I have 7speed freewheel on carrera zelos & I want to upgrade to 8 speed but cant find any freewheel How do I do it. Its my first road bike as I normally ride downhills and wanted to mix it up especially commuting to and from work and feel it needs better gears/ brakes it has the shimano tourney 2x7 set with a tz500 freewheel

1. 8-speed freewheels are rare. There is a reason for that because the unsupported length of axle outboard of the drive side axle bearing makes them prone to breakage. Honestly, 7-speed freewheel wheel sets are marginal for axle breakage.

2. What's your rear dropout spacing? If it's 126 mm you don't have room for an 8'speed gear cluster anyway.

Carrera is a store brand for Halford's, which calls itself "the UK's leading retailer of automotive and cycling products." https://www.cyclerepublic.com/carrer...bike-2020.html

I'd imagine the frame uses 130-mm spacing but i cannot tell from the few descriptions I have seen.However .... since as far as I know nobody makes 126-mm frames any more, and nobody makes 126-mm wheels except in 27-inch for retro/C&V riders(I have some ion my '83 Cannondale) and since Carrera makes a variety of bikes .... I'd bet they produce frames with modern dropout spacing just for simplicty's sake. One article mentions that the bike uses 700c wheels ....

There are 8-speed clusters for freewheels--i think I got mine from Sunlite?--https://www.greggscycles.com/product/sunlite-8-speed-freewheel-230906-1.htm---but be aware----if you get an 8-speed cluster you will need to buy 8-speed shifters or you won't be able to access the added gear. And a pair of Claris shifters ...... about $100.

(Further, the bike comes with a14-28 cluster---if you need more speed, you are out of luck (smallest is 13-tooth) but if you need more climbing ability you can get a 14-34 freewheel pretty cheap. ($12--https://www.benscycle.com/shimano-tz500-7-speed-14-34t-freewheel/multi-speed_freewheel_shimano_25028_fw8142/product) If you jump to 8-speed you can get and 11-30 for $40 (https://www.benscycle.com/dimension-...fw7208/product) whihc would offer you the same 8-tooth low gear of you chose to run it with your current shifters and only use 7 gears (always an option.)

Considering the whole bike sells for about £300 ($375 US) paying $40 for the cluster and $100 for the shifters .... another $20 for the cables ..... I wouldn't do it. Brakes would set you back another $50 and then more for cables and suddenly you are spending half the purchase price to get a better bike-----sell the thing and buy a $600 bike that already comes with better parts, including a freehub and cassette (much stronger than a freewheel and cluster) and just better everything.

In the US we have a company called BikesDirect which sells no-name bikes with decent components for low bucks. Not sure if there is a UK equivalent .... ask around.

You have a 25-pound all-aluminum road bike with very basic components .... I wouldn't put any money into it except lights, a bottle cage, a seat bag to hold my repair tools, and a cargo rack. it is a very basic bike and isn't really worth the upgrades. (IMO)

On another hand, the bike should be serviceable for basic commuting and, if maintained, should last a good long time. it will have lower theft potential because it has little resale value---which is perfect for a commuter bike.

I would just clean it up, lube it up, tighten and straighten and adjust everything that needs it, and ride the beast for the next couple years. Save your cash for a better bike if you find you want one. Again, just my opinion.

I wouldn't waste time or money on that bike and just ride it into the ground. Try to take care of it without putting much money into it. The only things I might buy are things I would use on another bike, like a bottle cage or a good tool kit.

A modern bike with a multi speed freewheel is just not worth it. Vintage bikes maybe if they are of quality then you can find some decent freewheels from IRD but that is for those who love vintage bikes. If you are commuting and riding around get something reliable that has modern standards and quality components. We are currently in the 11-12 speed era so generally it is tough to find decent quality below 9 or 10 speeds and as it goes up and up the quality on the lower speeds goes down.

Going from 7 to 8 speed opens a whole can of worms. Unfortunately everything has to match & fit for it to work. You will need special measuring equipment & tools. It's probably not worth the effort. You're much better off just buying another bike. But, if you're really interested in becoming a tinkerer. Start checking out the local for sale ads. Set price filters. Sometimes you can pick up a good condition 8, 9, or even 10 speed used bike or "parts bike" for anywhere between $75 to $150.

Agreed. Add in the increased propensity for broken axles, and it's hard to make the case for it.

Or just staying with 7-speed. How much "benefit" would that additional sprocket get you, and are there other ways to accomplish that goal?

It's getting hard to justify upgrading an old bike in this day and age when you can get a brand new road bike from bikesdirect.com for less than $300. The big factories in Taiwan can produce a new bike for less money than it cost to refurbish & upgrade a vintage bike. So, if you have an average ordinary bike that needs expensive repairs it often will wind up in the trash receptacle. The only bikes that get upgrades & repairs anymore are high end or collectable. And, even some of those wind up in the trash now. It's really tough to make a living off the margins on the average ordinary bike now.