tighten crank arms makes BB tight?- Mtbr.com
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  1. #1
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    tighten crank arms makes BB tight?

    I got a new crank set and BB when I tighten my crank arms the BB gets hard to turn. I have a spacer on each side of the BB just like the instructions say with a BB mounted chain guide.

    I have a 68mm BB shell and a 68mm BB. I have the howitzer crank and recommended isis BB from pricepoint.com

    any ideas?

  2. #2
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    what DH/FR bike has a 68mm BB? and why isnt this in the Drivetrain forum?

    i cant see you crushing any bearing bearings on an ISIS BB by over tightening. maybe somethings rubbing?

  3. #3
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    howitzer crank with an isis bb is your problem. you need the howitzer bb

  4. #4
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    wow i completely read over that

  5. #5
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    no its a howitzer BB and crank set, I just ment that the drive type is isis. Its a GT DHI that has a 68 mm BB shell. Its not over the recommended 40 ft lbs torgue and its not rubbing anything, there is nothing to rub.

    http://www.pricepoint.com/detail/155...acket-2008.htm
    http://www.pricepoint.com/detail/168...nkset-2008.htm

  6. #6
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    think maybe I need to pull the spacers out of the BB caps? They might be causing my arms to bottom out on the bearings instead of the spindle slines? Also whats the right way to measure the chainline? I think mine is off to the outside away from the BB more then its supposed to even with no spacer, which might mean I should have gotten a shorter BB. If I keep buying parts and answering my own questions here I might learn a thing or two I guess.
    Thanks for the help pff!

  7. #7
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    Pull the crank arms off and see if the spindle slides side to side in the bearings. If it does, you've got too many spacers. You can measure the distance the spindle moves to determine how many spacers to remove.

  8. #8
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    I got it thanks for the tip, I had to remove them all and the cranks went on good and no binding this time. Still couldnt get my chain line straight so I added some spacers behind the sprocket and this seems to work fine, the bike works, nothing falling apart, everything is snug as a bug in a rug so I think Im gonna go with it like this. Had to remove my rock guard in order to use the spacers for the sprocket, but I guess you can always have everything your way.

  9. #9
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    I thought about drilling 4 more holes in the sprocket so that I can mount my rock guard back, I just might take myself up on that :-)

  10. #10
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    truvativ howitzer XR BB and ruction crankarms

    I have the same problem on my '08 Big Hit FSR, I bought a slightly used 2008 Specialized Big Hit FSR. Rode it once and noticed the sprocket side 8mm hex crank nut was loose. when torqued just slightly and not even close to the recommended 35 to 40 ft pounds, it seems to pinch the bearings together and it is very hard to turn. It seems to me that the splines on the BB should be even with the end of the Howitzer XR BB male splines,so as not to put so much pressure on the bearings. but the crank arm splines are overlaped about 5 MM from the end of the BB shaft. Is there a spacer missing or sleeve that goes over the bolt threads to keep it from putting all the torque on the bearings? all the truvativ PDF files blowups are not helping with this. I will take the recommendation of pulling both arms and seeing if there is play side to side on the spindle. If it has play, then I have too many spacers, or have to take the chain tensioner out? The splines on my Ruction crank arm are approx 5 mm past the end of the BB spindle, and when you put just a little torque on the crank arm hex nut, you can feel the bearings bind right up. I thought about putting a small 5 mm sleeve over the crank arm bolt and in between the crank arm splines so the bolt bottoms on the spindle and not the arm, Any ideas with this will be very appreciated, as it cant be ridden as is.

  11. #11
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    make sure the BB shell is the right length for the BB you are installing. If it is then Im almost sure your problem is like mine and the spacers are holding the bearings out too wide and your crank arms are tightening up against them. Remove all the spacers and if you can tighten your crank arms and you have no side to side play after that and the crank spins good your all set. The reason for the spacers is if you had too much side to side spindle play after the crank arms are tight. Hope this helps, it cured my problem.

  12. #12
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    Thanks very much for the tip and response.My BB should be the right length, as this is a 2008 Big Hit and was only ridden once, I was told.But I will check it. I dont think my BB has any of the 2.5MM spacers, but I will check again. It looked to me before, if I removed the chain tensioner bracket that is acting like a 5MM spacer that that would bring the end of the crank arm splines even with the end of the BB shaft. I am wondering if I should remove it? ( waiting to get my Howitzer BB tool) Also, Did anyone post a response to your question (bluesbox) about how to measure the correct chainline? I think mine is sposed to be 51mm. Thanks very much for the help. I need to ride this bike!

