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Sub-65 HA on trail/mountain/endopru bike - who’s doing it?

fwp

Monkey
Jun 5, 2013
415
410
170 @ 13...definitely have to think of when i pedal at times. but it’s not bad. but i was also coming off of a 14.5bb w/175 cranks on my uzzi.
13 must rail corners man, I am scared even at 13.5 I was bucked after my bashguard hooked up in a rock garden and hit the eject button
 

xy9ine

Turbo Monkey
Mar 22, 2004
2,940
353
vancouver eastside
Garage build project I have been working on. 4130 fillet brazed. Suspension design very similar to the TR500 / Pulse / original DHR.

This is the 4th frame I've build and the 2nd suspension frame. First suspension frame was a classic singlepivot with no linkage driving the shock.

Hopefully I have the frame done this weekend.
sweet! looking forward to seeing this / hearing how it rides.
 

Gary

my pronouns are hag/gis
Aug 27, 2002
8,490
6,377
UK
170mm Ebike 650b 326mm 170mm cranks
170mm Capra (on 26") 318mm 170mm cranks

From all the uphill I ride I can think of two places where it's a problem. One is a stupid sticky uppy uphill rock "feature" on a purpose built trail where I'll bash the bashguard on the Capra if I'm tired and don't sprint before it, manual towards it and hop over it. The other is a natural eroded 20m of steep off camber with rocks, holes and roots where the high line to ride it combined with the camber, holes and two roots means I can't get a full pedal stroke for a few meters, lose too much momentum and come to a halt. I actually have cleaned the section but the effort needed to hit it fast enough to hold enough momentum to freewheel over the section where the inside pedal would ground just isn't worth There's an alternative route around it but it's 5 times as far so I usually just purposely stall and push up it. #DHer4LYF #Fuckduro
 

kidwoo

Artisanal Tweet Curator
I've ridden 175, 170 and 165 cranks on all kinds of bikes from 14+ bb heights to 12, all on suspension frames.

By far the best setup to avoid pedal strikes is to fucking pay attention to what you're riding on. Haven't seen that in stores though so you probably won't see many magazine/website reviews. But it really does work.
 

chris_f

Monkey
Jun 20, 2007
390
409
If magazine or website reviews and stories are anything to go by, I think that's no longer in production.
 

Nick

My name is Nick
Sep 21, 2001
24,861
16,399
where the trails are
I clipped a pedal Spring last year, blew up my elbow and a few ribs. That sucked. I agree you need to pay attention above all else.

(@kidwoo - remember the trail off of squaw pass I shuttled with you and Evan a couple years ago? That one. )
 

kidwoo

Artisanal Tweet Curator
I clipped a pedal Spring last year, blew up my elbow and a few ribs. That sucked. I agree you need to pay attention above all else.

(@kidwoo - remember the trail off of squaw pass I shuttled with you and Evan a couple years ago? That one. )

damn that sucks








I hope you've learned a valuable lesson here: pedalin's fer queers.




for real though that sucks

as does pedaling
 
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Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
No, not for me. Not anymore anyways.

I had my slack and low original model GG MT (in super g mode, 27.5"). With a sub 13" BB and slack ass HA. Was cool, but not cool for certain trails. Yes, any DH is sweet. But if you have to pedal with "land mine" rocks and off camber climbs, I had many 'oh shit' moments. Yes, on climbs, oh shit moments, where you pedal/crank hits a rock on the climb and you get ejected immediately. Sedona, Hangover trail, especially. Highline, not as much, but climb was a bit tricky. For my local trails and bike parks, very cool. But I do prefer a bit more confidence on the climbs. I can handle not being so low and slack on the downs.

That being said...Seeing as this is the DH forum, if you can rock the sub 13" BB and sub 64* HA, go for it!

But it's not for everyone, every trail.
Ya, but you are not separating HTA and BB height. For example, my 160 mm 29er has a 63 HTA and damn near a 14" bb, because I wanted to keep the CS down to 437 mm (don't ya love mixed inch/mm units?) I'm not sure it's the best combo and the next dropouts will be more like 13.6 " bb and 445 CS.

BUT, the thing handles. even in the flats. Once you learn to get forward and initiate turns, it seem like I have a ton of confidence in the front grip.

And I don't worry too much about pedal strikes, but even then, it's all relative. If I get too aggressive pedaling thru roots/rocks and/or out of corners...I can hurt myself. Pay attention. Timing. When I take beginners out and they ask about pedal strikes...same answer...you'll learn.
 

