Removing outer chain ring from a Shimano M739 crank

[jimo746]

£8.99 delivered to your door, worth it in my opinion to save on any damage caused by other removal methods.
http://www.chainreactioncycles.com/Mode ... elID=74219

 

[gdb2b]

Woz,
Decent tip on the technique that essentially bolts the removal tool to the lockring and the rest of the spider. Gonna try that next time. I did try the technique of clamping the removal in my bench vise. I was unable to apply sufficient torque on the crank arm to break the lockring loose.

Bolting the tool to the ring/spider, putting the tool in a vise, and then taking a rubber mallet to the crank arm might just do the trick.

 

[daugs]

apologies bit off topic but why the change in design from the earlier one piece spiders then removable rings to having spider part of large ring, this is still all fitting to square taper axle so just wondered on benefits ?

 

[legrandefromage]

apologies bit off topic but why the change in design from the earlier one piece spiders then removable rings to having spider part of large ring, this is still all fitting to square taper axle so just wondered on benefits ?

there are no benefits, just 'Faff'.

'Faff' is the new word to describe the 'new' that you must have before you even look at a bicycle let alone ride the damn thing.

'Faff' is what stops the spontaneous ride. 'Faff' can be be found in modern bikes taking up to 98% of a new bikes' design. Its in the pivots, the suspension settings, in between the 10spd cassettes, stuck halfway down a supposedly sealed shifter cable...

Faff has been known to cause the use of excess width riser bars and body armor for 'a quick blast'. Faff is also found in trail centres making up a good proportion of berms.

Faff has been with us since about 1996 when, under an EU directive, it had to be included in all new purchases which included cars, bicycles, TV's and so-on. Once perfectly good items that had a serviceable life of up to 30 years suddenly went wrong overnight due to 'Faff'. New purchases had to be made which included Faff, which we were told and assured about, they were the be all and end all of purchases, you wouldnt need another.

Of course, those new purchases became obsolete overnight as new Faff was available with the old immediately disintegrating rendering tools and repair shops redundant.

You only have to go to car-boot sales and recycling centres to see the amount of faff filled products being dumped or struggling to be sold...

Faff.

 

[Woz]

gdb2b - glad to help. I've had the STX version of this crank. That split ring just seemed like a belt and braces
solution if it wasn't done up properly. I'm a Middleburn user and I don't follow the instructions of putting thread lock on the threads. Just grease with a healthy torque because I know at some point I'll change spiders . Middleburns have a nice squared off machined crank arm which you can put in a vice with two pieces of wood and then use the big long 32mm spanner on the tool rather than bashing if needs be. In general I've never had any success with rubber mallets for anything stuck - just lump hammers and some hardwood.

LGF - agree with that. Anything with 4 arms is wrong too.

daugs - The Middleburn UNO for the RS7/8 is healthy faff - the real tangible benefit is you know that the chain ring is perfectly centered and you don't get any chain binding when running SS. The benefit when using the DUO is lower weight at a slight penalty of stiffness. No real benefit when using a normal spider with normal chain-rings except having a versatile set-up which appeals to constant tinkerers.

The Shimano system IMHO offered no benefit except that they could charge an extortionate amount of money for a new big ring in only the tooth size they decided we should all have. When the spare parts dried up, you would have to buy a whole new set-up because by that time they moved on to 14 speed drive and MegaGigaHzHollowTechPentaGonalHyper59BilletUnobtainuimScaffoldingPipe bottom bracket :roll:

 

[daugs]

daugs - The Middleburn UNO for the RS7/8 is healthy faff - the real tangible benefit is you know that the chain ring is perfectly centered and you don't get any chain binding when running SS. The benefit when using the DUO is lower weight at a slight penalty of stiffness. No real benefit when using a normal spider with normal chain-rings except having a versatile set-up which appeals to constant tinkerers.

The Shimano system IMHO offered no benefit except that they could charge an extortionate amount of money for a new big ring in only the tooth size they decided we should all have. When the spare parts dried up, you would have to buy a whole new set-up because by that time they moved on to 14 speed drive and MegaGigaHzHollowTechPentaGonalHyper59BilletUnobtainuimScaffoldingPipe bottom bracket :roll:

so, with my Deore LX M569 on the Dean project suffering same defects and needing bits, I am left with a quandary as to what chainset to use, see viewtopic.php?f=21&t=256972, all ideas gratefully received.

 

[firedfromthecircus]

M739 did offer a traditional five arm spider option which was also available to buy seperately.

They do come up now and again.

 

[Gruff]

M739 did offer a traditional five arm spider option which was also available to buy seperately.

They do come up now and again.

I have one on my M739.
I think you can still buy them new

On the side i do have an XT drive side crank with an outer ring which i'll Karma to anyone who wants it. Just want postage.

 

[daugs]

are all the bits interchangeable between different models, M739 and M569 for example, from pics looks like they should be ?

what bcd are the 5 bolt rings ?

 

[FluffyChicken]

yes you can switch between integrated spider, 5-arm CD and 4 arm modern. it may be possible but cannot remember if you can fit 5 arm atb from the xtr range, there are slight differences.
you can also get single speed ring from somewhere. a search on this topic should bring up a few threads with where and Whatnots.
that's the advantage of this FAFF, as middleburn found.
Of course by the time it became useful, shimano changed the FAFF.

Remember though, this is 98+ FAFF not true retro <97 FAFF