Introduction
Firstly, I should make clear that while I've been riding bicycles for many years and have done a fair amount of maintenance on them, I am by no means a bike mechanic (much more of my bike maintenance has been done by the LBS than by me). I have had a Trek Y-11 which I've used as a mountain bike on rough trails for ~15 years (much of that time was at a rate of perhaps 30 miles/week or so, although with a lot less riding in the past couple years). More about the bike below, but the frame and some fundamental components are starting to wear, and the replacement parts are not so easy to come by, since it has been out of production for so long. Rather than let it fall to pieces on limestone drop-offs, I decided to try converting it to a commuter bike -- enter the Cruzbike conversion kit.
At least a first pass of that conversion is now finished, and while there will be a good it more tweaking, I'm sure, it is now ridable.What I have tried to compile here is a list of problems that I came across during the conversion. I did not keep track of hours spent on this, but I'm sure it was somewhere between 10 and 15 hours over the course of a couple weeks. Somebody with a better shop space and more general experience could certainly cut my time in half. Note that this document is mostly about the problems I had -- overall I'd say that while it was a lot less "snap-together" than I expected, it does seem to work with this donor bike and components (with exceptions listed below), and I'm excited to start riding it!
Also note: some of these problems might have arisen from straight-up errors on my part, or may have standard solutions -- feel free to correct my evil ways, and I'll try to annotate this post to reflect the other suggestions. And, yes, I'll post some pictures of the conversion when I get a chance to take them (tonight or tomorrow I hope).
Donor Bike
Trek Y-11 purchased in 1994 (or 1995) -- this was the first full production year of the OCLV Y-frame from Trek. This frame had come out a year earlier with a limited run (I think it was just called a Trek Y-bike). It was sold in three models: the Y-11, Y-22, and Y-33, the difference being component levels (the frames were all exactly the same). In my case, little of the original was left, however (I believe it was one brake lever and the carbon portion of the frame). This bike has been used purely as a mountain bike, and as such the components are more of that ilk than of commuter-bike ilk.
Some key components:
The converted bike weighs in at about 35.5 lbs (16 kg).
Compatibility Issues
Front Fork
The front fork on my bike has (had) a mount for disk brakes. This mount interfered with the right FWD bracket where it is supposed to be clamped to the fork. Solution: I used an angle grinder to grind down the disk brake mount. BTW, it was both mounting holes that were problems -- the top one interfered with the FWD bracket, and the bottom one interfered with the chain moving over the cogs -- no matter, once one is ground off, the other is just extra weight anyway.
Bottom Bracket
The Cruzbike bottom bracket shell takes a 68mm english thread, while the Trek Y-11 uses a 73mm BB. I don't know if this is an issue for all types of bottom brackets, but for the sealed bearing cartridge style that I had it was. Solution: Buy a 68mm cartridge bottom bracket (I got a 118mm axle).
Seat Post
The seatpost on my bike (27.2mm, btw), was the style with integrated bracket, rather than the pillar style assumed by the Cruzbike seat. I was not successful at finding a 27.2mm pillar style seat post in my fair city (Austin -- pop. ~1,000,000) -- nearly all newer mountain bikes (here, anyway) use the style with the integrated seat bracket. Solution: It was easy to find online, and not very expensive, Also it could have been ordered by any of the LBSs.
Note that Acros makes a pretty cool looking option that I think would allow you to use the same post with either the Cruzbike seat or a standard seat, but it's >$100USD, and they seem to have stopped making it in 27.2mm diameter. The Cruzbike seat-back rails appear to match the pitch of standard seat rails, and it seems like there are many possible solutions here. In fact I was even able to use my existing seapost by turning the bracket sideways and using a zip-tie.
Seat Bottom Mount
The seat bottom is held to the frame with clamps. The kit ships with metal "plumbing clamps" that are too small to fit around the OCLV frame. Solution: Actually, I was able to get one of the clamps around the frame once I had the seat forward more (see pivot point, below). For the other, I just used 2 zip-ties for now. If turns out to be a problem, then certainly larger "plumbing clamps" are available.
Cabling
Well, I don't think this is really much of an issue, just something to be aware of: The conversion requires a new rear brake cable (this is mentioned right at the start of the instructions), but also, if your bike (like mine) has cable braze-ons on the frame that allow the cables to be largely run without a housing (i.e. there are just little bits of housing at the ends of the cables), then you will also need a decent amount of cable housing, given the new routing.
