I realised recently that I, and several of my engineer friends, will build little excel tables comparing bike geometry of potential new bikes, currently owned bikes, just seen on STW classified bikes...
I'll agonise about whether an extra 8mm of reach or 0.5 degrees of head angle will justify a potential new purchase or stop my neck hurting. Or I'll realise I sit right between a manufacturer's height range recommendations, and it'll stress me out.
Is this normal? Do you check geometry before buying, or just say 'I'm a Medium', and buy that?
B
PS apologies to whoever expected maths brain teasers from the title.
you've taken it to level 'nerd'
where's chiefgrooveguru when you need him?
I go by colour, and specialofferness
Only to a small extent.
Recently i found i don't like more than a 67.5 head angle.. but i'm ok with a 69deg too.... but 66, ewwwww.
Reach and length i'm not feeling the ultra modern settings.. but i guess sometimes you get used to things if you have to.
Get on, ride if good get.
For road bikes, yes.
Started off doing this int he 80's.
So actually scribbles and sketches in notebooks, rather than spreadsheets.
For MTB's, not so much. There are far more important things to worry about.
But then i'd not want to buy a gnarcoregravity sled. XC will do me fine.
This. Although now I've found what sort of geometry suits me, I do look for something similar when looking at other bikes. But I still wouldn't buy without riding.mikewsmith - MemberGet on, ride if good get.
The problem is that bikes feel so, so different. Every bike, every manufacturer - the reach could be only a 5mm difference, but with a HA of 0.5 degree different, and 15mm different length stem and a seat tube angle of 0.5 degree different, the whole bike feels far more different than the sum of it's parts vs something else almost identical.
Therefore, imo - people should RIDE bikes more than agonize over numbers, that's the only way to find out if you like a bike, otherwise you might find 'the perfect geometry' bike and actually, it doesn't feel any better than the bike you were just on.
I do this. Got a few bike comparitor spreadsheets.
Starting to realize it makes sod off difference though (and cost me a lot of brass)
I always look at the numbers and I understand a bit about linkage design, but tbh mostly I know enough to know that's not enough to really understand a bike without riding. If only because lots of claimed figures are wrong, and because quite a lot of it goes out the window when you get into suspension behaviour with different shocks and suspension setups. 2 bikes with outwardly similiar numbers can feel very different and I reckon sometimes little changes or hard to observe changes make all the difference.
I think only MBR journalists can truly know everything about a bike by looking at a spreadsheet
people should RIDE bikes more than agonize over numbers, that's the only way to find out if you like a bike, otherwise you might find 'the perfect geometry' bike and actually, it doesn't feel any better than the bike you were just on.
If you only plan to ride it on the internet having the right numbers is enough though 😉
I have absolutely no idea what any of the angles on any of my bikes are at all. I am perfectly comfortable with this.
I don't get into the geekery of geometry or suspension (ok a little on that one, does it boing?) and think like a lot of the comments above, a good sit, does it have good karma and ride ok for me (as opposed for uber fit bike mag whippet) is the only measure that matters isn't it?
Loved the comment from Mike above about riding on the internet, how many bikes only go there and never see the joys of mud I wonder?
James
I have spreadsheets 🙁 yet I have no prospect of getting a new bike anytime soon
I have, in my mind and written down somewhere, my ideal geometry. If something pops up in the classifieds that matches it and I need a new frame, then I'm all over it.
But I am fully aware that my ideal geometry is many years out of date. At some point in the future, when I actually buy a proper new bike, i'll have to forget all that and just get out a demo bikes with an open mind and start again.
So yes, I am a geek, but a well-out-of-date geek.
But the numbers will at the very least give you a short list. If you understand the numbers.Therefore, imo - people should RIDE bikes more than agonize over numbers, that's the only way to find out if you like a bike
But it's NEW. So thats ok.it doesn't feel any better than the bike you were just on.
If you only plan to ride it on the internet having the right numbers is enough though
Forum warriors UNITE! (Fortunately I'm on 4000+km's so far this year)
It's an influencer but not a sole ingredient.
I "bought" a Radon Slide having done a lot of research, it was delivered, I rode it 250m and sent it back.
I rode a Whyte G150, very similar geo, round a car park. Instant fit and bought it. Love it.
Road Bike - Very much so
MTB - Less so
I know the geometry of my previous road bike, and I know that for my particular frequency of riding (infrequently but long rides) it aggravated an existing back issue and gave me a sore neck. So now I'm only looking at bikes with more stack and or less reach.
So long as the MTB is not any more stretched or low than the road bike I'm happy, not interested in gnar and its attendant injuries and breakages any more 😥
people should RIDE bikes more than agonize over numbers, that's the only way to find out if you like a bike, otherwise you might find 'the perfect geometry' bike and actually, it doesn't feel any better than the bike you were just on.
