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Dumb 'New Geometry' question...

rideit

Bob the Builder
Aug 24, 2004
23,067
11,303
In the cleavage of the Tetons
So, I am in a quandary. My current Altitude fits me PERFECTLY with a 40mm stem. I mean perfectly. This is with a 22" TT (horizontal). The new bike's TT (h) clocks in at over 23". Is this standard for the 'new normal' long and slack bikes? Or should I be looking to drop down to a small?
I have already ordered the med, and have limited time to correct it if so...
 

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,541
5,472
UK
All new bikes are an inch or so longer per size. As ultimate stability is in current #Fashion
If you want a bike to fit as usual you will need to go a size smaller.

Check the reach of both tho as seattube angles affect TT length measurements.

Can't you ride the bike in question?
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
How tall are you?
It's pretty easy to think that a bike fits you "perfectly" when you've ridden it for a while, the human body excels at adaptation. Often people will jump on longer bikes and realise it gives them more confidence to go faster, of course there's tradeoffs but I think if you're buying a new bike you may as well embrace new sizing.

If the mfg provides a size chart (vs. height) then I'd probably use that as a rough guide, if they don't provide one then it's probably worth contacting them to ask for their recommendation.

The only reason I'd ignore it and get a smaller size is if you ride really tight trails where the wheelbase would become a limiting factor, I think in terms of physical fit most people adapt well to change when they actually give it a chance (i.e. owning the bike instead of just doing a ride or two).
 

iRider

Turbo Monkey
Apr 5, 2008
5,648
3,089
I think in terms of physical fit most people adapt well to change when they actually give it a chance (i.e. owning the bike instead of just doing a ride or two).
Funny, I had this discussion with friends recently. Should a new bike fit you like a glove or do you need to get used to it? I normally tend to only spend money on a bike if I can see the potential after a test ride. If it feels completely off I would not take the risk as I think I will never be able make it work perfectly, no matter how much others or the press say that it is the second coming of Christ. Maybe I am missing out on performance, but I have been burned before.
One of my friends did argue like you. He thinks you will be able to adapt to new things even if they feel awkward first and ultimately reap the benefits. We came to the conclusion that if you are not sponsored and have limited funds then my approach will let you waste less money, especially in times of changing standards and 80% devaluation of a bike within 3 months.
 

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,541
5,472
UK
How tall are you?
It's pretty easy to think that a bike fits you "perfectly" when you've ridden it for a while, the human body excels at adaptation. Often people will jump on longer bikes and realise it gives them more confidence to go faster, of course there's tradeoffs but I think if you're buying a new bike you may as well embrace new sizing.

If the mfg provides a size chart (vs. height) then I'd probably use that as a rough guide, if they don't provide one then it's probably worth contacting them to ask for their recommendation.

The only reason I'd ignore it and get a smaller size is if you ride really tight trails where the wheelbase would become a limiting factor, I think in terms of physical fit most people adapt well to change when they actually give it a chance (i.e. owning the bike instead of just doing a ride or two).

Wow!

Going by your logic... OP might as well jump the queue entirely and go for an XL 29er battleship.

Ever heard of personal preference @Udi ?

*2 years ago that exact same manufacturer's size chart would have given completely different height/sizing advice. While actual geometry hasn't changed very much at all in that time. Sizing chart boundaries have just been moved and true "small" has been removed.
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
Wow!
Going by your logic... OP might as well jump the queue entirely and go for an XL 29er battleship.
Ever heard of personal preference @Udi ?
I think you might have misunderstood my logic, but in fairness I'm still impressed that someone of your vintage is using a computer - so credit where credit is due.


A portrait of Gary and his ride, circa 2017
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,031
5,921
borcester rhymes
don't measure on eTT, especially on a DH bike.