Kit issues
FWD Brackets
Pivot Point in front triangle
Because the bottom bracket must have a constant distance to the front axle, adjusting its position relative to the seat causes it to pivot around the front axle. For this reason, and because the intent is to install this on a bicycle with front suspension, there is a pivot in the front triangle between the bottom bracket and the front chain stays. The problem (at least as I see it) is that this changes the angle between the front derailleur and the chain, as the bottom bracket pivots (or front suspension compresses and extends). Solution: push the seat and bottom bracket forward, and be ~6ft tall. I originally had the seat and bottom bracket further back, but could not get the front derailleur to work for all 3 rings. For what it's worth, I like the new position anyway. From pictures, I can tell that this problem is either not universal or a lot of people are fine with 2 chain rings (heck, for road riding I'm probably fine with it). Perhaps another valid solution is to be better at tuning the drivetrain than I am.
A pivot does need to be there, but I think it might be better for it to be between the bottom bracket and the steering tube, above the front derailleur mount. This would allow the front derailleur to have the proper angle no matter where the bottom bracket is adjusted to and no matter what state the suspension is in. The cost of this is a slight variance in the distance from saddle to bottom bracket as the suspension moves, but this should be very slight, and, in fact, more closely matches the way the rear triangle worked on the original Y-bike(s). This actually brings to mind another thought -- if I scrounged up a second rear triangle from a Trek Y-11 (or similar), then this could potentially be mounted as the new front triangle, which would probably be lighter and would avoid the problem I'm seeing with the pivot point.
I'll put some comments on my riding experience once I get a chance to ride it more (I only have 15 minutes or so on it so far).[/][/]
Firstly, I should make clear that while I've been riding bicycles for many years and have done a fair amount of maintenance on them, I am by no means a bike mechanic (much more of my bike maintenance has been done by the LBS than by me). I have had a Trek Y-11 which I've used as a mountain bike on rough trails for ~15 years (much of that time was at a rate of perhaps 30 miles/week or so, although with a lot less riding in the past couple years). More about the bike below, but the frame and some fundamental components are starting to wear, and the replacement parts are not so easy to come by, since it has been out of production for so long. Rather than let it fall to pieces on limestone drop-offs, I decided to try converting it to a commuter bike -- enter the Cruzbike conversion kit.
At least a first pass of that conversion is now finished, and while there will be a good it more tweaking, I'm sure, it is now ridable.What I have tried to compile here is a list of problems that I came across during the conversion. I did not keep track of hours spent on this, but I'm sure it was somewhere between 10 and 15 hours over the course of a couple weeks. Somebody with a better shop space and more general experience could certainly cut my time in half. Note that this document is mostly about the problems I had -- overall I'd say that while it was a lot less "snap-together" than I expected, it does seem to work with this donor bike and components (with exceptions listed below), and I'm excited to start riding it!
Also note: some of these problems might have arisen from straight-up errors on my part, or may have standard solutions -- feel free to correct my evil ways, and I'll try to annotate this post to reflect the other suggestions. And, yes, I'll post some pictures of the conversion when I get a chance to take them (tonight or tomorrow I hope).
Donor Bike
Trek Y-11 purchased in 1994 (or 1995) -- this was the first full production year of the OCLV Y-frame from Trek. This frame had come out a year earlier with a limited run (I think it was just called a Trek Y-bike). It was sold in three models: the Y-11, Y-22, and Y-33, the difference being component levels (the frames were all exactly the same). In my case, little of the original was left, however (I believe it was one brake lever and the carbon portion of the frame). This bike has been used purely as a mountain bike, and as such the components are more of that ilk than of commuter-bike ilk.
Some key components:
- Fork: Rock Shox Psylo SL (from maybe 2000 or so?)
- Wheels: Mavic Crossmax tubeless
- Shimano splined sealed cartridge bottom bracket
The converted bike weighs in at about 35.5 lbs (16 kg).
Compatibility Issues
Front Fork
The front fork on my bike has (had) a mount for disk brakes. This mount interfered with the right FWD bracket where it is supposed to be clamped to the fork. Solution: I used an angle grinder to grind down the disk brake mount. BTW, it was both mounting holes that were problems -- the top one interfered with the FWD bracket, and the bottom one interfered with the chain moving over the cogs -- no matter, once one is ground off, the other is just extra weight anyway.
Bottom Bracket
The Cruzbike bottom bracket shell takes a 68mm english thread, while the Trek Y-11 uses a 73mm BB. I don't know if this is an issue for all types of bottom brackets, but for the sealed bearing cartridge style that I had it was. Solution: Buy a 68mm cartridge bottom bracket (I got a 118mm axle).
