I have a dilema about which hub I should go with on my mongoose mountain bike. I have a sbp shift kit and currently a 7 speed cassette, but I want to try swapping the jackshaft chain to the inside of the final drive chain and having only 5 speeds. If I change the hub out for an old narrower 5 speed one fitted with a stronger & longer axle and with extra spacers fitted to the left side of the axle, the advantage is that I'll be able to use nearly equal spoke tension. If I stick with the 7 speed cassette hub and just don't use the first 2 gears I'll be able to easily pick and choose all 5 gear ratios independantly of each other and know that the right hand wheel bearing being further out is a stronger set up and that sealed bearings aren't gonna need servicing as often... hmmm thoughts anyone?
Which hub to use
- Thread starter Jonda500
- Start date
Not that I can help as I am still in the process of planning my new first build. However if you post some pictures of the setup you have and some of what you think you may want, it might make it easier for others to pipe in and help point you in the right direction.
I would sooo love to put up pictures but alas I have tried many times here but in this forum I am not able to- maybe newbies can't post pics?
I use photobucket for hosting pics. Easy to post here by using the IMG code.
And after 20 posts, you should be able to post pics Jonda
And after 20 posts, you should be able to post pics Jonda
Don't sweat it if the post doesn't show, go ahead & post 'em up anyway - new members' posts w/links are automatically held for staff review, just part of our anti-spam duties is all & sorry for the inconvenience 
The validation should be pretty quick, there's almost always somebody about
The validation should be pretty quick, there's almost always somebody about
Thanks - uploading to you tube and then posting a link was the next thing I was gonna try, but I did just reach 20 posts in this thread so I'll try one more time...
...nope the manage attachments button is still non reactive when I press it
...nope the manage attachments button is still non reactive when I press it
That's ...odd. I'm not sure why you'd have that problem, it's possible you've browser security setting conflicts but I'm jus' guessing, it's not an issue we've had reported before...
I personally prefer an external host & like maniac I use: http://photobucket.com/ ...although for absolute ease & simplicity w/o so much spam (I miss the old 'bucket) there's: http://tinypic.com/
Photobucket did buy tinypic, but so far they've not spammed it out *shrug* in any case, I've used both for years without any other complaint whatsoever
I personally prefer an external host & like maniac I use: http://photobucket.com/ ...although for absolute ease & simplicity w/o so much spam (I miss the old 'bucket) there's: http://tinypic.com/
Photobucket did buy tinypic, but so far they've not spammed it out *shrug* in any case, I've used both for years without any other complaint whatsoever
I joined tinypic so here's the bike:
and here's the drive train:
What I am proposing to do is to swap the jackshaft right side chain to the inside of the final drive derailieur chain. I'll probably stick with the cassette type hub so that changing individual gear ratios is easy- I might be able to use all seven gears after all depending on chain clearance.
and here's the drive train:
What I am proposing to do is to swap the jackshaft right side chain to the inside of the final drive derailieur chain. I'll probably stick with the cassette type hub so that changing individual gear ratios is easy- I might be able to use all seven gears after all depending on chain clearance.
I've run both derailleur & IGH jackshafts & I'm not sure your wheel issues will be resolved by this modification, as I've not had issue with any of the above... if you're having spoke tension problems it may be more likely caused by a problem with the wheel itself, rim flex or warp (single wall alloy or steel are prone to this) or it's simply damaged/trued incorrectly - while you can sometimes get a rim true even with unequal spoke tension, it'll likely not stay that way for long.
As for sealed bearing maintenance, they're all I run anymore for the very reason they need little to none. I do however take any new ones & very gently pry out the bearing seal, repacking them with a good marine-grade bearing grease like 2-4-C for it's far better water resistance & general quality, then clip the seal back in & reassemble.
I don't think that's really necessary for most, but I live in a harsh salt water environment & ride year-round so a little preemptive care seems in order. Having done that, I've never needed to attend to them again despite thousands of miles of abuse...
As for sealed bearing maintenance, they're all I run anymore for the very reason they need little to none. I do however take any new ones & very gently pry out the bearing seal, repacking them with a good marine-grade bearing grease like 2-4-C for it's far better water resistance & general quality, then clip the seal back in & reassemble.
I don't think that's really necessary for most, but I live in a harsh salt water environment & ride year-round so a little preemptive care seems in order. Having done that, I've never needed to attend to them again despite thousands of miles of abuse...