  13. #13
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    is your chain ring on the inside of the crank arm spider or outside? I think you can put it both on the outside and the inside depending where you need it, this may be an option for you, but it might be in the clostest position already. I could have removed my chain tensioner as well and got my chainline closer but I refused to do that because I love that chain guide and tensioner, so instead I took the 4 little spacers that came with the crank set and put them between the chain ring and the crank arm spider. This moved my chainline closer to the inside where I needed it.

    I dont think anyone replied to my chainline question, but I found the info online you measure from the center of your frame or BB shell to your sprocket and thats your chain line measurement. I think where I messed up is, I had two size options when ordering my crank arm set and I didnt quite know how to measure chainline so I just picked one and I think I picked the wrong size.

  14. #14
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    Hi, The chain ring is on the inside. I have pics, how do I post them? I now know I need to attain a 51MM chainline and I have a 73 MM BB shell. But I cannot find any info on what the spindle length should be on a '08 Specialized Big Hit FSR1 Howitzer XR Bottom bracket. Bluesbox mentioned that maybe Specialized ( mor someone) put the wrong length spindle or BB on it. because I think the bike had this problem since it was new from the factory. Does anyone know how to find the correct BB spindle length for this model '08 Big Hit FSR 1? This seems to be the most important info I need right now.My searching has not found the answer. Also I would like to ask, Is the Park BBT-19 bearing case removal tool the correct socket to get to remove the Howitzer XR bearing cases? Thanks so much for all the help. I just wanna get my material together for when I get another chance to work on the bike. JR

  15. #15
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    http://www.pricepoint.com/detail.htm...8&hprice=11.98

    This is the correct wrench to install and remove the howitzer BB's.
    They dont give a length on the spindles of howitzers I dont know why, all that they ask when buying one is your chainline measurement and BB shell size. I cant remember exactly but I want to say this howitzer spindle was way out there like 150mm or something, but thats because the bearins sit externally not internal like the gigapipe BB. But when you order a howitzer the only size to choose from is the BB shell width and the chainline measurement.

    You might actually have the wrong BB in there now that seems to me the only reason it would be hard to turn after you tighten the crank arms given the fact that you assured there are not spacers inside of the bearing caps on either side. Or the wrong crank set for that BB I dont think howitzer BB's are compatible with just any crank sets. According to pricepoint.com this is what they say:

    Question:
    Is the Truvativ Howitzer XR Bottom Bracket compatible with the FSA ISIS cranks?

    Answer:
    No, the Truvativ Howitzer XR Bottom Bracket will only work with the Truvativ Howitzer specific cranks.

    Im no expert on all of this, its still as clear as mud to me as well, I just so happen to worm my way out of the crank and BB mess I had myself but luck not knowledge or skill. So I hope all the info Im giving you might shed some light on your problem a littl.

  16. #16
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    If you're running a chainguide, you may only need one spacer on the non-driver side. That's what I've found.
    Meh.

  17. #17
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    Hi, thanks very much for the response. The truvativ

    Howitzer XR BB 22-07 BSA on it ( unless its the

    wrong one) has no spacers at all. i think this BB is

    supposed to have a 113 MM spindle. Yet the spindle

    seems to short to me. the spindle end falls about 5

    MM short of the end of the splines (which the bolt

    presses against) in the ruction crank arm.Isnt the

    end of the spindle supposed to be EVEN with the end

    of the splines in the ruction crank arm, so when you

    tighten the bolt it doesnt put pressure on the

    bearings?Or did they put the wrong size crankstop

    seal in it like they did Jettj45's bike? specs for

    my '08 Specialized Big hit FSR1 are a 73 MM long BB

    shell and a 51 MM chainline. Ive accurately measured

    these specs and they are spot on. I am trying to get

    a Park BBT19 socket tool to remove the bearing cap,

    because I want to use a torque wrench when I

    reinstall. I was recommended a BBT9 but this looks

    like a lever wrench and then how do you know you

    have the torque correct? The thing is Im not

    perfectly sure this is a Howitzer XR BB as per spec.

    So my question would be does anyone have a BBT19 or

    aBBT9 to measure and do they measure 44 MM INSIDE

    diameter, to match the OUTside of my outboard

    bearing cups? No One else online Ebay dealers or LBS

    will answer this question, but I need to make sure

    The BBT19 will fit my outboard cups. It does have

    the 16 notch's I just cant afford to waste any more

    cash on things that dont work. I have pics of the

    bottom bracket, crank ar etc. How do I post them?

    So far , my first thought's to solution, would be

    put a small spacer over the bolt and in between the

    crank arm splines( about 5 MM) or I hate to, but

    grind 5MM off the back of the ruction crank arm?

    Ouch! Thanks VERY much to all for your help. its

    killing me to have this advanced bicyle suspension

    technology just sitting there ( and all my money

    spent) and not being able to ride it!

