[Pau11y]

Here's the situation:
I bought a 204 Magnum and am trying to put a set of FSA X-Drive crankarm (Profile type of tubular steel) on this thing. With the longest spindle, a 170mm(FSA) or a 6 7/8"(Profile), the cranks sit so far over to the drive side it comes out to be something like 4.25" drive side and 2.75" non-drive side. So, to remedy this, I had a local machine shop make a 8.25" spindle for me. Now there's 4.25" on either side of the center of the BB shell (measured to the outer edge of the crank's splines).
Here's the question:
Does anyone know what kind of hardness the Profile spindles are heat treated to? The guy who made the 8.25" spindle made it w/ annealed 4130. A file can still mark the spindle, but then the Profile/FSA's spindle can also be marked. It's a 19mm dia solid hunk of 4130 that has a 170mm crank arm on it. Think it needs to be heat treated more to increase the hardness so it won't bend? Thanx in advance.

 

[Fulton]

damn, just out of curiosity, how much did it cost to get that axle made?

 

[partsbara]

i m prolly of no help, but i ran a 6 7/8" profile axle with profile cranks for 2 years... worked perfectly... mr. dirt guide, never dropped a chain once... why not just run profile arms ???? i m guessing you ll say weight - right ... the truvativ holzfeller / e13 i set up a couple of months back has been great... no complaints and waaayyyy lighter

 

[Pau11y]

$135.00
I know, I know... You can call me anal about symetry, even tho that rear triangle is anything but...

 

[DHS]

damn, just out of curiosity, how much did it cost to get that axle made?

also wondering.
and how much does it weigh....

 

[Pau11y]

i m prolly of no help, but i ran a 6 7/8" profile axle with profile cranks for 2 years... worked perfectly... mr. dirt guide, never dropped a chain once... why not just run profile arms ???? i m guessing you ll say weight - right ... the truvativ holzfeller / e13 i set up a couple of months back has been great... no complaints and waaayyyy lighter

Profiles and the FSA has the same width where it interfaces the spindle. I'm also trying to get an E13 on there, which sits wider than the Gizmo.

 

[partsbara]

also wondering.
and how much does it weigh....

i don t even wanna guess... the 6 7/8" i ran on my 204 was a fuggin boat anchor !!!

 

[Pau11y]

also wondering.
and how much does it weigh....

It's a boat anchor. But I'm hoping it'll never break (or bend). That's why I'm trying to see if further heat treat is necessary.

 

[zedro]

i really doubt they did anything but normalize it, which i assume it already is. Can you get a nitride coating for it?

 

[Pau11y]

i m prolly of no help, but i ran a 6 7/8" profile axle with profile cranks for 2 years... worked perfectly... mr. dirt guide, never dropped a chain once... why not just run profile arms ???? i m guessing you ll say weight - right ... the truvativ holzfeller / e13 i set up a couple of months back has been great... no complaints and waaayyyy lighter

Partsbara, how far off to the drive side is your cranks sitting? From what I've been reading the ISIS comes at 146 or 148 max width. Does it have any noticable effects on performance, cornering, ect?

 

[partsbara]

outta curiosity paully, what do you weigh ??? i m 220 - 225 and beat the p1ss outta my cranks in the past (more broken BB's than i care to remember)... the profile / mr. dirt set up took some big knocks and isn t a stranger to 25 - 30' jumps... i m hopin the holz set up works for my hefty anvs...

 

[Pau11y]

i really doubt they did anything but normalize it, which i assume it already is. Can you get a nitride coating for it?

Don't know where I can. Got any clues? The guy who made it made it .002 shy so there's room for a coating.

 

[Pau11y]

I'm 180 dry, 190 w/ gear. Pretty smooth rider, spin on a roadie for cardio. For BB I used the X-Drive dual bearing on either side w/ splines instead of wrench flats.