Step 1 is to measure on reach. What's your old reach and what's your new one? If you really want to keep the same geometry, keep the reach as close as possible. Personally, I think adding a little length adds a lot of stability, but I also ride 29ers, so what the fuck do I know?
 

ianjenn

Turbo Monkey
Sep 12, 2006
2,998
702
SLO
Screen Shot 2017-04-16 at 7.49.14 AM.png
don't measure on eTT, especially on a DH bike.

Step 1 is to measure on reach. What's your old reach and what's your new one? If you really want to keep the same geometry, keep the reach as close as possible. Personally, I think adding a little length adds a lot of stability, but I also ride 29ers, so what the fuck do I know?
EVERYTHING.....it's coming get ready.
 

kidwoo

Artisanal Tweet Curator
You need.......................

Bigger wheels: for "stability"
Longer reach: for "stability"
Longer wheelbase: for "stability"
More travel: for "stability"
Wider bars: for "stability"
Shorter stem: for "stability"




"Wtf, I can't turn this damn thing"







Give us a call. We can help.




















Sincerely,

The bike industry














 

Westy

the teste
Nov 22, 2002
54,241
20,022
Sleazattle
You need.......................

Bigger wheels: for "stability"
Longer reach: for "stability"
Longer wheelbase: for "stability"
More travel: for "stability"
Wider bars: for "stability"
Shorter stem: for "stability"




"Wtf, I can't turn this damn thing"

You forgot a step:

Widen, straighten and berm the trail so "stable" bikes can navigate.
 

rockofullr

confused
Jun 11, 2009
7,342
924
East Bay, Cali
Fit?? What's that?

I can "fit" on a bunch of different bikes with different geo and sizes. What you need to do is ride the bike and asses the performance. The goal is to go fast, not to have the same TT length as another bike you liked.
 

FlipSide

Turbo Monkey
Sep 24, 2001
1,376
804
@rideit:

My recent experience: I am 5'7" (170cm) and I am often in-between sizes. I have pretty much always ridden size Small bikes.

My previous bike was a 2013 Pivot Mach5.7c size small (574mm TTH; 389mm Reach) with a 50mm stem. That was a very short reach by today's standard. According to Pivot, I was riding the right size bike, but at the upper end of the small size. I was very comfortable on the bike and it was significantly longer than my previous bike.

My new bike is a Devinci Spartan size medium (605mm TTH; 445mm Reach), with a 50mm stem as well. According to Devinci, I barely fit the Medium and I was quite nervous to buy a Medium without trying it. Basically,I immediately felt super comfortable on the Devinci when I first tried it and I pretty much did not need any adaptation whatsoever. It felt like "my bike" right away. I am still waiting for my 40mm stem I ordered before trying it, but I could have kept the 50mm stem it has now without any problem.

Bottom line: Don't hesitate to go with a long reach. Just make sure the ST length and dropper post length matches your inseam length. I have a friend who recently wanted to upsize to a large, but the seat was too high at full extension so he had to get a Medium instead.

Edit: I just realized this thread dates back from April 2017...
 
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toodles

ridiculously corgi proportioned
Aug 24, 2004
5,480
4,720
Australia
I eliminated several bikes from contention when I was in the market recently for this trait
I kinda feel like manufacturers made crazy big increments when they extended reach on new geo bikes. A lot of bikes got extended by more than an inch/25mm with the new geo, essentially almost jumping a whole size up. Instead of slightly cramped front centres the new options are massive and take quite a bit of getting used to.
 

Electric_City

Torture wrench
Apr 14, 2007
1,993
716
A lot of bikes got extended by more than an inch/25mm with the new geo, essentially almost jumping a whole size up. Instead of slightly cramped front centres the new options are massive and take quite a bit of getting used to.
Word. I had a bike I rode for 15 years and wanted to replace the frame that broke. I found a similar one that was manufactured the same year, but with lesser quality components. The top tube ended up being 3/8" (9mm) shorter and it felt like shit. Point is, a little bit makes a lot of difference.
 

