Wobbly Oval Concepts 730 crank arm - Non drive side.

[Trebz]

Re:

Righty, I'm with you 100%. I think it's the bottom bracket.

I just quickly fitted the correct spacers for the frame with a 68mm bottom bracket shell as per the quote below:

'A 68mm or 83mm bottom bracket shell needs two of the 2.5mm spacers on the drive (chainring) side and one 2.5mm spacer on the non-drive side.'

When I tighten up the non drive side allen bolt the bottom bracket is being squashed. The evidence of this being that the chain set (cranks) do not freely spin backwards and have considerable friction when there should be none.

It has to be the bottom bracket and after reading your last few posts and looking at the ,links below it MUST be the bottom bracket, at some point someone has fitted the wrong one.

Notes about the chain set on this ebay page: https://www.ebay.co.uk/itm/OVAL-CONCEPT ... 2732222374

The currently fitted bottom bracket is this one: https://bike.shimano.com/en-EU/product/ ... -BB52.html

I should have one of these fitted (Is this the right one?): https://www.ebay.co.uk/itm/Bicycle-Bott ... SwD75fWi7Z

 

[ishaw]

Re:

That is the type of bb you need. I bought a few recently and they do come with the gxp adapter (pic of one I just took out of the box below).

 

[FluffyChicken]

Glad you're beginning to see what we have been saying

Modern stuff eh!

 

[Trebz]

Re: Re:

That is the type of bb you need. I bought a few recently and they do come with the gxp adapter (pic of one I just took out of the box below).

Do you have a link for those? I can't make out the manufacturer name hehe

 

[Trebz]

Glad you're beginning to see what we have been saying

Modern stuff eh!

Ohhh leave me alone you, stop picking on me heheheheheh

 

[ishaw]

Re:

Here are the ones I bought. Came pretty quickly too

https://www.ebay.co.uk/itm/153856230309

 

[Trebz]

Well. if were all happy that this is the solution i'll pull the pin and buy one of those. Thanks gents, I lost the plot part way through this but it's only because I'm not familiar with the modern components. Why oh why couldn't they just stick with Square Taper.

Just a reminder for me more than anyone else, this is the standard spec sheet:

https://www.thebikelist.co.uk/fuji/absolute-1-3-2013

And the Drive section states:

Drive
bottom bracket BSA external
cassette (rear cogs) SRAM, 11-32T, 9-speed
chain KMC X9, 9-speed
chainring(s) 50/34T
crank Oval 730
pedals Nylon body w/ alloy cage

 

[klunkrider]

Just putting it out there that personally I would not be content using an HT2 style bb with a 24mm nds bearing with an adpater in it with a GXP chainset. And yes, I know that the Hope bb uses a spacer and that lots of people seem to be very happy with them.

The nds bearing in a GXP bb has that special extended inner race that butts up against the step in the axle and has the nds crank pressed against it on the other side. That race that forms part of the bearing is the only thing supporting axial loads in a GXP set up.

With a spacer inside a 24mm bearing I don't see how those axial loads can be properly supported.

It might run fine when you put it together but GXP putting all those axial loads through the nds bearing is already a compromise, putting them through a spaced out bearing that was designed to share axial loads with the bearing on the other side of the bb seems like a compromise of a compromise.

There also seems to be a whole mess of possible (or definite) variances to get into when you think about the (a)symmetry of spacers, spindle lengths, the overall width of the bottom bracket...

 

[ishaw]

Re:

I'm with you. If it were me, I'd just get a set of shimano or equivalent 24mm crank arms, swap the rings over from the oval cranks and use the shimano bb with the correct spacer configuration. A set of crank arms could be had for not much £ but a gxp compatible bb or one with the adapter would cost much less and get the bike rideable.

If the bearings fail quickly, at least that option is still on the table in the future, but the bike gets ridden before that bridge needs to be crossed.

 

[Trebz]

Re:

I'm still confused as to why the thing won't work correctly with the standard hardware it left the factory with. The spec sheet for the bike from new shows that the Oval Tech crank and Bottom Bracket are both standard units. The bike is in pretty much as new condition with only visible wear on tyres and a few very minor marks on the frame and I mean minor. I took these pictures after giving it's first clean and before I polished it up. I've shown the factory specs below as well. Surely we can get it working without spending money on a new chain set when it has the factory installed unit fitted. I'm not doubting anything you have said but the bike should 'Just work' as it is hehe, I mean, look at the condition it's in for a 2013 model. Maybe the BB has been swapped out for a new one but it looks like they fitted the same unit as a replacement.








Specs
sizes 21 Inch, 17 Inch, 19 Inch, 15 Inch (Frame size guide)
How to beat back ache on a bike
colours Maroon
frame type Rigid
frame material Aluminium Alloy
(The quick guide to aluminium alloy)
gears 27 speed
chainset type 50-34
wheel size 700C
front derailleur
shifters Shimano Sora
brakeset Tektro linear pull, forged alloy Tektro linear pull, forged alloy Tektro, alloy 3-finger
chainset Oval 730
rear derailleur Shimano Tiagra
cassette SRAM, 11-32T, 9-speed
wheels Vera Corsa double-wall alloy rims
Frame
frame material A2-SL double-butted aluminium
frame description A2-SL butted 6061 alloy, w/ double water bottle mounts, Rear triangle: A2-SL butted 6061 alloy, w/ forged rear dropout and replaceable derailleur hanger
Braking
brake caliper front Tektro linear pull, forged alloy
brake caliper rear Tektro linear pull, forged alloy
brake levers Tektro, alloy 3-finger
Drive
bottom bracket BSA external
cassette (rear cogs) SRAM, 11-32T, 9-speed
chain KMC X9, 9-speed
chainring(s) 50/34T
crank Oval 730
pedals Nylon body w/ alloy cage
Gearing
derailleur front Shimano Sora, 31.8mm
derailleur rear Shimano Tiagra, 9-speed
gears 27
shifter(s) Shimano Sora, 9-speed
General
grips Oval ergo paddle
handlebar Oval 200, alloy, 31.8mm
headset FSA, integrated
rigid forks FC-770 carbon w/ alloy steerer
saddle Oval 300R
seat post Oval 300R, alloy, 27.2mm
stem Oval 313R, 3D-forged alloy w/ 7-degree rise, 31.8mm
weight 22.95lbs/10.43kg
Wheels
hub front Formula alloy hubs, 24H w/ quick-release
hub rear Formula alloy hubs, 24H w/ quick-release
rims Vera Corsa double-wall alloy rims
tire front Vera Helios, 700 x 25c, 30 tpi w/ Phanlanx PR
tire rear Vera Helios, 700 x 25c, 30 tpi w/ Phanlanx PR
wheel size 700C