 

[partsbara]

Partsbara, how far off to the drive side is your cranks sitting? From what I've been reading the ISIS comes at 146 or 148 max width. Does it have any noticable effects on performance, cornering, ect?

i m pretty sure (99%) my bb is a 143 (truvativ)... my eye gives it about 14 mm clearance between the swingarm and the cranks... this is on both sides... the left might be 1mm or so less... no worries with flex when cornering etc... the rear end is as stiff as any other DH bike i ve ever ridden... those 4 massive bearings do the trick...

 

[partsbara]

actually my bb axel must be 148... i think the RF i have is 143... sorry

 

[Pau11y]

i m pretty sure (99%) my bb is a 143 (truvativ)... my eye gives it about 14 mm clearance between the swingarm and the cranks... this is on both sides... the left might be 1mm or so less... no worries with flex when cornering etc... the rear end is as stiff as any other DH bike i ve ever ridden... those 4 massive bearings do the trick...

If it's 14mm off on either side, and the swing arm is asym (at least on mine it is), then you're prob. off to the drive side something in the area of 1 full inch. Do you notice that at all?

 

[partsbara]

i don t think it d be an inch, but whatever it is i can t say that i notice it mate... the bike has a wide ass, the crank platform is massive... a couple of my mates have noticed how broad it is but to me it feels like... well. it feels normal...

 

[partsbara]

i should add that these are blokes who ride 68 - 73 mm bb shells...

 

[Pau11y]

Yeah, this should be interesting. I'm coming off a Karpiel Army w/ 120mm spindle.

Edit: 73mm shell

Edit II: the clock that shows this post time is way off. Mine is telling me it's time to go home.

 

[zedro]

you know a 170mm spindle should be long enough for a 100mm BB shell. The crank arms only need 20mm of insertion and the required chainline is 65mm. So the spacing should be via axle length:

non-driveside arm (20mm), spacer (calculated from BB shell: 15mm), BB shell width (100mm), spacer+spider (15mm), driveside arm (20mm) = 170mm

since the middle ring on the spider sits approximatly in line with the crank face, that'll give the 65mm chainline

 

[Pau11y]

you know a 170mm spindle should be long enough for a 100mm BB shell. The crank arms only need 20mm of insertion and the required chainline is 65mm. So the spacing should be via axle length:

non-driveside arm (20mm), spacer (calculated from BB shell: 15mm), BB shell width (100mm), spacer+spider (15mm), driveside arm (20mm) = 170mm

since the middle ring on the spider sits approximatly in line with the crank face, that'll give the 65mm chainline

I had to add more spacers to get the proper spacing on the inner plate/ring/outer guide. Currently , it's as tight as I can get it, and that's w/ the Gizmo. The E13 requires me to add more spacers cause it's further out.

 

[dhmtbj]

I don't get why you can't just center the whole setup? Can't you just change around spacers and such to make it work or am I not understanding the problem?

 

[Pau11y]

I don't get why you can't just center the whole setup? Can't you just change around spacers and such to make it work or am I not understanding the problem?

Problem:
I think the dist. from bb shell center/bikes long axis to the outer face of the cranks where the pedal bolts in is called the Q. To get the Q even on the drive and non-drive side, only 1/8 - 3/16" of the spindle is left on either side to bold the crank arms on. The bb shell width is static. The space necessary for the chain guide is static (without any spacers). And, the proper space between the chain ring and the guide is also static. Then when you try to even out the dist. between either pedal to the center axis of the bike (by adding spacers to the non-drive side to account for the space taken up by the chain guide) there's just not enough spindle left to hold the crank arms on.

I've already solved this problem w/ a 8.25" spindle. The question is actually now a metallurgy one: will an annealed 4130 spindle hold it's shape w/ my 190# bouncing on it or will it need additional heat treating to keep it from bending?

 

[zedro]

I've already solved this problem w/ a 8.25" spindle. The question is actually now a metallurgy one: will an annealed 4130 spindle hold it's shape w/ my 190# bouncing on it or will it need additional heat treating to keep it from bending?

do you know if the stock came annealed? generally they come normalized i think.

its not hard to normalize if there a furnace available, the problem is keeping it from scaling.

 

[Pau11y]

do you know if the stock came annealed? generally they come normalized i think.

its not hard to normalize if there a furnace available, the problem is keeping it from scaling.

