Advertise on Bikeforums.net



User Tag List

Results 1 to 19 of 19
  1. #1
    Senior Member
    Join Date
    May 2008
    Location
    Putnam, CT
    Posts
    78
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    DPN Megagear 7 speed freewheel sprockets changable?

    This stupid thing has a close ratio 6 speed 13-24t with an extra 34t granny gear and I would like to think about evening the gear spacing out - is it possible?

  2. #2
    Senior Member
    Join Date
    May 2008
    Location
    San Diego, CA
    My Bikes
    '72 Schwinn Sports Tourer, '73 Schwinn Super Sport, '79 Schwinn Twinn Sport 10sp tandem
    Posts
    163
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Good luck. I asked the same thing about a Shimano "Megarange" 7-speed cluster that was 13-15-17-19-21-24-34. I gather it's possible to take them apart, but then you have to find the new cogs with (for me) 20 and (29 or 30) teeth. I don't even know where to look for such new cogs.

    I wound up going with a Sun Race HG-82 8-speed freewheel that's 13-15-17-19-21-24-28-32. Your LBS has them for around $25, or can order them. You may need a longer axle (another LBS item, bring in your old one to match threads, and keep your old cones), and the bike shop may need to sretch your rear wheel stays to accommodate the wider wheels and axle.

    Some people don't like 8-speed freewheels, because your right-side bearings wind up in about the middle of the wheel, with a long unsupported part of the axle from there thru the freewheel to the dropout. If you really crank hard in low gear, or hit a lot of hard bumps, you can bend or break your axle.

    You can also look on Ebay for a six-speed or seven-speed freewheel with more normal gear spacing. 13-34's are kind of hard to find. Check older bike shops for a NOS part.

    Finally, look for the "Loose Screws" website. They build custom freewheels, and will put together a six- or seven-speed with just about any gear pattern you want. Price around $50 or so, not the cheapest, but you get what you want.
    '72 Schwinn Sports Tourer, original except for seat and 116psi tires
    48V 1000W black unbanded rear hubmotor kit from YXM Corp, 48V 20Ah LiFePO4 batt
    '79 Schwinn Twinn Sport 10sp tandem, 47#, now 14-speed with 12/34, aero wheels
    '07 Trek 7700 hybrid, 27sp, 20" frame, Conti UltraSport 700Cx28 116# tires, sweet
    '04 Trek 7500 hybrid, 17.5" frame, soon to be 48V 1000W rear-hubmotor electric bike

  3. #3
    Senior Member
    Join Date
    May 2008
    Location
    Putnam, CT
    Posts
    78
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks L-A, great info!
    So, does anyone actually like these MegaRange/Gear ratios? I have a 12-32t even spaced SRAM cassette on my ride but this Mega thing is on a new ride I just bought for the wife.

  4. #4
    Senior Member Bill Kapaun's Avatar
    Join Date
    Feb 2007
    Location
    Mid Willamette Valley, Orygun
    My Bikes
    86 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.
    Posts
    6,801
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Just get a different 7 speed Free Wheel.
    http://sheldonbrown.com/harris/freewheels.html#7

  5. #5
    Senior Member Retro Grouch's Avatar
    Join Date
    Feb 2004
    Location
    St Peters, Missouri
    My Bikes
    Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
    Posts
    23,605
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by RoadRanger View Post
    this Mega thing is on a new ride I just bought for the wife.
    How does your wife feel about it? A relatively close ratio 6-speed plus a bail out gear for hills. There are people (I'm one) who think that's a good combination for the way that they really use their bike.

  6. #6
    Rider
    Join Date
    Oct 2007
    Location
    New Orleans, LA
    Posts
    1,061
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by RoadRanger View Post
    Thanks L-A, great info!
    So, does anyone actually like these MegaRange/Gear ratios? I have a 12-32t even spaced SRAM cassette on my ride but this Mega thing is on a new ride I just bought for the wife.
    I have one, on a bike with a triple, on my recumbent that I use on the road. On a typical ride in my area, I manage to use the full range of gears available to me, so yes.
    Current stable: Sun Atlas X-type (mine), Trek Navigator 3 (wife), two Sun Revolution cruisers (wife, daughter)

  7. #7
    Senior Member
    Join Date
    May 2008
    Location
    Putnam, CT
    Posts
    78
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    J-Z, you wouldn't rather have evenly spaced gears with the same small and big cog size? Does having closer spaced gears up top somehow makes up for that big gap between the 24 and the 34? Of course I see you are running a triple and I'm looking at running a single 36 or 38T. All of the new 7 speeds around now seem to be using the megagear ratios as that is all that is commonly available in a wide ratio? I like my older freehub with my (discontinued?) SRAM PG730 12-14-16-18-21-26-32t and was trying to gear my wife's new ride somewhat the same . The big jump is about a 3 gear difference compared to the other spacings - worse than shifting a front ring!
    Last edited by RoadRanger; 06-08-08 at 08:25 PM.

