Hi guys, I'm trying to set my dad's 2008 Gary Fisher Mullet SS mountain bike up with some gears and could use some help pointing me in the right direction. The goal is to have just to put a rear derailleur with a single ring up front. My question is, can I just use the SS crank ( Bontrager Earl Singlespeed, 32T w/bashguard) and put a hanger/RD/new cassette on? If so, any suggestions as to a decent entry level (cheap) groupo? Thanks in advance!

Bike: https://www.trekbikes.com/us/en/bikes...hive/mullet_ss

A bicycle is a simple machine but the devil is in the details.

Cable routing, chain line, rear hub design, rear hub dish, chain width, derailleur mounting are all important details. This isn't likely to be a simple project.

How about IGH? That would eliminate some of the issues (and bring a few of its own, I'm sure).

Rear OLD may not be wide enough to fit a cassette hub. There won't be a derailleur hanger or accomodation for cables. The 32t ring will likely be too thick for multispeed chain.

None of that is a dealbreaker, but a IGH would be a better fit; then you're pretty much only adding a single clamp-on cable stop.

Don't let the IGH proponents discourage you. Why throw an $800 hub at a $600 bike?

I don't know anything about GF Mullets, but a two minute search shows it to be a Hybrid that was available as a SS and a geared bike. Beyond that I couldn't find much. Don't know if they used the same frame, with the same dropout spacing, and kept the cable stops, used a freehub body with a single cog attached, or what. Can't see them having two different frames on an entry level hybrid.

It may be something as simple as adding some parts, or maybe not. You'll have to make that determination as you have the bike to look at. Don't know what your intention is. If you just want more gear choices, you might be money ahead to find a road bike. Show a pic of the drive side rear hub. That will help.

I agree -- you can get IGH kits for under $150, depending on how many speeds you want/need.

Narrow dropouts, there are narrow axle IGH, just not more than a 5 speed..

a better approach than a freewheel hub and a 5 (max) speed freewheel on the hub.

to fit in a 120 spaced frame (?)

I have converted single speed bikes to 3 and 5 speed IGH. It's not at all difficult or particularly expensive if you have a small amount of mechanical skill.

I don't know where you've been buying your IGHs, but they've been ripping you off spectacularly if you can't find one for less than $800....

Rohloff is quite possibly the only IGH in that price range. Maybe NuVinci (I've no idea how much that costs).

The IGH seems to be a viable choice. Where are you finding these at the 150ish price point? And thanks for the input =)

3-speed wheels start @ $103 + shipping.
https://www.niagaracycle.com/product_...ducts_id=16381

$21 for gripshifter.

https://www.niagaracycle.com/product_...ucts_id=503843

Here's an 8-speed wheelset w/shifter for $270.

https://www.americasbikecompany.com/S...o8wheelset.htm

https://store.somafab.com/sts5hubwtw.html

The Mullet SS is a 26" trials bike with an eccentric bottom bracket and disc brakes. The OLD is most probably std MTB=135mm.
Shimano Alfine will fit and give you 8 or 11 gears with a good chainline. Sturmey Archer X-RK8 is similar.
The frame seems to have a replaceable hanger but the one supplied has no hanger. Try swapping for a std gary fisher one.

The bike still lacks derailleur cable stops which are needed for high precision shifting. Hub gears use fully sheathed cables that plug directly into the hub.

The Mullet SS is such a unique bike that is is probably more valuable as a SS than geared.
There are plenty of 1x8/1x9 trials bikes around.

Good point about replaceable hanger. Just gotta find one with a hole that fits the frame.

Awesome, thanks for all the help guys!

The eccentric BB would make for an odd combination with a derailleur, but it's the bomb for SS & IGH.

+1

This isn't just some SS MTB. It's a purpose built trials/dirt jumper. If you sell it as such, you should be able to get good money for it (as trials/DJ bikes are a lot less common than plain ol' MTBs) and buy something that you actually want with that money. I'm all for experiments, but I see no benefit putting gears on this bike.

There are already tons of MTBs out there with gears. There are a lot less that were build for SS.

An IGH conversion is easily reversible; just hang onto the wheel and shifter when you sell the bike.

+1 check out craigslist and ebay--chances are you can find a geared mountain bike pretty cheap--and you can keep the SS as is.

train safe-

+100 Jake nailed it. Geared MTBs are a dime a dozen. Sell this unique one for real $$, pocket part of it, and use the rest to buy a nice geared bike of your choice.

I don't intend on selling the bike right now, I'm just letting my dad use it. Personally I'd rather keep it as a SS, but he wanted something with a few extra gears. I think using an IGH will be the cheapest and easiest to reverse option.. that way I can put things back as they were when he buys a new bike.