Replacement freewheel to go faster in top gear

easybiker

My 7-speed shimano freewheel MF-TZ21 (14/28 tooth) is worn out and I need to replace it. But I would like to be able to push the bike faster in top gear, as I am freewheeling a lot of the time even on the flat, unable to turn the pedals fast enough! Can anyone recommend a compatible part that has fewer teeth on the smallest sprocket? I can't see a variant of MF-TZ21 that provides this. Front crankset is 22/32/42 and recently replaced, so I don't really want to have to change that again. Any advice most welcome.

rockmonkeysc

The freehub and cassette are separate components.
I'm not sure what the smallest cassette ring is on 7 speed cassettes but I expect most cassettes will have the smallest size. You're other option is a bigger big ring on the front, I guess you are riding more on road than off?

easybiker

No, it's not a separate freehub & cassette. It's an integrated freewheel unit which comes with the sprockets attached.

If it were a standard freehub/cassette system, I would have no problem finding an e.g. 11/30 tooth sprocket set, but this is a combined unit.

cooldad

I don't think you get one.
So solution would be a new wheel with a freehub.

stubs

I think your stuck with a 14T on a MTB freewheel but you can get road freewheels that go down to 12T iirc. Not sure if its a straight swap maybe Sheldon Brown or Park tools will have the info. You will also be stuck with a fairly small big cog so might need some steel leg muscles.

http://www.ebay.co.uk/itm/Shimano-Dura-ace-MF-7400-freewheel-12-21-7speed-rear-cogs-screw-on-chain-vintage-/261559791788?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item3ce62db0ac

easybiker

cooldad wrote:

I don't think you get one.
So solution would be a new wheel with a freehub.

Well that's one way. I'll cost it out. Maybe I should have just got a new bike.

easybiker

Or is there a way to convert (easily) the MTB freewheel into a freehub/cassette system? Seems a shame to discard a whole wheel.

cooldad

Nope

Mister_g

easybiker wrote:

My 7-speed shimano freewheel MF-TZ21 (14/28 tooth) is worn out and I need to replace it. But I would like to be able to push the bike faster in top gear...

Hi, new here, and prepared to be shot down...

Is that a 'normal' screw on freewheel?

It was a while ago, but if it's the same fitting, I replaced an MF-HG-40-7 freewheel (40-14T Megarange) with one that I'm pretty sure goes 28-11T. I can't seen any markings on it, but it would have come from Halfords.

Maybe one of these: http://www.halfords.com/cycling/cycling ... tte-11-28t

If this isn't suitable, I'd be interested to understand why (please!).

easybiker

Mister_g wrote:

easybiker wrote:

If this isn't suitable, I'd be interested to understand why (please!).

This is a cassette for a freehub/cassette system. I need a freewheel.
See http://sheldonbrown.com/free-k7.html for clarification.

jimothy78

easybiker wrote:

Or is there a way to convert (easily) the MTB freewheel into a freehub/cassette system? Seems a shame to discard a whole wheel.

Well, you could save the rim and get it re-built onto a different hub, but that's likely to be more expensive than just buying a cheap new wheel.

One thing to bear in mind, though, is that a lot of folks on this forum use 1x10 gear systems that actually have a lower "top gear" than yours (42/14 is exactly equivalent to 33/11 - and on lots of 1x10 systems, top would be 32/11). I suspect that the difference is in the type of trails being ridden; If you're regularly spinning out your top gear, then I presume you're riding a lot of fireroads or tarmac - try finding some more interesting offroad trails - lots of corners, technical features or just twisty narrow singletrack will make your current top speed feel insanely fast, and force you to slow down a bit. Undulating terrain can also be "pumped" for extra speed, even if you're travelling at speeds that would be impossible to pedal...

Mister_g

easybiker wrote:

This is a cassette for a freehub/cassette system. I need a freewheel.

D'oh! Sorry - I thought I had linked to a freewheel (I understand the difference). Whatever, it was definately a *freewheel* that I found with an 11 or 12T small sprocket.

Hmm... looks like they are no longer available: http://harriscyclery.net/site/itemdetails.cfm?ID=1724

Sorry!

easybiker

jimothy78 wrote:

I presume you're riding a lot of fireroads or tarmac - try finding some more interesting offroad trails...

Unfortunately I have to cover a fair amount of tarmac to get to the off-road stuff.