "playfulness" than chainstay length. If we're talking about a 6 mm adjustment on a given bike (not two different bikes), this is probably at the threshold of what most people could notice.
flag Pigglet13
Posted: Mar 22, 2021 at 0:09 Quote
Define playfulness! If you mean ‘will it make it harder to pop the front up?’ Maybe, maybe not. For that characteristic it’s just about getting your mass to rotate around the rear axle. Bb height, stack, bar height all come into play. I also think seat tube angle/seat position does to some degree as some times you want to lift the front while seated or just off the saddle. You can’t look at one geo value in isolation, they all interact. You’ll probably be able to ride around a 6mm difference by adapting technique even if you did notice a negative impact as it’s a pretty small increase. I’ve got a hardtail with sliding dropouts and I don’t notice 5mm difference but I do notice 10 to 12mm alterations.
If you increase the length of the bike, you can increase the bb height to increase agility yet still have a good level of stability due to being well positioned between the wheels.

If you are asking for yourself then you need to understand your own physiology, where you carry your mass on your body and what geometry attributes work for you as an individual. If you’ve got a massive head or big arms and shoulders or a long torso, you may want a longer ett and /or higher bars than someone of the same height who has a lighter or shorter torso and longer legs. Conversely, big legs and weeny arms and you may want longer chainstays and shorter ett.

I’m a massive believer in bikes being more customisable, especially being able to significantly alter BB height in isolation (not just a high/low flip chip gimmick). It can transform a bike from something that climbs like an XC bike (high bb) into something that descends and corners like it’s on rails (low bb)
I also think we should all be experimenting more with bike set up as the riders mass and it’s position between the axles has such a massive impact on how a bike rides and no two people are the same.



If you are just talking about wheelbase and getting it around corners, then no. You won’t notice 6mm.
flag R-M-R
Posted: Mar 22, 2021 at 10:45 Quote
Pigglet13 wrote:
I’m a massive believer in bikes being more customisable, especially being able to significantly alter BB height in isolation (not just a high/low flip chip gimmick).

This is something I have to wrestle with.

In a sense, bikes are already completely adjustable, you just have to adjust which frame you choose! Almost anything you could want is already available.

If you want all the adjustments in a single frame, to what extent are you willing to accept increases in:

• Cost
• Mass
• Flex, or yet more mass if all the adjustments are designed for zero added flex
• Fasteners to check
• Likelihood of additional creaks
flag Pigglet13
Posted: Mar 23, 2021 at 0:31 Quote
R-M-R wrote:

This is something I have to wrestle with.

In a sense, bikes are already completely adjustable, you just have to adjust which frame you choose! Almost anything you could want is already available.

If you want all the adjustments in a single frame, to what extent are you willing to accept increases in:

• Cost
• Mass
• Flex, or yet more mass if all the adjustments are designed for zero added flex
• Fasteners to check
• Likelihood of additional creaks

I appreciate your comment. Whilst you are right, you can order a frame with pretty much whatever attributes you want now, once you have done so you are stuck with it. Plus not every frame out there is available in every country. By adjustability I mean short head tubes and seat tubes, you can increase stack easily but it’s harder to reduce it etc. Head angle is easy to play with on any bike and on my bike, the BB height is varied by means of a shim in the end of the seat stay. Simple, robust and adds minimal weight and 4 fasteners BUT it allows me to optimise that one bike for multiple disciplines when combined with a firmer spring.
My preferred set up is different to the manufacturers and its resulted in me feeling more at one with this bike than any other in a relatively short time without having to resort to more expensive or drastic alterations.
flag R-M-R
Posted: Mar 23, 2021 at 0:58 Quote
The question wasn't rhetorical, I need to know these things for designing bikes!

• Stack: My observation has been that more people are struggling with too little than too much. We don't see many people opt for flat bars, but there are plenty of people with a tower of spacers and still seeking more. I've directed plenty of people to the ProTaper 3" rise bar. A longer head-tube also makes life easier for frame designers to create sufficient strength in that area.
• Head-tube angle: Yes, that's a place where a big win doesn't have to have huge drawbacks. Even if the bike doesn't have built-in adjustment, spec'ing a huge ZS headset allows room for off-axis ZS or EC headset cups.
• Your bike: If your preferred set-up is different from the stock set-up, was there not a stock set-up that was a better match? What made you choose a bike that wasn't quite right?
flag flickr
Posted: Mar 23, 2021 at 4:53 Quote
Snake-Plisskin wrote:
Yes. 16.9” is perfect. 17.1” is harder to get the front wheel up.

