Reach, Stack, and general fit on DH bikes

PB Forum :: Downhill
Reach, Stack, and general fit on DH bikes
Author Message
flag Loki87
Posted: Oct 3, 2020 at 9:18 Quote
sdaly wrote:
Am I wrong thinking that top tube lengths only matter for seated position? On a DH bike where you are standing all the time, the number you really should be looking at us reach

For general fit, yes.
Not to forget stack height though, as a very low stack can require you to raise the bars to not feel totally hunched over, which most often happens with spacers and results in an effective reduction of reach. So don´t be surprised when your super long reach feels deceptively average after you´ve slapped a handful of spacers on it.
For most people this isn´t massively important, but if you´re already shopping for numbers, better factor it into the equation as well if possible.
It´s also the reason why comparing two bikes only based on their feel and reach or top tube length is really kinda pointless unless you also adjust for the accompanying factors as well.
flag ybsurf
O+
Posted: Oct 11, 2020 at 15:47 Quote
My pivot phoenix have 611 stack I have a 20mm rise handlebar with a 15mm spacer under stem would it be too low to remove that 15mm spacers? I want to not use any spacer to optimize full reach I guess best way to find out is too try but anybody go that low?
flag sdaly
O+
Posted: Oct 11, 2020 at 16:31 Quote
Nobody knows how big you are, or even what size frame you're riding. That's really a silly question to ask.

Can you do it? Yes
Will it work best for you? Try it, only you will know
flag georgewilsoniv
O+
Posted: Oct 28, 2020 at 23:27 Quote
Complete newb here with a similar question/concern. Went overboard and got myself a Ripmo after not owning a bike for 4 years which at the time was a 6 year old Trek Fuel Ex 5. Needless to say a big upgrade, I'm on a medium Ripmo with a reach of 460. As I've recently moved to Whistler I'm lusting a 2016 Transition TR500 small frame they have on closeout but, am worried as the reach is only 367. Does this seem like something to be concerned about? Has the geometry on DH bikes changed as much as enduro/AM bikes over the last ~6 years or so? I'm 5'5'' so I'm usually on the cusp between small & medium. During the Ibis demo they put me on the medium on 2 different occasions, just concerned the cockpit on a small TR500 will feel small even though I'm enticed at having a smaller DH rig. Thoughts? Comments?
flag kiksy
FL
Posted: Oct 29, 2020 at 0:06 Quote
Here's a direct comparison of geo of Ripmo and Transition.

https://geometrygeeks.bike/compare/ibis-ripmo-2020-medium,transition-tr500-2016-sm/

Personally, more than the reach I'd be concerned about the shorter wheelbase of the Transition, it's way shorter.

It obviously depends on what you want the bike for, but if it's for charging in Whistler on the steep and rough then the increased stability from the length and 29s on the Ripmo might make the Transition feel inferior, despite the extra travel.
flag Loki87
Posted: Oct 29, 2020 at 8:24 Quote
What @kiksy said.
The TR500 was a rather compact bike to begin with, even during its time. Downhill bikes have evolved a lot as well and I wouldn't be surprised if your Riomo will feel a lot more aggressive than the TR500.
To be honest, I personally would not want to ride a bike with old geo anymore, no matter if it's Enduro or downhill.
The differences in reach we discussed in this thread, between dh and Enduro, are small and can be attributed to the necessary adaptations to account for different angles and measurements on other parts of the bike. As I already explained, those differences between a modern Enduro and modern dh bike are just minor adjustments, not something you will be able to feel, given both bikes are of appropriate size for your height.
The differences between the TR500 and Ripmo are huge, especially since the rest of the geo numbers on the TR500 were never anything extreme to begin with.
Also, small dh bikes are stupid. If you don't need the high speed stability, stay with the Enduro, because what else is a dh bike good for? Don't buy a dh bike you can ride easily, buy the one that is the best tool for the job and learn how to ride it properly.
flag ybsurf
O+
Posted: Oct 29, 2020 at 9:02 Quote
Small dh bike can be fun depending on what you intend to use it for, I'm mostly a jump guy and my small Phoenix 27.5 with 408 reach and a 50mm stem and it works perfectly for me. I'm a 5'7.5" and the medium would have worked but very happy with the small frame. My trail bike is a medium with 440 reach with 35mm stem.
flag englertracing
O+
Posted: Oct 29, 2020 at 9:56 Quote
ybsurf wrote:
Small dh bike can be fun depending on what you intend to use it for, I'm mostly a jump guy and my small Phoenix 27.5 with 408 reach and a 50mm stem and it works perfectly for me. I'm a 5'7.5" and the medium would have worked but very happy with the small frame. My trail bike is a medium with 440 reach with 35mm stem.