  18. #18
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    I dont know the BB's by part number can you select which one you have from this link http://www.pricepoint.com/thumb/3-Pa...ckets-True.htm

    I have the 24.00 XR BB
    if you have to modify anything, dont put a washer between your arm and the spindle I think thats what wore out my set, because the spindle splines are tappered you would be better off grinding the rear of the arms to insure you have proper crank arm to spindle spline tapper tightness going on when you tighten them up, putting the washer wont let that happen and you might run them to far out and too loose.

    I had to do some modding to my set up to make it work, like you I wasnt going to spend more money on an unsure thing so I went for it hook or crook and everything worked out in the end.

    To tell you the truth if I were you, I would grind the rear of the arms until they fit with out squeezing the BB bearings, then put a little paint where you grinded and then you will be riding.

  19. #19
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    Sounds like you need a 118 mm spindle BB.
    Balls to the wall until you see god. Turn Left!

  20. #20
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    tight bearings when crank arm tightened

    Thankyou for the reply's and the help. I do believe with looking at the pics online that I do have the truvativ Howitzer XR bottom bracket. its a 22-07 and I seen 36-07 etc in pics. It seems to me that this might be the date of manufacture, with the month and the year the way they do on tire dates. the 118 MM spindle would be great and that would probably be the ticket, but that only comes on the 56MM chainline and my specs are sposed to be 51MM which checks out perfect now. I may take Blues advice of grinding the crank arm to relieve the pressure on the crankstop/bearing. and repaint. the howitzer splined spindle is tapered? I didnt know that. Im still waiting on my BBT-9 lever wrench from Park to take the cups off. I was thinking off taking the boxguide chain tensioner backet and wheel off from behind the bearing cup and it seems that would put me where I want to be also. splines even with the spindle end. Question is will the bike shift OK, and will the chain stay on the front chain ring if I remove the chain tensioner, box guide? By the way, I came too close to buying the BBT-19 socket bearing cup removing tool, because i wanted to use a torque wrench to reinstall. To all those thinking of this, dont waste your $20. I found out at the last minute that the BBT-19 will not fit over the spindle of the Howitzer. ( straight from Calvin Jones at park) I still may end up grinding 5MM from the back of this ruction arm. seems crazy to have to go thru this, with a bike that was $1,750. plus tax and my 14 yr old D'back sorrento and GF tassajara just keep cranking on with not even a creak. To the inquiry about the crank arm's, I have heard that the truvativ Holtzfeller crank arms will fit the Howitzer XR BB also, but I would research it more to confirm. Again , thanks to all for the info. This is an awesome forum!

  21. #21
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    Yeah trailtwister the spindle has a very slight tapper to it, thats how the crank arm gets a snugg fit, and thats where if you were to use washers the arm would be allowed to have the right sugg tappered fit onto the spindle. An unworn spindle and arm when taking off will be really tight to remove the arm because it had seated on the tapper of the spline, thats the reason for the crank arm pulling bolt tool, because I guess they can get so tight on there that they would need to be pulled off with a tool. I havnt had to use a puller tool because my first set up was worn so bad it practically fell off, and the new set I never put the arms super tight until I was sure I had everything in working order and then I tightened it.

  22. #22
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    Thanks for that info blues. I knew my old bikes had the square type tapered spindles, but I wasnt aware that the isis splined type were tapered.my crank arm literally "fell off too", so with this new info, its obvious that there isnt enough spindle sticking out.I need about 5 or 6MM more extended spindle to match the crank arm splines.I posted a pic, but I dont think it went. I got a minute to look at the ruction arm last eve ( you can probably tell I dont get a lot of spare time)and it looks like only about a sixteenth of an inch to grind off it,before it grinds into the splines, and that wouldnt be enough.Someone had mentioned a while ago that truvativ or specialized put "too thick" a crank stop/ seal on their BB. I will check on getting a thinner one. I wish I could just leave it out, but without a seal, I guess the bearing would self destruct on the first few trailrides. Still thinking of taking out the Boxguide and then putting the chainring on the outside of the spider to keep my 51MM spec chainline. I think DHTahoe mentioned maybe to use the 56MM chainline 118MM spindle, Might work if I can adjust the chainline back to 51MM. If all else fails I will try one. I think I will pull the other left arm off ( hope I dont need a puller) and measure the spindle. Its sposed to be 113MM. This is definitly a strange prob. because the chainline checks out perfect right now at 51MM with the 73MM long BB shell.I also noticed something strange on the BB shell it looks like cast in bosses that are threaded for screws, as if to suggest another means to mount the boxguide? I like this bike, i will trailride it! ( someday) soon I hope. Thanks to all for the awesome tips and help!