  8. #8
    Senior Member Bill Kapaun's Avatar
    Join Date
    Feb 2007
    Location
    Mid Willamette Valley, Orygun
    My Bikes
    86 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.
    Posts
    6,801
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    A bailout gear is great if you need to get bailed out!
    If not, it's a waste of a useful gear.
    I use a bail out gear
    12-13-14-15-16-17-19-23

  9. #9
    Senior Member
    Join Date
    May 2008
    Location
    Putnam, CT
    Posts
    78
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I come stock with "bailout feet" .

    My question at this point is what is the advantage of a:
    13-15-17-19-21-24-34 (Megarange/gear = only commonly avalable wide ratio freewheel)
    vs.
    13-15-17-20-24-29-34 (old Shimano "K" cassette)
    , especially for a 7 speed (single front ring) for a "new" rider?

    I just don't get it .

  10. #10
    Senior Member mechBgon's Avatar
    Join Date
    Jul 2002
    Posts
    6,957
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If you decide to spend some money on the problem, also consider switching to a freehub setup while you're at it.

  11. #11
    Senior Member Sci-Fi's Avatar
    Join Date
    Sep 2006
    Posts
    1,250
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by mechBgon View Post
    If you decide to spend some money on the problem, also consider switching to a freehub setup while you're at it.
    If the OP is going that route, then why not just upgrade to a 9-speed cassette and shifter plus chain. Makes it easier to find what you want in a cassette.

  12. #12
    Senior Member mechBgon's Avatar
    Join Date
    Jul 2002
    Posts
    6,957
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Sci-Fi View Post
    If the OP is going that route, then why not just upgrade to a 9-speed cassette and shifter plus chain. Makes it easier to find what you want in a cassette.

  13. #13
    Senior Member
    Join Date
    Mar 2008
    Posts
    4,138
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Little-Acorn View Post
    Some people don't like 8-speed freewheels, because your right-side bearings wind up in about the middle of the wheel, with a long unsupported part of the axle from there thru the freewheel to the dropout.
    There s a guy who thinks that he's found a workaround to that:http://www.cyclingforums.com/t442815.html

    Scroll down to post 6.

  14. #14
    Rider
    Join Date
    Oct 2007
    Location
    New Orleans, LA
    Posts
    1,061
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If I am shifting into the big cog, I am not so worried about cadence as I am worried about being able to keep the bike moving while still pedaling in an aerobic manner rather than a series of anaerobic powerlifts. Most of my distance is in the tighter upper end, so that I can mind cadence better. When I drop into 1-1 on the huge cog, I abandon being nitpicky about 'cadence', usually I run my cadence up to 100-140.

    I do most of my riding in the middle of the rear cogs. If I get close to 1 or 7, I am overdue to shift the front. However, a typical ride has both sharp inclines and slight declines, among others.
    The gentle declines are spots that on the map look like a flat plain with evenly spaced sparse contour lines crossing it. You're losing altitude, but you'd be hard-pressed to point at a spot and say 'there's the hill'. It looks flat, but you can ramp it up to the top end of the bike and spin. Usually this is a good idea because there's a steep hill up ahead that i'm going to want some existing momentum for an assist on.
    The sharp hills can be brutal. A lot of them I can deal with in higher gears to some extent, but some of them are naaastyy. I have three choices here - mash like crazy at very low RPM and hope my anaerobic can hold out to the top of the hill - and on some of the longer ones, that is severely unlikely until late in the season especially if I have cargo at the time; get off and walk; or drop down into the lowest gear, run my cadence up to 120+, and attack the hill. I found one the other day on the MUP beside the freeway that I actually was having issues with breaking the drive wheel away from the ground on.
    Moose Creek Hill and Bailey Hill are common things for me to deal with; MCH has a quite steep grade and gains something like 300-400 feet in one short twisty climb, and Bailey gains the same 300-400 in one 200 foot rise with no shoulder where you have to share the lane and keep up enough speed to have good control followed by a more gentle bit of incline to foul up recovery. Both are steep enough that the the AKDOT removed shoulders in favor of a truck climbing lane. Both are steep enough that I get use out of the huge cog. The huge low gear lets me continue to spin my way up the hill. None of my stable are set up to let me come out of the saddle and stomp my way up hills, and I don't really like doing that anyways. One is a bent, the other has the handlebars adjusted in a quite vertical riding position that just doesn't work very well out of the saddle
    Current stable: Sun Atlas X-type (mine), Trek Navigator 3 (wife), two Sun Revolution cruisers (wife, daughter)

