Long-stroke Hightower

It's a niche topic and I figure it's a long shot, but I'm curious if anyone else is running a longer stroke shock on their Santa Cruz Hightower. 

For context, the Hightower is spec'd with a 200x51 shock, however folks were quick to discover a 200x57mm shock (same eye to eye, obv.) will do the job just as well while allowing for 16mm of extra wheel travel. Decent.

This might all be a moot point shortly, as it's rather expected that a revised 29er enduro machine is set for release in the nearish (maybe?) future.  From the aftermarket world, it seems custom linkages may soon be on the market to allow for a more kosher source of extra rear travel. 

Nevertheless, there still seems to be enough interest that it warranted a response from Santa Cruz engineer, Nick Anderson, "We know there are people out there running the Hightower in some non-spec configurations and we highly advise against doing so. [...] running the bike with anything other than 135mm of rear travel is potentially dangerous. [...] there’s the risk of the tire hitting the seat tube, and/or the shock over-centering the linkage. If the shock has a reservoir it could hit the top tube. Any one of these scenarios could cause a crash."

Moving forward, I've had some time to ride the bike with the configuration of a 200x57mm shock and I thought I'd share my experiences and see anyone else can chime in.

I've had success (and I believe other anecdotal stories online confirm this) with the long-stroke option only in the high (29er) geometry setting. Therein, using my 27.5x3.0 tires in the aforementioned configuration resulted in a silly-low bottom bracket and very slack ride. 

I'm running a DBcoil [IL] and initially was afraid I'd be blowing through travel since it's not the most progressive suspension design out there, but I've been pleasantly surprised with the performance. I suspect the leverage ratio continues to increase progressively throughout the travel extension. I've bottomed out the bike once using 29x2.4 DHRIIs (I deserved it, after an awful double-case). Luckily the rubber bumper on my shock lessened the impact which I was expecting. Still, no tire-frame contact was experienced. 

So far so good, I'm feeling pretty comfortable about the configuration. Anyone else?

No experience with the HT myself, but I keep reading rumours of a Hightower LT model coming to market in Q3 (150mm wheel travel?). Also your pic isn't showing up for me for some reason.

Pretty sure the next hightower will replace my slash 29. Loved my nomad.

There is an extended post over on the MTBR.com forums under the santa cruz subforum with a lot of feedback from people who have done it.

Seems like a lot of work, possibly a voided warranty, and expense for just over a half-inch of travel.  I'd be amazed if more than 50% of riders could tell the difference in blind trials, particularly when running 3" tires.

But hey, bikes are fun to fuck with right?

I've read about this being done quite a bit and people seem to be happy with the results.  How does the travel feel during the last bit of end stroke?  Just curious since Santa Cruz would have not tuned the suspension with the linkages moving that far.

The LT 29er SC has in the works is a bit of a lunch-bag letdown if it doesn't follow the N4 linkage style.

Posted by: Endur-Bro

The LT 29er SC has in the works is a bit of a lunch-bag letdown if it doesn't follow the N4 linkage style.

Why do you say that out of curiosity?

The HTs the EWS guys are racing this year look to be a HT revision not a redesign.  We'll see what drops for the presser, I could be wrong.  

Much talk has been made of the N4 additional travel but for myself and many others the real winner is the reworked rear suspension, including the shock being driven via the lower linkage V10 style.  

Hope to get a demo ride on a N4 and HT LT this summer to see myself.

Posted by: Ninjatarian

Posted by: Endur-Bro

The LT 29er SC has in the works is a bit of a lunch-bag letdown if it doesn't follow the N4 linkage style.

Why do you say that out of curiosity?

Because New Bike Tractor Beam.

Posted by: tashi

Seems like a lot of work, possibly a voided warranty, and expense for just over a half-inch of travel.  I'd be amazed if more than 50% of riders could tell the difference in blind trials, particularly when running 3" tires.

But hey, bikes are fun to fuck with right?

Indeed, bikes are fun to fuck with. I also like servicing and riding mine. 

Strange metric you chose there.... 50% of people noticing a difference in blind trials. It's like LD50, but for justification of bike parts? What about variance of the mean? What N should we deem significant for our sample size to feel justified in our purchases. /S

In fact, it's pretty easy to tell a difference. You're sitting deeper in the travel and can achieve a pretty different suspension feel, but what do I know, I'm just some asshole with 3"tires.

I've only recently started paying more attention to suspension tuning curves, anti-squat, and all that. With how sensitive VPP bikes are generally with being at the right sag point, I would suggest you leave the sag where it should be with the spec shock stroke, and the extra 1/4" of shock stroke at the the of the travel should allow for less ramp up to be needed. I feel it's highly unlikely the suspension curve will make any drastic direction changes in this uncharted part of travel.

Posted by: UFO

I've only recently started paying more attention to suspension tuning curves, anti-squat, and all that. With how sensitive VPP bikes are generally with being at the right sag point, I would suggest you leave the sag where it should be with the spec shock stroke, and the extra 1/4" of shock stroke at the the of the travel should allow for less ramp up to be needed. I feel it's highly unlikely the suspension curve will make any drastic direction changes in this uncharted part of travel.

Yea man, it was considered before I went around willy nilly changing things.

The anti-squat profile of the Hightower sits around 100% right around 30mm-65mm of wheel travel... See antisquat profile below. Plenty of room to play around there.

"Highly unlikely the suspension curve will make any drastic direction changes in this uncharted part of the travel."

Well, I agree with you there.. The third generation of VPP in the Nomad III and Hightower show consistently progressive leverage ratios near the end of their travel. In contrast to the second generation of VPP (Tallboy LTC, Nomad II, Bronson I), there is an inflection point in their wheel travel near the end of the stroke. (I believe it was so prevalent in the Bronson, that the CCDB airs that were initially supplied as OEM shocks had special negative spring tunes to accomodate the kinematics.)

So yea, I assume the leverage ratio is only becoming more progressive in the supplementary 15mm of travel, which is dandy with me... some rainy day I'll find time to quantify that.

Posted by: jan

Posted by: tashi

Seems like a lot of work, possibly a voided warranty, and expense for just over a half-inch of travel.  I'd be amazed if more than 50% of riders could tell the difference in blind trials, particularly when running 3" tires.

But hey, bikes are fun to fuck with right?

Indeed, bikes are fun to fuck with. I also like servicing and riding mine. 

Strange metric you chose there.... 50% of people noticing a difference in blind trials. It's like LD50, but for justification of bike parts? What about variance of the mean? What N should we deem significant for our sample size to feel justified in our purchases. /S

In fact, it's pretty easy to tell a difference. You're sitting deeper in the travel and can achieve a pretty different suspension feel, but what do I know, I'm just some asshole with 3"tires.

I apologize if my post was rude, I in no way intended to imply that you were an asshole. 

I'm glad that there are folks like you out there messing with your bikes like this. It results in better bikes for those of us who don't want to spend the time.