Upgrade to 105 Hollowtech II - benefits?

sparkins1972

Hi - my bike is currently set up with an old Tiagra 9 speed triple chainset -it has been suggested to me by my a mate to start looking to upgrade to a 105 Hollowtech, but am just trying to get my head around the benefits of doing so.

I see the obvious benefits of lighter weight and less flex - is this a significant improvement over what I currently have, does anyone know?

Secondly I see the following in a lot of the blurb

'HollowTech II allows the bottom bracket bearings to be spaced wider apart (outboard from the frame), enabling the use of larger bearings and an increased axle diameter'

I am maybe being a bit thick here, but so what if the bearings are bigger - what benefit does this deliver to me?

thanks for educating a novice!

peanut1978

it gives smoother rolling.
Stronger bearings.
Very happy with mine, no flex at all

sparkins1972

Thanks Peanut - think I will go ahead and make the upgrade.

fuzzynavel

peanut1978 wrote:

it gives smoother rolling.
Stronger bearings.
Very happy with mine, no flex at all

Wiggle were doing the dura-ace version of the Hollowtech BB at a decent price a while ago....Massive difference....but then even a bargain basement set would have made a difference to worn bearings!

sparkins1972

Does anyone know of suppliers of Shimano OE stuff?

I saw that Wiggle had the 105 and Ultegra Hollowtech OE chainsets a while back and it was miles cheaper - they suggested it was exactly the same as standard Shimano just without the relevant packaging and in some cases instructions - they don't seem to be stocking it now though unfortunately.

Headhuunter

What's the difference between a standard 105 external BB and a Hollowtech one? Has anyone compared the 2 and noticed a difference?

edindevon

Headhuunter wrote:

What's the difference between a standard 105 external BB and a Hollowtech one? Has anyone compared the 2 and noticed a difference?

The standard 105 external BB is Hollowtech II, so there aren't two different ones to compare.

In fact the old Octalink 105 chainsets are also branded Hollowtech, but they're not Hollowtech II. That is to say, they don't use the Hollowtech II BB.

Personally I'm not at all convinced that Hollowtech II offer improvements that your average rider will genuinely notice. If I had a perfectly good Octalink BB already fitted to my bike and was set on upgrading the chainset, I'd look to get a quality Shimano Octalink chainset, as they're heavily discounted right now. For example, if a 170mm crank length suits, Chain Reaction currently have the Dura Ace 7703 Octalink triple chainset for £115.

Edindevon

a_n_t

the hollowtech bb on my tt bike creaks like a b!tch!!

salsarider79

Edindevon wrote:

Personally I'm not at all convinced that Hollowtech II offer improvements that your average rider will genuinely notice. If I had a perfectly good Octalink BB already fitted to my bike and was set on upgrading the chainset, I'd look to get a quality Shimano Octalink chainset, as they're heavily discounted right now. For example, if a 170mm crank length suits, Chain Reaction currently have the Dura Ace 7703 Octalink triple chainset for £115.

Edindevon

I changed my Single speed over to external BB and it was a damm sight stiffer and quicker. On a single speed you notice that difference in the stiffness. I think he would notice a difference to be honest.
I think it's a worthy upgrade, but then why not look at going the whole way and go 10speed. If you look around, you can get some good deals on Shimano 105 and SRAM Rival...
Lastly, bear in mind you have a triple, so if you change (unless your moving to a triple) you will need to adjust your front mech.

sparkins1972

Thanks for the ideas chaps.

Just for clarification I am considering swapping the original Tiagra 9 speed triple ( I guess Octalink, but I don't really know) for a 105 Hollowtech Triple, as the Tiagra chainset is getting towards the ned of its useful life. I am led to believe that I can swap in the 105 Hollowtech without having to swap shifters, front mech etc.

Thanks

Stephen

edindevon

sparkins1972 wrote:

Just for clarification I am considering swapping the original Tiagra 9 speed triple ( I guess Octalink, but I don't really know) for a 105 Hollowtech Triple, as the Tiagra chainset is getting towards the ned of its useful life. I am led to believe that I can swap in the 105 Hollowtech without having to swap shifters, front mech etc.
Stephen

You might not have an Octalink chainset, as there are also Tiagra square taper chainsets, so you're as well to go straight to Hollowtech II if you're not sure.