  15. #15
    Senior Member
    Join Date
    May 2008
    Location
    Putnam, CT
    Posts
    78
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Retro Grouch View Post
    How does your wife feel about it? A relatively close ratio 6-speed plus a bail out gear for hills. There are people (I'm one) who think that's a good combination for the way that they really use their bike.
    My grip here is that they are targeting these 7 speed bicycles to people who are coming back to bicycles after last riding a coaster or SA 3 speed 20+ years ago. I want my wife to have an immediate positive experience here and I suppose I shouldn't have cheesed out and gone instead with a 8 speed internal gear hub for her. She's willing to learn to shift down before stopping but I fear that she really needs more low gears than high to get back into shape with. My seven speed has evenly spaced gears that are about half the distance between them as an old 3 speed had plus two of them half gears below what the 3 speed gave me so I'm happy with that. I definitely use that gear between 1st and 3rd that she will be missing!
    Last edited by RoadRanger; 06-09-08 at 07:47 PM.

  16. #16
    Senior Member
    Join Date
    May 2008
    Location
    Putnam, CT
    Posts
    78
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks for the dissertation J-Z. I guess for those who are used to a second derailer up front the megagear is just giving you a virtual forth "ring" to jump down to? My point is that going with a seven speed to get rid of dealing with the big jump front ring shifting is kinda silly if you're just going to add back a "virtual" second front ring with this mega thingie. I do understand that all you uberbikers would find the spacing of my evenly spaced 12-32T 7 speed cassette to be way too wide for you.
    Last edited by RoadRanger; 06-09-08 at 03:17 PM.

  17. #17
    Senior Member
    Join Date
    May 2008
    Location
    Putnam, CT
    Posts
    78
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Sci-Fi View Post
    If the OP is going that route, then why not just upgrade to a 9-speed cassette and shifter plus chain. Makes it easier to find what you want in a cassette.
    Argh - I replied to this but it disappeared? Let's see if I can re-create it .

    Yes, a 11-13-15-17-20-23-26-30-34T 9 Speed would be ideal but I hate to have to retire/replace a brand new wheel or worse cut it up for the rim - I'd like to get some use out of it . Plus a new shifter and chain - this is only a $300 bike after all. I'm already putting an extra $50 into it to get her a properly sized crank. These geniuses designed an XS size women's bike with a 170mm crank! If another $50 would get me gears I like I would be OK with that.

    My older 7 speed has a 12-14-16-18-21-26-32t cassette on it that I'm happy with. It seems silly that nobody makes an evenly spaced wide ratio 7 speed freewheel for the cruiser bike market!

  18. #18
    Senior Member Sci-Fi's Avatar
    Join Date
    Sep 2006
    Posts
    1,250
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Well...my post was in response to the suggestion to switch to a freehub setup. But back to the chase...

    Unfortunately, a 12-14-16-18-21-26-32t only comes in cassette form, none for freewheels:
    http://sporting-goods.listings.ebay....istingItemList

    14-16-18-20-22-24-28 is about as close as you can get for even numbered cogs (NOS or New):
    http://www.loosescrews.com/index.cgi...d=843700914242
    or http://www.jensonusa.com/store/produ...Freewheel.aspx
    http://www.jensonusa.com/store/produ...Freewheel.aspx

    Getting hard to buy even the Shimano MF-HG50 7spd 11-34 Megarange or 11-28 freewheel. You are almost forced to buy at least a rear wheel with a freehub. Then you need to use a spacer so the 7-speed cassette can be locked. Since the freehub is 8 and 9-speed compatible, might as well just go 9-speed since those parts will be around for awhile and there are plenty of choices. I may have to go this route myself as (the right) 7-speed freewheel parts are getting harder to find and would suspect 9-speed parts will be around for awhile. My GF will appreciate the extra middle gears since she goes shopping with it most of the time. It's only a matter of whether or not she wants a twist or Rapidfire shifter.

  19. #19
    Senior Member
    Join Date
    May 2008
    Location
    Putnam, CT
    Posts
    78
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Well, I got tired of whining about it so went with L-A's advice to go with the Loose-Screws's custom freewheel set up as 13-15-17-20-24-28-34T for $63.45 delivered. Not quite perfect as that 28 should be a 29 (they don't have a 29) but it does get a gear between the 24 and 34 where God intended it to be . A pox on these MegaRange/Gear/Drive abominations !
    Thanks all for your help!

    <update> Installed the new custom freewheel - two thumbs up for sure!
    Last edited by RoadRanger; 06-20-08 at 05:26 PM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •