Mountain Bike Reviews Forum banner
1 - 20 of 28 Posts

·
Registered
Joined
·
203 Posts
Discussion Starter · #1 ·
Do you guys have any suggestions for lightening up a Sram X.0 drivetrain?

I have
Sram X.0 rear trigger shifter (225g for the pair, so should be 112.5g for just the rear)
Sram X.0 short cage rear derailleur (192g)
Sram PG-990 11-32 cassette (275g)
Sram PC-991 Cross Step chain (300g @ 114 links)
Truvativ Holzfeller OCT 170mm cranks (550g actual)
E.13 34t guidering (32g actual)
Truvativ Howitzer Team bb (383g actual)
E.13 LG-1 chainguide (231g actual)

All are 2007 products and all weights claimed by Sram unless noted.
I have the stock brake lines and I think housing that came with the shifters.

What are some good options for using ti or aluminum bolts and which bolts can be replaced in those components? I don't think there is much that can be done with the cassette and chain other than using something else. They both work well and I think the cassette is among the lightest for that gear spread. I could lose 21g with the PC-991 hollowpin chain. The E.13 guide rings are the lightest chain rings that I know of as is the LG-1 chain guide, although maybe some aluminum or ti-bolts could be used? I could droop a considerable amount of weight with XTR cranks and bb, but I am not too interested in that right now. What kind of bolts should I use for the chain ring and anything else that could be lightened up?
What bolts can be replaced in the X.0 rear derailleur and shifter? Maybe even the ones that clamp the shifter to the bar?

Are aluminum bolts lighter? I should only need to use titanium bolts where the bolt sees a high load right?
 

·
Hack Racer
Joined
·
2,559 Posts
I'm a shimano XTR fan. So off the top of the head I do not know how accurate Sram's weights are.

I do know that an XTR M970 11-32 cassette is 220grams.
The shimano XTR chain weighs 290 grams for 114 links.

For the middle ring (30T and above) you can use aluminum bolts no problem. If you have a granny and you use aluminum, I find you need to replace them once a season as they start to crack after a summer.

Not being familiar with an X.O. rear derailleur and which bolts are non steel as supplied by Sram... From tuning XTR derailleurs you can use:
aluminum pivot bolt
aluminum jockey bolts with a dab of blue loctite
aluminum or nylon hi/low limit screws
titanium cable pinch bolt (you can use aluminum if you are careful)
titanium spring

For brake levers and shifters you can use aluminum bolts with a dab of blue loctite.

You need titanium bolts in the following areas:
1.) seatpost binder
2.) seatpost adjust/tilt clamp
3.) stem
4.) cable pinch bolts
5.) disc brake bolts
6.) suspension pivot bolts
7.) and any bolt you know you will be doing and undoing often.

for the cost of all the bolts possible to tune your bike... you could order a brand new XTR M970 crankset from an european mail order online bike store and save more weight than just replacing bolts.

Bolt tuning should be the final touches on your build to accentuate your other fully optimized light weight parts. Else all you are doing is polishing a turd.
 

·
Registered
Joined
·
203 Posts
Discussion Starter · #3 ·
What's a good lightweight 34.9 seat clamp?

I currently have an anodized dangerboy setup... not light, just something that I threw on there cause it wouldn't work on any of my other bikes and it looks nice. I have a stock Intense seat clamp that looks fairly light and I could just put a ti bolt in there. But otherwise, if I do buy something new, what is worth buying for the lightest seat clamp?
 

·
Registered
Joined
·
682 Posts
How are you using the bike? With a 34t ring on Holzfeller cranks with a chain guide system I'm guessing you're not climbing a whole lot on this bike. Do you really think aluminum bolts will make that big a difference to the overall weight of the bike to offset the reduced reliability of the stock steel bolts? Is your goal to have the lightest bike around, or to have a fun and reliable bike that you can actually ride?

Aluminum and titanium bolts have their place, but if I'm interpreting the build of your bike correctly I'd say that this is not that place.
 

·
Registered
Joined
·
203 Posts
Discussion Starter · #6 ·
MichauxYeti said:
How are you using the bike? With a 34t ring on Holzfeller cranks with a chain guide system I'm guessing you're not climbing a whole lot on this bike. Do you really think aluminum bolts will make that big a difference to the overall weight of the bike to offset the reduced reliability of the stock steel bolts? Is your goal to have the lightest bike around, or to have a fun and reliable bike that you can actually ride?