Seat Post
The seatpost on my bike (27.2mm, btw), was the style with integrated bracket, rather than the pillar style assumed by the Cruzbike seat. I was not successful at finding a 27.2mm pillar style seat post in my fair city (Austin -- pop. ~1,000,000) -- nearly all newer mountain bikes (here, anyway) use the style with the integrated seat bracket. Solution: It was easy to find online, and not very expensive, Also it could have been ordered by any of the LBSs.
Note that Acros makes a pretty cool looking option that I think would allow you to use the same post with either the Cruzbike seat or a standard seat, but it's >$100USD, and they seem to have stopped making it in 27.2mm diameter. The Cruzbike seat-back rails appear to match the pitch of standard seat rails, and it seems like there are many possible solutions here. In fact I was even able to use my existing seapost by turning the bracket sideways and using a zip-tie.
Seat Bottom Mount
The seat bottom is held to the frame with clamps. The kit ships with metal "plumbing clamps" that are too small to fit around the OCLV frame. Solution: Actually, I was able to get one of the clamps around the frame once I had the seat forward more (see pivot point, below). For the other, I just used 2 zip-ties for now. If turns out to be a problem, then certainly larger "plumbing clamps" are available.
Cabling
Well, I don't think this is really much of an issue, just something to be aware of: The conversion requires a new rear brake cable (this is mentioned right at the start of the instructions), but also, if your bike (like mine) has cable braze-ons on the frame that allow the cables to be largely run without a housing (i.e. there are just little bits of housing at the ends of the cables), then you will also need a decent amount of cable housing, given the new routing.
Kit issues
FWD Brackets
- The bolts supplied fit neither the FWD bracket mounting holes nor the front fork drop-outs. I believe my fork supports a 9mm axle. Solution: I went out and bought some 3/8" stainless steel bolts, that fit (barely). I believe the kit is supposed to come with 3/8" bolts, but it appears that for some reason mine shipped with 7/16" bolts or something (unless the thread diameter of the SS bolt is just slightly narrower or something weird that I'm unaware of).
- The derailleur hanger threads appear to be off from 10x1mm (which I thought was "standard"). This could be an issue of the powder-coating adding just enough to the threads to make the derailleur bolt not fit. Solution: re-tap the threads to 10x1mm. After having done this, I have become convinced that it was just the powder coating blocking the threads.
- The bracket interferes with the derailleur cage for high gears. This is likely dependent on the chain length, which, in turn is dependent on the gear range that is on the bike. Using a mountain bike as a donor, in my case meant a pretty big gear range. Solution: grind off part of the bracket that is interfering, and sacrifice the smallest cog.
- When the rear derailleur is screwed in all the way, the bolt actually contacts the chain in the smallest cog. Solution: (not yet tried) I think I'll try inserting a spacer between the cassette and the bracket -- this might also help with the problem above, since the derailleur might then not need to "overlap" the bracket. For now, I just don't use the smallest cog.
Pivot Point in front triangle
Because the bottom bracket must have a constant distance to the front axle, adjusting its position relative to the seat causes it to pivot around the front axle. For this reason, and because the intent is to install this on a bicycle with front suspension, there is a pivot in the front triangle between the bottom bracket and the front chain stays. The problem (at least as I see it) is that this changes the angle between the front derailleur and the chain, as the bottom bracket pivots (or front suspension compresses and extends). Solution: push the seat and bottom bracket forward, and be ~6ft tall. I originally had the seat and bottom bracket further back, but could not get the front derailleur to work for all 3 rings. For what it's worth, I like the new position anyway. From pictures, I can tell that this problem is either not universal or a lot of people are fine with 2 chain rings (heck, for road riding I'm probably fine with it). Perhaps another valid solution is to be better at tuning the drivetrain than I am.
A pivot does need to be there, but I think it might be better for it to be between the bottom bracket and the steering tube, above the front derailleur mount. This would allow the front derailleur to have the proper angle no matter where the bottom bracket is adjusted to and no matter what state the suspension is in. The cost of this is a slight variance in the distance from saddle to bottom bracket as the suspension moves, but this should be very slight, and, in fact, more closely matches the way the rear triangle worked on the original Y-bike(s). This actually brings to mind another thought -- if I scrounged up a second rear triangle from a Trek Y-11 (or similar), then this could potentially be mounted as the new front triangle, which would probably be lighter and would avoid the problem I'm seeing with the pivot point.
I'll put some comments on my riding experience once I get a chance to ride it more (I only have 15 minutes or so on it so far).[/][/]
