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I put a heavier fork on my bike and was trying to get some components down cheaply to offset the weight gain.
I use Shimano boost cranksets nowadays as living in China we find Shimano pricing to be very, very attractive. The cheaper shifters/mechs can sometimes be more expensive than Shimano here, which is telling.
Anyhow, a seller I trust has SLX m7120 2 ring cranksets that, with a cheap 3rd party single chainring, would be cheaper to buy, and the chainrings I've found about half the weight of an SLX single ring. (I already have the tool to remove chainrings on these direct drive cranksets)
Being lighter made me start reading why. There had to be a catch. The 3rd party chainrings are fully CNC Alu. A read of the descriptions on the Shimano website lists their m6120/m7120/m8120 cranksets with steel, or steel plated teeth. The m8120 system can change gears under load too apparently.
Since Shimano are doing this, and the weight of the m8120 steel plated chainrings is still far higher than what 3rd party manufacturers are producing in Alu, would you say not to touch these fully Alu chainrings with a bargepole? That the teeth would grind away too fast, wear the chain, and wear the cassette much faster, and increasing shifting issues along the way?
Note: Went from a 2.2kg fork to 3.05kg. I can save 150g going from m6120 to m7120 cranks (£62). 65g more saving if I chose that 3rd party Alu chainring and bought the 2 ring crankset (£58 total) Already saved 150g going from 25.4mm Alu slopestyle bars to 35mm DH carbon (£22.50). Can save 225g changing rear cassette soon (£76). Not going for ridiculously priced branded parts. Some of these brands you may not know the name, or they're rebranded for the Western market. Trying to be sensible and not turn my bike into a tank, but I'll take some higher weight against products obviously made from cheese which is where the Deore steel/steel plates teeth chainrings discussion comes in. Can't ride, if I can't pedal and change gears because the parts deformed under stress.
We did this recently but based on a reasonable guess of the materials you can expect the steel chain rings to last at least twice as long as alu.
And twice the weight is equivalent to how many Snickers bars?
https://singletrackmag.com/forum/topic/steel-vs-aluminium-direct-mount-chainrings-wear-rate/
I guess from that discussion I ought to go full Shimano parts then. The hardness numbers posted are a pretty clear indicator, and a wearing chainring will have a domino effect.
I'll find some weight savings elsewhere. Each component, taken together becomes less one chocolate bar, and more a family bag of them, and is needed to eat into that extra weight of the fork, and my budget build. There's a point where the weight tips over the scales and the whole bike suddenly gets less enjoyable to ride. Not sure how I managed with my 55lb 26" DH rig in the past, but this one is currently 37.5lbs and I want to get it down to 35lbs.
Shimano has made plenty of alu rings in it's time. Two things to consider are lifespan - how much use will they get? Say for average use you get 3years from alu, 5 from steel, which do you prefer? Quality - not all alu is the same, not all rings are, how much do you trust the manufacturer?
Alu rings will be fine, if well made. I'd probably take the alu myself if wanting to save weight on the overall bike.
I wouldn't bother, if your new fork is over 3kg then I'm assuming it's not an XC bike we're talking about
Ah, it's a locally produced trail full-suss. I bought when they first came out on a promo (£235 inc DNM shock) but I was having problems with handlebars to reach the best Stack height because I have long legs, and also suffering too many pedal strikes which was leading to some spills.
There's 3 generations of my frame (2nd and 3rd officially Enduro. 4th Gen will be a DH class frame (I was shared the design geometry drawings) taking a 200mm fork, and a 230mm E2E shock competing against another company which just released theirs, only in 16.5 and 18" frames) Gen 1-3 officially take 160mm forks but my 1st Gen has the steepest headangle, as the geometry got slacker and slacker. Sticking a 200mm fork in there sorted all the problems. I did measure all the angles and they're acceptable compared to other companies.
I can also buy normal upreach handlebars now, and my BB shell is not 'too' high to cause gravity/cornering issues. The bike is used for seriously steep mountain trails, (not big jumps and drops even though it's warrantied for 2m drops with a 160mm fork.)
1st and 2nd Gen has a design issue with the seattube shock mount area. Positioned too low, and the welding section choice stresses the seattube until it inevitably cracks. Company has acknowledged this. The riders know they're part of a homegrown cycle company development phase. The pricing reflects it and it's got a lot of young people over here riding at an affordable price point.
Could you save it from a non-wearing part instead of one where there's a clear downside?
It'll be about 60g difference.
e.g. you'd save 40g doing from a Deore derailleur to SLX, or 70g going to XT.
You’ve got a 200mm forked bike and you’re worried about a few grams??? 😳
Just have a poo before you ride. 😂
1st and 2nd Gen has a design issue with the seattube shock mount area. Positioned too low, and the welding section choice stresses the seattube until it inevitably cracks.
Don't worry doomanic, between this and the 200mm forks on a 160mm frame, I reckon he'll be saving the weight of a set of teeth soon enough.