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I don't have any wheel issues yet but I hate the inherent weakness that derailleur rear wheels have i.e. the tighter drive side spokes do most of the work. Despite that, however, I have abandoned my idea of evening out the spoke tension somewhat by using an old narrower hub as periodically tightening the drive side spokes 1/4 turn each to re-center the rim is easier than replacing a bent axle!(screw on freewheels don't have an outboard bearing like cassette freewheels do).
My thoughts are that I could live without 2nd and 4th gear and make 5th a little lower as bicycle gears are far closer together in the lower gears than the engine needs. If I put dummy gears in the 1st and 2nd gears place and use a 5 speed shifter set so number 1 is 3rd on the wheel then I can exactly align the drive chain with the 5th gear cog(which will be 3rd on the shifter) and also have ample room to move the jackshaft drive chain to the inside chain wheel- first I have to remove the sealed bearing pedal crankshaft and put the much narrower original non-sealed one back in - it rarely turns and only has any force at all put on it when starting the engine (or when you break down and have to pedal the thing home!) so I don't feel that a sealed bearing cartridge is necessary.
My thoughts are that I could live without 2nd and 4th gear and make 5th a little lower as bicycle gears are far closer together in the lower gears than the engine needs. If I put dummy gears in the 1st and 2nd gears place and use a 5 speed shifter set so number 1 is 3rd on the wheel then I can exactly align the drive chain with the 5th gear cog(which will be 3rd on the shifter) and also have ample room to move the jackshaft drive chain to the inside chain wheel- first I have to remove the sealed bearing pedal crankshaft and put the much narrower original non-sealed one back in - it rarely turns and only has any force at all put on it when starting the engine (or when you break down and have to pedal the thing home!) so I don't feel that a sealed bearing cartridge is necessary.
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Ok I've done it and taken a picture so you will know what I meant now!! The jackshaft chain is now the inner chain and the chain that goes to the rear wheel is the outer chain.
From this:
to that!
I still have seven gears but when in first the chains are only 1mm apart- this is not too alarming as any resulting problems that this may cause will only happen at a walking pace (rather than possibly over 45mph when it was the bikes top gear that saw the chains close to touching!)
Now I just need the gearing a tad lower - I think changing the outer chainwheel from 36T to 30T will nail it!
From this:
to that!
I still have seven gears but when in first the chains are only 1mm apart- this is not too alarming as any resulting problems that this may cause will only happen at a walking pace (rather than possibly over 45mph when it was the bikes top gear that saw the chains close to touching!)
Now I just need the gearing a tad lower - I think changing the outer chainwheel from 36T to 30T will nail it!
The gearshifts are much snappier now, but will the derailliuer jockey wheels or the freewheel that the chain wheels bolt to wear out prematurely from turning faster? -time will tell!
EDIT:I wasn't thinking- the speed of the derailleur cogs wont be any different!
EDIT:I wasn't thinking- the speed of the derailleur cogs wont be any different!
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Update: Ok I was so curious whether my idea of evening out the spoke tension in the rear wheel spokes would work that today I swapped the 7 speed cassette rear wheel for an old chrome all steel 5 speed rear wheel. First thing I checked was that my sunrace 8 speed indexed thumb shifter would work just as well for a 5 speed as it did for the 7. Then I put a spacer (just like the one used on the gear cluster side) between the bearing cone and locknut on the non gear side. This made the wheel just a tad wider between the drop outs than the seven speed one was. Then I wound out all the spoke nipples on the gear side 1 full turn looser, and wound in all the nipples on the other side one full turn tighter. Then I trued up the wheel and hey presto rear wheel spokes are now all at the SAME TENSION unlike most of the rear wheels (with derailleur gears) on the road! (The spokes all play the same note when I dong them with a screwdriver now!) Now to finish off I just want to shave a millimetre each off the two spacers, remove the chrome rim and lace the alloy velocity rim back on, and when it arrives screw on the 14-38 5 speed freewheel I scored on ebay the other day.
I will take some pictures tomorrow to post so that it will hopefully be a bit more obvious what I'm talking about.
I will take some pictures tomorrow to post so that it will hopefully be a bit more obvious what I'm talking about.
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Wow thats quite a step up in the gearing! Those little jockey sprockets in the derail must be really spinning! Will the bike pull the higher gears?
Are you trying to add or subtract dish from the rear wheel? A derail wheel should have even spoke tension like all wheels, that's why the different size spokes from side to side. Are you trying to center the wheel? If you want to move the rim away from the derails side unlace the wheel and swap the spokes from side to side and relace(keep em separated!) Trying to follow what you are doing.