Yeah 16,9 inches is around 430mm which to me seems to be the perfect length for size M bike to be able to get front tire in the air easily, but I can also see how it would be too short for someone riding an XL. Imo all manufacturers should do different sized CS based on bike size like Norco does for example.
flag Pigglet13
Posted: Mar 23, 2021 at 6:22 Quote
R-M-R wrote:
The question wasn't rhetorical, I need to know these things for designing bikes!

• Stack: My observation has been that more people are struggling with too little than too much. We don't see many people opt for flat bars, but there are plenty of people with a tower of spacers and still seeking more. I've directed plenty of people to the ProTaper 3" rise bar. A longer head-tube also makes life easier for frame designers to create sufficient strength in that area.
• Head-tube angle: Yes, that's a place where a big win doesn't have to have huge drawbacks. Even if the bike doesn't have built-in adjustment, spec'ing a huge ZS headset allows room for off-axis ZS or EC headset cups.
• Your bike: If your preferred set-up is different from the stock set-up, was there not a stock set-up that was a better match? What made you choose a bike that wasn't quite right?

Stack: Your observations are interesting in that I have always (for 25 odd years) run my bars significantly higher than was the norm or what at times seems to have been perceived wisdom (all those articles in bike tests saying you need to slam the bars on a 29er to get them to handle). I always seem to end up with my grips around the same height as my saddle in its fully extended position. It has always worked for me and I’ve never had issues with front end washout but I have had issues with the bike feeling very noseheavy at times with it lower where I feel my hands are too close to my hips for maximum manoeuvrability.

My bike: I’d better qualify how I ended up with my bike. It’s going to long winded.....
I’m a naturally tinkerer and over thinker ( Sunday’s ride had me thinking why is the sole of my 5.10s thicker at the heel when it makes it harder to get your heel below the peddle axle when descending???). I’ve always felt that my bikes have never fitted me as well as they could have and not really fully gelled with my riding style. Don’t get me wrong, I’ve had some great bikes and got on very well with them and felt totally confident on them but I couldn’t help thinking they could be improved on, usually in terms of geometry and suspension.

Physiologically I’ve got short relatively slight legs and a long torso which is disproportionately heavy compared to below the waist due to big ish arms and shoulders. Pre droppers I always ran a large bike as I found mediums too short. When droppers came out I struggled with getting a large frame that would fit me with even a 125mm dropper due to my lil legs.
When slackerisers came out I fitted them to all my bikes. It just made them handle better. Then I got s mondraker to try their forward first geo. Another big improvement over old school geo for me. Hmmm, it that’s good will a Geometron be better? Only 1 way to find out. In 2017 I ordered a G16. I went to Bike park wales and demoed one. It felt very different even to my mondraker. The guy who ran the demo for me said I should be on a medium, I wouldn’t fit a large with a 150mm dropper. I was riding unfamiliar trails but mellow flow trails. It felt very fast and planted but a a little sketchy on takeoff and in the air, tending to nosediving. Demo guy says I need to get used to the bike. Ok.
A couple of weeks later my medium G16 turned up. Long story short it was too small and resulted in me having a massive accident at speed. At the time I couldn’t believe it was too small as it was the longest bike I’d owned by some margin but it was. It took another bike to suss this out!

Fast forward a year and I can ride again. There was still nothing other than a pole with such radical geometry but pole and Geometron took slightly different approaches with stack and chainstay lengths. I could replicate pole geo with the Geometron but not the other way around. With the mutators I could try different parameters in one bike.
I spoke at length to a couple of people about my issues with the G16 and was advised at my height I should be on a medium, I may get away with a large but that it would probably be tiring to ride for long.
I ordered s medium G1. It rode very similar to the G16. Nose heavy. Rolling the bars forward helped, I played with head angle, bb height , bar height and got it to ride very well but still the nagging feeling it wasn’t right. Was it too small???

I tried a large G1. Eureka. Complete revelation. Despite going bigger, it’s the most agile bike I’ve owned and I instantly felt 100% at 1 with the bike. But, it’s got so much adjustability, I should see if I can make it better for me.
I prefer 25% sag for my usual all mountain riding whereas stock advise is 30%ish. With the mutators I can run 25%sag without raising the bottom bracket.

If I want to do a ride with a lot of climbing I can raise the bb or if I want to do an uplift day or go to the alps I can lower the bb without effecting suspension. It does make a noticeable difference to the handling.

Why did I choose a G1 over something else?
I believed in the geometry concept and that it would work for me. I liked the idea of a storia tuned for me and designed for the bike (that is also a revelation the traction it offers is amazing). I wanted the adjustability it offered to allow me to optimise the bike for different types of riding and I thought the build quality was superb.

