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• #2
What's the axle length on your BB?
You'd be better off getting a longer axle to push your crank arm further out. I think those Miche BBs are only meant to be adjustable + or - 2mm?You might also want to check your cranks, they might be JIS instead of ISO (look up on Sheldon) which I think means they would sit closer in on the axle which could be contributing to your problem.
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• #3
Your Micke cranks are definitely ISO, which would be part of the reason the Shimano (JIS) bb put the chainline way out.
Given you're running a track frame with (presumably) track cranks, a (presumably) 107mm Miche ISO bb (track standard for Miche track crank/track hub) and a 120mm spaced hub, you shouldn't have anything like the problems you're having, unless the frame/bottom bracket shell or bottom bracket are damaged.
As someone suggested in your original thread, I'd check the frame alignment. I'd also have your bb shell chased and faced before installing a new Miche bottom bracket.
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• #4
What's the axle length on your BB?
You'd be better off getting a longer axle to push your crank arm further out. I think those Miche BBs are only meant to be adjustable + or - 2mm?You might also want to check your cranks, they might be JIS instead of ISO (look up on Sheldon) which I think means they would sit closer in on the axle which could be contributing to your problem.
Your Micke cranks are definitely ISO, which would be part of the reason the Shimano (JIS) bb put the chainline way out.
Given you're running a track frame with (presumably) track cranks, a (presumably) 107mm Miche ISO bb (track standard for Miche track crank/track hub) and a 120mm spaced hub, you shouldn't have anything like the problems you're having, unless the frame/bottom bracket shell or bottom bracket are damaged.
As someone suggested in your original thread, I'd check the frame alignment. I'd also have your bb shell chased and faced before installing a new Miche bottom bracket.
yeah cranks are definitely iso taper, miche bb is 107mm as Bluah says.
hub is a gran compe so is 120mm, miche advanced track cranks and miche sprocket and lockring too. bit of a puzzler especially since the previous miche bb provided a satisfactory set up. only thing i can think is that the previous bb was 110mm (as miche do manufacture them) however looking online in the the shops there is only dotbike that sell them and they have to order them from miche so i'd be surprised if that was the case.
is a frame alignment check something i can do myself or is it best getting taking it back to the lbs? just looking at the frame now everything seems to be ok although i'm not sure what the indicators of a misaligned frame would be?!
would facing the shell make any difference given the miche cups have no flanges? should note i torqued the cranks and bb on to the right tension and chased the shell myself in the workshop at the lbs
have though about swapping the miche out for a campy but they are alot more expensive and i don't want to have to buy a couple in order to find one that gives a good chainline.
is it likely that i've bent the drive side crank arm, might explain the arm scrubbing the chainstay?
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• #5
Try the string method to check your frame alignment, see towards bottom of page:
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• #6
What are the cranks? Reason I ask is that there are a lot of 'track' and 'single speed' cranksets knocked out cheap that are actually doubles and to get a 42mm chainline you need to mount the ring on the inside of the spider, which of course looks a bit cack in comparison but that's why they're cheap.
If this isn't the case (I don't ever remember seeing miche doing this on-the-cheap type of c/set), then I'd definitely check frame alignment as per the Sheldon link above.
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• #7
Try the string method to check your frame alignment, see towards bottom of page:
awesome, i'll give that a go, hopefully it's not the case
What are the cranks? Reason I ask is that there are a lot of 'track' and 'single speed' cranksets knocked out cheap that are actually doubles and to get a 42mm chainline you need to mount the ring on the inside of the spider, which of course looks a bit cack in comparison but that's why they're cheap.
If this isn't the case (I don't ever remember seeing miche doing this on-the-cheap type of c/set), then I'd definitely check frame alignment as per the Sheldon link above.
miche advanced cranks, track specific
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• #8
The Miche cranks are ISO, you've rammed them onto a JIS taper Shimano BB, if the chainline is now different when going back to the Miche I'm afraid to say it sounds like you have distorted the tapers on the cranks when you used the Shimano BB - ISO and JIS are not really meant to be mixed - you can do it, I've done it myself (with cheap cranks!), but there is always the risk that permanent changes to the crank tapers will result... I very much doubt there is anything wrong with the frame, it would have to be bent like a banana for that amount of difference at the chainstay result!
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• #9
The Miche cranks are ISO, you've rammed them onto a JIS taper Shimano BB, if the chainline is now different when going back to the Miche I'm afraid to say it sounds like you have distorted the tapers on the cranks when you used the Shimano BB - ISO and JIS are not really meant to be mixed - you can do it, I've done it myself (with cheap cranks!), but there is always the risk that permanent changes to the crank tapers will result... I very much doubt there is anything wrong with the frame, it would have to be bent like a banana for that amount of difference at the chainstay result!
ah, bollocks, that's all i need. thanks for clearing it up though. at least i've got a good idea whats wrong with them now.....