He told me it was annealed. Said it was heat treated and then backed off so you can use normal machining tools on it. Otherwise he would of had to buy a $170 carbide bit to cut hardened stock. For comparison, he took a file to a 6" version of a FSA spindle and marked it. Then he used the same force and marked the one he just made. He judged that they're "almost" as hard as each other. From his experience, he's telling me I'd be hard pressed to bend it, but then he doens't bomb down sides of mountains on a bike either.

 

[zedro]

H For comparison, he took a file to a 6" version of a FSA spindle and marked it. Then he used the same force and marked the one he just made. He judged that they're "almost" as hard as each other. From his experience, he's telling me I'd be hard pressed to bend it, but then he doens't bomb down sides of mountains on a bike either.

yup, that sure sounds like a machinist

the annealed material is about 83% the strength of the normalized one...its upto you.

 

[Rockland]

He judged that they're "almost" as hard as each other. From his experience, he's telling me I'd be hard pressed to bend it, but then he doens't bomb down sides of mountains on a bike either.

You might want to be shure, and get a Rockwell hardness test on the stock spindle and the new machined one. From the sounds of things your machine shop does not have this test equipment.

 

[Pau11y]

Well, are Profile steel spindles known to bend? I'm not sure about the 83% as I have quite a bit more length than even the longest Profiles....hum?!

 

[TWISTED]

I remember the Profile Lawill downhill bike having a really wide BB. So Profile might still have some of those extra long spindles around. You should call them up and ask real nice for them to try to dig one up.

 

[Pau11y]

I remember the Profile Lawill downhill bike having a really wide BB. So Profile might still have some of those extra long spindles around. You should call them up and ask real nice for them to try to dig one up.

Daaaahhhh! Best idea I've heard yet! Thanx man.

 

[partsbara]

Daaaahhhh! Best idea I've heard yet! Thanx man.

the best idea is to go and buy yaself a set of holzfellers

 

[TWISTED]

Daaaahhhh! Best idea I've heard yet! Thanx man.

No problem. Now there is a good chance that the sales person at Profile that you talk to won't know what your talking about since it's an older spindle that they don't make anymore. So you'll have to really convince them to take a look around their factory.

It's the same thing here at Kinesis. We've still got old Mountain Cycle Pro-Stop disc brakes and purple Suspenders forks stashed away in the corners of our building, but they aren't listed in the catalogs and the sales guys might have trouble finding them.
Good luck,
Tim

 

[Pau11y]

No problem. Now there is a good chance that the sales person at Profile that you talk to won't know what your talking about since it's an older spindle that they don't make anymore. So you'll have to really convince them to take a look around their factory.

It's the same thing here at Kinesis. We've still got old Mountain Cycle Pro-Stop disc brakes and purple Suspenders forks stashed away in the corners of our building, but they aren't listed in the catalogs and the sales guys might have trouble finding them.
Good luck,
Tim

Right, this is the 6 7/8" spindle. So, back to square one.

 

[Pau11y]

Ok, don't mean to bring back the dead here but got some progress reports:
Spindles (2) are coming back after heat treating. They were taken to 41 - 43 RC hardness, matched against the Profile sample I sent them. Cost is $99.42 for heat treating, and $135.00 for the machining. Ouch! Haven't gotten my grubby little hands on them yet as they're sitting in UPS. Hope they're not warped!

 

[spookydave]

135.00 to machine that spindle sounds like a pretty good price to me. No one got rich making that ONE part. I bet you could get 'em under 50 bucks if you bought 500 of them.

Post a pic of it when it's in your gurbby hands.

 

[Pau11y]

135.00 to machine that spindle sounds like a pretty good price to me. No one got rich making that ONE part. I bet you could get 'em under 50 bucks if you bought 500 of them.

Post a pic of it when it's in your gurbby hands.

Will do. I'll also shoot some of the bike w/ a 170mm spindle w/ cranks mounted and the new spindle w/ cranks mounted and let you guys judge if this effort was worth the cost.

Edit: haha, check the post number

 

[DHS]

nope the RF is 148. i think they make the biggest one.