Any double chainset with external BB deals?

sandbag

I am interested in switching from square taper to Hollowtech II for the extra stiffness. Worth it? I understand the bearings don't last as long.

Is there any great deals on a double chainset including the BB?

If not, can you recommend me a seperate chainset and BB that is quality enough to be worth the upgrade.

English thread.

and is it essential to get the BB faced? I will be upgrading the frame in the summer.

Thanks.

JohnnyAllez

Frame shouldn`t need facing. Upgrade "worth" depends on what you have at the moment. Cheap Tiagra chainset and BB (ordered seperate) from Ribble. They usually work out cheapest for groupset stuff from what I`ve found.

http://www.ribblecycles.co.uk/sp/road-t ... HIMCHAR460

http://www.ribblecycles.co.uk/sp/road-t ... HIMBTBR710

http://www.ribblecycles.co.uk/sp/road-t ... 0000000000

http://www.ribblecycles.co.uk/sp/road-t ... 0000000000

keef66

My only comparison has been in moving from a slicked up rigid mtb with Octalink, to a HTII 105 road bike. From an engineering point of view it should be stiffer, but I can't say I've noticed the difference. Bearings still silky smooth after 2 winters.

The outboard bearings do look nice though.

edindevon

£46 for the Truvativ Elita chainset with GXP BB from Merlin seems to be a very good deal if you're looking for a standard double:

http://www.merlincycles.co.uk/road-bike-chainsets/truvativ-elita-chainset.html

Edindevon

tenor

just bought and istalled a Campagnolo Centaur UT CT chainset from GB Cycles; £64 for the chainset + £13 for the BB Cups. Nice bit of kit.

salsarider79

You haven't said what rings you want 50/34, 39/52 or 39/53. The stiffness is there, I went from Dura Ace track cranks to a cheap FSA Gossamer set up, and the difference is amazing.
The only other question I have is why you want to change? Is it just an upgrade thing or....?

dennisn

I would suggest that you SEARCH(as JohnnyA said at the end of his post). Plenty
of online parts catalogs out there.

Slow Downcp

Merlin have FSA Gossamer for £90 (or there's a nearly new in classifieds for £70).

redddraggon

£40

http://www.chainreactioncycles.com/Mode ... elID=41442

Crankmeister

i would face the BB for definate.if it out slightly your chainset wont spin as freely and youll get premature bearing wear which is a pain in the wallet.

sandbag

Food for thought. Thanks alot.

salsarider79 wrote:

You haven't said what rings you want 50/34, 39/52 or 39/53. The stiffness is there, I went from Dura Ace track cranks to a cheap FSA Gossamer set up, and the difference is amazing.
The only other question I have is why you want to change? Is it just an upgrade thing or....?

Sorry, I didn't say, meaning i was looking for the double standard of 53/39 and considering anything tasty. I want to maximize power transfer. A more upto date crank and more modern BB should be stiffer and alittle lighter. I have a broken tooth on my inner ring. They are showing signs of heavy wear. A new chainring is nearly the price of a discounted crankset. I might as well upgrade the whole lot and get some more benefit.

I don't visit all the stores. I spotted a couple of discounted Ultegra BB cranksets. I wanted Shimano particularly. Smaller bearings wear out faster. Hearing of newer BB's wearing out after a couple of months is amazing. I put off with Megaexo BB reading numerous bad experiences from roadbikereview.com , even if they are cheap cranks. I would prefer Tiagra over that.

ride_whenever

Don't worry about the bearing quality, get a good crankset, because there are decent aftermarket external bottom brackets available for just about every crankset now. You'll get good life on most BB setups though if the shell is true (either correct or faced)

Measure the BB shell in a few places with a vernier caliper, face the frame if it is outside the manufacturers tolerances, all painted frames should be faced, anodized ones more often than not don't need it.

sandbag

Edindevon wrote:

