Login required to started new threads

Login required to post replies

Shimano 105 & Ultegra FDs - what can they actually handle?
Quote | Reply
Hi All,

I'm potentially looking to change crankset size, and am looking for some practical experience with Shimano's mid level front derailleurs & big chainrings.

Shimano state a max size of 53t - Is anybody out there running something bigger than this with no issues?

Thanks
Quote Reply
Re: Shimano 105 & Ultegra FDs - what can they actually handle? [Liaman] [ In reply to ]
Quote | Reply
55t works

Ive only done a couple of TTs on it so far (season has now ended) but no problems to report other than the front gear changing not being as slick as it was before. For next year will try a 42t inner rather than a 39t to improve this.

I hadnt actually realized 53 was the max size in the documentation, so maybe my experience is just luck rather that applicable for everyone
Last edited by: huphup: Oct 2, 18 5:36
Quote Reply
Re: Shimano 105 & Ultegra FDs - what can they actually handle? [Liaman] [ In reply to ]
Quote | Reply
The biggest standard chainring shimano sells is 53t although they have been making bigger rings for the pros for a while. So 53t is the max you can run on a standard Shimano system but is not the true max that will work with the FDS.

In terms of fitting a bigger aftermarket ring I think the limit in most cases will be the height adjustment on the FD. Both band-on and braise-on FD have a max height limit which is frame dependent but a 56 or 58 should be workable in most cases. However the UK 25 mile record was just set using a 64 tooth front ring and I think that would be a struggle to fit on many frames with a FD.
Quote Reply
Re: Shimano 105 & Ultegra FDs - what can they actually handle? [Liaman] [ In reply to ]
Quote | Reply
Liaman wrote:
Hi All,

I'm potentially looking to change crankset size, and am looking for some practical experience with Shimano's mid level front derailleurs & big chainrings.

Shimano state a max size of 53t - Is anybody out there running something bigger than this with no issues?

Thanks

105 and Ultegra both have max front difference 16T so you can have 58-42 if you want to.
Quote Reply
Re: Shimano 105 & Ultegra FDs - what can they actually handle? [sebo2000] [ In reply to ]
Quote | Reply
sebo2000 wrote:
Liaman wrote:
Hi All,

I'm potentially looking to change crankset size, and am looking for some practical experience with Shimano's mid level front derailleurs & big chainrings.

Shimano state a max size of 53t - Is anybody out there running something bigger than this with no issues?

Thanks

105 and Ultegra both have max front difference 16T so you can have 58-42 if you want to.

Half true.

Yes, there is a 16t max difference between chainrings. But there is also a maximum chainring size which I suspect is smaller than 58t
Quote Reply