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  1. #1
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    SA 8 Speed Hub Adjustment/ DownTube 8H/ gear ratios

    Out of the box my bike was in 4th gear, and the arrows were lined up but 6th gear slips. The rest are OK. And I wasn't touching the shifter. Is there a second step?

    Also, now that I've ridden the bike I understand the high gearing issue. It's way too high-geared, IMO, and I don't know jack about gearing. I'd like at least one more lower gear if not two. I'm not sweating top end speed. It's a big dissapointment to have to put out $ to replace the chainring/rear cog on a brand new bike. I'm not sure I'm going to do it but could someone tell me what size I need and # of teeth to improve the lower range? Thanks in advance.

  2. #2
    Eschew Obfuscation SesameCrunch's Avatar
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    Quote Originally Posted by tgzzzz View Post
    Out of the box my bike was in 4th gear, and the arrows were lined up but 6th gear slips. The rest are OK. And I wasn't touching the shifter. Is there a second step?

    Also, now that I've ridden the bike I understand the high gearing issue. It's way too high-geared, IMO, and I don't know jack about gearing. I'd like at least one more lower gear if not two. I'm not sweating top end speed. It's a big dissapointment to have to put out $ to replace the chainring/rear cog on a brand new bike. I'm not sure I'm going to do it but could someone tell me what size I need and # of teeth to improve the lower range? Thanks in advance.
    Just tweek the arrows and you'll get it dialed in. 6th gear is notoriously "delicate". Don't worry, it's not a defect. Remember to re-check this alignment periodically, too. The cable will stretch a little over time.

    As for gearing, my preferred chainring size is 39t. Relatively inexpensive and easy modification.
    Last edited by SesameCrunch; 08-27-07 at 11:07 PM.

  3. #3
    jur
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    +1 on 39T. I have 42T and it's plenty.

    And +1 on 6th being delicate. I have a procedure where I dial around on the shifter until 6th slips, go the other way until it slips again, then try to get the middle. then I check where the marks are and try to remember it.

    Not ideal but it works.

  4. #4
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    +2 on Jur's and Sesame's comments
    Another 39T user on a DT 8H

    Adjustment hints - first make sure the cable moves smoothly, then shift down to 1st gear and then slowly up to 4th gear. Then adjust the grip-shifter cable adjuster to the middle of its range. Using a combination of cable adjustments and hub cable adjuster, get the arrows on the hub indicator lined up. Then ride the bike and use the adjuster at the shifter small amounts to get 6th to work right. Starting with the adjuster in the middle of its range makes these adjustments much easier. Usually all of the other gears will work if 6th works.

    If you have problems with slippage after down-shifting it usually indicates a problem with sticky cables or shifters. The SA shifter will move a bit if you keep a firm grip on it. Try and relax your shift hand and see if the slipping goes away.

    You might want to grease the cable with lithium grease if the cable is sticky. You have to take the cable out of the housing to do this. You want to get grease onto the cable and then get that grease inside the housing. If there are any bends in the cable it should be replaced, and any crimps in the housing are fatal. Another common problem is burrs on the ends of the housing where it has been cut. You can use a flat file to get rid of these burrs.

    I you can't resolve the gear-slipping problem, DO NOT ride hard in that gear. You can permanently damage hub gears by riding them when they are out of adjustment.

    For my 3 SA8 hubs it has taken 2 to 5 rides to dial them in. It is normal for all bike cables to stretch and seat into position in the first 20 or 30 hours of riding. This will cause some readjustment of all cables in the first month or two of use. Most of this will happen in the first 10 hours of use if you shift and brake alot.
    Last edited by Pine Cone; 08-28-07 at 12:31 AM.

  5. #5
    Part-time epistemologist invisiblehand's Avatar
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    Quote Originally Posted by Pine Cone View Post
    +2 on Jur's and Sesame's comments
    Another 39T user on a DT 8H

    Adjustment hints - first make sure the cable moves smoothly, then shift down to 1st gear and then slowly up to 4th gear. Then adjust the grip-shifter cable adjuster to the middle of its range. Using a combination of cable adjustments and hub cable adjuster, get the arrows on the hub indicator lined up. Then ride the bike and use the adjuster at the shifter small amounts to get 6th to work right. Starting with the adjuster in the middle of its range makes these adjustments much easier. Usually all of the other gears will work if 6th works.

