what specs do i need for a sporcket on a Rise with the shimano spider gear?

[Cavi]

I bought the spider gear so i can use different sprockets, I know I bought the correct one as there are two, but I seem to remember that I need the correct offset for the sprocket. Anyone know which one?

 

[BiGJZ74]

53mm chainline

 

[Cavi]

so I recieved my 53mm spider and bought a 30 tooth race face sprocket. When they went to install it they had to mount the sprocket on the outside and could not run the chain guide. Is this normal or is it possible that the people from the store in Germany might have sent me the 51mm spider? My chainline looks fine, but I will say that the 30 tooth is sht smallest that can be run on this bike as the chain is real close to the plastic protector on the chain stay.

 

[ebsocalmtb]

I run the shimano spider and stock shimano 34t chainring that comes with it. I have a funn brand chain guide that "works" with it, but it's a zero tolerance fit between the crank, chainstay/pivot, spider, chainring, guide and chain.

Not surprise that a 30t would not fit... 30t chainrings on 104bcd require threaded chainrings or offsets so that the spider/chain don't conflict in the same space. The smallest I could see getting to work would be a 32t, and even then, I'd expect potential clearance problems. Hard to see from my pov how any guide would work with the shimano spider and a 32t chainring.

 

[Cavi]

you missunderstand me the 30 tooth fits fine, it is the smallest that would fit but it does fit. After all the stock one is 32 tooth

 

[ebsocalmtb]

you missunderstand me the 30 tooth fits fine, it is the smallest that would fit but it does fit. After all the stock one is 32 tooth

With all due respect, I don't actually misunderstand you. You have a 104bcd 30t chainring bolted on backwards. In order to have a 30t - 104bcd chainring, the chainring needs to be threaded to accept the crank/chainring bolts. This is because if you do not, the chain does not have the clearance between the links and the 104bcd spider. This means that it needs to be installed in a particular way to have the correct chainline for 12 speed drivetrains to operate properly. You, have it installed in such a way that you have a chainline that is many MM off of design spec. It may function properly in the bottom handful of gears (hardest/fastest gears) but about 4-5 gears into the cassette, you are way, way out of optimum.

To that end, if you want the correct chainline so that you are not wearing out your chain, chainring and cassette prematurely, and not causing excess drag... the smallest you can fit is a 32t direct mount such as the e13 chainring that comes with the bike... or move to the shimano 104bcd spider, which can support a minimum of 34t without being modified.

 

[nrgbod]

30t is the smallest size specified in the blue paper for the Rise, but I don't think anyone makes a direct mount chainring in 30t.
You may be able to flip the chain ring over so the writing faces the motor to correct the alignment. The Funn chain guide might fit then.
I've seen lots of reports that the chain guide is not needed on the Rise anyway.

 

[Cavi]

well I was almost convinced to go back to stock, but then I rode it on the trail this weekend, loved it, made the gearing feel like I wanted it to feel, no shifting issues at all, and I tried both the top and low end gears. I also took out my calipers and did a measurement and honestly I am within 1mm of my wife's rise which is stock. I honestly do not believe 1mm will kill anything, but if it does wear out earlier then I will reacess, for now I am keeping it.