Aluminum and titanium bolts have their place, but if I'm interpreting the build of your bike correctly I'd say that this is not that place.
It's an Intense Socom dh bike. I'd say that most of the time though it is used for some mild dh stuff or xc trails with emphasis on the downhills. I don't freeride huck to flat or anything like that on this bike. I do go to some races and ride some tech trails like windrock and snowshoe, but most of the time I have to ride what I go down.

Anyways, I want it to be light as long as it is still safe. Currently the bike weighs about 37-38lbs depending on tires and pedals in a downhill setup. When I put xc tires on it gets down to about 35lbs.

I don't really see ti and al bolts reducing the strength of a dh bike if they are used in the drivetrain. If anything, I think it sees less stress than an xc bike there.

I've got carbon bars too so ti stem bolts shouldn't hurt anything since I can't tighten the stem bolts down too much without cracking the bar... same goes for all of the other items that clamp onto the bar.

Seat post clamp shouldn't see any more stress.

Since ti has the same shear strength as steel, I don't think it would be any more likely to fail. The only bolts to worry about are the ones that require high torque loads.
 

·
himom!
Joined
·
684 Posts
The point is that Ti bolts are freaking expensive and you'd get a bigger benefit from spending the money instead on a lighter wheelset. As Cheers! said above, bolt tuning is the LAST thing you do to lighten a bike up.
 

·
Registered
Joined
·
203 Posts
Discussion Starter · #8 ·
dmcgoy said:
The point is that Ti bolts are freaking expensive and you'd get a bigger benefit from spending the money instead on a lighter wheelset. As Cheers! said above, bolt tuning is the LAST thing you do to lighten a bike up.
Most everything else on the bike is light, that's why it's a DH bike that only weighs 37lbs.
 

·
Registered
Joined
·
203 Posts
Discussion Starter · #9 ·
Here is the build

Frame: Intense Socom (med/white) Fox DH-X 5.0 shock (need to get ti spring)
Fork: Fox DH 40 RC2
Headset: FSA Orbit Xtreme Pro 1.5r
Stem: Easton Havoc 50mm
Bars: Easton Monkeylite DH Carbon
Grips: ODI Ruffian Lock on
Brakes: Avid Juicy Carbon w/ 203mm rotors f&r
Shifter: Sram X.0
R. Der: Sram X.0 w/ short carbon cage
Cassette: Sram PG-990 (11-32)
Chain: Sram PC-991 Cross Step
BB: Truvativ Howitzer Team
Crankset: Truvativ Holzfeller OCT 170mm 34t E.13 guidering right now
Chainguide: E.13 LG-1
Post: Thomson Elite
Seat: Selle Italia Flite ti tt or something... it's 165g
Wheels: Industry Nine DH/FR w/ Mavic X-823 rims
Tires: Michelin
 

·
Registered
Joined
·
203 Posts
Discussion Starter · #10 ·
Now there are some places that I could drop some serious weight, but then I might as well buy a new bike and it wouldn't be as strong. Nothing I have right now compromises strength.

I lose about 3/4 lb with a Rock Shox boxxer team, 1/2 lb with the ti spring, probably another 3/4 lb with an XTR crankset and bb, and 1/4 lb with lighter rims, but I want UST and Mavic's other option is an all mountain rim. Still I would consider running the 819rim on the front wheel.

I can also lose a little bit of weight with a different headset and integrated stem top crown which i am already planning on doing.
 

·
Registered
Joined
·
682 Posts
The pro DH riders from the team I wrench for were riding Stans Flow rims last year with phenomenal success. The rims held up really well and the reduction in pinch flats was very noticable. The Flow rims are the same width as your 823's and 120 grams lighter per rim. Pair that weight savings with non-UST tires converted with sealant and you'll have a very noticable weight savings where it really makes a difference, and probably for about the same cost as some bling bolts.
 

·
Hack Racer
Joined
·
2,559 Posts
????? said:
Now there are some places that I could drop some serious weight, but then I might as well buy a new bike and it wouldn't be as strong. Nothing I have right now compromises strength.