Doesn't work if the difference in geometry only becomes apparent after 5 hours in the saddle, but suspect you were talking more about MTBs.
In terms of angles? Not really. But for my last build I did replicate my old XC bike reach but with a 50mm stem. It has got me to the bike I wanted it to be (i.e. a good all rounder that I can ride in comfort all day, but point down hills and have fun) however it feels massively different to my other (undoubtedly too short for me) bike - and not in an entirely positive way on the downs.
So none of you have drawn out your frame geometry in CAD?..
Nah - hand-drawn sketch. Old-skool 😉
Jon Taylor - Member
So none of you have drawn out your frame geometry in CAD?..
only before making them...
So none of you have drawn out your frame geometry in CAD?..
I have a few of the original drawings of frames that were made for me. But nothing on CAD, mostly A4 (or A3)
I do sometimes, mainly to compare with existing bikes. And trigognometry is fun.
I know the geometry of every one of my road bikes and none of the mtbs. I spend a lot more time standing on an mtb, so geometry is less of an issue. Reach and Stack can be set easily, provided the stem length and saddle setback can be adjusted appropriately.
73 degrees parallel for road, 55.5 cm effective top tube, 110 mm stem. Makes for a perfect handling bike for my completely average dimensions.
If you only plan to ride it on the internet having the right numbers is enough though
😆
Comparing both my HT frames back to back (built up with the same parts) was interesting- one is newer by a couple of years and was marketed as a rowdy hardtail, the older one (by a couple of years) is slacker and a little shorter and when I went back to the original (newer) frame I found it twitchy and too tall and have swapped back over to the slightly older frame. Both are 26" steel HTs.
I suppose looking at numbers on a page is a start for choosing a new bike or frame but it shouldn't stop there.
[swoons]Can tell just by looking at it if it'll be any good[/swoons]
My mind goes blank when I read the geometry figures in magazine bike reviews.
[i]I go by colour,[/i]
I think it's cycleworld.co.uk - the top filter they have when browsing bikes is "colour" Brilliant! 😆
Fussy rather than geeky, I'd say.
sort of, I pay attn to the bits that matter about whether It'll fit me. but suss design and angles I pay less attn to TBH I've ridden single pivot (for instance) that shouldn't be as "good" and multi link bikes that just wipe the floor with them. I do try to ride bikes first, but failed to do that for the last couple I bought, and it was cool.
Yes, I compare all the angles and lengths when I'm looking at a new frame and I have spreadsheets saved showing all of the details. I have similar for component weights. Unfortunately I have no idea what it will really feel like once you put it all together as a bike so test rides are the only way for me.....or in the case of my last two frames order them and hope for the best!
I have just bought a road bike (I had ridden the geometry I finally bought 4 times by the time I paid for it)
My "One Note" page has 15 bike geometries listed 15 bikes in it
It is really hard to find many bikes in XL for me to ride. But if a bike with say 630mm stack felt a bit low until it has had its stem flipped then there isn't much point trying to test ride one with 598mm stack
my engineer friends, will build little excel tables
Imaginary, right?
Jon Taylor - Member
So none of you have drawn out your frame geometry in CAD?..
I have all of my frames laid out in CATIA with fully parameteised sketches which allows for the comparisson of new frames to old frames.
It's how I knew the Trek Stache would be the spiritual successor to my old Chameleon and that a 55.5 Tripster was (despite advice) better for me than the 57cm despite being over 6'.
Jon Taylor - MemberSo none of you have drawn out your frame geometry in CAD?..
No but I have a 3D image rendered in my brain
I'm [s]faster[/s] geekier than you.
I'm usually right too. 😛
When choosing my road bike I wrote some software to calculate and display the geometry of loads of bikes. Also allows me to add spacers, vary stem length, seatpost layback etc.
Was useful. Took a wee bit of time but test rides weren't available on many of the options!
similar thoughts to Northwind. Little changes here and there can make a big difference to how it rides. Also suspension characteristics has a big part too.
I have a quick glance at the numbers to check its roughly in the right ball park but a test ride is what I base my choice on.
I spend a lot more time standing on an mtb, so geometry is less of an issue
Aaarghhhhhh!!!! 😉
I guess I think about BB height/drop, wheelbase, chainstay length, front-centre, reach, stack, seat angle (actual, effective and offset), head angle, suspension sag, suspension behaviour, tyre diameter, stem length (including bar backsweep), bar width and ETT. But I'm an engineer and product designer. If you can actually understand geometry at this level of geekiness and you're not working in a similar field then you should probably consider a career change to better utilise your talents!