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• #10
Sounds like the best thing to do is go back to the JIS taper BB - the cranks fit that now so you just need to measure chainline and fit a longer JIS BB accordingly (take difference in mm between current chainline and 42mm ideal, double that figure and that's how much longer the BB axle needs to be - sorry if I'm teaching you to suck eggs there!).
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• #11
Another option is a longer ISO, like a 111mm Campy - the older Athena ones were made like the Miche with 2 adjustable cups so you can still tweak the chainline. Although the cranks no longer work perfectly with the 107, the cranks are still probably more ISO than JIS...
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• #12
Another option is a longer ISO, like a 111mm Campy - the older Athena ones were made like the Miche with 2 adjustable cups so you can still tweak the chainline. Although the cranks no longer work perfectly with the 107, the cranks are still probably more ISO than JIS...
cool, i'm trying a 111mm centaur bb today, fingers crossed. will keep an eye out for one of the athena ones too. thanks for your help
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• #13
One option with the Centaur is there is room to fit a 1 or 1.5mm spacer between the BB and the frame to move it a nats further right, there's plenty of thread to do this. The spacers used in SS conversion kits for Shimano cassette hubs are the right diameter. I might even have an odd one somewhere if you need it.
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• #14
A bit of a thread hijack, but the above does seem to be solved;-)
Any chance any of you can advise if i have caused a similar problem in reverse. I'm using a cheapish andel 165mm crank on a miche BB.
The problem i'm having is the crank arms keep slackening off when i ride. I'm concerned to over tighten and sheer off the crank bolts. Will this eventually stop, if i keep tightening them when they feel loose, or do i need to buy a compatible crank set, or compatible BB. SHeldon suggest mixing ISo and JIS is not a problem, so shall i just 'crank' them on as hard as i can?Any help would be much appreciated. Thanks
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• #16
dave - just a note on tightening just in case - bollock your crank bolts nice and tight regardless of what you're doing with tapers, if you're using a regular allen key (or even worse, one from a multi-tool) you won't get enough leverage to get it properly tight.
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• #17
Another option is a longer ISO, like a 111mm Campy - the older Athena ones were made like the Miche with 2 adjustable cups so you can still tweak the chainline. Although the cranks no longer work perfectly with the 107, the cranks are still probably more ISO than JIS...
turns out the bb my friend has was a 111mm athena not a centaur as i thought, this was a clear bonus as the factor of it being adjustable has solved the problem of the crank scrubbing the chain stay.
also discovered the cause in checking the frame alignment with some fishing line. turns out the drive side of the rear triangle was sticking out 8mm or so further from the seat stay than the non-drive side, hence why i'm having problems all of a sudden with the miche bb.
not crashed the frame recently just the incident with the drivechain locking up and the wheel moving, can only guess this has deformed the rear triangle?!
anyway, new frame time..... maybe go for a nice steel one...
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• #18
dave - just a note on tightening just in case - bollock your crank bolts nice and tight regardless of what you're doing with tapers, if you're using a regular allen key (or even worse, one from a multi-tool) you won't get enough leverage to get it properly tight.
From what i've heard, JIS cranks can work fine together with an ISO BB providing i get them on tight, i'm just concerned i'm gonna sheer of the cranks bolts in the BB. Not what i wanta be dealing with!
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• #19
Being lazy and drunk i've only read 50% of this thread.
... but for what it's worth, check the frame is straight (string round the headtube innit).
This shit should be simple.
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• #20
From what i've heard, JIS cranks can work fine together with an ISO BB providing i get them on tight, i'm just concerned i'm gonna sheer of the cranks bolts in the BB. Not what i wanta be dealing with!
Virtually impossible as long as the threads are good and greased lightly, and you're using ordinary hand tools - if in doubt, borrow a torque wrench and Google a suitable torque figure for the bolts.
Following on from the issues i recently had with my previous miche BB http://www.londonfgss.com/thread19544.html i temporrarily installed a cheap shimano BB to tide me over till the replacement miche turned up at my LBS.
the shimano wasn't great and the chainline was way out so decided to reinstall a miche despite my previous problems (the bb is english threaded incidently)
the issue i'm having now is that although the previous miche BB stuck out a few mm drive side, this one now needs to stick out even more and has reached a point where in order for my drive side crank to clear the chainstay the bb has to be shifted over quite alot to the drive side.
this then means the non drive side crank is right up against the BB shell
as it is the drive side crank just about clears the chainstay but everytime i accelerate the crank flexes and knocks the chainstay which is really pissing me off.
the frame is a dolan pre cursa with no history of collisions and miche advanced cranks and chainring. totally confused as to why i'm now having problems with a setup that was fine initially
any help would be really appreciated