Framosophy!

[Snot-Rocket]

Tonight I will determine if I have a $100.00+ or $1500.00+ problem with my Primary Ride...I highly suspect that my 5-yr old CK headset which survived a crash where my fork was bent into my frame has finally went kaput- or I have a out of wack headtube! An outlier is the star nut in the steering tube not being able to remain in place- either way my stem assembly and spacers are coming loose...

This got me thinking of the worst case scenario- obviously I'd send the frame in for warranty work or may consider getting a whole new ride...granted, this is the first time in years where I'm really happy with a design and ain't eager to replace it anytime soon...however, I find myself plagued with the eternal questions on frame geometry- what are the perfect numbers...I thought this mental meandering would be an interesting thread. In me days, I concur the Frame is the heart and soul of a bike and have focused on obvious metrics that indicate a bike of choice....here be my preferences, interested in other folks opinions, perspectives (these are numbers for a 19-19.5 Inch seat tube length...top tube is only relative measure for this detail in most instances):

HeadTube Angle- between 68-69.5, but closer to 68 is desired if designed for a 130-mm fork...this gives me the option to run 100-mm for a more XC ride. I like this because this allows for great low speed handingly and also great highspeed handling...can't corner as tightly as steeper angles and can lend to lazy steering on climbs, but there are ways around that.

SeatTube Angle- I always thought I liked the classic 72 degrees, but I'm finding I like steeper angles dependent on the design, can you say 74 degrees! Granted, this depends on the bike design in general, but this seems to provide great biomechanical leverage and awesome Bottom Back clearance!!!

Chain Stay- this is a go-no go issue for me, less the 17.0 inches hands down! Great cornering, easy manuals, great low speed handling and technical riding- climbing and big obstacles, etc. On a hardtail this can be rough on one's arse, but for duallies...all love...does hamper Descending speeds at the ludicrous level- but this is balanced by headtube angle preference...

Top Tube - I ignored this for years until I bought an Ellsworth Id and hated this details...but sub- 24" is a must...I'd be all over the Ellsworth Moment if it wasn't for this detail- Ellsworth needs to design a bike for the East Coast- Commies!

Finally, Bottom Bracket Height- 13-13.25 is the preference for duals, allows for great cornering, but high enough to not be banging your pedals on every rock!

I don't care about wheel base, because I think the above factors define the characteristics of the frame for my biases...for duals, I love 4xBar Horst (different discussion)- but I've sacrificed this preference to get the numbers above...in frame geometry, stable platform technology is a life saver!

Anyway, I think these numbers are definitive for a premiere east coast MTB...if I was in open country, I think I would make allowances for a longer chainstay...but that's about it...

Interested in other folks views, especially if they think I'm blowing off a metric that they found to be critical to their riding preferences?

Rah,

[themonkeyman]

That is a very tough bill to fit.

may I suggest an IF frame? Because I think that's what it's gonna take.

--Graham
P.S. I think 68 is a bit slack for slower riding (like around here)--but if it feels good to you, go for it.

[markie]

I thought all bikes since 1990 had 71degree head, 73 degree seat and 11.5 to 12 inch bottom brackets.

I guess I like hardtails.

:)

[Snot-Rocket]

That is a very tough bill to fit.

P.S. I think 68 is a bit slack for slower riding (like around here)--but if it feels good to you, go for it.


That's why I like it for a 130-mm fork- rarely run 130-mm, always 100mm...but it is nice to have that option for more aggressive riding (granted, as I get older- can't remember the last time I did that)?

[Nick]

Check out Kona - They've got the measurements you're looking for... and I swear I'm not biased or anything...

[Billy Mathisen]

This is somthing I am really interested in. So hears my two worn pennies.

Sounds like you know exactly what you want in geomtry, so I don't want to offer any suggestions about that. Although I defiantly agree with you that a shorter top tube serves East Coast better. But it seems like no matter what you do, there is always going to be trade off trying to find the best geomtry.

My only suggestion is get the fit perfect. The better the fit, the better the balance, control and comfort. There is alot more to fit than top tube length and standover. While you know exactly what you want out of the geomtry, your numbers might not be the perfect formula for you once you calculte your fit.

2 years ago I had custom Seven steel hardtail made. I was very suprised with the size and geomtry that they came up with -but it is perfect. I never have to think about adusting anything -stem, seat, or fork length because it works great. Still my fav bike. Not sure how much you want to invest, but I would definatly look into getting professionally sized through Serrotto, IF or Seven, and possbily having a custom built. It is a good learning experience too. Good luck with it.

[CountZero]

A large ML-8:

Head Angle 68.5
Seat Angle (effective) 71
Seat tube (BB to top) 18.9" (not as important as top tube)
Top Tube (effective C-C) 24.1" (6" fork should be run with a short stem)
BB Height (2.3 tire) 13.7"
Head tube length 5.9"
Front center 27.3"
Chainstay 17.3"
Stand over Height 29.1"

Chainstays are a bit long, for tire clearance, but they are tucked under the virtual seat tube, so they feel shorter. The bike wheelies up very well.

Top tube is long, but IMO that's necessary for long forks, which ride best when mated to short stems.

The frame is extremely stout, yet relatively light in weight.

Mine is a medium sized frame, too small for you, but you're welcome to check it out.

Tommy O

[drevil]

Your post was too long so I just skimmed it. Regardless, a Karate Monkey is perfect for you. I even voted it on it, and the results were Karate Monkey:1, anything else:0.
:p

So was it your headset or frame that's screwed?