You'll obviously need a new BB as well, but everything else such as mechs and shifters should be fine.

Just to be clear though, you'll only be 'a damn sight quicker' in your imagination, as not even the most fervent marketing man will claim any objective evidence of significant performance improvements with the Hollowtech II system.

Edindevon

nmcgann

Edindevon wrote:

.....
Just to be clear though, you'll only be 'a damn sight quicker' in your imagination, as not even the most fervent marketing man will claim any objective evidence of significant performance improvements with the Hollowtech II system.

Edindevon

Agreed. I replaced a 105 Hollowtech/Octolink setup with 105 HT2/External BB setup on my summer bike when I upgraded the frame and although the HT2 crank setup is nice I can't say I've noticed any improved performance at all. (not that I was expecting any)

sparkins1972

I am going to strip my chainset down and see if it is Octalink or Square - if it is Octalink then I think I might go for those Dura Ace ones on Chain Reaction, if it's square then I will go down the 105 Hollowtech route.

I am realistic enough to know that it's not the odd component that is slowing me down, it is my legs and gut!

Airwave

a_n_t wrote:

the hollowtech bb on my tt bike creaks like a b!tch!!

Same hear,and that's after two services at the local LBS :x

Headhuunter

Edindevon wrote:

Headhuunter wrote:

What's the difference between a standard 105 external BB and a Hollowtech one? Has anyone compared the 2 and noticed a difference?

The standard 105 external BB is Hollowtech II, so there aren't two different ones to compare.

In fact the old Octalink 105 chainsets are also branded Hollowtech, but they're not Hollowtech II. That is to say, they don't use the Hollowtech II BB.

Personally I'm not at all convinced that Hollowtech II offer improvements that your average rider will genuinely notice. If I had a perfectly good Octalink BB already fitted to my bike and was set on upgrading the chainset, I'd look to get a quality Shimano Octalink chainset, as they're heavily discounted right now. For example, if a 170mm crank length suits, Chain Reaction currently have the Dura Ace 7703 Octalink triple chainset for £115.

Edindevon

But I've got a 105 chain set on my Focus Cayo and it hasn't got that hollow bit running through the middle. The BB is external but not hollow. The bike is from 2007, but I think Hollowtech has ben around since before then hasn't it? Unless the BB is not 105 and only the chainrings are, but there is no hollow bit on the chainrings themselves... Sorry, I'm confused! Thanks for the clarification.

soveda

I think the "hollowtech" bit refers to the crank arms rather than the spindle (hence there being hollowtech without external bearings). The road hollowtech II looks "solid" through the spindle but if you have the type of crank with two pinch bolts on the non-drive side arm you have hollowtech II.

FWIW when I moved from square taper bb to external bearings on the MTB I got ship splints initially because of the increased stiffness...

Headhuunter

soveda wrote:

I think the "hollowtech" bit refers to the crank arms rather than the spindle (hence there being hollowtech without external bearings). The road hollowtech II looks "solid" through the spindle but if you have the type of crank with two pinch bolts on the non-drive side arm you have hollowtech II.

FWIW when I moved from square taper bb to external bearings on the MTB I got ship splints initially because of the increased stiffness...

Oh OK. It sounds like I have got Hollowtech then. Does Hollowtech just mean external BB then? Both my bike to work bike and my weekend bike have the pinch bolts on the non drive side and the silver ring next to the frame/between the frame and crank arms which I have always understood indicates an external BB. The bike to work is Tiagra and the Focus is 105. I have to agree with others that external BBs seem to creak a lot more. Don't know if it's the BB or something else but the bike to work creaks quite a lot when I put hard pressure on the pedals and it's a brand new bike (well about a month old). The Focus has developed an annoying "tick" when I cycle.

furrag

I've read a lot of reviews saying it creaks loads. Does anyone have Hollowtech II which doesn't creak?

sparkins1972

Ok my undeerstanding of Hollowtech is as follows.

Hollowtech relates solely to the fact that the cranks are hollow and not solid. the first generation of Hollowtech was available with Octalink BBs so the hollowtech cranks fitted to the Octalink BB.