You could hop on a medium dh and feel like it's too big.
But once you get used to it, it would be hard to go back the other way
flag georgewilsoniv
O+
Posted: Oct 29, 2020 at 13:50 Quote
kiksy wrote:
Here's a direct comparison of geo of Ripmo and Transition.

https://geometrygeeks.bike/compare/ibis-ripmo-2020-medium,transition-tr500-2016-sm/

Personally, more than the reach I'd be concerned about the shorter wheelbase of the Transition, it's way shorter.

It obviously depends on what you want the bike for, but if it's for charging in Whistler on the steep and rough then the increased stability from the length and 29s on the Ripmo might make the Transition feel inferior, despite the extra travel.

Thanks for the info and insights. Seems to make sense and what I was concerned about. As I had read so much more on enduro bikes from March til the July purchase of the Ripmo reach was something that was continually spoken heavily about with the newer bikes compared to ones from a few years ago. Plan is to ride Whistler but, not super aggressively so I'll keep on looking and hopefully test ride something to get an idea of what suits me best.
flag will54869
Posted: Oct 29, 2020 at 15:35 Quote
Loki87 wrote:
What @kiksy said.
The TR500 was a rather compact bike to begin with, even during its time. Downhill bikes have evolved a lot as well and I wouldn't be surprised if your Riomo will feel a lot more aggressive than the TR500.
To be honest, I personally would not want to ride a bike with old geo anymore, no matter if it's Enduro or downhill.
The differences in reach we discussed in this thread, between dh and Enduro, are small and can be attributed to the necessary adaptations to account for different angles and measurements on other parts of the bike. As I already explained, those differences between a modern Enduro and modern dh bike are just minor adjustments, not something you will be able to feel, given both bikes are of appropriate size for your height.
The differences between the TR500 and Ripmo are huge, especially since the rest of the geo numbers on the TR500 were never anything extreme to begin with.
Also, small dh bikes are stupid. If you don't need the high speed stability, stay with the Enduro, because what else is a dh bike good for? Don't buy a dh bike you can ride easily, buy the one that is the best tool for the job and learn how to ride it properly.
I have a slightly different take on this, I think people on the shorter side need a short reach IF they want to learn how to ride steep stuff like tech trails in whistler. if you aren't riding steep stuff I would ignore this whole post. for shorter people the new school long reach geometry could be great on flatter downhill trails or XC but the problem comes from the time it takes to shift your weight from forward to back or visa versa. Also if your reach is too long, you will not be able to absorb bumps correctly when it gets steep. your elbows will be to straight and your arms will be reaching out to much, which will cause you to lower your butt and bend your knees too much, which will bring you to close too the rear wheel and the bike wont be able to move underneath you properly.

in my opinion, if you want to ride steep stuff, 400-420 mm reach is perfect for someone around 5'7". There are a lot of other factors though like bar height/ suspension set up/ and the geometry of your specific bike
flag georgewilsoniv
O+
Posted: Oct 29, 2020 at 18:26 Quote
will54869 wrote:
Loki87 wrote:
What @kiksy said.
The TR500 was a rather compact bike to begin with, even during its time. Downhill bikes have evolved a lot as well and I wouldn't be surprised if your Riomo will feel a lot more aggressive than the TR500.
To be honest, I personally would not want to ride a bike with old geo anymore, no matter if it's Enduro or downhill.
The differences in reach we discussed in this thread, between dh and Enduro, are small and can be attributed to the necessary adaptations to account for different angles and measurements on other parts of the bike. As I already explained, those differences between a modern Enduro and modern dh bike are just minor adjustments, not something you will be able to feel, given both bikes are of appropriate size for your height.
The differences between the TR500 and Ripmo are huge, especially since the rest of the geo numbers on the TR500 were never anything extreme to begin with.
Also, small dh bikes are stupid. If you don't need the high speed stability, stay with the Enduro, because what else is a dh bike good for? Don't buy a dh bike you can ride easily, buy the one that is the best tool for the job and learn how to ride it properly.
I have a slightly different take on this, I think people on the shorter side need a short reach IF they want to learn how to ride steep stuff like tech trails in whistler. if you aren't riding steep stuff I would ignore this whole post. for shorter people the new school long reach geometry could be great on flatter downhill trails or XC but the problem comes from the time it takes to shift your weight from forward to back or visa versa. Also if your reach is too long, you will not be able to absorb bumps correctly when it gets steep. your elbows will be to straight and your arms will be reaching out to much, which will cause you to lower your butt and bend your knees too much, which will bring you to close too the rear wheel and the bike wont be able to move underneath you properly.

in my opinion, if you want to ride steep stuff, 400-420 mm reach is perfect for someone around 5'7". There are a lot of other factors though like bar height/ suspension set up/ and the geometry of your specific bike

Thanks for the additional insight. I'm only 5'5" but losing a 100mm of reach seemed concerning and I'm aware other geometry numbers matter. Not sure what qualifies as steep stuff but, I've lived in Lake Tahoe and rode around there with mostly climbs for descents. The few laps I got in the Whistler bike park this fall was the first time I was so far back on the Ripmo that I felt like I might drag my ass on the rear tire but, those experiences felt unbalanced like I was probably doing a handful of things wrong.
flag Frontrange
O+
Posted: Dec 14, 2021 at 19:13 Quote
Reviving an old thread...

