JMI Wheeley Bar Accessories

Every JMI Wheeley Bar can be enhanced, upgraded, and customized to suit your specific observing setup and site conditions. This collection covers the complete range of official JMI Wheeley Bar accessories — from essential safety hardware to all-terrain wheel upgrades, battery management, and full motorized drive.

Whether you are rolling across a cracked driveway, through a backyard field, or deploying a fully automated observatory setup, there is an accessory here that makes your Wheeley Bar more capable, more secure, and more suited to your night-by-night conditions.

Accessory Guide — What Do You Need?

Tie-Down Bracket Kit — Essential for Every Setup

The single most important Wheeley Bar accessory. Sturdy steel brackets bolt to your Wheeley Bar frame and heavy-duty ratchet straps cinch over each tripod leg, locking the telescope firmly to the dolly during transport. Without it, a jolt or uneven surface can tip your tripod sideways — potentially destroying expensive equipment.

• Standard Kit: Fits the Medium Universal, HD Medium, HD Large, and Astro-Physics Pier Mount Wheeley Bars
• Half Kit: Required for the HD Shorty Wheeley Bar only — do not use the standard kit on a Shorty

Battery Pack Holders — Keep Power on the Dolly

Mount your field power supply directly to the Wheeley Bar frame so it rolls out with the telescope instead of being carried separately. Heavy-duty steel trays with rimmed edges keep the battery securely in place during transport, even on rough terrain.

• Standard Battery Pack Holder (BRKTBP): Fits battery packs up to 5½″ × 10″. Compatible with all Universal Wheeley Bar models.
• Battery Pack Holder XL (BRKTBP-XL): Fits larger packs up to 15¾″ × 11¾″. HD Medium and HD Large only — does not fit the standard Medium or HD Shorty.

Wheel Upgrades — Match Your Terrain

The standard 2-3/8″ hard-rubber casters are designed for smooth, flat, hard floors. If your terrain is anything else, upgrade:

• 5″ Polyurethane Wheels: Best for hard surfaces with imperfections — cracked concrete, patio pavers, rough aggregate, sidewalk seams. Raises setup ~6″. Lower your tripod 6″ before measuring tip-to-tip if ordering a new Wheeley Bar with this upgrade.
• 10″ Pneumatic Wheel Upgrade + Tow Handle: Full all-terrain capability — grass, dirt, gravel, and uneven ground. Includes a tow handle for pulling the loaded rig from the front. Raises setup ~3¼″. Lower your tripod 3.5″ before measuring tip-to-tip. Two versions available — select by leveling screw size (5/8″ or 1/2″).

Motor Upgrade — Powered Roll-Out

Converts your existing Wheeley Bar into a motorized telescope dolly. Requires both the 10″ Pneumatic Wheel Upgrade and a Battery Pack Holder to be already installed. Two versions available based on your Wheeley Bar's leveling screw mounting style (new style block-thread or old style welded-nut). Contact us before ordering to confirm availability and the correct version for your setup.

Frequently Asked Questions

Do I really need the Tie-Down Bracket Kit?
Yes — for any setup worth protecting. Wheeley Bars are stable at rest, but rolling over uneven surfaces can cause the tripod to shift or tip sideways. The Tie-Down Kit is inexpensive insurance against a very expensive tip-over.

Which Tie-Down Kit do I need — Standard or Half?
If you have an HD Shorty Wheeley Bar, order the Half Kit. For all other Universal models (Medium, HD Medium, HD Large, Astro-Physics Pier), order the Standard Kit.

Which Battery Pack Holder fits my Wheeley Bar?
The standard Battery Pack Holder (BRKTBP) fits all Universal Wheeley Bar models and holds packs up to 5½″ × 10″. The XL (BRKTBP-XL) fits HD Medium and HD Large only and holds packs up to 15¾″ × 11¾″. If you are on an HD Medium or HD Large with legs near minimum extension, use two standard holders side by side instead of the XL.

What is the difference between the 5″ polyurethane and 10″ pneumatic wheel upgrades?
The 5″ polyurethane wheels are for hard surfaces with imperfections — cracked concrete, rough pavers, aggregate paths. They will not work well on grass or gravel. The 10″ pneumatic wheels are full all-terrain tires for grass, dirt, gravel, and uneven ground, and include a tow handle. If your observing surface is consistently flat and hard (even if imperfect), choose the 5″. If you ever go off pavement, choose the 10″.

How do I know if I have 5/8″ or 1/2″ leveling screws for the 10″ Pneumatic Upgrade?
Measure the outer diameter of one of your leveling screws with a caliper. All newer HD Medium and HD Large Wheeley Bars use 5/8″. The standard Medium and older HD models use 1/2″. When in doubt, contact us before ordering — using the wrong version means the tow handle bracket won't fit correctly.

Can I add the Motor Upgrade to my existing Wheeley Bar?
Yes — provided you already have the 10″ Pneumatic Wheel Upgrade and Battery Pack Holder installed. These are non-negotiable prerequisites. Contact us to confirm availability and the correct motor version for your specific Wheeley Bar model.

Can I mix accessories across different Wheeley Bar models?
Most accessories are specific to Universal-style Wheeley Bars (Medium, HD Shorty, HD Medium, HD Large, AP Pier). The Battery Pack Holders, Tie-Down Kits, and wheel upgrades are not compatible with Dobsonian-style Sky Trekker or Triangle Wheeley Bar models. When in doubt, contact us with your model name before ordering.

Do I need to modify my Wheeley Bar to install these accessories?
No. All accessories mount using the existing Wheeley Bar hardware. No drilling, welding, or permanent modification is required for any item in this collection.

I want to add the Motor Upgrade but am not sure where to start. What do I do?
Start by confirming your Wheeley Bar model, current wheel configuration, and leveling screw type. Then purchase the 10″ Pneumatic Wheel Upgrade and Battery Pack Holder if not already installed. Once those are confirmed, contact us to order the Motor Upgrade with the correct version for your bar. We recommend contacting us before ordering any part of this chain — we can help you plan the full upgrade path in one conversation.