  23. #23
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    yeah there is two types of chain guides, one mounts to the BB bearing cap and the other with 3 screws if your bike has the threaded area for these screws around the BB then you might be able to change to the other type of guide which will give you a little more room.

  24. #24
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    Finally!Nice , smoothe free spinning Cranks!

    Finally got my BBT-9 botttom bracket bearing removal tool, and it worked great to get the bearing cup off. I did find one spacer in there, that I didnt see when it was assembled and took the Boxguide. chain tensioner off completly. After moving the chain ring to the out side of the howitzer crank spider to regain the 51MM chain line, and reassembling. All of 20 minutes work, the crank is now spinning freely! Got a chance to ride it 5 or 6 miles yesterday, and after adjusting the cable and rear deraileur to get the gears shifting correctly, everything is working smoothe as butter! Woohoo! I launched a few curbs( for now) to test the suspension which is amazing, and to see if my chain would stay on without the boxguide. There was no problem, as the rear deraileur seems to have plenty of tension. Although I will look into a tensioner/guide that mounts to the bolt holes that are cast right into the BB. Thanks to Bluesbox and all others that gave me suggestions! It was all of great help! So nice to finally get to ride the Big Hit! i was looking at a 1999 MBAction mag last eve, and saw an add for a 1999 Specialized Big Hit! Wasnt aware that they made that model back then. Thanks Again for all your help!

  25. #25
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    Trailtwister,
    As a guru on cranks/Bighits/chainguides...this is what you should have for a setup:

    You have Truvativ Howitzer-style cranks. This is a different interface than "ISIS" style cranks (which was sort of like the previous industry standard).

    Your Bighit has a 73mm BB shell, and needs a 51mm chainline. For a 73mm Howitzer setup...you need ONE 2.5mm black bottom bracket spacer on the driveside typically.

    Now, you also have a Boxguide. These come in one of two models...ISCG (3 bolt holes that mount to the frame) or Bottom Bracket mount. You have the BB mount. The Boxguide should be 2.5mm thick at the mounting point, which means that it should mount on the driveside.

    Final install should look like this:

    Left Crank -> Left BB cup -> 73mm BB shell (Frame) -> BB mount boxguide -> Right BB cup -> Right crank.

    Your chainring should be in the middle position as well, no need for it to be on the outside. Your cranks shouldn't be binding as long as you follow this for the setup.

    And of course, this is the info:
    http://www.sram.com/_media/techdocs/...itzer-e-r0.pdf
    http://www.sram.com/_media/techdocs/...guide-e-r6.pdf

    Just thought I'd get a fellow rider set up proper. Of course, if you still have issues our e*thirteen guides are pretty slick. We also just released a new line of pricepoint guides designed to retain the functionality of our flagship aluminum stuff...

    Cheers,
    philip

  26. #26
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    Bighit howitzer BB ruction arms

    Hi PhilW86, Thanks very much for the follow up and the diagrams. they are very useful. So in your assembly instruction. Left Crank -> Left BB cup -> 73mm BB shell (Frame) -> BB mount boxguide -> Right BB cup -> Right crank. if I read it right, I still dont put the shim back in o the drive side, but I can put my 2.5 MM thick boxguide back on and it will still spin freely? I took it on about a 5 mile ride without the Boxguide and the shim in there( drive side) and readjusted the gears and it seems to be great, but I guess I would put the boxguide back in if I could. With the boxguide and the shim in there it tightened up immediatly upon any torque and wouldnt spin,, so I know that cant be right. So just leave the shim out? Thanks VERY MUCH for your help! It is VERY appreciated!

  27. #27
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    Hi PhilW86, Thanks very much for sending the Truvativ Boxguide diaghrams and charts. I didnt have this for reference., before. On the chart's I see no application that calls for less than a 118MM spindle length. Looking at the specs for an '08 Big Hit FSR1, they specify a 113MM spindle length on the Howitzer XR Bottom bracket. I think this has been my underlying problem the whole time. Too short a spindle length, from the factory. Question is now, will the chain stay on, if i get big air? with no Boxguide or tensioner ? as of now,just for normal riding and curb jumping, the rear deraileur seems to be putting enough tension on the chain to shift the gears perfectly, and it doesnt skip or fly off the chainring as of now. Thanks to all for the help and recomendations! This forum rocks!

  28. #28
    moaaar shimz
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    Get a new bottom bracket with longer spindle and a e13 guide... presto!

  29. #29
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    Howitzer

    Quote Originally Posted by tacubaya
    Get a new bottom bracket with longer spindle and a e13 guide... presto!
    Yep, thanks for the reply tacu, That might be the ticket.

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