Thoughts on what people think of sizing of this rider and this bike?




photo




That's me in Whistler a couple years ago on an Xtra Long YT Tues. I'm 5'11.5" tall. YT says I should be between 6'3" and 6'9" to ride this bike. My Enduro bike has a longer reach than the "Long" Tues, and the wheelbase is almost similar. I bought a new Scott Gambler in a size Large and it felt horrible because it was smaller than my enduro bike. I ended up promptly selling it. I'm a big fan of sizing up for your DH bike. Otherwise you don't need a DH bike. FWIW I also ride everything at whistler including a lot of stuff not on a trail map.
flag Tripmo
Posted: Dec 14, 2021 at 20:11 Quote
Frontrange wrote:
Reviving an old thread...

Thoughts on what people think of sizing of this rider and this bike?




photo




That's me in Whistler a couple years ago on an Xtra Long YT Tues. I'm 5'11.5" tall. YT says I should be between 6'3" and 6'9" to ride this bike. My Enduro bike has a longer reach than the "Long" Tues, and the wheelbase is almost similar. I bought a new Scott Gambler in a size Large and it felt horrible because it was smaller than my enduro bike. I ended up promptly selling it. I'm a big fan of sizing up for your DH bike. Otherwise you don't need a DH bike. FWIW I also ride everything at whistler including a lot of stuff not on a trail map.

You cannot compare reach numbers of other bikes with DH bikes. DH bikes are always having a shorter reach. Because the dual crowns (longer travel) and slacker headtube angle makes your bars closer to you compared to other bikes.

Also don't forget you hardly sit on the saddle of a DH bikes, you most of the time have your body hanging over the rear wheel.
So while sitting on a DH bike might feel cramped etc, that is not the position you ride the bike in most of the time.
flag Frontrange
O+
Posted: Dec 15, 2021 at 8:58 Quote
Tripmo wrote:
Frontrange wrote:
Reviving an old thread...

Thoughts on what people think of sizing of this rider and this bike?




photo




That's me in Whistler a couple years ago on an Xtra Long YT Tues. I'm 5'11.5" tall. YT says I should be between 6'3" and 6'9" to ride this bike. My Enduro bike has a longer reach than the "Long" Tues, and the wheelbase is almost similar. I bought a new Scott Gambler in a size Large and it felt horrible because it was smaller than my enduro bike. I ended up promptly selling it. I'm a big fan of sizing up for your DH bike. Otherwise you don't need a DH bike. FWIW I also ride everything at whistler including a lot of stuff not on a trail map.

You cannot compare reach numbers of other bikes with DH bikes. DH bikes are always having a shorter reach. Because the dual crowns (longer travel) and slacker headtube angle makes your bars closer to you compared to other bikes.

Also don't forget you hardly sit on the saddle of a DH bikes, you most of the time have your body hanging over the rear wheel.
So while sitting on a DH bike might feel cramped etc, that is not the position you ride the bike in most of the time.


I think you’re confusing reach and effective top tube length. Reach is measured from the bottom bracket so being seated doesn’t matter. You should never be hanging over the rear wheel either, you should be centered on the bike regardless of what type of bike you’re riding. Check the photo again for an example.

Personally I think DH bike design just hasn’t caught up with the progressive geometry in enduro bikes. There’s no money in it for bike companies, DH bikes are losers. This makes it hard to size a DH bike if you’re going back and forth between an “enduro” bike and DH bike. If you buy the same size in both bikes, most likely your DH bike will feel smaller than your enduro bike which defeats the purpose IMO. Head tube angles are mostly identical now as well between Enduro and DH bikes. Some bikes are pushing slacker than 63* HTA but I’ve found the front pushes too much requiring you to get too far over the front to maintain traction. The sweet spot for me is between 63 and 64 degrees, which ironically is the same as my enduro bike. My size large enduro bike has a reach of 487mm. My XL DH bike in that image is 505mm. Feels perfect
flag Oro
Posted: Dec 16, 2021 at 13:45 Quote
I run size small in both my DH and enduro bikes at 5'5. 430 reach on the Enduro and 405 on the DH. Ridden the DH most of this year, the shorter reach is never something I think about or even notice. Rode the same park on both on the same day a couple times, only thing I really noticed was how much more lively and poppy the Enduro was even with a coil shock. And just how much difference a dual crown makes for braking bumps and the rough bigger repeated hits, absolutely night and day for me. Haven't touched the Enduro almost at all this year, it's probably had 5 hours total including those park days mentioned above. Every time I ride i just grab the DH. Reach stack etc isn't the be all and end all for me.

 


Copyright © 2000 - 2024. Pinkbike.com. All rights reserved.
dv42 0.024492
Mobile Version of Website