BB & Chainset upgrade
So far since joining this forum I've learned amongst other things that my 50/36 constitutes a 'Comapct' and that the Shimano Hollowtech II BBs are effectively interchangable ie I could use a Tiagra BB with a DA Chainset if I really wanted.
My bike is a second hand Halfords Carrera thing which was intially bought for the 2.5 mile commute to work but has since been put to use as a training bike. Such is the enthusiasm I've gained, I've tinkered a bit with it, replacing the saddle and seatpost, pedals and also the all metal front fork for a CF one. Whilst I had it in at the LBS recently getting the gear cables replaced (autochanging and skipping) they mentioned the BB will need replacing in the not too distant future. This was no biggie at the time but now that I'm getting into it a bit more, I've thought about replacing it myself but in the process going from the square taper type that it currently has to a HT II type. I have the tools for it now that Santa has been but I also know that I'll need to replace my chainset and thus chain as well if I upgrade to the HT BB.
I have a 8 spd 12-26 on the back and I've yet to fail or even struggle seriously on anything here around Winchester with the 36 x 26 but I'm not so sure I'd get up some 'proper' hills that are more than a mile (about 5-7% avg) in length and/or greater than 13% (a short few hundred metres max) which is as long and steep as I've encountered round here. Put another way, I used to live in Catterick and know some hills in N Yorks that would have me hooped compared to the tiddlers I have down here. In other words, if I was to enter the likes of the Fred Whitton, Cheshire Cat , Etape du Dales, insert any other big sportive with big climbs here next yr, there'll be some serious hills for which my 36 x 26 coupled with my lungs and legs will possibly fail on. Thus a 34T would buy be a bit more breathing space as opposed to a 53/39 which would defo be a step in the wrong direction for my ability and fitness level as well as my desire to complete some sportives and definately NOT race!
My questions are thus:
In upgrading to a HT II will I need to alter anything if I put on a 50/34 at the front ie will the mech position be ok for the mere 2T difference on the smaller ring?
Will an 8 spd chain still be ok? I presume it will.
Will I actually see or feel any kind of worthwhile enhancement? I've heard that the new HT brackets are smoother and lighter and this translates to effectively more power between the legs and wheel and thus slightly more speed for the same effort.
Is there a discernible difference between the Shimano Sora and Tiagra chainsets? The reason I ask is there is an ebay seller with a 50/34 Sora for just under £35 inc postage as compared with another who is doing the Tiagra at £50. Is the extra £15 for what are bottom end components worth the while? There is no point putting on Ultegra or even 105 as the bike is not high spec elsewhere and would not justify the added expense surely?
OR -
Would I be better off just replacing the sqaure taper BB for a new one and keeping my current 50/36 on?
OR
Try and source a 34T ring and replace the 36T one?
Sorry for the plethora of questions, but as I've found out on this forum, there is a lot of knowledge around so I'm hoping to get it all answered albeit not necessatrily by the one person (although that would be nice!!!). Thanks in advance.
My bike is a second hand Halfords Carrera thing which was intially bought for the 2.5 mile commute to work but has since been put to use as a training bike. Such is the enthusiasm I've gained, I've tinkered a bit with it, replacing the saddle and seatpost, pedals and also the all metal front fork for a CF one. Whilst I had it in at the LBS recently getting the gear cables replaced (autochanging and skipping) they mentioned the BB will need replacing in the not too distant future. This was no biggie at the time but now that I'm getting into it a bit more, I've thought about replacing it myself but in the process going from the square taper type that it currently has to a HT II type. I have the tools for it now that Santa has been but I also know that I'll need to replace my chainset and thus chain as well if I upgrade to the HT BB.
I have a 8 spd 12-26 on the back and I've yet to fail or even struggle seriously on anything here around Winchester with the 36 x 26 but I'm not so sure I'd get up some 'proper' hills that are more than a mile (about 5-7% avg) in length and/or greater than 13% (a short few hundred metres max) which is as long and steep as I've encountered round here. Put another way, I used to live in Catterick and know some hills in N Yorks that would have me hooped compared to the tiddlers I have down here. In other words, if I was to enter the likes of the Fred Whitton, Cheshire Cat , Etape du Dales, insert any other big sportive with big climbs here next yr, there'll be some serious hills for which my 36 x 26 coupled with my lungs and legs will possibly fail on. Thus a 34T would buy be a bit more breathing space as opposed to a 53/39 which would defo be a step in the wrong direction for my ability and fitness level as well as my desire to complete some sportives and definately NOT race!
