Quick inquiry about changing 6-speed to 7-speed freewheel
07-04-13 | 09:34 AM
#1
Thread Starter
Junior Member
Joined: Jul 2013
Posts: 7
Likes: 0
Bikes: Maruishi Rx-7
Quick inquiry about changing 6-speed to 7-speed freewheel
I have a late 80s Maruishi Rx-7 with full Shimano 105 6 speed groupset. I am looking to change the freewheel to a 7-speed (13-28). Currently I have a 6 Speed 14-24 and I'm looking for slightly better spread, and a better gear for tougher hills. The bike has 128mm dropout spacing, 52-42 biopace up front. My research (mainly here and sheldon brown's website) leads me to believe I can change out this part with no other changes to the bike, aside from switching my 6-speed shifters from indexed to friction.
If anyone can give me a little insight on if this will work well that would be great. I just don't wanna order a part and have it installed only to find out it doesn't work at all, or doesn't work well. To me this seemed like the least expensive option to give me a better experience climbing.
-Sean
*edit - first time post so I hope this is the correct sub-forum.
If anyone can give me a little insight on if this will work well that would be great. I just don't wanna order a part and have it installed only to find out it doesn't work at all, or doesn't work well. To me this seemed like the least expensive option to give me a better experience climbing.
-Sean
*edit - first time post so I hope this is the correct sub-forum.
07-04-13 | 09:45 AM
#2
Super Moderator
Joined: Jul 2004
Posts: 21,987
Likes: 1,169
From: Ffld Cnty Connecticut
Bikes: Old Steelies I made, Old Cannondales
You may find that the axle on the right hand side is not long enough for the 7 speed. In many cases, you can take a washer off the left side and move it to the right side to give enough clearance.
If you do, then theoretically the wheel should be re-dished to realign the rim between the axle locknuts, but you may be able to get away with it as-is if you are not too picky. Depends on your budget (or handiness) and how OCD you are.
If you do, then theoretically the wheel should be re-dished to realign the rim between the axle locknuts, but you may be able to get away with it as-is if you are not too picky. Depends on your budget (or handiness) and how OCD you are.
__________________
Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.
FYI: https://www.bikeforums.net/forum-sugg...ad-please.html
Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.
FYI: https://www.bikeforums.net/forum-sugg...ad-please.html
07-04-13 | 09:46 AM
#3
Really Old Senior Member
Joined: Feb 2007
Posts: 14,667
Likes: 1,904
From: Mid Willamette Valley, Orygun
Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds. 2019 Giant Explore E+3
Shouldn't be a problem. You "might" possibly have to add a 1mm spacer to the DS axle if the small cog has clearance issues with the drop out.
07-04-13 | 09:58 AM
#4
Thread Starter
Junior Member
Joined: Jul 2013
Posts: 7
Likes: 0
Bikes: Maruishi Rx-7
[MENTION=78399]Bill Kapaun[/MENTION] | [MENTION=13460]Homebrew01[/MENTION]
Awesome so the spacer is to keep the chain from rubbing the frame when on the smallest cog? Thanks for giving me some peace of mind, I think I'll go ahead and order it. I'll probably take it into my local shop and have the put it on and get things aligned. I kind of like indexed shifting. I was looking at 'plug and play' options for this and think the SL-1051 (I have the SL-1050) would work. Any foreseeable problems with that change?
Awesome so the spacer is to keep the chain from rubbing the frame when on the smallest cog? Thanks for giving me some peace of mind, I think I'll go ahead and order it. I'll probably take it into my local shop and have the put it on and get things aligned. I kind of like indexed shifting. I was looking at 'plug and play' options for this and think the SL-1051 (I have the SL-1050) would work. Any foreseeable problems with that change?
07-04-13 | 10:04 AM
#5
Senior Member
Joined: Dec 2007
Posts: 3,518
Likes: 40
From: San Jose, California
Bikes: 2001 Tommasini Sintesi w/ Campagnolo Daytona 10 Speed
BEFORE YOU DO ANYTHING!!!
Grab a pair of calipers and a straight edge rule...
Run the straight across the lock nut face...
Measure distance from freewheel stop on the hub to the end of the lock nut (represented by the edge of the rule.)
Turn axle 180 and repeat...just to be sure...
If that distance is at a minimum 36mm - you are qualified for a "road" 7-speed freewheel (Shimano MF-HG-37-7)
If that distance is at a minimum 39mm - you are qualified for a "mtb" 7-speed freewheel (Shimano MF-HG-40-7)
Chances are pretty good you'll find your measurement to come out to be 37mm - and that you're already good for road 7-speed. Just make certain you buy the correct freewheel.
=8-)
Grab a pair of calipers and a straight edge rule...
Run the straight across the lock nut face...
Measure distance from freewheel stop on the hub to the end of the lock nut (represented by the edge of the rule.)
Turn axle 180 and repeat...just to be sure...
If that distance is at a minimum 36mm - you are qualified for a "road" 7-speed freewheel (Shimano MF-HG-37-7)
If that distance is at a minimum 39mm - you are qualified for a "mtb" 7-speed freewheel (Shimano MF-HG-40-7)
Chances are pretty good you'll find your measurement to come out to be 37mm - and that you're already good for road 7-speed. Just make certain you buy the correct freewheel.
=8-)
__________________
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
07-04-13 | 10:04 AM
#6
Senior Member
Joined: Aug 2005
Posts: 33,657
Likes: 1,119
From: Pittsburgh, PA
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
07-04-13 | 10:26 AM
#7
Thread Starter
Junior Member
Joined: Jul 2013
Posts: 7
Likes: 0
Bikes: Maruishi Rx-7
[MENTION=108770]mrrabbit[/MENTION] I read BEFORE YOU DO ANYTHING!!! and although I really needed to use the bathroom I took your advice and began frantically searching for a straight edge rule. lol turns out you were right, 37mm it is. Thanks
[MENTION=38165]HillRider[/MENTION] Fantastic thanks
[MENTION=38165]HillRider[/MENTION] Fantastic thanks
07-04-13 | 10:32 AM
#8
Senior Member
Joined: Dec 2007
Posts: 3,518
Likes: 40
From: San Jose, California
Bikes: 2001 Tommasini Sintesi w/ Campagnolo Daytona 10 Speed
=8-)
__________________
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
Thread
Thread Starter
Forum
Replies
Last Post
vintagerando
Bicycle Mechanics
36
02-06-16 12:34 AM
