Utah Trikes - Idler Kit: TerraCycle HP Idler Kit for Zoomer/Elite

Hours: Mon-Fri 10-6 (MST), 10-4 Saturdays, Closed Sundays | 110 N Main Street, Spanish Fork, Utah 84660
Toll Free: 866-446-2065 | Local: 801-804-5810 | trikes@utahtrikes.com

NO PAYMENTS/NO INTEREST FOR 6 MONTHS ON MOST TRIKES (OAC)

Sitemap

Product Category: Catalog -> Idlers View all TerraCycle products
Idler Kit: TerraCycle HP Idler Kit for Zoomer/Elite

Price: TBA

Coming Soon

The TerraTrike Zoomer/Elite is an interesting model when it comes to making modifications. The frame is constructed such that there are some very tight tolerances, and the moveable boom adds some interesting challenges to the equation.

At first look, simply swapping the stock Delrin idlers for the TerraCycle idlers seems like it will work. We soon find that the stock idler positions do not provide the right clearances between the chain and frame in all rear gear positions when using the larger TerraCycle idlers.

If we look at the frame, a variation of the stock chainline will provide us with the best solution. Looking at the sideview we see that there are three frame/chain clearances that we must account for. To complicate this, all of the clearances will change depending on which gear the chain is in.

Clearance A: The power side of the chain must run over the "wheel stay" in order to drive the wheel. When in the highest gear (11T sprocket) the chain will ride at its lowest position. The stock rear idler position causes the chain to have about 1/16" clearance when being pulled tight, but when slackened the chain will rub on the "stay" causing damage to the paint. One goal of our new chainline is to raise this clearance to a minimum of 1/4".

Clearance B: When the chain is in the lowest gear (34T or 32T) the path will be raised to the point where we must be mindfull of the clearance between the chain and the bottom of the rear seat support. Since the chain will fall away from the frame when not under tension, a clearance of 1/8" while under tension will be adequte.

Clearance C: Running the power side of the chain over the front cross arm is not something that we want to do because it could come into contact with the seat mesh. By running the chain under the cross arm we must deal with the clearance of the chain and the bottom of the cross arm frame. We must account for this clearance when the chain is riding in the largest chainring. The angle of the chain will change as the boom length is changed. It will be most severe as the boom is placed in its shortest position. A minimum clearance of 1/8" is adequate under tension.

Clearance D: Since we are running the chain under the Zoomer's frame we will also want to take into account the ground clearance from the bottom of the idlers.

The main goal of our new chainline is to reduce idler count (and noise), simplify the chainline, and increase chainline efficiency. We would like to propose a new chainline consisting of just one pair of idlers, with as much float as possible to promote efficient shifting. This will keep the cost of the kit down, and provide maximum performance.

In working with TerraCycle to come up with a solution, they have provided us with a variety of idlers. We decided that their new 4" power idler would provide us with the best clearances. We have combined it with a TerraCycle return idler.

Since Clearance C is going to be the hardest to adjust for, and the most variable, we decided to set the position of the idler to maximize first for Clearance A and then Clearance B. We are using a custom three-hole idler clamp that allows us some flexibility. Keeping the idler in position 1 will maximize Clearance D. So we can have a consistent point of reference, we are measuring the position of the idler clamp from the front of the rear idler bolt mount.

If we are only using one set of idlers, we need to set the position based on Clearance C. In order to maximize Clearance C, the Idler Clamp should be moved forward as much as possible while using the lowest camp hole possible. In order to get the maximum ground clearance (Clearance D) we want to use the highest clamp possible. So, we must balance both of these clearances based on the position of the boom.

This will be the best option to provide the best chainline efficiency and performance. But, it does not allow for the most flexibility in adjusting the boom. If moving the boom to extremes is required,or if the boom needs to be moved on a regular basis, then we recommend going with a three idler configuration. This is done be adding the additional power idler to the stock front idler position. This allows you to have the most flexibility with the idler kit. This provides for the maximum adjustability of the front boom and we no longer have to worry about Clearance C.

Clearance A
This is the tightest clearance with the stock idlers. Our goal is to increase this so that the chain will never come in contact with the frame.

Clearance B
Once we add our kit and move the new idlers forward we must be mindfull of this clearance. When the chain in in the lowest gear, the angle will be higher and the distance between the chain and the bottom of the seat frame will decrease.

Clearance C
Some of the boom positions will allow us to completely eliminate the front idlers. In this case we must make sure that the chain cannot come in contact with the frame when the largest chainring is in use. The alternative here is to use one power idler in the stock front mounting position. This will give us maximum flexibility, and allow the boom to slide to all positions.

Clearance D
The new power idler is larger than the stock idler and therefore will have a lower ground clearance. We minimize that as much as possible by sliding the idlers forward as much as possible.

Share your comments below:
So any ETA / Price on this?
Posted by Wuss912
10/09/2008 11:37:45 AM

Comments:

Nickname:

All comments are moderated by Utah Trikes staff. We reserve the right to remove or edit any comment that we deem to be inappropriate. After you add your comment it will not immediately appear until a moderator has read it.

Other Items you may be interested in:

Chain Keeper: TerraCycle Stainless Steel Double
$14.95

Idler Kit: Trice T Over/Under Idler Kit
$147/$167

Chain Keeper: TerraCycle Bolt On Single Stainless Steel
$12

TerraCycle Clamp On Idler Mount
$29.95 and up