Will I die if I modify my new frame? Materials engineers??

Home Forum Bike Forum Will I die if I modify my new frame? Materials engineers??

Viewing 32 posts - 1 through 32 (of 32 total)
  • Will I die if I modify my new frame? Materials engineers??
  • Premier Icon oxym0r0n
    Subscriber

    So, new frame – hoping to fit most of my existing parts – thought I’d just test-fit the rear brake before taking the headset off the old frame…
    [/url]
    Brake problem by oxym0r0n, on Flickr[/img]
    It doesn’t fit!

    So – will I die if I file away a bit of the dropout for the caliper to fit (It’s a NOS Salsa El-Mariachi with Magura Marta)

    New frame – not really an option as I chose this specifically due to geometry, component compatibility(!),swingers etc.
    New brakes not really an option, as I have another set of Marta’s and like to share pads, bleed kit etc.

    I’ve already taken apart my old 26″ wheel to be built into a 29″ and bought a few finishing components…

    Thoughts (mainly on filing away a bit of the dropout?)

    Thanks

    cynic-al
    Member

    If you can get a spare dropout, maybe try it. But you’ve got a lot of material to lose and I certainly wouldn’t file the frame, unless it’s a small amount and the frame is a keeper.

    New caliper is the best solution IMO.

    inbred853
    Member

    Got the same frame and use XT 775, no problems with frame/ dropout clearance.
    I take it the caliper is hitting against the frame as you try and locate the top bolt into the dropout?
    If that’s the case I would swap brakes rather than modifying the frame, however really depends on how much metal you would be removing.

    First, take your spoon….

    andysmiff1
    Member

    What about using a Hope +20 is/is mount? Will mean increasing rotor size by 20mm but will allow you to keep same brakes and not modify the frame in any way?

    A

    Edit – just checked CRC and no stock, but I’ve got one in the spares box you can have if you want to go down this route?

    Quick visual guess would suggest you’d be about half way through the dropout before it fitted ok so It looks like you will have to go for a bigger rotor or change brakes.

    Tracker1972
    Member

    Bigger rotor was my thought (once I understood the problem and picture 🙂 )

    Just out of interest, I’m not sure I understand how that dropout attachment works, could you enlighten?

    By the look of it the upper dropout securing bolt also holds the caliper? So the upper hole on the dropout itself is not threaded and it uses the caliper as a ‘nut’? Not sure I like the idea of that, I’d want that bolt pretty tight and the caliper is made of ally.

    How about on the lower bolt, is the dropout threaded or is it clearance with a nut behind?

    Premier Icon firestarter
    Subscriber

    Bigger rotor for more space 🙂

    Premier Icon njee20
    Subscriber

    Wow that second picture is screwing my eyesight!

    Premier Icon ahwiles
    Subscriber

    this isn’t a ‘materials’ problem.

    andyl
    Member

    the OP left me wondering what the problem was too.

    Definitely +20mm IS to IS adapter and a bigger rotor.

    Premier Icon oxym0r0n
    Subscriber

    Thanks all – sorry, maybe didn’t explain the problem fully – the upper botl is also designed to hold the top of the caliper.

    Frustrating, because in theory it should work i.e. if the dropout had more of a sweep to it – bur then I guess you might have frame clearance issues.

    Hadn’t thought of +20, so that is def an cheaper option than new brakes. Just wanted to keep it neat and clean looking with minimum boltage.

    Firestarter – are you running a 180? Any clearance problems with the frame?

    Thanks all… still tempted to get the file out 😳

    Premier Icon oxym0r0n
    Subscriber

    By the look of it the upper dropout securing bolt also holds the caliper? So the upper hole on the dropout itself is not threaded and it uses the caliper as a ‘nut’? Not sure I like the idea of that, I’d want that bolt pretty tight and the caliper is made of ally.

    How about on the lower bolt, is the dropout threaded

    ^This. Seems like a pretty neat solution to me and AFAIK there have been no problems. The lower bolt seems to take the brunt of the force.

    Premier Icon parkesie
    Subscriber

    Go +20 put the file away and step away from the frame.

    druidh
    Member

    By the look of it the upper dropout securing bolt also holds the caliper? So the upper hole on the dropout itself is not threaded and it uses the caliper as a ‘nut’?

