SRAM crankarm spider cross compatibilty

[Mark McM]

Originally Posted by macaroon

Unforntunatley I'm not in the US......and I'm struggling to find a 30t 80BCD chainring
I did manage to buy the spider though!

You can buy the Super Compact 46/30 chainrings directly from TA Specialites:

https://specialites-ta.com/double/33...ta-kpl009.html

[robt57]

Originally Posted by Mark McM

When installing an MTB spider on a road crank, you want to use the GXP MTB spider.

What I learned. Have a new BB30 MTN 3 bolt 120/80 spider if anyone needs. And a few GXP 110 3 bolt ones as well loose.

Gearing wise I think the 30/46 is quite viable. I do like the 28/42 14t difference VS 16t for a tad more capacity on my woods and gravel bikes. The 30/46 for road I do favor.

[macaroon]

Originally Posted by Mark McM

You can buy the Super Compact 46/30 chainrings directly from TA Specialites:

https://specialites-ta.com/double/33...ta-kpl009.html

Those look like a good option.
I did manage to find a 30t Stronglight for a reasonable price, but I've yet to purchase it.
It's odd there aren't many options for SRAM; prior to looking, I assumed a subcompact setup would be straightforward to achieve, due to the replaceable spider.
I could probably get away with a <46t chainring, but my front mech won't go any lower as the braze on tab position is fixed.
I understand there're adapters to allow a lower position, but I'm concerned they'll negatively impact shifting performance.
Has anyone successfully drilled and retapped a new hole in a front mech (Campagnolo)?

[Mark McM]

Originally Posted by macaroon

It's odd there aren't many options for SRAM; prior to looking, I assumed a subcompact setup would be straightforward to achieve, due to the replaceable spider.

Sub-compact road cranks are a bit of niche - mainstream cranks with 46/30 chainrings are mostly designed for gravel groups, which often use a wider chainline (for clearance with wider tires). Still, there are several options for 46/30 road cranks, just not many for SRAM cranks. Non-SRAM 46/30 options include Sugino OX901 cranks (110/74 BCD), IRD Vortex and Defiant cranks (94 BCD), Rotor Aldu (110/80 BCD spider), Dixna La cranks (110/74 BCD), etc.

Originally Posted by macaroon

I could probably get away with a <46t chainring, but my front mech won't go any lower as the braze on tab position is fixed.
I understand there're adapters to allow a lower position, but I'm concerned they'll negatively impact shifting performance.
Has anyone successfully drilled and retapped a new hole in a front mech (Campagnolo)?

I've used a WickWerks Fit Link adapter with both 46/30 and 44/28 chainrings with a Campagnolo 11spd front derailleur, and I've found the performance nearly as good as with standard size chainrings. I suspect the minor reduction in performance had more to do with using sub-compact size chainrings with a standard derailleur than with the derailleur height adapter. There is a lower cost lost front derailleur adapter from Bikingreen that is similar to the WickWerks adapater that is available from multiple sellers on ebay, but I have no experience using it:

https://www.ebay.com/itm/12556051132...3ABFBMzrDDzrlk

[macaroon]

Originally Posted by Mark McM

Sub-compact road cranks are a bit of niche - mainstream cranks with 46/30 chainrings are mostly designed for gravel groups, which often use a wider chainline (for clearance with wider tires). Still, there are several options for 46/30 road cranks, just not many for SRAM cranks. Non-SRAM 46/30 options include Sugino OX901 cranks (110/74 BCD), IRD Vortex and Defiant cranks (94 BCD), Rotor Aldu (110/80 BCD spider), Dixna La cranks (110/74 BCD), etc.




I've used a WickWerks Fit Link adapter with both 46/30 and 44/28 chainrings with a Campagnolo 11spd front derailleur, and I've found the performance nearly as good as with standard size chainrings. I suspect the minor reduction in performance had more to do with using sub-compact size chainrings with a standard derailleur than with the derailleur height adapter. There is a lower cost lost front derailleur adapter from Bikingreen that is similar to the WickWerks adapater that is available from multiple sellers on ebay, but I have no experience using it:

https://www.ebay.com/itm/12556051132...3ABFBMzrDDzrlk

Coincidentally bikingreen do a subcompact chainring set for a 110BCD chainset, but a couple of reviews suggest there's interference between the spider and smallest ring which means it might not work.....

Have you seen the Shimano GRX front derailleurs? I'm considering trying one of those (the 400 10 speed model) on the front, to replace a Veloce model, if I can find one at a reduced cost. I've read a couple of forum posts that state the new Shimano mechs are compatible with Campagnolo shifters. These particular mechs have a cage that's designed to work with smaller chainrings

[Mark McM]

Originally Posted by macaroon

Coincidentally bikingreen do a subcompact chainring set for a 110BCD chainset, but a couple of reviews suggest there's interference between the spider and smallest ring which means it might not work.....

Normally, the limitation for the smallest chainring for a given BCD is that below a certain size the chain will contact the ends of the spider arms. To avoid concact between the chain and the ends of the spider arms, the Bikingreen shifts the chainrings inboard, to move the chain away from the spider arms. The potential consequences are larger chain angles in the large chainring, a greater propensity for the chain to rub against the large chainring when using the small chainring, and in a a few cases there maybe clearance issues between the small chainring and chainstay and sometimes the derailleur may not be able to swing inboard far enough. The Bikingreen chainrings may sometimes be a solution for using smaller chainrings, but they are an imperfect solution.

Originally Posted by macaroon

Have you seen the Shimano GRX front derailleurs? I'm considering trying one of those (the 400 10 speed model) on the front, to replace a Veloce model, if I can find one at a reduced cost. I've read a couple of forum posts that state the new Shimano mechs are compatible with Campagnolo shifters. These particular mechs have a cage that's designed to work with smaller chainrings

The GRX derailleurs use the Shimano Link (toggle) system, and in my experience these derailleurs do not match well with Campagnolo shifters. Link derailleurs use shorter cable travel and higher cable force than Campagnolo shifters are designed for. The higher travel between detents in the shifter reduces the ability to fine tune the indexing adjustment of the derailleur, and eliminates the ability to use derailleur trim. In addition, it requires more lever force to shift, and in some cases the shifter detents may not be strong enough to hold the derailleur in position.

[saintruggler]

This is a step up from the 46/30 mentioned above, but I have an unused set of 48/32 rings for sale that fit on SRAM's 104/64 3-bolt spider, and presumably would fit the 3rd party spiders from makers like North Short Billet, etc. I can confirm that the 3-bolt spider and 48/32 ring setup fit perfectly on SRAM/Truvativ alloy crankarms.

Pics and other related parts here: https://forums.thepaceline.net/showt...errerid=250554

I also have several of the GXP spiders in 1x and 2x configurations if anyone's still looking.

-Eric