Sizing vs reach

[cammas]

Not looking to open a can of worms here but here it goes.

So I’m looking to go back to a dual suspension as my current and only ride is a rigid steel hard tail so old school geometry, my last dual suspension was a medium 2018 Giant Anthem 29er. I am now looking for more of trail bike a 29er 130-140mm like a trance or a stumpy not new, probably around 2018 to 2020.

If I look at reach and compare it to my old anthem it puts me onto a large for some brands, now I’m only 173cm tall. My anthem had a reach of 437mm with a 73.5 degree seat angle, to make it comfortable I had to change the factory 70mm stem out for a 90mm, so I guess I’m not an out of the box type of guy. I really prefer the in the bike feel then on the bike if that makes sense.

So with a steeper seat tube angle, should I be looking at something with similar or longer reach?

 

[Tubbsy]

You need to see a doctor.

@beeb

 

[Rorschach]

Paging Dr @beebenson

 

[Ash HT]

What's the STA?

At your height 437mm is way too short.

 

[beeb]

Ooft, there's a lot to unpack in this query. Firstly - what sort of trails do you ride, or are you intending to ride on the new bike? Not so much degree of technicality (ie: amount of roots/rocks) - more are you riding steep hills up and down, or more time on gentle rolling trails and flatter transfers?

Regardless, if you're currently riding an old-school hardtail and your previous dually was a '18 Anthem, whatever you get will be a very different (in feeling and body weight distribution) to ride, and the sizing will be very different to accomodate that.

Starting with the broad-strokes, yes - you will most likely want a much longer reach. (You might already be across all this about to come, but...) Technically you could still run a long like you have previously stem, but 90mm is huuuuuuuuuuuuuuuuuuuuge by today's standards. The old-school long-stem geo was intended to place lots of weight over the front wheel and having good leverage on the steerer for light feeling steering, and having that same long stem provide the directional stability (keep it pointing where you want to go). It works well on flatter, flowy trails and moderate trails with good traction, but (IMO) can be very sketchy when trail conditions becomes loose or chunky. Modern geo is more about making you feel "between the wheels", particularly by getting the front wheel further in front (so you can smack it into things and not get flung OTB). Stems become shorter, and because as head angles get slacker steering starts to feel slower & heavier - you have a short stem so the steering remains quick feeling, but widers handlebars provide the stability. If you were comfortable with longer stems previously, moving to a stem of around 50mm length might feel more natural to you than a 40mm stem, but that's the kind of difference you'll looking at compared to what you ran in the past. If you ran a 90mm stem on the Anthem and felt comfortable, you probably want something roughly 30-40mm longer in reach to accommodate your wingspan (assuming similar stack heights). The wider bars pull you forward a little more too, hence not suggesting 40mm longer reach as a minimum.

Other thoughts about head angle and STA depend on intended usage a fair bit, so I'll hold off on them for now.

I notice your profile says "from the marsh", is that possibly Bacchus Marsh? If so maybe one of our newly liberated regional 'burners might be able to meet up with you and loan a bike for a couple of hours so you can try and get a feel for it. It will feel very different though. Expect more of a lay-the-bike-over-and-carve the corners type handling.

 

[cammas]

Ooft, there's a lot to unpack in this query. Firstly - what sort of trails do you ride, or are you intending to ride on the new bike? Not so much degree of technicality (ie: amount of roots/rocks) - more are you riding steep hills up and down, or more time on gentle rolling trails and flatter transfers?

Regardless, if you're currently riding an old-school hardtail and your previous dually was a '18 Anthem, whatever you get will be a very different (in feeling and body weight distribution) to ride, and the sizing will be very different to accomodate that.

Starting with the broad-strokes, yes - you will most likely want a much longer reach. (You might already be across all this about to come, but...) Technically you could still run a long like you have previously stem, but 90mm is huuuuuuuuuuuuuuuuuuuuge by today's standards. The old-school long-stem geo was intended to place lots of weight over the front wheel and having good leverage on the steerer for light feeling steering, and having that same long stem provide the directional stability (keep it pointing where you want to go). It works well on flatter, flowy trails and moderate trails with good traction, but (IMO) can be very sketchy when trail conditions becomes loose or chunky. Modern geo is more about making you feel "between the wheels", particularly by getting the front wheel further in front (so you can smack it into things and not get flung OTB). Stems become shorter, and because as head angles get slacker steering starts to feel slower & heavier - you have a short stem so the steering remains quick feeling, but widers handlebars provide the stability. If you were comfortable with longer stems previously, moving to a stem of around 50mm length might feel more natural to you than a 40mm stem, but that's the kind of difference you'll looking at compared to what you ran in the past. If you ran a 90mm stem on the Anthem and felt comfortable, you probably want something roughly 30-40mm longer in reach to accommodate your wingspan (assuming similar stack heights). The wider bars pull you forward a little more too, hence not suggesting 40mm longer reach as a minimum.

Other thoughts about head angle and STA depend on intended usage a fair bit, so I'll hold off on them for now.