Wasn't at all until recently. Then, before getting my new bike, i dabbled a little, got lost and confused and bought a bike i liked the look of (colour, lines, material and suspension design). Only took an interest to begin with as i knew i wanted a bit more room between the seat and bars than my previous bikes.
I didn't like the geo / handling of early 29er "norms", so I made my own frame - does that count?
[quote=13thfloormonk ]Road Bike - Very much so
MTB - Less so
Doesn't work if the difference in geometry only becomes apparent after 5 hours in the saddle, but suspect you were talking more about MTBs.
Some of us ride MTBs for more than 5 hours. 😆
Having ridden a few bikes I went through a few geometry charts to work out what I like best and had Brant build me a frame that matched that.
Jon Taylor - Member
So none of you have drawn out your frame geometry in CAD?..
I would love to do this, but have zero knowledge of CAD. Can anyone recommend a good program for a CAD-newbie to play around with bike geo in?
I tried the online BikeCAD thing, but couldn't get it to run properly on my mac, even with the help of actual IT people.
Sort of ex-geometry geek here. More of a ride-feel geek now, prefer to judge the end result by riding it. If we're talking about welded frames, alu in particular, I think mass-production reality makes worrying about 0.5 degree +/- on paper between 2 bikes seem less important. Also, we can adapt to different geometries really well if we get over the idea of muscle memory familiarity meaning 'right'.
Some of us ride MTBs for more than 5 hours.
Yes yes, what I meant was you could arguably get a feel for an MTB's handling in a 15 minute test ride outside the shop, but if you're buying a road bike for it's (lack of) stack and reach, you'll only really know after five hours on the road and whether your back and neck are hurting. I can get on a slammed racing bike and ride it round the car park and it feels awesome, doesn't tell me much about how it'll feel at the end of a long day.
I've not progressed to the stage of spreadsheet yet but last night was spnt comparing reach, ETT, HA and hedtube of two well known steel hardtail manufacturers on print outs from their respective websites.... 😳
I didn't used to be like this but knowing what I like and what I [i]think[/i] I want has made me this way...
Colour, although vitally important, is definitely secondary. Whilst I want to admire it in all its glory it doesn't really matter when I'm rattling along a tech bit going 'oh shit, oh shit....'
Not a geek but I know what I like, so tend to try & stick to stuff in that relative area.
Here's what I made to play about and help choose my new road bike:
[img] 
[/img]
I do the same thing as robertgray05.
Mainly because the last bike I had was the perfect fit, so when I fancied something new it had to be as close to it as possible, but slacker and longer travel. I had about 15 bike in excel with all the geometries and then scored each component of the geometry, as well as overall. Funnily enough I ended up with another Whyte and it fits like a glove.
With road bikes, is geometry mostly a case of fit or is there much variation in handling too?
I look at the geometry table, then realise head angle is the only one I'm that bothered about, then realise that sag is probably not taken into account in the same way by different manufacturers so just take a punt on things.
Is this normal? Do you check geometry before buying, or just say 'I'm a Medium', and buy that?
Check geo. Always.
How reliable are the published geo's? I know in the ski world, even pretty straightforward measurements like ski length go through the marketing department before being published.
Also, as some have said above, I can make my mtb handle like a POS if I change the setup, so it's all done by feel. I didn't test ride my last new bike, but it's generally well regarded, and was an especially good deal. Is it perfect? Don't know, but it got me through Swiss Epic in good shape and I had lots of fun doing it!
I pay a lot of attention to top-tube length and BB drop - those number make the biggest difference to me.
How reliable are the published geo's
Depends on the manufacturer. There are two issues - sometimes there's a communication issue between the engineers and the marketeers, and with any welded frame there's a certain amount of manufacturing tolerance. On a decent alloy or steel frame you'll have about 0.5 deg tolerance on the head angle but some will be more like 1 deg.
I've measured my Banshee and Bird as best I can and they seem to be very close to the charts, within 0.1 deg or so. Tube lengths should always be pretty bang on and as seat angle and BB drop are constrained by two triangles they should be very close to spec.
Some of my geometry obsession came out here: http://singletrackworld.com/forum/topic/bird-zero-am-review-warning-bicycle-content
The key thing is to know that when it feels right and makes you comfortable and confident then it is right!
I haven't used it but this looked full on geek to me...
[url= http://gearinches.com/blog/misc/bike-geometry-comparator ]comparison tool[/url]
Massive geek, i'll dismiss a well regarded bike on HA alone.
I like to know the angles of what i'm buying first....then i know it'll do the job i want or the type of riding i do....then i can make it fit with little tweaks like bars, stems, seatposts, saddles etc.
Its the main reason i have no interest in a 29er Enduro, didnt Dirt Mag have to fit the 650b linkage, use offset shock bushings and a neg rise stem to get it working as you'd hope a 3k bike would straight from the box?!....bugger that.