Are you trying to add or subtract dish from the rear wheel? A derail wheel should have even spoke tension like all wheels, that's why the different size spokes from side to side. Are you trying to center the wheel? If you want to move the rim away from the derails side unlace the wheel and swap the spokes from side to side and relace(keep em separated!) Trying to follow what you are doing.
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Now that I've changed the outer chainring to 30,
the old ratio (10/21 x 10/44 x 48/34-13) and the current one (10/21 x 9/24 x 30/34-13) both give the same final drive ration only the chainwheels turn faster now.(Making pedal assisting impossible!)
The jockey wheels dont turn any faster but the pedal crank freewheel does which I guess must give it more momentum to change the gears quicker?
I am going to use my velocity rim and a narrow 5 speed hub with the bearings spaced the same distance in on both sides and equal length spokes on both sides set at equal tension- note: wheel dish is achieved by having greater spoke tension on the dished side(and slightly shorter spoke length as a result). Aside from a 14-38 freewheel screwed on one side, my wheel will be exactly symmetrical with no dish at all and therefore no tendancy for the rim to become uncentred over time!
I will try and get some pic along the way tomorrow to clarify what I am doing.
the old ratio (10/21 x 10/44 x 48/34-13) and the current one (10/21 x 9/24 x 30/34-13) both give the same final drive ration only the chainwheels turn faster now.(Making pedal assisting impossible!)
The jockey wheels dont turn any faster but the pedal crank freewheel does which I guess must give it more momentum to change the gears quicker?
I am going to use my velocity rim and a narrow 5 speed hub with the bearings spaced the same distance in on both sides and equal length spokes on both sides set at equal tension- note: wheel dish is achieved by having greater spoke tension on the dished side(and slightly shorter spoke length as a result). Aside from a 14-38 freewheel screwed on one side, my wheel will be exactly symmetrical with no dish at all and therefore no tendancy for the rim to become uncentred over time!
I will try and get some pic along the way tomorrow to clarify what I am doing.
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If you go to Sheldon Browns page on wheel building, in the spoke calculation section he states that the right side spokes of a dished wheel are generally 1-2 mm shorter than the left. I found this out the hard way replacing a rim on a wheel that I didn't catch was dished. I mixed the spokes and laced twice with a lot of head scratching until I realized what I had done.
Heres the link.
Go to the spoke calc section. http://sheldonbrown.com/wheelbuild.html#different
Heres the link.
Go to the spoke calc section. http://sheldonbrown.com/wheelbuild.html#different
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Here is the chrome wheel (with an extra spacer installed) fitted as a precheck. This wheel does have slightly shorter spokes on the gear side, so evening out the spoke tension to remove the dish resulted in the threads showing on all the gear side spokes.(oops pic's sideways..)
Here's a shot of the two hubs- the 7 speed one is offset(dished) around 7mm to the left and is 13mm wider between the drop outs- by chance the gearside spacer used in the 5 speed one is also 13mm so adding an extra spacer on the left side of the hub makes it exactly the right width to use instead of the seven speed one, no need to file down the spacers!
The spokes from the seven speed wheel turned out to be all 262mm - the same on both sides. This is fortunate for what I am doing!- but is a very dodgey practice that you find mainly done in modern cheap department store bikes. The left side spoke nipples (which are less tight than the right side ones to achieve wheel dish) dont end up screwed all the way onto the spokes as the left side spokes are actually meant to be longer!
Here's the wheel laced up symmetrically like a front wheel is(a non disc one)
Here's a shot of the two hubs- the 7 speed one is offset(dished) around 7mm to the left and is 13mm wider between the drop outs- by chance the gearside spacer used in the 5 speed one is also 13mm so adding an extra spacer on the left side of the hub makes it exactly the right width to use instead of the seven speed one, no need to file down the spacers!
The spokes from the seven speed wheel turned out to be all 262mm - the same on both sides. This is fortunate for what I am doing!- but is a very dodgey practice that you find mainly done in modern cheap department store bikes. The left side spoke nipples (which are less tight than the right side ones to achieve wheel dish) dont end up screwed all the way onto the spokes as the left side spokes are actually meant to be longer!
Here's the wheel laced up symmetrically like a front wheel is(a non disc one)
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and here it is with the axle, bearings and two spacers installed
this pic makes it look like it's a little dished on the wrong side, only because I didn't lean over far enough to centre the camera over the rim when I took it
this pic makes it look like it's a little dished on the wrong side, only because I didn't lean over far enough to centre the camera over the rim when I took it
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Thanks for that link its a great read and I never stop learning new things about wheel building!!