I lose about 3/4 lb with a Rock Shox boxxer team, 1/2 lb with the ti spring, probably another 3/4 lb with an XTR crankset and bb, and 1/4 lb with lighter rims, but I want UST and Mavic's other option is an all mountain rim. Still I would consider running the 819rim on the front wheel.

I can also lose a little bit of weight with a different headset and integrated stem top crown which i am already planning on doing.
These are not light. You would get better weight per dollar than ti/aluminum bolts by changing these items out first.

Sram PG-990 11-32 cassette (275g)
Sram PC-991 Cross Step chain (300g @ 114 links)
Truvativ Holzfeller OCT 170mm cranks (550g actual)
Truvativ Howitzer Team bb (383g actual)

Pick anyone and buy the best equivalent (XTR or what not) and you would save more than completely outfitting your entire bike with bolts. Best bet for max dollar per weight saved is to get an XTR M970 crankset with an acutal weight of 780 grams.

Max weight you can save if you to do every single bolt tuning is about 3/4 of a pound. It is costing me about 300 to 350 bucks including shipping to have every single bolt tweaked to the limit. This is including suspension pivots and all component bolts.

An XTR crankset if gotten online from europe mail order is only 250 euros or 360 USD or so and usually with free shipping.

In reality there are two things.
1.) To benifit from Ti bolt tuning you better have the best of the best for everything (Components, frames, wheels... etc). Else it's kinda a moot point
2.) It is your bike and you can do whatever you want. However... why not learn from others who have gone down this road and optimize the process.

If you want real bang for the buck. Buy a new bike and keep all your X.O. parts and swap over to a new bike and sell the old bike with mediocre parts. You will come out ways ahead. I know because I went from 26 lbs stumpjumper hardtail to 20 lbs by changing out every single part except for the fork. I should've just bought the top end stumpjumper and saved money.
 

·
Registered
Joined
·
232 Posts
Nice ride Bro!

Light and strong DH bikes are fun. you should be able to drop 1-2 pounds if you want, no prob, without sacrificing strength, just $$$. i've done everything, including titanium and alloy where appropriate, to my rig to keep it light AND strong; here's what i would do to your bike:

- Ti spring is a must but you know that
- e13 reducer cups are about 50g lighter than your headset and minimize stack height for a nice low front end, cheap too
- not sure about that havoc stem but a thomon X4 DH is 175g and is as light as any integrated set-up
- Ti bolts on brake calipers and adapters and a smaller rear rotor
- 11-27 durace is 175g and has sweet tight ratios but involves a cog swapping to get the 11T
- cranks/bb - socom is 73mm bb right? Hones or Gravity lights could work and are both about 850g with BB - probably at least a 1/2 pound lighter than the holzfeller + bb
- masterpiece post is 35g lighter and basically as strong
- LG1 is pretty close to a Gamut i believe?
- mag pedals
- hollowpin chain

Nice wheels!

bolts are totally obsessive and i'm guilty in that regard. total bolt tweaking will save you 50-100g depending on your setup. ti bolts are good for brakes, shock pivots, stems. alloy are good for chainring bolts, headset bolt, derailleurs, and shift/brake clamps (although they need frequent replacement as they sometimes bend in a crash)

here's my rig at 35.5lbs - frame is a bit flexy but i love it so much i just live with it
 

Attachments

·
Registered
Joined
·
203 Posts
Discussion Starter · #14 ·
MichauxYeti said:
The pro DH riders from the team I wrench for were riding Stans Flow rims last year with phenomenal success. The rims held up really well and the reduction in pinch flats was very noticable. The Flow rims are the same width as your 823's and 120 grams lighter per rim. Pair that weight savings with non-UST tires converted with sealant and you'll have a very noticable weight savings where it really makes a difference, and probably for about the same cost as some bling bolts.
I don't doubt that it would save a good bit of weight, but I'm not a fan of Stan's and the added complexity and decreased reliability over a UST setup has kept me clear.

I've had Stan's a while ago and it was just a huge pain.
 

·
Registered
Joined
·
203 Posts
Discussion Starter · #15 ·
Cheers! said:
These are not light. You would get better weight per dollar than ti/aluminum bolts by changing these items out first.