Then along came Hollowtech II which still had the hollow cranks, but also introduced the new external bearings and hollowtech II BB.

Octalink stuff is still available to buy but I guess will gradually be phased out, forcing Shimano users to move to Hollowtech II, which will then be phased out to be replaced by Solidtech or whatever the next generation is called.

Personally I am not a good enough cyclist to be too fussed about saving the odd gram here and there, I just want the best quality components that will last and wont negatively impact my riding. I have been happy enough with my old Tiagra chainset, but now I am looking at upgrading I just want to consider the options.

keef66

You understand correctly.

I have a sealed Octalink BB on my mtb which is now 12 years old and still works silently and smoothly! I did once have a creak on one crank, but silenced it with a hefty tweak of the crank bolt.

When ordering my road bike I specced 105 and that is Hollowtech II. 2 years on and it's still silent. No creaking, no tweaking.

The theory is sound; larger bearings, further apart, allowing lighter components while delivering a stiffer pedalling platform. TBH I can't detect a difference in stiffness or anything, but I'm a spinner rather than a Chris Hoy type of cyclist.

I like the simplicity of the outboard bearings; I'm able to dismantle and reassemble the crankset in a few minutes. I also get the impression the bearings are less likely to become permanently attached to the BB shell like some internal cartridge types can.

I wish the bearings could be accessed for cleaning / regreasing, but that's just to satisfy my urge to tinker. The old MTB cartridge BB is still OK without any maintenance.

I'd say if you find a good deal on an older chainset, go for it. Despite the marketing hype, the benefits of the latest technology are marginal for an ordinary joe like me.

topdude

I wish the bearings could be accessed for cleaning / regreasing, but that's just to satisfy my urge to tinker. The old MTB cartridge BB is still OK without any maintenance.

You can do this by prising off the outboard seal, the bearings are then exposed for tinkering

bill57

The issue of cranks and stiffness is the marketing man's dream come true. They should give away a free copy of "The Emperor's New Clothes" with each one.

Note I'm not saying don't buy one, just don't kid yourself.

Headhuunter

To be honest "Emporer's New Clothes" can be applied to many cycling "innovations". I've had/got old but decent spec steel framed bikes with period componentry and they perform just as well as my fancy carbon and aluminium models with fancy new kit.

keef66

@ Topdude.. thanks for that, I'll give it a try when the urge next descends upon me. Is it easy to get them out without damaging them?

sparkins1972

Hi Bill - I am not kidding myself that a new set of cranks will have any effect , either positive or negative, on my cycling as my previous comments have made clear. The thing is my existing chainset is about knackered so I have to replace with something - given that I only have experience of Shimano and am not inclined to change manufacturer, I have to consider either Hollowtech II or one of their older models. I am just trying to gather as much info as possible from others' experiences.

nmcgann

Furrag wrote:

I've read a lot of reviews saying it creaks loads. Does anyone have Hollowtech II which doesn't creak?

Mine doesn't creak. I did grease well and tighten everything up carefully using a torque wrench though.

dennisn

nmcgann wrote:

Furrag wrote:

I've read a lot of reviews saying it creaks loads. Does anyone have Hollowtech II which doesn't creak?

Mine doesn't creak. I did grease well and tighten everything up carefully using a torque wrench though.

No problem with mine. I lightly oil the crank arm face where it comes into contact with the bearing face(both sides). No squeaks.

borisvanhalen

mine creaked after being abused for abouit 8000miles... tried tightening, greasing but the bearings were simply knackered, new set of externals equals no creaking for another 8000 or so

balthazar

sparkins1972 wrote:

Hi Bill - I am not kidding myself that a new set of cranks will have any effect , either positive or negative, on my cycling as my previous comments have made clear. The thing is my existing chainset is about knackered so I have to replace with something - given that I only have experience of Shimano and am not inclined to change manufacturer, I have to consider either Hollowtech II or one of their older models. I am just trying to gather as much info as possible from others' experiences.

Knackered, how? if the chainrings are worn out, they are replaceable: they need not be Shimano. If the BB is worn out, then it is replaceable. You only need new cranks if they are damaged.

bill57

Balthazar, the man wants to upgrade, and why not - who wants an old tiagra triple? Don't spoil his fun.