Is it perfect? No, there Are no bottle mounts. Not a deal breaker,a fidlock uni mount gets around it when. I need one.
The rear end doesn’t have enough clearance for anything bigger than a 2.5 tyre. Again not ideal but it’s fine for me.
It’s heavy BUT the superb suspension and geometry go a long way to negating that by making it the most comfortable bike I’ve ever ridden, up, down or on the flat.

Buying one supports a UK company and comes with excellent uk based support.

There you go. A very long winded but comprehensive answer to your question Smile
flag R-M-R
Posted: Mar 23, 2021 at 10:05 Quote
Thank you for that great response.

It's not surprising that off-axis headsets improved your old bikes. The average head-tube angle has dropped a couple of degrees in the past decade, so you were just "correcting" that issue. Similarly unsurprising that you struggled to fit a decent dropper into a frame with adequate reach, as the relationship between reach and seat-tube length has changed dramatically.

Are there further fit and handling changes you want to explore?

Finally, regarding the drop of your shoes' soles: Are you sure the thicker shoe heel makes it difficult to drop your heels? You should be able to put your feet in whatever position your anatomy permits, and the pedal will rotate as necessary; I see no way in which the angle of a shoe's sole determines the angle of the foot. See the photo below, but imagine her shoes had a continuous sole, rather than a separate heel.

photo
flag Pigglet13
Posted: Mar 23, 2021 at 16:04 Quote
Fit and handling: No, I’m 100% happy with the G1 in terms of fit and handling. I get to ride quite a lot of bikes as I service and maintain a lot of my friends bikes which include my old bikes and every time I get on the G1 after riding something else it just feels so right. It’s hard to explain how a bike can climb up stuff comfortably that I can’t do on most other bikes and yet still pop off anything I want it to with minimal weight shift/ body position change. It’s just incredibly balanced and neutral.
After riding mtbs for 30 odd years it’s been a revelation in how a bike can be so competent over varied terrain and yet still be so comfortable. I can throw on a terrain approprate wheelset and alter the bb height and cover the trail riding / all day epics and uplift days with one bike where previously I had two ( a trail bike and an enduro / fr bike) it’s impressive how versatile this bike is.

I’m fully aware that everything is a compromise but one of the reasons I wanted to try a Geometron originally was the potential for it to be be less compromising across multi disciplines/ terrain and once I got the size issue sorted, I’m very impressed with the versatility of the frame.

Taking the hunters anology of ‘ beware of the man with only one gun’ into mtb parlance, I wanted to reduce the amount of bikes I was riding in order to better gel with the ones I wanted to keep/ needed ( when I used to do a
Lot of shooting, I was pretty competent with a browning 425 then got delusions of grandeur and started playing with multiple guns and my clay scores went to poo, a lesson that has stuck). I do have other bikes, I recently built a pipedream moxie hardtail that’s longer than the Geometron ( I went XL then chucked a minus 2 deg Angleset on it to bring it in line with the G1) to see how that felt and despite having a shorter chainstays it’s harder to manual than the g 1, due to the longer front centre. It is however super stable in really sloppy and slippy winter conditions which is Primarily why I built it.

Shoes: yep you are right. Thanks for pointing out a brain fart moment on a public forum! Even so, with the overly thick sole at the heel, your shoe ends up being lower off the back of the peddle than it needs to be and so more likely to clatter something or hit the deck in a bottom out scenario than if the sole at the heel was thinner ( trying to recover some credibility here).
flag R-M-R
Posted: Mar 23, 2021 at 17:44 Quote
Nicolais typically have high pedaling anti-squat and steep seat-tube angles, so there's no reason they can't be efficient trail bikes with fast tires, per your light-duty set-up. That brings up a second issue, though. For context, I've spent time on a large number of bikes and my main bike is a Bird AM9, which has geometry roughly between your M and L Geometrons, but a steeper head-tube angle. Compared to traditional geometry, the AM9 makes tame trails feel rather boring, and I imagine your G1 ratchets up this effect a few notches. Does this create a mismatch in your light-duty set-up between the tires and the geometry, with little to no overlap between situations in which the tires and the geometry are, respectively, the right tools for the job?

Re: manuals. Do both bikes have a 29" rear wheel?