£46 for the Truvativ Elita chainset with GXP BB from Merlin seems to be a very good deal if you're looking for a standard double:

http://www.merlincycles.co.uk/road-bike-chainsets/truvativ-elita-chainset.html

Edindevon

I read the review of the compact Truvativ on Bikeradar.. If it the same kind of basic quality then it a very good deal. http://www.bikeradar.com/gear/category/ ... nset-10182

sandbag

Can the Tiagra crank mentioned, fit fine onto this Ultegra BB?
http://www.chainreactioncycles.com/Mode ... elID=38998
or this Dura Ace
http://www.chainreactioncycles.com/Mode ... delID=4162

triMPW

would the truvativ elita be a better option than the 105 octalink that chainreaction have for £30?
my frame will be a specialized transition comp 07 - what is facing?

redddraggon

Megaexo chainsets work with Shimano BBs. I have a Gossamer chainset with a 7900 BB

sandbag

triMPW wrote:

would the truvativ elita be a better option than the 105 octalink that chainreaction have for £30?
my frame will be a specialized transition comp 07 - what is facing?

Another Octalink deal.
http://www.chainreactioncycles.com/Mode ... ModelID=96

In a word, Yes it should be stiffer.

The Truvatic Elita sounds stiff and easier to fit. Probably harder material than the Gosammer.

Now as i understand it, facing is making the BB faces and threads exactly parallel and square with the frame. Even build up of paint can offset it. LBS use a special tool to correct it. By doing this, the external crank spins better with less wear on the bearings. This is probably the main reason why external BB wear out fast if BB not exactly square. Maybe on newer factory frames or higher quality frames it less of a problem, i don't know.

triMPW

Yeah i like the look of the truvativ Elita, i think i have a truvativ touro on my carrera vanquish.

Quite bad reviews of the octalink on that link.

sandbag

You can buy the replacement BB here.
http://www.merlincycles.co.uk/mountain- ... v-gxp.html
http://www.chainreactioncycles.com/Mode ... elID=19366

This could be the same Truvativ here. It 2008 10 spd. Not sure. It a higher RRP.
http://www.chainreactioncycles.com/Mode ... elID=30123

I tempted to get that or the Tiagra.

redddraggon

Cheap GXP is worse than Megaexo

At least with Megaexo you can use a Shimano BB

sandbag

I am also now wondering if not bother to get it faced, that i be could better off getting a higher model Octalink for the same sort of price. I get some stiffness and be lighter and not risk it not spinning so free, plus not wearing out the bearings as fast.

triMPW

but what about the octalinks coming loose?

sandbag

reddragon made a good point. If you go with GXP your stuck with the GXP BB.

I'm going with the Tiagra and the same 4500 cups. See how i get on...

Thanks everybody.

JohnnyAllez

sandbag wrote:

I'm going with the Tiagra and the same 4500 cups. See how i get on...

Thanks everybody.

It`s Shimano, it`ll fit fine, it`ll work fine

sandbag

JohnnyAllez wrote:

sandbag wrote:

I'm going with the Tiagra and the same 4500 cups. See how i get on...

Thanks everybody.

It`s Shimano, it`ll fit fine, it`ll work fine

Thanks,

Looking at the drivetrain compatibility, it would appear only the 4500 BB is compatible with Tiagra as it in a seperate box on the PDF, but apparently not, higher Shimano BB can be used.

There is a Hope adapter kit to make Truvativ GXP work with Shimano BB.

http://www.parktool.com/repair/readhowt ... 95#shimano

The No.1 problem with the Shimano Hollowtech II system is that the bearings are not designed to take side loadings, being simple annular 'cartridge' assemblies. Therefore, side-loading is to be avoided as far as possible since it causes wear. Such side loading can be applied by the crank end cap prior to clamping the crank; this is why the cap must be finger-tightened using the knurled plastic wheel supplied. This ensures that only enough side-loading is applied to remove any free play between the crank and bearing face. Of course there will be a tiny amount of axial load, but since an annular bearing tends to 'seat' down into the grooves in the races under radial load, this is acceptable. Do this right and the bearings last almost indefinitely. I have a pair installed in 2005 that are still going on my Roberts Audax. The system used for the XTR crankset applies exactly the same kind of loading but is perhaps more sensitive as a means of adjustment as might be expected of components designed for off-road use.