I notice your profile says "from the marsh", is that possibly Bacchus Marsh? If so maybe one of our newly liberated regional 'burners might be able to meet up with you and loan a bike for a couple of hours so you can try and get a feel for it. It will feel very different though. Expect more of a lay-the-bike-over-and-carve the corners type handling.

Thanks @beeb yep in Bacchus so have access to wide variety of trials I am a bit You Yangs whore and ride most weekends there or Gisborne, when we’re allowed out. As for what style of trails I will be riding, probably cressys is my limit of tech, I quite enjoy Junction but on the rigid and my broke arse body, it’s taking it’s toll.
Here is a shot of my current ride as it was built up for long days of bike packing and gravel grinding so is quite upright and very old school, so no matter what I get will feel completely different

 

[beeb]

Thanks @beeb yep in Bacchus so have access to wide variety of trials I am a bit You Yangs whore and ride most weekends there or Gisborne, when we’re allowed out. As for what style of trails I will be riding, probably cressys is my limit of tech, I quite enjoy Junction but on the rigid and my broke arse body, it’s taking it’s toll.
Here is a shot of my current ride as it was built up for long days of bike packing and gravel grinding so is quite upright and very old school, so no matter what I get will feel completely different
View attachment 380037

Proper response later, but bloody hell that's a pretty bike!

 

[HamboCairns]

That steerer tube though...

 

[Dales Cannon]

Can you get rid on a few duallies owned by others? Way better than relying on crunched numbers.

Hardtail is purty, you still a cadence machine?

 

[cammas]

That steerer tube though...

That’s been trimmed since then its the best picture I’ve got, in all the rest of them it’s dirty ,

 

[cammas]

Can you get rid on a few duallies owned by others? Way better than relying on crunched numbers.

Hardtail is purty, you still a cadence machine?

It’s been a bit hard with lockdown to get a ride on anything and I don’t want to waste time going to look at something, liking it then it doesn’t fit.

My riding buddy Wally and I have a loop on the Kurrajong side of the Youies of 50k’s and aim for around 2.5 hours, it’s a good night when we hit that or 100 in just over 5. We’ve been trying to get out into wombat and lerderderg but it’s still closed plus lockdown isn’t helping as I need to get climbing again.

 

[yuley95]

Don’t confuse reach with top tube length. Very different. The same reach but a steeper seat tube will have you much closer to the bars. Conversely, a longer reach and steeper seat angle could keep you in a similar spot for seated climbing but would also deliver a longer wheelbase and more stable ride.

There is of course a limit to how long you want reach to be. This is an interesting take on sizing

 

[cammas]

Proper response later, but bloody hell that's a pretty bike!

Thanks, I bloody love it! it’s also has dynamo in the front hub for lights and charging my cache battery electronics etc.

 

[moorey]

@cammas, I’m only 45 min away and have various mediums and larges in various travel if you want to sit on any to compare.

 

[beeb]

@cammas, I’m only 45 min away and have various mediums and larges in various travel of you want to sit on any to compare.

I was hoping you'd chime in.

@cammas - get onto this. I'm guessing you probably want a short-mid travel bike, but you'll still be able to get plenty of valuable geo and sizing impressions, even from longer travel bikes or if the build is a bit heavier duty than what you might have planned.

 

[moorey]

I was hoping you'd chime in.

@cammas - get onto this. I'm guessing you probably want a short-mid travel bike, but you'll still be able to get plenty of valuable geo and sizing impressions, even from longer travel bikes or if the build is a bit heavier duty than what you might have planned.

Yeah. Only new bike is Felix’s Revel (large, but he’s only about 173), other than Quinn’s ebike (medium, and she’s maybe 155). Other vary in age and size, but all the numbers are on Geometry Geeks.
Plenty of bush trails on my block to get a real world test as well, @cammas

 

[greendream]

Thanks, I bloody love it! it’s also has dynamo in the front hub for lights and charging my cache battery electronics etc.

now i like even more. noice touch. your body will love the full sus even more.

 

[moorey]

Jumping from those bars to any bike with regular bars is going to feel weird. Have they got like 130-150mm back sweep?

 

[beeb]

Yeah. Only new bike is Felix’s Revel (large, but he’s only about 173), other than Quinn’s ebike (medium, and she’s maybe 155). Other vary in age and size, but all the numbers are on Geometry Geeks.
Plenty of bush trails on my block to get a real world test as well, @cammas

Despite how it appears, I have nothing against older or used bikes, but whenever I'm looking there's never anything I want come up. Then when I've just bought something, finished building and am broke - it's time for @Rusty_68 to list exactly what I've been looking for for several months...

 

[cammas]

Jumping from those bars to any bike with regular bars is going to feel weird. Have they got like 130-150mm back sweep?

45 degree back sweep, 210mm grips and 710mm wide but look wider than they are, riding normal bars do feel weird at first but these are so comfortable and handle surprising well in the rough stuff. Thanks for the offer too and may take you up on the that, I remember reading somewhere in here that you said about going up a size with Norco which is what got thinking about this.