StiHacka

Compensating for something
Jan 4, 2013
21,560
12,508
In hell. Welcome!
Ya, but you are not separating HTA and BB height. For example, my 160 mm 29er has a 63 HTA and damn near a 14" bb, because I wanted to keep the CS down to 437 mm (don't ya love mixed inch/mm units?) I'm not sure it's the best combo and the next dropouts will be more like 13.6 " bb and 445 CS.
Hmm, my Riot has (with undersized wheels) 13" BB height yet 414mm CS and ~65.5deg HTA with a 160mm fork. Bike is a riot.
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,589
2,021
Seattle
Hmm, my Riot has (with undersized wheels) 13" BB height yet 414mm CS and ~65.5deg HTA with a 160mm fork. Bike is a riot.
How long reach/what size? I'm sold on the notion that having the chainstay length increase with front center length makes sense. It's not one size fits all.

Also that bike has a pretty rearward axle path initially, right?
 

StiHacka

Compensating for something
Jan 4, 2013
21,560
12,508
In hell. Welcome!
How long reach/what size? I'm sold on the notion that having the chainstay length increase with front center length makes sense. It's not one size fits all.

Also that bike has a pretty rearward axle path initially, right?
438mm reach for size M and that's how I like them. I don't think this bike has much of rearward axle path, unlike their Jedi.

 

Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
Hmm, my Riot has (with undersized wheels) 13" BB height yet 414mm CS and ~65.5deg HTA with a 160mm fork. Bike is a riot.
makes sense. They list BB height at 350=13.78". Or at least they did. I didn't see anything current...

Also, 140 mm travel. Adding 20 mm of travel means the wheel has to go somewhere.

Having said all that, my shit currently takes a touch more room to package anyway.

I also claim a low and centered CG makes more difference, for example, to manualling, than a short CS. All those bikes wityh a forward and high mounted shock attached to the TT or upper DT....better have short CS to overcome the leverage needed.

So....ya, I don't think short CS is any answer to everything, just a couple things
 

Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
They do, with 29" wheels. I run mine with 27.5 and 2.3 tires.
Oh. Well, I already have the mixed wheel or 170/160 27.5 with 63HTA and 13.2 bb with 427 CS. So that end is covered.

And ya, I run a 170 crank, because you better watch your pedals

Stuff the 29er back there with 165 mm travel...lotsa stuff
 

SylentK

Turbo Monkey
Feb 25, 2004
2,634
1,084
coloRADo
12.5" BB w/ 170mm cranks oh my Low Slack Formula 1 trail bike. AKA first gen GG Megatrail in super g mode.

My local trails I know well and good and how/when to time the pedal strokes.

I definitely know what it's like to rail trails with such a low and slack bike, trust me!

But really, if you have to smash the short, techy ups, because it's part of a "downhill" race, (common out here in sunny CO) you need to be able to smash the cranks/pedals like a goon and not have to pay much attention to the 'landmines'. Just sayin'

And right now I can do that with my GG Smash. Sometimes I long for my F1 Mega. But the Smash does it so well on EVERYTHING. That I don't.
 

HardtailHack

used an iron once
Jan 20, 2009
7,667
7,022
I was told by RM members that my hardtail is not low at 315mm but I went to 165mm cranks with the lowest Q factor I could find.
My last HT was lower and felt fine but the wheelbase was 4" or so shorter and the stays were also shorter, the current 435mm stay length is perfect for me.
 

Happymtb.fr

Turbo Monkey
Feb 9, 2016
2,066
1,437
SWE
By far the best setup to avoid pedal strikes is to fucking pay attention to what you're riding
This!

Then I find that discussing pedal strikes based on static BB height isn't very precise since the dynamic BB height is based on many factors like dynamic front and rear SAG, progression of the linkage, geometry... all this is actually quite difficult to assess from the information we get from the suppliers.
 

iRider

Turbo Monkey
Apr 5, 2008
5,686
3,143
Another funny observation I made is that the number of pedal strikes seem to increase when I am switching from flats to clipless or the other way. Same bike, switching results in more pedal strikes initially until I seem to have adapted. Somehow I ride different with the different pedals. Thickness and width of the pedals may play a role, but as it goes both ways I don't think this is the reason.
 

William42

fork ways
Jul 31, 2007
4,012
771
I only ride hiking switchbacks uphill, so i prefer a 72 degree HTA.
I too, set up shuttling so that I can ride up the hill, and drive the car down it so I don't have to do anything scary. Glad to know there's another one of me out there.
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,918
1,213
I find that discussing pedal strikes based on static BB height isn't very precise since the dynamic BB height is based on many factors like dynamic front and rear SAG, progression of the linkage, geometry
100%
It's interesting to share this stuff but it's worth noting that others' numbers particularly with BB height aren't very useful. Many people run the rear suspension on trail bikes stupidly firm, which only exacerbates issues with air shocks and less-than-great leverage curves which at least 1/3 of the current field still suffers from. Rear suspension setup alone can easily throw the dynamic BB height 0.5-1" and HA 1-2° in either direction.

