Author Topic: Frames / heavier riders / leverage ratio  (Read 2590 times)

sdplinker

Frames / heavier riders / leverage ratio
« on: April 20, 2020, 05:05:17 PM »
Been reading up a lot prior to my first ever MTB purchase.  A thread about 'clydesdales' (me - 250 lbs) and leverage ratios sent me down a rabbit hole.  I know you can have fun on any bike, but figure I should get something that will work best for me.

MTBR thread:  https://forums.mtbr.com/clydesdales-tall-riders/clyde-friendly-leverage-ratios-1099505.html

With that in mind I pored over this website - amazing amount of data:  http://linkagedesign.blogspot.com/

Researching so far, the following bikes seem to have the linkage/ratio characteristics that would be more optimal:

Diamondback Release
Transition Sentinel and Smuggler
Guerrilla Gravity Trail Pistol (trail) and Smash (enduro)
BMC Agonist
Banshee Phantom
Guerrilla Gravity Trail Pistol (trail) and Smash (Enduro)

Before I start poring over all the Chinese frame specs (if accurate) - any that y'all know of that match these designs most closely?  I'm in on the AM831 Hightower group buy but even though it's a great bike I'm now questioning it based on the suspension travel/leverage.



Sitar_Ned

Re: Frames / heavier riders / leverage ratio
« Reply #1 on: April 20, 2020, 08:42:54 PM »
The Ican P8 and P9 are based off the Transition bikes you listed I think. I could be wrong about that.  I actually emailed Ican asking about price for a P8 a couple of months ago and never got a reply (I assume due to Corona) but then the SC group buy came up.

As for your rabbit hole... I've been dipping my toe into the linkage/optimal leverage rate hole recently, and I'm also in on the group buy. Are you saying the SC linkage design isn't optimal in general or specifically for riders above 250 lbs? Do you mind sharing what your learned about the Hightower to make you question the design?

Thanks and good topic.
« Last Edit: April 20, 2020, 09:01:19 PM by Sitar_Ned »

scourge

Re: Frames / heavier riders / leverage ratio
« Reply #2 on: April 20, 2020, 09:24:27 PM »
I'm a clyde and also in on the group buy. Guess I'll find out.

sdplinker

Re: Frames / heavier riders / leverage ratio
« Reply #3 on: April 21, 2020, 12:33:43 AM »

The Ican P8 and P9 are based off the Transition bikes you listed I think. I could be wrong about that.  I actually emailed Ican asking about price for a P8 a couple of months ago and never got a reply (I assume due to Corona) but then the SC group buy came up.

As for your rabbit hole... I've been dipping my toe into the linkage/optimal leverage rate hole recently, and I'm also in on the group buy. Are you saying the SC linkage design isn't optimal in general or specifically for riders above 250 lbs? Do you mind sharing what your learned about the Hightower to make you question the design?

Thanks and good topic.

I'm way too inexperienced to know for sure.  I came across this when over-analyzing my decision on what to buy (which is normal for me).  Also some work-related COVID income stuff has me a little more reticent to take a flyer on a Chinese frame.  In any case, check out the data at the frame analysis site.  Here's the Hightower:

http://linkagedesign.blogspot.com/2019/09/santa-cruz-hightower-2020.html

Note the curve vs something like the Transition Sentinel
http://linkagedesign.blogspot.com/2018/01/transition-sentinel-29-2018.html

From the reading I've done (with no expertise) a curve that stay at or under 2.3-2.5 is better for heavy folks.  Shocks have longer stroke and can be run at non-maxed out air pressure. 

chetosmachine

Re: Frames / heavier riders / leverage ratio
« Reply #4 on: April 21, 2020, 02:23:48 AM »
I have an Ican P9, and being 230lbs, i run 230 psi on the shock, with no issues so far. BTW, max pressure on this shock is 300psi rated by the manufacturer, so I guess you should not worry much on that side.
Oh, i contacted www.icanbikes.com like 1 month ago and got my answer in less than a day, no issues from my side. It is the web where i bought my frame.

Sitar_Ned

Re: Frames / heavier riders / leverage ratio
« Reply #5 on: April 21, 2020, 09:09:52 AM »

I'm way too inexperienced to know for sure.  I came across this when over-analyzing my decision on what to buy (which is normal for me).  Also some work-related COVID income stuff has me a little more reticent to take a flyer on a Chinese frame.  In any case, check out the data at the frame analysis site.  Here's the Hightower:

http://linkagedesign.blogspot.com/2019/09/santa-cruz-hightower-2020.html

Note the curve vs something like the Transition Sentinel
http://linkagedesign.blogspot.com/2018/01/transition-sentinel-29-2018.html

From the reading I've done (with no expertise) a curve that stay at or under 2.3-2.5 is better for heavy folks.  Shocks have longer stroke and can be run at non-maxed out air pressure.

Thanks for the reply, I'll check it out.

Sitar_Ned

Re: Frames / heavier riders / leverage ratio
« Reply #6 on: April 21, 2020, 09:10:33 AM »
Oh, i contacted www.icanbikes.com like 1 month ago and got my answer in less than a day, no issues from my side. It is the web where i bought my frame.

Hmm okay, thanks. Maybe I'll double-check my inbox

goyo46

Re: Frames / heavier riders / leverage ratio
« Reply #7 on: May 24, 2020, 01:29:00 AM »
One point to consider for heavier riders is the tuning of the rear shock, a big part of the leverage ratio equation. I’m 220 or so kitted out and tend to weight the rear pretty well. Currently on a Phantom v2, kinda heavy but totally solid for big guys, I would have broken a carbon frame by now, judging from the scratches and scrapes. I had to revalve the Debonaire shock (it was too soft), easy with info on line, and run it around 270 psi. Nice and plush, and good support. Also, running a 36 spoke back wheel helps things feel a lot more solid.
If you’re not set on a chiner, I’d look at the new Titan. If I didn’t have the phantom that’s what I’d spend my money on.

scourge

Re: Frames / heavier riders / leverage ratio
« Reply #8 on: May 24, 2020, 12:18:45 PM »
I'd love to have a TItan. They look amazing. But the price is what brings me here. I am a serious budget bike.

endo.alley

Re: Frames / heavier riders / leverage ratio
« Reply #9 on: August 31, 2020, 08:56:48 PM »
To me, my P9 seems a lot like a Norco.