Granny gear advice...
I've recently started getting back into biking (now that the kids are getting a little older). I have a 13 year old Trek 800 steel mountain bike that I love. It fits me well and it was the first bike that I bought with my own money.
I bought the bike when I was a student in central NJ. I now live in New Hampshire where the hills are a little steeper. I'd like to use this bike for touring and for riding with my kids on their tag-along bike (which attaches to my bike). My bike currently has 3 chain rings and 6 cogs. The smallest chainring has 28 teeth, and the largest cog also has 28 teeth. This gives me 26 gear inches for my lowest gear combination.
So far, this low gear combo has been adequate for the hills around my home, but I'm thinking that I might want to upgrade my drivetrain system to provide an even easier pedaling low gear. When I tow the kids with the tag along bike, I am able to tackle some fairly steep hills in my current low gear. However, on some of the steeper and longer hills, the climbing is fairly strenuous and slow going. The tag along bike and a kid add about 65 or so pounds tow weight.
I'm not too concerned about losing some upper end speed if I switch to a lower granny gear. I mostly ride for fun and to see the countryside. Speed isn't too big of a concern. However, I would like to keep fairly even gear steps.
I would like some advice on how to upgrade my drivetrain to accomodate an even lower gear. Can anyone tell me what a typical touring bike has for a low gear (in gear inches)? What would be a good way for me to switch my configuration to provide an even lower gear? Should I replace the inner chain ring and the inner cog? Or would it be better to replace my whole freewheel set and my chain rings?
How can I tell if my derailleurs and shifters will accomodate my planned changes in gear combinations?
I'm planning on doing an overhaul (or replacement if necessary) of my bottom bracket and I thought it might be a good idea to also change the gear ratios while I'm at it.
Thanks in advance...
Hi, this page could help you out some sheldonbrown.com.
A quick check would start by shifting onto your largest cog. If you can pull the swinging arm of the derailluer further back you might be able to add a larger cog. See if your LBS (local bike shop) will let you try out a rear wheel with larger cogs, up to 34 teeth, to see if your shifter can handle them.
Mad bike riding scientist
An old Trek 800 should have a long cage derailer on it. It probably also has a 7 speed freewheel but that should be a problem either. Nashbar sells a 7 speed 13-32 freewheel for $15 or a Shimano megarange freewheel for $20 (probably $40 at a bike shop). Changing the freewheel will increase his range. The crank probably has a 74mm bolt circle so he can change the inner ring to a 24 tooth ring. That should give him a fairly low gear with a minimum of fuss and expense.
Originally Posted by ken cummings
I'm not sure what parts you'll need because I can't see your bike! Being 13 years old, I'm betting it has a rear cassette style with 7 speed cassette (my wife's 830 Analope does--about the same age as your bike). It might have a freewheel on it and the older style freewheel style hub.
First, you need to find this out. Go to your local bikeshop and ask. Then buy a special tool to take off the cassette and a chain tool if you don't have one already. This process is real easy, the tools aren't too expensive ($20) and this is something every cyclists should know how to do.
You might want to repack the hubs with new grease as well (check the Mechcanics forum)
After this, you can buy a new chain and cassette/or freewheel from a local shop or from Nashbar (mail order parts are WAY cheaper) and install lower gears yourself.
Yeah, I know all of this sounds like a pain in the rear, but I highly reccomend learning to fix easy stuff on your own bike. Check with your local bike club for help.
Sorry for the long post...PM if you have more questions.
Thanks for the posts. Sorry - I forgot to provide additional info in my original post. The bike only has 6 cogs on the rear wheel. I think (but am not sure) that it is a 6-speed freewheel. I checkd out bike nashbar and performance bike and they only offer 6 speed freewheels, with the teeth count the same as mine (28 on the largest cog).
Can I switch out the 6-cog freewheel to a 7 cog freewheel?
Thanks again for the replies. This is a grat forum. tacomee - I'm definitely planning to do most of the work myself, provided that the cost of tools isn't too high. I have a Bicycling Magazine book on bike mechanics and currently do my own maintenance. I haven't removed the freewheel and repacked the hubs yet, but I think it's about time I do. I wonder how worn/corroded my bearings are...
I think I found a solution for my bike. It's not that cheap, but I found a Shimano crankset that has a 22 tooth inner chain ring. I think I will switch out my crank to this one - this would allow me to use my existing shifters and freewheel. The only thing I would need to change out is the crankset.
with a 22 tooth inner chain ring and a 28 tooth inner cog, I'd have a 20.4 gear inch low gear, without having to switch out any other parts.
Much easier to change out the freewheel. Go to Sheldon Brown's site and find the Cassette and Freewheel area. You should still be able to get a 6-speed 13-34. If you get desperate, I suppose I could let you have one of my spares if you pay the shipping.
Originally Posted by cynergy
Thanks for the tip. I'll check out Sheldon's site again and see if I can find a 6 speed freewheel.
**EDITED** thanks again - I found the 6 speed freewheels with the megarange gears (34 teeth).
Last edited by cynergy; 04-23-07 at 03:35 PM.
Originally Posted by cynergy
Another satisfied customer!
PS the Sheldon Brown site is a great reference (as well as the Park Tools website)!