Cage length

dandl

My 15 year old regular hack has ended up with a mixture of Sora, Tiagra and 105 components, some probably older than the bike. I decided that this year I would give it a complete rebuild and fit it with a Tiagra 4700 10 speed groupset. It isn't worth it or even possible to fit an 11 speed 105. As it seems what I want is very difficult to find as a complete groupset at the moment, I am probably going to have to source components separately (or at least the chainset separate from the rest). I plan to use a 50/34 tooth chainset with an 11-34 tooth cassette (got some serious hills here in Cumbria). What length rear mech cage would I need for this combination? I have seen a groupset (out of stock) with the specs I want and it includes a medium length cage. However, there is a long cage available in the range and I just wondered what gear combination this would be for. Thanks

masjer

Hi
the 4700 rear mech comes in two sizes- ss (short cage) and gs (medium cage).
The ss takes a max 28t. The gs 34t- the one you'd need.
Rather than reading the description as short, medium or long(not in 4700) it's probably better to look whether it's ss or gs.

akh

Probably not the case anymore, but pre Brexit and pandemic 105 was almost the same price. If you don't mind being locked it to one cassette option, I've heard the 11 speed 11-34 cassette can actually fit on a 10 speed freehub. See link below for more details.

https://youtu.be/cazQt5oleo4

I had 4700 for a while and couldn't fault it, I'm not suggesting 105 is a huge upgrade, but availablity seems better currently (albeit at a higher price).

darrell1967

I’ve had Tiagra on a few commuters. Love it because it’s simple, non-complicated and robust.

dandl

Happy to fit with Tiagra as it is an older bike and I am hoping to get another higher spec bike in the not too distant future. A couple of the reasons I did not consider 105 was that the front mech has to be band on and all the 105 mechs I saw were braze on. The other was that I wasn't sure what size bars the 105 shifters fitted. I have the older thinner bars and don't really want to replace these along with the stem.

dandl

I just want to add something to my post above if I may. I am moving from 8 speed triple to 10 speed double. From what I have read, the only problem with fitting a 10 speed cassette to an 8 speed hub is that the splines can become dented over time due to the thinner sprocket width. Is this a problem?

MattFalle

dandl said:

I just want to add something to my post above if I may. I am moving from 8 speed triple to 10 speed double. From what I have read, the only problem with fitting a 10 speed cassette to an 8 speed hub is that the splines can become dented over time due to the thinner sprocket width. Is this a problem?

the cassette may also be too wide for the freehub unless the wheel is 10 speed compatible

MattFalle

dandl said:

Happy to fit with Tiagra as it is an older bike and I am hoping to get another higher spec bike in the not too distant future. A couple of the reasons I did not consider 105 was that the front mech has to be band on and all the 105 mechs I saw were braze on. The other was that I wasn't sure what size bars the 105 shifters fitted. I have the older thinner bars and don't really want to replace these along with the stem.

tiagra is as good as 105 which is as good as Ultegra - some say better, so good choice.

bar size doesn't matter - everything fits everything

band on/braze on doesn't matter - just get an bracket to fit your frame size.

dandl

Thanks for all the helpful answers. Have all the info I need now.