My questions are thus:
In upgrading to a HT II will I need to alter anything if I put on a 50/34 at the front ie will the mech position be ok for the mere 2T difference on the smaller ring?
Will an 8 spd chain still be ok? I presume it will.
Will I actually see or feel any kind of worthwhile enhancement? I've heard that the new HT brackets are smoother and lighter and this translates to effectively more power between the legs and wheel and thus slightly more speed for the same effort.
Is there a discernible difference between the Shimano Sora and Tiagra chainsets? The reason I ask is there is an ebay seller with a 50/34 Sora for just under £35 inc postage as compared with another who is doing the Tiagra at £50. Is the extra £15 for what are bottom end components worth the while? There is no point putting on Ultegra or even 105 as the bike is not high spec elsewhere and would not justify the added expense surely?
OR -
Would I be better off just replacing the sqaure taper BB for a new one and keeping my current 50/36 on?
OR
Try and source a 34T ring and replace the 36T one?
Sorry for the plethora of questions, but as I've found out on this forum, there is a lot of knowledge around so I'm hoping to get it all answered albeit not necessatrily by the one person (although that would be nice!!!). Thanks in advance.
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Comments
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GavH wrote:My questions are thus:
In upgrading to a HT II will I need to alter anything if I put on a 50/34 at the front ie will the mech position be ok for the mere 2T difference on the smaller ring?
I think it will be fine - since the large ring is the same size and therefore the mech will be at the right height. limit screws might need to be changed though - which is no big deal.
Will an 8 spd chain still be ok? I presume it will.
i think so - you are still retaining 8-speed right? - chainsets are largely "speed" independant
Will I actually see or feel any kind of worthwhile enhancement? I've heard that the new HT brackets are smoother and lighter and this translates to effectively more power between the legs and wheel and thus slightly more speed for the same effort.
they are stiffer and lighter and easier to work on - will you feel it? - hard to say - a worthwhile upgrade imo though.
Is there a discernible difference between the Shimano Sora and Tiagra chainsets? The reason I ask is there is an ebay seller with a 50/34 Sora for just under £35 inc postage as compared with another who is doing the Tiagra at £50. Is the extra £15 for what are bottom end components worth the while? There is no point putting on Ultegra or even 105 as the bike is not high spec elsewhere and would not justify the added expense surely?
I think that the sora one is a bargain and would go for it if I were you. not sure if it is worth the extra for the tiagra one.
OR -
Would I be better off just replacing the sqaure taper BB for a new one and keeping my current 50/36 on?
I say go for the HT2
OR
Try and source a 34T ring and replace the 36T one?
that might be the easiest route right enough - try Ribble they usually have a decent selection of chainrings.
Sorry for the plethora of questions, but as I've found out on this forum, there is a lot of knowledge around so I'm hoping to get it all answered albeit not necessatrily by the one person (although that would be nice!!!). Thanks in advance.0 -
Hi, i'll have a stab at your list of questions :shock:
1- no need to move the front mech just limit screws and cable adjustment.
2 - 8 speed chain should be ok, it is only the cassette that needs a matching chain.
3 - compact HT2 chainset and BB is a good upgrade, lighter and stiffer but don't expect a massive difference.
4 - difference between Sora and Tiagra is weight, steel rings on Sora, alloy rings on Tiagra.
5 - forget the chainring / new BB option and go for HT2
I fitted a Tiagra 34/50 compact and 105 bearings on mine and it is a good upgrade.
Some points to watch out for, removing the old BB can be an absolute b*****d so get your LBS to do it. Also get them to chase out the BB threads and face the frame ready to fit the outboard bearing cups. The cups need to be fitted very tight so use the correct tool.
Good luck
He is not the messiah, he is a very naughty boy !!0 -
Hi, i'd just change the BB (like for like). Its very easy to do with your new tools. If you do need to use a bit of leverage I slip an old pair of flat handlebars over the tool handle.
Being a slightly tight bugger if the bike fits its current purpose why mess with it.0
