Mechanics Quick Question Thread [Ask Questions Here]

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Mechanics Quick Question Thread [Ask Questions Here]
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flag seraph
Posted: May 22, 2019 at 12:19 Quote
BaGearA wrote:
so I have a Hope 30mm thread in BB

I currently run A raceface turbine crank and would really like to get A carbon Sram Xo crank ( the red and white will look sick on my bike ) but I remember reading somewhere A BB30 crank won't fit , is this true and if yes why ? The spindle too short ?


GXP is uncommon here and I'd like to keep this BB

Yes the spindle is too short on a BB30 crank to fit in a BSA 30.
flag Nobble
Posted: May 22, 2019 at 19:09 Quote
demo7jumper wrote:
potato wrote:
demo7jumper wrote:

So do you have any idea why it hits the frame?

94bcd is the chainring circle, 104mm is your bb shell width, they are unrelated.
The problem is that you don't have a descendant dh crankset.
It is too short because you have 68/73 crankset which have chain lines for 49mm or somewhere close to that.
The dh crankset will have a 57mm chainline which is much further out and wont hit the frame.
But the problem is that the crankset is 83mm
It is the truvativ descendant dh crankset
Brought it over to the lbs and they don't know why it doesn't fit
what BB did you get? a gxp crankset should have one bearing that’s a 22mm diameter, and one that’s a 24mm. If you didn’t buy a gxp BB then you won’t have the step for the spindle to butt up against, and that would result in the chainring hitting the frame.

The gambler is a BB104 which has the same bearing spacing as a threaded 83mm BB.
flag Nobble
Posted: May 22, 2019 at 19:11 Quote
Anyone know if you can swap boost lowers onto a non-boost pike?
flag freestyIAM
Posted: May 22, 2019 at 19:27 Quote
I don't know for sure but I wouldn't think so. That would mean the crowns were somehow not wider that on boost forks, and that math doesn't work. Lowers are wider, upper us narrower, stanchions are straight, they won't go together.
flag Dougal-SC
Posted: May 22, 2019 at 20:31 Quote
Nobble wrote:
Anyone know if you can swap boost lowers onto a non-boost pike?

No go. The crown is 10mm wider on the boost forks.
flag sunpunkMTB
Posted: May 22, 2019 at 21:40 Quote
I am rehab-ing a 2005 Marz EXR Pro coil fork 120mm. Here's a pic of the innards. According to Marz manual & exploded view, the 120 should not have the black plastic (preload spacers?) above rebound springs on the push rods. I'm trying to eliminate a bad top-out clunk in the fork. Hoping a rebuild and 10wt oil will help. One of the spacers is cracked & pretty rough along bottom edge. Should the spacers even be there and can they be omitted? What would change?

internal parts of Marzocchi EXR Pro coil
flag Bflutz625
Posted: May 23, 2019 at 5:07 Quote
Dougal-SC wrote:
Nobble wrote:
Anyone know if you can swap boost lowers onto a non-boost pike?

No go. The crown is 10mm wider on the boost forks.


This. The only exception is for Fox 32 SC. Every other fork the CSU is wider for boost.
flag Duderz7
Posted: May 23, 2019 at 6:20 Quote
sunpunkMTB wrote:
I am rehab-ing a 2005 Marz EXR Pro coil fork 120mm. Here's a pic of the innards. According to Marz manual & exploded view, the 120 should not have the black plastic (preload spacers?) above rebound springs on the push rods. I'm trying to eliminate a bad top-out clunk in the fork. Hoping a rebuild and 10wt oil will help. One of the spacers is cracked & pretty rough along bottom edge. Should the spacers even be there and can they be omitted? What would change?

internal parts of Marzocchi EXR Pro coil
If I'm understanding you, it's a spacer on the negative spring. In which case or would raise the fork and increase the travel by the size of the spacer. Don't do this ones you can be sure the stanchion fully engages the lower bushing when topped out. Is it possible your fork is actually 100mm travel and that's why your not seeing that spacer on the diagram for the 120mm.
flag sunpunkMTB
Posted: May 23, 2019 at 7:16 Quote
Duderz7 wrote:
sunpunkMTB wrote:
I am rehab-ing a 2005 Marz EXR Pro coil fork 120mm. Here's a pic of the innards. According to Marz manual & exploded view, the 120 should not have the black plastic (preload spacers?) above rebound springs on the push rods. I'm trying to eliminate a bad top-out clunk in the fork. Hoping a rebuild and 10wt oil will help. One of the spacers is cracked & pretty rough along bottom edge. Should the spacers even be there and can they be omitted? What would change?

internal parts of Marzocchi EXR Pro coil
If I'm understanding you, it's a spacer on the negative spring. In which case or would raise the fork and increase the travel by the size of the spacer. Don't do this ones you can be sure the stanchion fully engages the lower bushing when topped out. Is it possible your fork is actually 100mm travel and that's why your not seeing that spacer on the diagram for the 120mm.

Measured travel was 4.75" range (120mm). So this could possibly be the 105 model in which someone added spacers to increase to 120? Exploded view of 105 model does show spacers. Didn't quite understand your second comment. Are the spacers a good thing or a bad thing in this case? I'd rather keep 120 travel if having the spacers accomplishes that; however, if removing them resolves top out clunk, I would def leave them out.
flag El-Mustachio
Posted: May 23, 2019 at 9:09 Quote
Whats better?
Getting a cheaper bike and upgrading as I go?
Or saving up for a generally better specced bike/custom build?
flag R-M-R
Posted: May 23, 2019 at 9:27 Quote
El-Mustachio wrote:
Whats better?
Getting a cheaper bike and upgrading as I go?
Or saving up for a generally better specced bike/custom build?