The use of a hard plastic for the 'top hat' sleeve, with its attendant low modulus of elasticity, means there is no need to make the bearing a press-fit on the axle, which would itself preclude the ease of assembly of the product. For evidence, look to Campagnolo's Ultra-Torque system. If a sliding fit inner bearing race was fit for the purpose, you can be sure Campag would have gone for it. In fact, a sliding fit in this application is an invitation to rapid wear or even fatigue failure through work-hardening of the mating surfaces. Bearings fitted to gearbox shafts are a press-fit for this reason.
Anyone who believes they can sense give in the plastic sleeve is welcome to their view, of course.The Hollowtech II bearings are also of large diameter in relation to their ball size. Fitted to a bottom bracket with non-square faces, the inner race of one bearing will not be running true to the other and one will have to run askew, with high loading at one point on the races. Again, this will accelerate wear to the bearing, which is why an accurately 'faced' bottom bracket shell will prolong the life of the Hollowtech II system. Incidentally, while I don't consider it optimal in execution, it does work very well if put together correctly.

Anyone who doubts that the faces of the bottom bracket affect Hollowtech II bearing alignment should try assembling them in a shell with non-aligned faces as I did once. The axle hit the second bearing offset by at least 0.5mm, meaning that it needed deflecting before it would go through the bearing. This deflection left the bearings misaligned and may have contributed to the short lifespan of the only set of HT II bearings I have worn out. (I got the shell faced before fitting the next set.)

sandbag

From comments i read, the quality difference between Shimano models of external BB is suprisingly minimal.

edindevon

sandbag wrote:

From comments i read, the quality difference between Shimano models of external BB is suprisingly minimal.

There again, the price differential is pretty minimal as well.

Given that the Dura Ace bb cups are only around £6 more than the 105 bb cups at Ribble, I suspect that anyone who has spent over £300 on a new Dura Ace chainset might feel that getting the cheaper bb cups might mean a case of spoiing the ship for a ha'porth of tar.

Edindevon

sandbag

My SRAM PC-971 chain has snapped again. Only had it 2 months or less and it's snapped 4 times, loosing a link each time, quite short now :twisted:. I connect it correctly. I think the old worn chainrings must be contributing to it snapping and they are not 9 speed compatible. So the new chainset can't come sooner.

Cheap biking is a myth for me at moment.

sandbag

Ok i have now fitted the Tiagra chainset and cups. Fitting it was the easy bit. Getting the old crank off wasn't. The chain side i got off. With the other side, the cover that covers the crank bolt wouldn't come out with the allen key. So i had to cut it out, in doing so i damaged the threads :twisted: I could screw in the crank puller well, but not all the way home. This forced it out on turning the bolt. So in the end i had to use a mini hacksaw(no suitable machinery ie. axle grinder) and cut the crank away in little bits from the spindle :shock:. 18 blades later i did it. In my haste, i forgot to remove the pedals first, so i had a had a right job removing, without no vice.

Talk about relief.

Bit too early to say but all in all it better, certainly very solid and stiff. It would appreciate a stiffer frame more i'm sure. I got a 175mm instead of the same 170mm. I feel the difference straightaway. I have more leverage. My knees feel to be going higher. Need to adjust my seat post and get used to it. Glad to loose the weight of the heavy square taper.

Spoke to nice patient guy on phone and said it will be dispatched tomorrow. The day after it arrived.

Well done Ribble.

sandbag

Now that i'm more used to the longer crank, i find climbing hills faster and easier. It feels more powerful. The faster speed is down to the more solidness of the crank. It is akin to pushing a slightly harder gear due to the extra circumference. I just change down a gear. The wider chain line feels better, more comfortable. More knee bend though. I will be changing to thinner soles sometime soon.

JohnnyAllez

Ride it, enjoy it, don`t analyse the feck out of it It`ll ruin your day out Welcome to the world that is "UPGRADE"