    If you are using an IS-PM adapter 8) then that top bolt is only threading in to the adapter and so what that it’s made of alloy? In addition to the two nuts on the dropout there’s also the bolt that stops it moving forward.

    Premier Icon oxym0r0n
    Subscriber

    New dropout = £25 – worth a shot? I still fancy doing this, but will I compromise the strength too much?
    (In which case it is a material’s question :|)

    gee
    Member

    I had exactly the same problem with exactly the same brake. I posted something about it on here and on the Salsa forum on MTBR as a warning! Don’t go anywhere near the steel dropout with a file. Yes, a new one is only £25 but that’s not really the point as you’d have to file away the frame itself as well to get the calliper to fit. I did brake-musical-chairs with my other bikes so ended up with Hopes on the El Mar instead. Cheapest way out has to be a +20mm adaptor or a post-mount calliper plus IS adaptor, which fits fine.

    The top dropout bolt also secures the calliper, yes, but as its a massive 6mm steel jobbie it can go pretty tight into the calliper without stripping. The bottom one threads into the dropout.

    GB

    Premier Icon oxym0r0n
    Subscriber

    Okay problem may be solved – just realised I have a “spare” 160 front caliper, which would become a 140 rear, so +20 would become 160 😀

    Only problem is, it is silver, so might be looking for someone to anodize it black (cos I am that fussy 😉 )

    cynic-al
    Member

    Looking at it more closely, if you could avoid filing the frame, I’d have done it.

    watsontony
    Member

    if someone wants to anodize your caliper black i would be happy to get send a couple of bits to be done and split the cost,,, or maybe open a thread and try get a load done, hopefully cheaper still 🙂

    andyl
    Member

    but surely a 160mm front caliper that would sit as 140mm on the rear would move the piston part closer to the axle and put you right back in the same position with a +20mm adapter? I’d go with the 180mm rotor and be safe.

    Premier Icon oxym0r0n
    Subscriber

    but surely a 160mm front caliper that would sit as 140mm on the rear would move the piston part closer to the axle and put you right back in the same position? I’d go with the 180mm rotor and be safe.

    Yes and no – the calipers are different, but I think I will have to trial it and see…

    Premier Icon Rusty Mac
    Subscriber

    If you have the adapter then you may as well give it a bash. I can’t get my head around how it would but it would be far better than attacking the drop out with a file. Would the calliper not be wider than the drop out anyway?

    Premier Icon oxym0r0n
    Subscriber

    Have emailed the guy who was in the anodising thread from a year ago. I will try to source an adapter from lbs to try and post the results. I think the 140 will sit further around the arc of the disc and therefore fit… We’ll see!

    andyl
    Member

    take a look at the PDFs on the right hand side here to see the caliper positions: http://www.hayesdiscbrake.com/support/ which might help you work out the clearances before you buy anything else.

    Premier Icon firestarter
    Subscriber

    my disc is 185 and have no problems with anything used with m4 and x2 calipers too

    andysmiff1
    Member

    If you don’t have any joy with the LBS drop me a message back and I’ll bung the spare is +20 mount I have in the post for you!

    A

    Premier Icon oxym0r0n
    Subscriber

    Andysmiff you are a gent – can I ask what make and colour it is please?

    Premier Icon oxym0r0n
    Subscriber

    Ah, I’m guessing silver and hope, looking back at the earlier post!

    andysmiff1
    Member

    It’s a genuine Hope one, was silver in colour but has had a coat of black spray paint to match my old calipers.

    Spray paint is a bit tatty after its been knocking round the spares box but I’m sure you can fix that!

    It’s of no use to me anymore, so it’s yours!

    My email is in profile – send me your address and I can post it tomorrow.

    A

    Premier Icon oxym0r0n
    Subscriber

    UPDATE:

    [/url]
    +20 hope by oxym0r0n, on Flickr[/img]

    So, +20 Hope and front 160/rear 140 caliper together kind of fits, but the hope adapter would need some modding(!)

    Looking forward to recieving a Magura +20 kindly donated by TheGingerOne, which will hopefully fit with no modifications at all.

    Now to get a longer brake hose…

Viewing 32 posts - 1 through 32 (of 32 total)

The topic ‘Will I die if I modify my new frame? Materials engineers??’ is closed to new replies.

Comments are closed, but trackbacks are open.

Skip to top