michiganmarty

My son and I are trying to fix his el-cheapo mountain bike and it needs both deraileurs and shifters. The originals (it is a cheap bike) were TD-One's (are junk and useless), I assume some flavor made just for these department store bikes.

This is a Pacific 15 speed bike (I think we bought it at Target) and does not have the direct mount rear deraileur. I am familiar with the brackets to allow using direct mount deraileurs.

Can I use the SRAM twist grip shifters for any brand deraileurs?

Is there an inexpensive way to turn this bike into a click shifter?

Can I change out the rear cog assembly to a 7 speed? What about the width of the rear fork opening?

I'm not going to spend a whole lot of money here, I just want him to learn how to work on his bike. He is also going to get the experience of tearing it completely down and repainting and rebuilding it this winter.

I have enough tools to do the job, though I may end up buying a couple for the rear cogs (Cassette?)

sch

Sram has two types of twist grips, one for their line of der which have a
different pull ratio and another (attack series) for Shimano style der.
Most after market cheapies (cheap is not necessarily bad) will be Shimano
compatible. Check Nashbar.com for something suitable. If the rear opening
is under 130mm inside to inside you may not be able to change especially
if the bike is Al framed. Nashbar has 5-6-7 spd freewheels and 7spd
cassettes for cheap. Yours is probably freewheel.

ogbigbird

i know cheap bikes. if you have a 5speed rear end, you most likely have a freewheel, and not a cassette. you can find a 7speed freewheel in nashbar or somewherelike that, but the cog spacing may be narrower. you may need spacers to fit it, but a 6speed could go right on. just readjust the low/high range govener screws on your new derailleur to accept the wider range. for rear derailleurs that have the built in mounting "claw", shimano tourney may be about as good as it gets. they simplely don't make high end deraileurs with that mounting system.

shifters, i don't know if sram shifters are compatable with the cheap 7speed freewheel you want to put on there as far as spacing goes. of you want a cassette, you will need an entirely new rear wheel eith a freehub set up on it to accept the cassette. then there is the new chain you may need to run a 7speed rear freewheel, but you may be ok with what you got now. changing this bike to an indexed (clicker) style shifter will need to make sure your freewheel cog spacing is compatable with your shifter's indexed spacing. brand with brand compatability is a good rule for this. good luck.

Retro Grouch 

The last time that I looked, you could still get SRAM 6-speed MRX (Shimano compatable) shifter sets. Shimano Tourney derailleurs come with the bracket for installing on the frame. Neither is very expensive. If you get a non-indexed front shifter (they come both ways) any front derailleur will work. Make sure you get the clamp diameter that matches your seat tube. A new 6-speed freewheel should spin right onto your existing hub but you will need a special tool for that.

The learning process is what makes this project worth while. Good luck.

wrk101

For the cost of shifters and derailleurs, you might be able to find a good/decent mountain bike used. Check C/L and similar.

Retro Grouch 

Yeah, but part of the attraction is reworking the bike with his son. How can you put a price tag on that?

joejack951

Yes, but you need to make sure you buy the right shifters. SRAM makes both Shimano compatible and SRAM compatible shifters (the compatibility issue is strictly for the rear derailler as far as I know).

Cheap twist and trigger shifters available here: https://www.universalcycles.com/shopp...rder=price_asc

I'm not that familiar with the frames on cheaper bikes but the standard rear dropout spacing for a 6/7 speed bike is 126mm whereas 5 (and sometimes 6) is typically 120mm. If the frame is steel, you could always apread the rear triangle to accomodate the wider spacing (if it's currently 120mm) though you'd also need a longer axle and some spacers for the rear wheel in addition to having to redish the wheel. This would be a great learning experience if that's what you are looking for.

You'll need the correct freewheel remover but that should be the only special tool you need. A chain whip is useful but not necessary for installing the freewheel. There are a few different versions of freewheel removers out there so make sure you get the correct one(s) (for old and new). www.sheldonbrown.com is a great resource for that type of information.

bluenote157

I want to say that SRAM has a 6speed grip shifter. I'm not sure about your direct mounting issues with your derailleurs, but if you can get a shimano derailleur used on ebay you might be golden. Isnt this just a piece of metal that simulates the drop to hold the rear derailleur?? It can be pretty much any shimano except pre1997 dura ace. Do a search on XT or XTR or Deore..

Your 5speed is probably a freewheel. Buy a cheapo 6speed and thread it on.

This is the shifter..
https://www.jensonusa.com/store/produ...p+Shifter.aspx

michiganmarty

Thanks to all for your help.

I went with a Shimano Tourney GS RD and Pyramid FD and Pyramid Combo 3x7 Shifters/Brake Levers and Pyramid 7 spd freewheel. Total cost was about $38 + shipping.

We are waiting for the bike to come back from sandblasting & I will be adding some braze-ons before painting and building.

wrk101: As Retro Grouch said, "...but part of the attraction is reworking the bike with his son. How can you put a price tag on that?" This is the whole intent of the project. It is to teach him how to wrench on his bike(s) now and forever.

It is not about saving money. The entire project is going to cost about triple the cost of the original bike, but there are many components that are much upgraded from the factory production bike, including wheels and tires. As it stands right now, the only thing that is going to be left on this bike that came from the factory is the crankset and chainrings. Everything else is going to be new, front fork, handlebars, stem, brakes, seat, seatpost, cables etc.

We're upgrading from el-cheapo Caliper brakes to Shimano Cantilevers. This requires brazing the posts on the seat stays and replacing the front fork that already has the posts. The brake upgrade is pretty cheap too, since the fork only cost $18.00 and the braze-ons are only about $4.00 (+ shipping). We're using the (like-new but outdated) Shimano Deore XT Canti's that came off my old MTN bike after upgrading that one to V-Brakes. New brake shoes are in order also, about another $20.00 total.

We're having fun, and he is learning a lot.

Thanks to all.

michiganmarty

P.S. It didn't start out as a "money is no object" project,
but the further we went, the more I said, let's just do it !

MichiganMarty

Retro Grouch 

Yeah, those projects have a way of doing that.