    If you have problems with slippage after down-shifting it usually indicates a problem with sticky cables or shifters. The SA shifter will move a bit if you keep a firm grip on it. Try and relax your shift hand and see if the slipping goes away.

    You might want to grease the cable with lithium grease if the cable is sticky. You have to take the cable out of the housing to do this. You want to get grease onto the cable and then get that grease inside the housing. If there are any bends in the cable it should be replaced, and any crimps in the housing are fatal. Another common problem is burrs on the ends of the housing where it has been cut. You can use a flat file to get rid of these burrs.

    I you can't resolve the gear-slipping problem, DO NOT ride hard in that gear. You can permanently damage hub gears by riding them when they are out of adjustment.

    For my 3 SA8 hubs it has taken 2 to 5 rides to dial them in. It is normal for all bike cables to stretch and seat into position in the first 20 or 30 hours of riding. This will cause some readjustment of all cables in the first month or two of use. Most of this will happen in the first 10 hours of use if you shift and brake alot.
    Excellent advice from all.

    On my SA 8 hub, I have found that when my hub in tune for all 8 gears, the arrow is on the high end of the two lines; i.e., I use the barrel adjuster to shorten the housing.

    Someone else also made a similar observation ... I believe in the Mini thread.

    Although I have a Mini, I switched from a 48 to a 44t chainring for a little lower gearing.

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    Quote Originally Posted by invisiblehand View Post
    Excellent advice from all.

    On my SA 8 hub, I have found that when my hub in tune for all 8 gears, the arrow is on the high end of the two lines; i.e., I use the barrel adjuster to shorten the housing.

    Someone else also made a similar observation ... I believe in the Mini thread.

    Although I have a Mini, I switched from a 48 to a 44t chainring for a little lower gearing.
    High end being towards the front of the bike? I haven't had any slippage problems on my VIIIH, but I rarely go above second gear (I haven't decided if really low gears are more important to me than a chaincase or not).

  7. #7
    Part-time epistemologist invisiblehand's Avatar
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    Quote Originally Posted by makeinu View Post
    High end being towards the front of the bike? I haven't had any slippage problems on my VIIIH, but I rarely go above second gear (I haven't decided if really low gears are more important to me than a chaincase or not).
    Hmmmmm ... how about this ...

    the arrow is biased in the direction of a higher gear.

    I find myself in gears 4-6 on the flats ... 2-3 on most hills ... 1 on a handful of hills.

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    Quote Originally Posted by invisiblehand View Post
    Hmmmmm ... how about this ...

    the arrow is biased in the direction of a higher gear.
    ...which is a looser cable...clockwise when looking at the side of the wheel where the hub enters

    right?

  9. #9
    Part-time epistemologist invisiblehand's Avatar
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    Quote Originally Posted by makeinu View Post
    ...which is a looser cable...clockwise when looking at the side of the wheel where the hub enters

    right?
    yep.

    ... just trying to figure out your location ...

  10. #10
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    Quote Originally Posted by SesameCrunch View Post
    Just tweek the arrows and you'll get it dialed in. 6th gear is notoriously "delicate". Don't worry, it's not a defect. Remember to re-check this alignment periodically, too. The cable will stretch a little over time.

    As for gearing, my preferred chainring size is 39t. Relatively inexpensive and easy modification.
    Good to know it's not a defect. I guess if 39T works in SF, it'll work anywhere. Using Sheldon Brown's data, I take it I want a 130mm BCD/39 teeth. Apparently there's no need to change rear gear?

    I will start tweaking the yellow marks per all remarks above. Thanks.

  11. #11
    finding the path migjet's Avatar
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    Quote Originally Posted by SesameCrunch View Post
    Just tweek the arrows and you'll get it dialed in. 6th gear is notoriously "delicate". Don't worry, it's not a defect. Remember to re-check this alignment periodically, too. The cable will stretch a little over time.

    As for gearing, my preferred chainring size is 39t. Relatively inexpensive and easy modification.
    I have the DT IX and experience the same. Yes, it is delicate, but after moving from high to 6 is better than low to 6. Overall, the gear does work.