Generally saving up for better spec., but there are so many caveats.

How long would you have to save up and how bad is the current bike? How expensive is the better spec. you're considering? It's generally better to get a better spec. initially because then you're essentially "buying" the parts at wholesale (i.e. the price difference is less than the MSRP difference) and you don't have to sell the used parts, but if you buy a modest bike now and upgrade only with used or tremendously discounted items, then you'll be buying parts at good prices - and maybe you don't mind having to sell the original parts.

So many variables! One thing is always true, though: a custom "dream bike" build is always a terrible value.

Some general advice:

1. A frame with good, modern geometry. You don't want to upgrade the frame.
2. Modest drivetrains are perfectly good, ex. Shimano SLX, Sram NX.
3. Carbon is never worth it when you're on a budget.
4. 203 mm rotors make mediocre brakes feel decent.
5. When you wear out your rear tire, move the front to the rear and get a new front. Always have a fresh front tire.
6. A comfortable saddle makes more difference to your happiness than almost anything else. If you're three hours into a six hour ride and your crotch is already in agony, you won't care whether your shifting is electronic or every part of your bike is carbon.
7. There's no such thing as too much drop for your seatpost.
8. There are ways to spend your bike fund beyond the bike: You'll be happier taking a mid-priced bike to great destinations than always riding a dream bike on the same local trail.
flag chinaboy
O+
Posted: May 23, 2019 at 9:38 Quote
El-Mustachio wrote:
Whats better?
Getting a cheaper bike and upgrading as I go?
Or saving up for a generally better specced bike/custom build?
I would get the newest bike you can with low end parts and just upgrade as you go along, then at least geometry and technology will be current. But depends on your own timeline and how quickly you want to be riding I guess. I’m sure everyone’s priority will be different depending on their timeline and budgets.
flag naptime
Posted: May 23, 2019 at 11:04 Quote
Number 8!!!!!!!!
flag oldmanDan
Posted: May 23, 2019 at 12:15 Quote
R-M-R wrote:
El-Mustachio wrote:
Whats better?
Getting a cheaper bike and upgrading as I go?
Or saving up for a generally better specced bike/custom build?

Generally saving up for better spec., but there are so many caveats.

How long would you have to save up and how bad is the current bike? How expensive is the better spec. you're considering? It's generally better to get a better spec. initially because then you're essentially "buying" the parts at wholesale (i.e. the price difference is less than the MSRP difference) and you don't have to sell the used parts, but if you buy a modest bike now and upgrade only with used or tremendously discounted items, then you'll be buying parts at good prices - and maybe you don't mind having to sell the original parts.

So many variables! One thing is always true, though: a custom "dream bike" build is always a terrible value.

Some general advice:

1. A frame with good, modern geometry. You don't want to upgrade the frame.
2. Modest drivetrains are perfectly good, ex. Shimano SLX, Sram NX.
3. Carbon is never worth it when you're on a budget.
4. 203 mm rotors make mediocre brakes feel decent.
5. When you wear out your rear tire, move the front to the rear and get a new front. Always have a fresh front tire.
6. A comfortable saddle makes more difference to your happiness than almost anything else. If you're three hours into a six hour ride and your crotch is already in agony, you won't care whether your shifting is electronic or every part of your bike is carbon.
7. There's no such thing as too much drop for your seatpost.
8. There are ways to spend your bike fund beyond the bike: You'll be happier taking a mid-priced bike to great destinations than always riding a dream bike on the same local trail.


^^^ what he said!
flag El-Mustachio
Posted: May 23, 2019 at 12:43 Quote
R-M-R wrote:
El-Mustachio wrote:
Whats better?
Getting a cheaper bike and upgrading as I go?
Or saving up for a generally better specced bike/custom build?

Generally saving up for better spec., but there are so many caveats.

How long would you have to save up and how bad is the current bike? How expensive is the better spec. you're considering? It's generally better to get a better spec. initially because then you're essentially "buying" the parts at wholesale (i.e. the price difference is less than the MSRP difference) and you don't have to sell the used parts, but if you buy a modest bike now and upgrade only with used or tremendously discounted items, then you'll be buying parts at good prices - and maybe you don't mind having to sell the original parts.

So many variables! One thing is always true, though: a custom "dream bike" build is always a terrible value.

Some general advice:

1. A frame with good, modern geometry. You don't want to upgrade the frame.
2. Modest drivetrains are perfectly good, ex. Shimano SLX, Sram NX.
3. Carbon is never worth it when you're on a budget.
4. 203 mm rotors make mediocre brakes feel decent.
5. When you wear out your rear tire, move the front to the rear and get a new front. Always have a fresh front tire.
6. A comfortable saddle makes more difference to your happiness than almost anything else. If you're three hours into a six hour ride and your crotch is already in agony, you won't care whether your shifting is electronic or every part of your bike is carbon.
7. There's no such thing as too much drop for your seatpost.
8. There are ways to spend your bike fund beyond the bike: You'll be happier taking a mid-priced bike to great destinations than always riding a dream bike on the same local trail.

Thats really helpful. Thanks!
I've just been wondering cause I'm moving to the alps sooner than expected and my current mountaibike will be way out of its depth there.

 


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