Upgrading

[Snapper88]

My old MTB needs an upgraded drivetrain but I'm not sure where to start.
I keep running out of gears
I've currently got 3 ring chain set & 7speed cassette. The derailleur's are rubbish & shifters are terrible.
I'm not sure how to measure for the right parts. Any help is greatly appreciated

 

[Rickshaw Phil]

First thing is what do you have already? What's the bike and what's the drivetrain set up? IE: How many teeth are on the chain rings and how many on the largest and smallest sprockets at the rear. What derailleurs and shifters are currently fitted?

Is it definitely a cassette? 7 speed could be either a cassette or a screw on freewheel depending on how well specced the bike was from new. Sheldon Brown explains the differences here.

It would also be helpful to know what you want from the bike at the end of it. Are you looking to set it up for climbing ability or speed?

Photos of the bike may help.

 

[Snapper88]

Bike is a Peugeot Mtb. Want to use it as a winter trainer/commuter. I will have to get back to you on cassette & chain rings tomorrow

 

[Rickshaw Phil]

Winter trainer/commuter suggests mainly road work to me. Making the gearing more suitable for quick road cruising is quite possible and without spending a fortune.

 

[Snapper88]

So the teeth count is 48/38/28 my cyclocross is 50/34t the front derailleur is Shimano Altus A10 the rear is Shimano SIS & the shifters are Sachs twist grips.
I've had the bike 2months but only got round to changing the brakes

 

[Rickshaw Phil]

So the teeth count is 48/38/28 my cyclocross is 50/34t the front derailleur is Shimano Altus A10 the rear is Shimano SIS & the shifters are Sachs twist grips.
I've had the bike 2months but only got round to changing the brakes

48/38/28 is a good start - fairly high geared. The derailleurs and the shifters sound like quite old versions so may benefit from updating. I can recommend SRAM MRX Comp shifters (Links: left & right) as a direct update of the old Sachs ones. I like these because they work as well as more expensive shifters. (MRX are Shimano compatible by the way)

The front derailleur might not need replacing unless the cage is badly worn. You'll probably find it works much better with a new shifter.

For the rear derailleur it depends what you want to spend. Even their entry level Tourney range is decent these days (it's doing a good job on my knockabout bike), but perhaps choose Acera spec or higher for better quality and longevity.

The rear gear cluster is the thing we need to know about next. There should be markings to show what is currently fitted. If not it's a case of counting teeth on largest and smallest.

 

[Snapper88]

Sorry for slow replies. Rear is 30-13 (still trying to upload pics)
I thought as I've got some spare cash I would upgrade with new parts & learn how to do it all (save on labour fees) on an old bike

 

[Rickshaw Phil]

No worries.

 

[Snapper88]

Was quicker with taptalk app

 

[Rickshaw Phil]

Oops - accidentally posted before I finished composing.

The fact it's a 13-30 suggests to me that it's more likely to be a cassette than a freewheel. A straight swap with a one that has an 11 or 12 tooth top gear will give extra gearing at the top end. Approx 7 gear inches extra for the 12 tooth and approx 16 gear inches for the 11 tooth, which would be a noticeable difference. There's a good selection of 7 speed cassettes here.

Another option is to change to 8 or 9 speed, (you'd need shifter, cassette, chain and 8 speed compatible derailleur) but it is possible with an older freehub these won't fit as 7 speed freehubs are shorter than 8/9 speed ones. If it is an 8/9 speed hub fitted there will be a spacer at the back of the cassette.

 

[Snapper88]

That's brilliant I will take a look next weekend & assess what I should do.
Thanks for the help