Another question about the old bike I have recently purchased please.
I have very little experience with old Shimano stuff as I always used Campag back in the day and until fairly recently.
The rear hub on the bike is uniglide, with the biggest sprocket being 21, and would prefer something bigger.
I wouldn’t think you could change the freehub to hyperglide, or if you could it probably would be impossible to find one now, I may be wrong.
I seem to remember reading some time ago that you could modify a low hyperglide sprocket to fit on a unigllide freehub,is that so?
Shimano uniglide sprocket mod.
- Vetus Ossa
- Posts: 1591
- Joined: 22 Oct 2012, 7:32pm
- Location: Plymouth
Shimano uniglide sprocket mod.
Beauty will save the world.
Re: Shimano uniglide sprocket mod.
What Shimano hub is it?
As that Sheldon Brown link makes clear, for a short period around the time that Shimano introduced Hyperglide cassettes they produced hubs which were Uniglide/Hyperglide compatible. If you have one of these a Hyperglide cassette should be a straight swap. If your hub is an earlier, exclusively Uniglide model, and is other than Dura-Ace, then you can I believe fit a more modern Hyperglide freehub body. The exception is the early Uniglide Dura-Ace hubs (7400 series) which will only accept the correct Uniglide/Hyperglide 7400 series freehub. This is an odd design and is secured with a unique fixing bolt rather than the more usual hex bolt. Removing and refitting the freehub requires a special tool (TL-FH10)
I've got a very nice wheeset with Dura-Ace 7400 Uniglide hubs. A couple years ago I sourced the correct Uniglide/Hyperglide NOS freehub body for the rear hub but I'm still searching for the special tool to fit it.
As that Sheldon Brown link makes clear, for a short period around the time that Shimano introduced Hyperglide cassettes they produced hubs which were Uniglide/Hyperglide compatible. If you have one of these a Hyperglide cassette should be a straight swap. If your hub is an earlier, exclusively Uniglide model, and is other than Dura-Ace, then you can I believe fit a more modern Hyperglide freehub body. The exception is the early Uniglide Dura-Ace hubs (7400 series) which will only accept the correct Uniglide/Hyperglide 7400 series freehub. This is an odd design and is secured with a unique fixing bolt rather than the more usual hex bolt. Removing and refitting the freehub requires a special tool (TL-FH10)
I've got a very nice wheeset with Dura-Ace 7400 Uniglide hubs. A couple years ago I sourced the correct Uniglide/Hyperglide NOS freehub body for the rear hub but I'm still searching for the special tool to fit it.
Last edited by Norman H on 7 Dec 2021, 9:54am, edited 1 time in total.
- Vetus Ossa
- Posts: 1591
- Joined: 22 Oct 2012, 7:32pm
- Location: Plymouth
Re: Shimano uniglide sprocket mod.
From that article…
Alternatively, you can fit Hyperglide sprockets onto a Uniglide body by grinding or filing off the one wide spline. You'll still need a threaded Uniglide sprocket for the top-gear position.
That’s what I was looking for, will give it a go.
Thanks slowster.
All I need now is a 23/24 sprocket
Beauty will save the world.
Re: Shimano uniglide sprocket mod.
Check your freehub. Some 7 speed versions were threaded internally for a lockring and externally for a uniglide top sprocket, so dual purpose for uniglide and hyperglide sprockets. Could save you having to modify your sprockets.
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway X2, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840
-
- Posts: 3436
- Joined: 10 Jul 2014, 1:12pm
- Location: Norfolk
Re: Shimano uniglide sprocket mod.
You may also find the sprockets are all joined together (for ease of assembly) they don't need to be. They may have thin screws/bolts which pass through all sprockets (except the small screwed-on one) into a thread in the largest sprocket - just unscrew them and you are then able to separate all the sprockets/ switch the larger as required. There are also screws with very small socket head (ie for fallen key which can be confuse with rivets. I have also seen rivets which, to remove them need grinding or drilling. No great problem if the 'cassette' is re-assembled with no screws, as the splines and smallest sprocket hold everything in place. One benefit of the uniglide sprockets is the facility to turn them around to get twice the use from them - the shaped nature of hyperglide doesn't allow this 'luxury'
- Vetus Ossa
- Posts: 1591
- Joined: 22 Oct 2012, 7:32pm
- Location: Plymouth
Re: Shimano uniglide sprocket mod.
The problem is I think finding sprockets now to replace the ones you want to replace.fastpedaller wrote: ↑6 Dec 2021, 5:42pm You may also find the sprockets are all joined together (for ease of assembly) they don't need to be. They may have thin screws/bolts which pass through all sprockets (except the small screwed-on one) into a thread in the largest sprocket - just unscrew them and you are then able to separate all the sprockets/ switch the larger as required. There are also screws with very small socket head (ie for fallen key which can be confuse with rivets. I have also seen rivets which, to remove them need grinding or drilling. No great problem if the 'cassette' is re-assembled with no screws, as the splines and smallest sprocket hold everything in place. One benefit of the uniglide sprockets is the facility to turn them around to get twice the use from them - the shaped nature of hyperglide doesn't allow this 'luxury'
Beauty will save the world.
-
- Posts: 3436
- Joined: 10 Jul 2014, 1:12pm
- Location: Norfolk
Re: Shimano uniglide sprocket mod.
The hyperglide can be used with a little modification though.Vetus Ossa wrote: ↑6 Dec 2021, 7:41pmThe problem is I think finding sprockets now to replace the ones you want to replace.fastpedaller wrote: ↑6 Dec 2021, 5:42pm You may also find the sprockets are all joined together (for ease of assembly) they don't need to be. They may have thin screws/bolts which pass through all sprockets (except the small screwed-on one) into a thread in the largest sprocket - just unscrew them and you are then able to separate all the sprockets/ switch the larger as required. There are also screws with very small socket head (ie for fallen key which can be confuse with rivets. I have also seen rivets which, to remove them need grinding or drilling. No great problem if the 'cassette' is re-assembled with no screws, as the splines and smallest sprocket hold everything in place. One benefit of the uniglide sprockets is the facility to turn them around to get twice the use from them - the shaped nature of hyperglide doesn't allow this 'luxury'