Re: shoes. If that's as bad as your mental lapses get, you're doing well! Continue to enjoy your fabulous taste in footwear, secure in the knowledge it's not harming your ability to drop your heels and get rowdy.

photo
flag Pigglet13
Posted: Mar 24, 2021 at 0:46 Quote
Is the G1 boring on mellow trails?
This is a very subjective topic and I suppose depends on your own riding style and what you do for kicks on a ride. It's also quite difficult to explain and put into context in written form.
I can understand how a bike with too much travel for the terrain can mute trail features to the point they effectively become non existent. Where I live I'm fortunate in that I have 350 meters of elevation via the North Yorkshire moors literally 5 minutes ride from my door. I know that's not much compared to the Alps or the rockies but it's enough to provide 40 minute suffer fest climbs and around 8 minutes of flat out National series downhill track with everything in between and it's about as good as it gets in England.
Prior to the G1 my favourite bike was a pivot switchblade. It was great bike, probably ideal for 90% of the miles I do on a typical ride but it left me under biked on the DH tracks and and when messing about scoping daft new lines in the woods.

For me, the way I have the G1 set-up now it is just as much fun to ride on a typical mellow trail ride as the switchblade was as it's so agile I can pop of even the smallest feature, pick the front wheel up just as easily as on the switchblade and throw it around turns by leaning it further than any other bike I've had. But when I get to the steep and fast stuff though it's like a mini DH bike.
For me, the geometry doesn't make the bike unsuitable for mellow terrain, the suspension COULD and initially for me it did with 30-33% sag but going to a firmer spring and then lowering the BB to preserve geometry changed that. The Storia is an amazing shock, it provides great support to prevent it muting all the trail features and let you pump terrain but as you go faster and hit bigger stuff it just deals with it without feeling harsh. Cake and eat it? Yes, it would appear I can. Without riding one it's very difficult to appreciate what it will be like. For me, I find this bike rides like a MUCH smaller bike than the numbers would suggest hence me not at all getting on with a medium.

The biggest negative of the G1 for me is the weight and that really only manifests itself to the point of being an issue when I put it on my back for a 15 minute hike up some steep rocky paths (it's compounded by being a pretty uncomfortable shape to carry, if it was the same shape as the Switchblade it would be less of an issue) or on really long fire road climbs when I'm out with the XC whippets.

It's not 1 element that makes this bike stand out as so versatile for me, it's the way it all works together. It's such a complete package and if needed to be it would be my 1 and only bike but it isn't and so if I was going on a relatively flat 5 hour moor top loop on a gravel trail or mellow xc ride I would take the moxie with fast XC tyres.
Anywhere with anything fast or interesting it's the G1 with terrain appropriate rubber. I should probably point out that on the G1 I typically run a relatively light carbon wheelset (28 hole LB carbon rims with sapim CX rays) and I have a garage full of tyres as I like to try different stuff and hate feeling I am either dragging around too much tyre or don't have enough grip so I'm probably not typical in that respect. I also appreciate that someone who just goes out, buys a bike and rides it without spending days on cockpit set-up, suspension set-up and geometry tweaks may not feel the advantages of the bike that I do and to be fair, that is a significant portion of my riding mates who's bikes I fettle and is also probably why the Geometron boys ideally want to see everyone in person for a demo ride and set them up on their new bike.

RE MANUALS: yep, both bikes are running 29 rear wheels. I preferer the terrain gobbling characteristics of a 29" wheel so not interested in mullet options. I've not spent the time on set-up on the moxxie I have on the geometron but my gut feel is that with it I've reached my only personal threshold of a a bike thats too big. I'll endeavour to see if I can get it to feel more agile and still climb well when I get chance to spend more time playing. Shortening the chainstays further, swapping and raising the bars are on the to do list.

RE SHOES: they look like the ideal winter option for the flat pedal rider. I'd just need to add purple laces to tie them in with my colour scheme Big Grin
flag R-M-R
Posted: Mar 24, 2021 at 0:57 Quote
It's always nice to hear when someone has found a bike that's so ideal for their needs.

For me, the geometry has been a bigger factor than travel in making mellow trails less exciting. Mind you, that could be because the travel range I've tested could be considered narrower than the geometry range. Difficult to define the realistic boundary conditions for either range.

I'm familiar with EXT products. Running an Arma on my Bird.
flag Pigglet13
Posted: Mar 24, 2021 at 1:41 Quote
R-M-R wrote:
For me, the geometry has been a bigger factor than travel in making mellow trails less exciting. Mind you, that could be because the travel range I've tested could be considered narrower than the geometry range. Difficult to define the realistic boundary conditions for either range.

I suppose it’s a combination really. The G1 feels more engaging on mellow terrain than hardtail at the moment despite having 160mm of rear travel. So that’s down to geometry. Back in 2001i bought a Santa Cruz Bullet with 5th element shock that was supposed to be the first true all mountain full susser that would rip the downhills and climb really well too. I drank the cool aid, it was a tank. I dragged it around for 2 years and went back to a hardtail. That thing ruined mellow trails with its suspension.
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