    Sesame, did you always have a merc? I have been away and just noticed your avatar....nice!

  12. #12
    Eschew Obfuscation SesameCrunch's Avatar
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    Quote Originally Posted by migjet View Post
    I have the DT IX and experience the same. Yes, it is delicate, but after moving from high to 6 is better than low to 6. Overall, the gear does work.

    Sesame, did you always have a merc? I have been away and just noticed your avatar....nice!
    I just got it! I am going to post it in the Merc thread. It's quite a character!

  13. #13
    Senior Member stevegor's Avatar
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    How timely is this post as I'm having the exact same problem with the Wasp after her recent rebuild, glad it's not just me. Only real problem I forsee is, SWMBO will have another reason to say "All you EVER do is fiddle with that bike!!" : rolleyes:

    BTW, I'm using 451 rims with the standard 25t rear and a 48t chainring, so far it seems ok, I'm using 3rd to 7th mostly on the flats, 1-2 on climbs and 8th for downhill. I did use the Raleigh 46t cottered crank for awhile but found I wanted more from 8th, while I could climb a brick wall in 1st. It looks like most people are using 44t or smaller and with smaller wheels, the low gearing must be incredibly low, too low IMHO.
    Speaking with Jur about my choice of 48t, he commented that my 8th gear would be very tall, true, and I don't use it all the time, but then how often does anyone use the 11t on a 52/53 on a full size roadie? Maybe I could using a dble chainring?

  14. #14
    jur
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    Quote Originally Posted by stevegor View Post
    How timely is this post as I'm having the exact same problem with the Wasp after her recent rebuild, glad it's not just me. Only real problem I forsee is, SWMBO will have another reason to say "All you EVER do is fiddle with that bike!!" : rolleyes:

    BTW, I'm using 451 rims with the standard 25t rear and a 48t chainring, so far it seems ok, I'm using 3rd to 7th mostly on the flats, 1-2 on climbs and 8th for downhill. I did use the Raleigh 46t cottered crank for awhile but found I wanted more from 8th, while I could climb a brick wall in 1st. It looks like most people are using 44t or smaller and with smaller wheels, the low gearing must be incredibly low, too low IMHO.
    Speaking with Jur about my choice of 48t, he commented that my 8th gear would be very tall, true, and I don't use it all the time, but then how often does anyone use the 11t on a 52/53 on a full size roadie? Maybe I could using a dble chainring?
    I agree with all you say. I used a 46T in Tassie, and the back has a Big Apple on it, so that increases the circumference and therefore the gearing as well. I was fine with it, but would tend to spin out on the downhills on my commute where I go 70km/h. That is slightly worse now with 42T, so I just spin like hell to get the speed up to 70, then go into an aero tuck to keep the speed up.

    Also, in Tassie there was just one set of hills I couldn't climb, they were about 20% slope, I think if I wasn't heavily loaded I would have been fine even on them.

    So on your lighter nimbler Wasp with the blokes, 48T sound right and you could probably go to 50T without a problem.

  15. #15
    Senior Member stevegor's Avatar
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    Quote Originally Posted by jur View Post
    I agree with all you say. I used a 46T in Tassie, and the back has a Big Apple on it, so that increases the circumference and therefore the gearing as well. I was fine with it, but would tend to spin out on the downhills on my commute where I go 70km/h. That is slightly worse now with 42T, so I just spin like hell to get the speed up to 70, then go into an aero tuck to keep the speed up.

    Also, in Tassie there was just one set of hills I couldn't climb, they were about 20% slope, I think if I wasn't heavily loaded I would have been fine even on them.

    So on your lighter nimbler Wasp with the blokes, 48T sound right and you could probably go to 50T without a problem.

    I don't know, Jur, 8th gear with the 48t seemed similar to 52/11 or even 53/11, so a 50t might snap my ageing legs in two and I would lose too much in 1st & 2nd.
    If I don't take the tandem to Wang/Bright later this year, I might take the Wasp.....at present SWMBO wants to ride solo, might be a good chance to see how she goes.....The Wasp...not SWMBO.

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