[Billy Mathisen]

Just when you thought your thread was beginning to go well - it becomes infected with single speeders.

Get back single speeders, go back to your dungeons!

The next group who will pop up will be the unicyclists.

[Snot-Rocket]

It seems like the headset was the culprit, but not done yet...in the diagnosis!

I first pounded in a new star nut- thinking it was slipping, no love there.

I then swapped the stem, thinking- maybe the stem just ain't binding and it is working its way loose- no love there.

I then swapped out the fork- thinking I might as well do this...cause I really don't want to swap out my headset...at this point it is obvious I was in the denial phase- it is a money, ano-orange headset! Er, no love!

Finally, I swapped out the headset- only a true bike geek would have a 'spare' Chris King Headset in their parts bin (like- where did that come from)...in fact, when I sold my heckler, Mike had a 108-mm BB and I just happened to have a 113-mm BB laying around- what the heck, where did and when did I buy/acquire this crap- ha, ha!

Anyway, it seems like it is working, I feel no play- but I'm super paranoid now, so I'm not sure. When I inspected the CK headset, there seems to be some play in the bearing cartridge- granted, I'm in the paranoid hallucination phase- not sure what is reality?

Anyway, I need to do some test rides...and see if problem is solved...I got some slight creaking when I was dorking around last night- but no play in the headset. My bike was muddy- so I got to clean and lube it up and if there are no creaks- I'll be ready to evaluate if the HS issues is resolved...AAAGGGHHHH!!!!

As for any hardtail options, didn't those go out with the velocipedes?

Rah,

[Snot-Rocket]

Check out Kona - They've got the measurements you're looking for... and I swear I'm not biased or anything...

I think the Canadians got the numbers right; I be patrolling on bikes from up north- unfortunately both Kona and Cove subscribe to the 'Fo-Bar' (as Dan H. calls it) rear suspension linkage paradigm. So this is a huge opportunity costs...when it comes to pedal induced bop and braking locking up suspensions... the stable platform technology helps with the pedal induced bob...in general it is a compromise. I know Norco used the Horst linkage...but that's about as much as I know about their bikes.

Santa Cruz is developing the Blur LT- which should be interesting, I wish they made the Blur 4x in a 19" configuration...that would be interesting?

Joy!

[Snot-Rocket]

A large ML-8:

Mine is a medium sized frame, too small for you, but you're welcome to check it out.

Tommy O

Okay, another idiosyncracy...shock mount points, must lend to a conventional shock design...I think the Maveric is a sweet bike, but I have this paranoia about not liking the suspension or not being able to get parts/upgrades, etc. Now this is an irrational anxiety- I've not had a dual-suspended bike last very long under my roof...

Thanks,

[themonkeyman]

It terms of getting a FS frame that is relatively uneffected by braking and pedalling input, go Specialized. The new Enduro looks really nice, and has their 4-bar linkage that is very good at isolating pedalling and braking forces.

Ellsworth also has a great design that isolate those forces as well. Don't know if those companies have the angles you're looking for, but they have the right suspension design.

--Graham

[Snot-Rocket]

Dude, have you checked out the TT on the Moment- it is insanely long...

[themonkeyman]

I meant the suspension:Don't know if those companies have the angles you're looking for, but they have the right suspension design.

BUt yeah, I don't know why they made it so long, I guess they want you to use a longer fork with a shorter stem, but it's stil a bit long

[Snot-Rocket]

I meant the suspension:

BUt yeah, I don't know why they made it so long, I guess they want you to use a longer fork with a shorter stem, but it's stil a bit long

I may be talking out of my depths- I'm from Northern California...but them thar water thieves, think MTB is ripping up fire breaks- they are notorious for long TT and wheel bases- ha, ha! It is kinda interesting, like check out east coast and Canadian manufacturers bike geometries and manufacturers based out of S. California or originated from there and there are obvious trends...er, save this task for a long boring day. For Example, Intense bikes- they amazingly opt for short chainstays, sub 17" on their VPPs- but opt for long TTs also...

The only thing I don't like about long TTs is that it is hard to come off the back of the seat for steep drops and what not, this also lends to challenges w/ really large logs- etc. Granted, I recognize, that modern MTBs may not require such extreme behavior of back in the day- the bikes are more stable and can be ridden more normally- but dropping off the back of the bike is a hard habit to break...

Joy,

[themonkeyman]

Yeah, I know what you mean about breaking old habits. Maybe try Trek, since they're a little closer to the east coast scene. The new Fuel EX looks pretty sweet:
13.25" BB height
23.1" TT
73.5* Seat tube angle

But the head angle is steeeper than you wanted at 71*. Still, it may be worth a look, as it may feel a lot different than the angles state.

--Graham

[Snot-Rocket]

But the head angle is steeeper than you wanted at 71*. Still, it may be worth a look, as it may feel a lot different than the angles state.

--Graham

I wonder if the 71-degree HT Angle is so steep to compensate for the angle when someones fat-arse is on the bike and the HT slakens up a bit...

S'well I'm not getting an new bike until next year anyhow (that's my plan- but if baby 2 actually happens, we'll see what my plans are- ha, ha)- I was getting all sexed up about 29'rs and realize my fat-arse would just wreck havoc on those wheels...right now, I want to see where the Blur LT goes after one year of production...