Sram PG-990 11-32 cassette (275g)
Sram PC-991 Cross Step chain (300g @ 114 links)
Truvativ Holzfeller OCT 170mm cranks (550g actual)
Truvativ Howitzer Team bb (383g actual)

Pick anyone and buy the best equivalent (XTR or what not) and you would save more than completely outfitting your entire bike with bolts. Best bet for max dollar per weight saved is to get an XTR M970 crankset with an acutal weight of 780 grams.

Max weight you can save if you to do every single bolt tuning is about 3/4 of a pound. It is costing me about 300 to 350 bucks including shipping to have every single bolt tweaked to the limit. This is including suspension pivots and all component bolts.

An XTR crankset if gotten online from europe mail order is only 250 euros or 360 USD or so and usually with free shipping.

In reality there are two things.
1.) To benifit from Ti bolt tuning you better have the best of the best for everything (Components, frames, wheels... etc). Else it's kinda a moot point
2.) It is your bike and you can do whatever you want. However... why not learn from others who have gone down this road and optimize the process.

If you want real bang for the buck. Buy a new bike and keep all your X.O. parts and swap over to a new bike and sell the old bike with mediocre parts. You will come out ways ahead. I know because I went from 26 lbs stumpjumper hardtail to 20 lbs by changing out every single part except for the fork. I should've just bought the top end stumpjumper and saved money.
Mediocre parts?!? This isn't an xc hardtail! It's a built to the hilt dh race bike. It is going to be heavier because it has to be stronger and it has 8" of travel front and rear and 2.5" dh casing tires.

The frame is the lightest DH frame made, there is only 1 fork that is lighter, and that is the boxxer team, but it uses an air spring instead of coil and the stanchions are smaller. The fox 40 has 40mm stanchions and is a beast of a fork, yet is still very light.

All parts are top of the line, I'm just looking to further lighten them up or possibly replace some of the overbuilt parts in some areas that don't require so much strength.

An XTR crankset is something that I'm looking at though, but I don't want or need the chainrings on it. I only need 1 ring up front and i already have it. Have you seen any places that sell just the crank arms without the chainrings?
 

·
Registered
Joined
·
682 Posts
Regular rims plus the strips, or the Stans rims? I'd argue that a Stans rim plus tire is equal or better than UST in complexity and reliability, plus it's lighter.
 

·
Registered
Joined
·
232 Posts
best of both worlds IMO is regular rim, rim strip, stans and UST tire. for example, Minion DH UST tires are lighter than regular Minions due to the kevlar bead and require less sealant as the sidewalls are already air tight. works for me.
 

·
Registered
Joined
·
88 Posts
I'd also check into different tire options. For example a 08 schwalbe big betty 2.4" comes in as low as 850grams compared to michelins dh series coming in at 1150grams and over.
Run the tires on a ust rim with juice and eliminated the tubes.
If your after ti bolts try http://www.torontocycles.com/. You can also find them on ebay. I've been using these guys for a couple years now and they've been great. Prices are better than anyone else out there.
 

·
Registered
Joined
·
88 Posts
Don't use ti bolts on suspension pivots, shock mounts or brake mounts. Not worth the headache and trust me i've already gone through the creaking nightmares. Also remember when you install ti fasteners use copper anti seize and bump up your torque specs about 10 percent.
 

·
The MTB Lab
Joined
·
2,556 Posts
Hmmm...I have bolt tuned a lot of bikes and never even been close to 3/4 a pound lost by going to Ti and Al bolts. Thats 340 grams! On my full susy I did around 90 grams which is almost a 1/4 pound (its actually .2 lbs). With the weight difference between Ti and Steel, saving 340 grams meant you had around 1000 grams of bolts or 2.2 lbs of bolts, which seems pretty heavy?

I also haven't ever had any creaking bolt issues in the 2 years I have been using Ti bolts on the pivot bolts? As you stated make sure you use a bit of anti-seize and you should be good to go. Also I would not ever over torque any Ti bolt, thats disaster waiting to happen. So its a great place to switch out bolts due to there very large size and heavier weight, meaning better grams per dollar weight savings.
 
1 - 20 of 28 Posts
Top