toodles

ridiculously corgi proportioned
Aug 24, 2004
5,480
4,720
Australia
Word. I had a bike I rode for 15 years and wanted to replace the frame that broke. I found a similar one that was manufactured the same year, but with lesser quality components. The top tube ended up being 3/8" (9mm) shorter and it felt like shit. Point is, a little bit makes a lot of difference.
I'm super picky on hand-foot distance for some reason. A 10mm longer top tube is a lot really, what happened in the past couple years is manufacturers jumping whole frame size increments. It makes the bikes nice and long and "safe" but I'd argue they feel less fun to ride and less flickable, at least until you really learn to muscle them around. When I jump from the Kona (450mm reach) to my Scout (432mm) it feels like I'm on a BMX now. It's terrifying to ride down steep stuff till I adapt to the tiny cockpit feel again.
 

slimshady

¡Mira, una ardilla!
I'm super picky on hand-foot distance for some reason. A 10mm longer top tube is a lot really, what happened in the past couple years is manufacturers jumping whole frame size increments. It makes the bikes nice and long and "safe" but I'd argue they feel less fun to ride and less flickable, at least until you really learn to muscle them around. When I jump from the Kona (450mm reach) to my Scout (432mm) it feels like I'm on a BMX now. It's terrifying to ride down steep stuff till I adapt to the tiny cockpit feel again.
I tried the next generation of my Rallón (2014 vs 2016). It has a 5mm longer reach if I recall correctly. If I wasn't broke as fuck I'd seriously consider moving to that generation, even with the whole boost bullshit and stuff. Even when my bike was pretty roomy in the reach department that stupid five millimeter expansion felt like heaven.
 

toodles

ridiculously corgi proportioned
Aug 24, 2004
5,480
4,720
Australia
I tried the next generation of my Rallón (2014 vs 2016). It has a 5mm longer reach if I recall correctly. If I wasn't broke as fuck I'd seriously consider moving to that generation, even with the whole boost bullshit and stuff. Even when my bike was pretty roomy in the reach department that stupid five millimeter expansion felt like heaven.
Have you tried an offset headset? Obviously they're dependant on fork steerer stack height etc, but I offset my medium Gambler forward for about 12 months before getting a Large frame. Just 6 - 10mm of reach is quite a bit.

I'd offset the Scout longer, but I don't have enough steerer available on the fork to do so. Plus the missus has been eyeing it off for herself and I'm using that as an excuse to try and get a 2018/19 Scout as the new ones have 450mm reach.
 

rideit

Bob the Builder
Aug 24, 2004
23,067
11,303
In the cleavage of the Tetons
:happydance:
I tried the next generation of my Rallón (2014 vs 2016). It has a 5mm longer reach if I recall correctly. If I wasn't broke as fuck I'd seriously consider moving to that generation, even with the whole boost bullshit and stuff. Even when my bike was pretty roomy in the reach department that stupid five millimeter expansion felt like heaven.
YEAH, BUT HOW DID IT WHEELIE?:happydance:
 

norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
Wow!

Going by your logic... OP might as well jump the queue entirely and go for an XL 29er battleship.

Ever heard of personal preference @Udi ?

*2 years ago that exact same manufacturer's size chart would have given completely different height/sizing advice. While actual geometry hasn't changed very much at all in that time. Sizing chart boundaries have just been moved and true "small" has been removed.
I didn't know personal preference means you don't like something you haven't tried.

@rideit just find a mate with a bike that has similar size since many new bikes went larger. See how it feels. I hated super long bikes long time ago when the trend was to go shorter but somehow other factors in bike design made me like some of the new longmobiles. Yeah some are too long but not all.
 

norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
What makes you so sure I've not ridden a 29" wheeled juggernaut?
I'm not really interested about you have ridden. I commented on the fact that you suggested that rideit already knows what he prefers despite not trying a longer bike. Personal preference as you responded to Udi only works in your argument if rideit tried a longer bike and knows he won't like it.
 