With that said - when it comes to 63° HAs on trailbikes - I say just send it!
If "the front is wandering" stop riding up hills and/or stop being a pussy.
 

'size

Turbo Monkey
May 30, 2007
2,000
338
AZ
Hmm, my Riot has (with undersized wheels) 13" BB height yet 414mm CS and ~65.5deg HTA with a 160mm fork. Bike is a riot.
my 2650b 140mm bike also has a 13"bb, 65.5* HA with 160mm fork. most fun bike i've ever owned.
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,589
2,021
Seattle
With that said - when it comes to 63° HAs on trailbikes - I say just send it!
If "the front is wandering" stop riding up hills and/or stop being a pussy.
If your steering feels floppy, you just aren't going fast enough.
 

rideit

Bob the Builder
Aug 24, 2004
24,579
12,414
In the cleavage of the Tetons
I too, set up shuttling so that I can ride up the hill, and drive the car down it so I don't have to do anything scary. Glad to know there's another one of me out there.
Haha, last year riding in Vail there was a group of older guys on Moots ybbs that were getting on the gondola at the top to get a ride down.
Hilarious.
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,918
1,213
What a useless article!
People need more information about their bike, not less... what about actual and effective seat angles? Effective could even be given for several saddle height.
I actually thought the whole article was quite good and sheds light on a lot of caveats with geometry tables (particularly "why the seat angle number alone means nothing"), without making (m)any incorrect statements.

It's just the last paragraph (the writer's opinion on the matter) which ruined it, hopefully people can ignore that. What would have been better is some practical info on how to better understand/utilise the info given, and perhaps to ask for more complete data instead of none at all.
 

Kanye West

220# bag of hacktastic
Aug 31, 2006
3,767
501
64 works great on my Transition Sentinel with the reduced offset.

Riding conventional offset bikes now makes me feel like the front end is going to wiggle out from under me all the time basically unless I'm going in a dead straight line. Shit's ruined me.
 

Jm_

sled dog's bollocks
Jan 14, 2002
20,065
10,630
AK
My RFX is probably sitting around 65 with the 170mm fork. I recently bought an angleset as a method to try and get rid of some creaks (that turned out to be the fork, not the headset/frame). The angleset slackened it 1°.

Generally, I do not like it. There is no improvement downhill and it only makes my turning suck more, makes the front end rise up easier on climbs and generally feels "floppy". Previously it was tuned much better for all-around riding. The whole "go super slack" thing is overblown IMO. Making super-slack 29ers that don't need to be more stable because they are freaking 29ers, making 62° all-mountain bikes and everything else. The tradeoff is too much in many cases IMO. It kind of matches the "put really heavy over-size tires on your bike" thing though, leading to a general slowing of riding speeds and ability to get aggressive. I'm just saying that some stuff has definitely gone over the line in this pursuit. Lots of fan-boys will be on-board of course, but I'm not looking for the stupid-slackest bike.
 

kidwoo

Artisanal Tweet Curator
My RFX is probably sitting around 65 with the 170mm fork. I recently bought an angleset as a method to try and get rid of some creaks (that turned out to be the fork, not the headset/frame). The angleset slackened it 1°.

Generally, I do not like it. There is no improvement downhill and it only makes my turning suck more, makes the front end rise up easier on climbs and generally feels "floppy". Previously it was tuned much better for all-around riding. The whole "go super slack" thing is overblown IMO. Making super-slack 29ers that don't need to be more stable because they are freaking 29ers, making 62° all-mountain bikes and everything else. The tradeoff is too much in many cases IMO. It kind of matches the "put really heavy over-size tires on your bike" thing though, leading to a general slowing of riding speeds and ability to get aggressive. I'm just saying that some stuff has definitely gone over the line in this pursuit. Lots of fan-boys will be on-board of course, but I'm not looking for the stupid-slackest bike.

My rfx is about that too, with an angleset and a 180mm fork.


You are crazy.
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,918
1,213
There is no improvement downhill and it only makes my turning suck more, makes the front end rise up easier on climbs and generally feels "floppy".
Depends what you call downhill.
Horses for courses, it's good to have chorses.
 

HardtailHack

used an iron once
Jan 20, 2009
7,667
7,022
What a useless article!
People need more information about their bike, not less... what about actual and effective seat angles? Effective could even be given for several saddle height.
I have seen someone doing actual angles at a few different heights, can't remember who it was, Canyon....?

I wish everyone would be like Nicolai and show their leverage ratios, I guess theirs are all pretty much linear and that is boring, people want bumps, dips and whatnot.