vincent

Monkey
Aug 22, 2004
180
17
Bromont, Quebec
I tried the next generation of my Rallón (2014 vs 2016). It has a 5mm longer reach if I recall correctly. If I wasn't broke as fuck I'd seriously consider moving to that generation, even with the whole boost bullshit and stuff. Even when my bike was pretty roomy in the reach department that stupid five millimeter expansion felt like heaven.
Maybe the way the bikes were set up was giving you a much more than the additional 5mm reach as many setup changes make a bigger impact on fit than a 5mm change on reach.
It seems crazy but on the exact same bike, you can easily add 20mm of effective reach (horizontal distance from feets to hand) by slightly altering sag, cockpit spacers, bar roll etc. For sure you also impact other aspects of the geometry and bike feel but we all do alter the static geo tables when tuning our ride.
 

slimshady

¡Mira, una ardilla!
Maybe the way the bikes were set up was giving you a much more than the additional 5mm reach as many setup changes make a bigger impact on fit than a 5mm change on reach.
It seems crazy but on the exact same bike, you can easily add 20mm of effective reach (horizontal distance from feets to hand) by slightly altering sag, cockpit spacers, bar roll etc. For sure you also impact other aspects of the geometry and bike feel but we all do alter the static geo tables when tuning our ride.
The new version was from a friend I use to switch bikes and components with pretty often, all in lieu of experimentation and testing. When we switch bikes/components/whatever, we take the necessary time to adjust them to our own morphology and riding style. Given he bought the 2016 Rallón after testing mine and on my on recommendation, we were both driven to confirm if those extra 5mm would make any difference. Hence the back-to-back testing.
 

vincent

Monkey
Aug 22, 2004
180
17
Bromont, Quebec
The new version was from a friend I use to switch bikes and components with pretty often, all in lieu of experimentation and testing. When we switch bikes/components/whatever, we take the necessary time to adjust them to our own morphology and riding style. Given he bought the 2016 Rallón after testing mine and on my on recommendation, we were both driven to confirm if those extra 5mm would make any difference. Hence the back-to-back testing.
I wasn't implying you didn't test well or anything, sorry if it came out like that! My point was that many things alter the perceived reach on a bike other than the actual reach.
Just to illustrate my point with actual numbers;
On a medium 2018 transition patrol with a raceface 35mm rise race face bar.
You can lengthen the effective reach by 6mm with the following small settings changes:
-removing a 5mm spacer under the stem
-running 2% (3mm) less rear wheel sag
-rolling the bar 5 degrees to the front from parallel to head angle

Again, I didn't mean you were not pragmatic in your testing and that you did not feel what you felt, I just wanted to illustrate how 5mm on a geo chart can easily be overridden by actual riding settings.
 
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slimshady

¡Mira, una ardilla!
I wasn't implying you didn't test well or anything, sorry if it came out like that! My point was that many things alter the perceived reach on a bike other than the actual reach.
Just to illustrate my point with actual numbers;
On a medium 2018 transition patrol with a raceface 30mm rise race face bar.
You can lengthen the effective reach by 6mm with the following small settings changes:
-removing a 5mm spacer under the stem
-running 2% (3mm) less rear wheel sag
-rolling the bar 5 degrees to the front from parallel to head angle

Again, I didn't mean you were not pragmatic in your testing and that you did not feel what you felt, I just wanted to illustrate how 5mm on a geo chart can easily be overridden by actual riding settings.
I didn't take your comment badly! Actually, I really appreciate the tips you gave me up there. I just felt I needed to give my previous affirmation a better context.
 

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,541
5,472
UK
I'm not really interested about you have ridden. I commented on the fact that you suggested that rideit already knows what he prefers despite not trying a longer bike. Personal preference as you responded to Udi only works in your argument if rideit tried a longer bike and knows he won't like it.
You're commenting on a comment I made to another commenter about another commenters comment five fucking months back.

Seriously?

I know this place is dying but FFS! surely there must be something moar worth discussing than this.