2026 Forest River Sierra3710HBFB

The Sierra 3710HBFB has 2,851 lbs of cargo capacity between 12,649 lbs dry and its 15,500 lbs GVWR, 18% of that rating; filling its 50-gallon fresh tank at 8.3 lb a gallon uses 415 lbs of it (how to read trailer weights).

Pin weight is 2,405 lbs, 19% of the dry weight as published; it rises as the trailer is loaded and comes off the truck’s payload, not its towing rating, so check it against the payload on your own door sticker (pin weight and payload).

Off hookups: 208 gallons of grey and black capacity against 50 gallons of fresh water, so fresh water runs out first (tank sizes by length).

Against the rest of the Sierra roster this is the 5th of 9 floorplans by dry weight, in a line that runs from 10,869 lbs to 13,864 lbs. It sits in the middle of the line by weight.

Plan the tow on loaded weight, not the 12,649 lbs dry figure: half the published cargo capacity brings this plan to about 14,075 lbs, and the published GVWR of 15,500 lbs is the limit (how to read trailer weights).

Forest River’s line listing and this floorplan’s own factory page agree on all 4 shared figures. Dry weight plus cargo capacity equals the published GVWR exactly. A missing row means Forest River does not publish that figure (how figures are verified).

Forest River publishes no floorplan description for this plan in the channel this page is built from - only the numeric specification block. Rather than describe a layout from the floorplan code, which would be a guess dressed as a fact, this page carries what the factory publishes and says where it stops. 3710HBFB is a Sierra designation and this site does not decode it into a layout claim.

How the 3710HBFB differs from the other eight Sierra floorplans. Most distinctive first. Sibling pages may cover other model years than this one (2026). How these ranks are worked out.

• Pin weight as a share of dry weight, 19%: second-largest of nine, between the 3100RD (18.8%) and the 3990FL (22.7%).
• Dry weight, 12,649 lb: fifth-lightest of nine, between the 4003MB (12,609 lb) and the 3800RK (12,849 lb).
• Cargo capacity, 2,851 lb: fifth-smallest of nine, between the 3900HBLR (2,801 lb) and the 4003MB (2,891 lb).
• Cargo capacity as a share of GVWR, 18.4%: fifth-smallest of nine, between the 3900HBLR (17.4%) and the 4003MB (18.7%).
• Black tank, 104 gal: largest of nine, level with the 3900HBLR; next is the 4002FB (100 gal).
• Pin weight, 2,405 lb: shared with the 3800RK; of nine, six lighter and one heavier, nearest the 4002FB (2,340 lb) and the 3990FL (2,825 lb).
• Exterior height, 13 ft 5 in: tallest of nine, level with the 3100RD and 3844QUAD; next are the 3480RL, 3800RK and four others (13 ft 4 in).
• Grey tank, 104 gal: shared with the 3100RD, 3480RL and 3844QUAD; of nine, four smaller and one larger, nearest the 3800RK, 4002FB and 4003MB (100 gal) and the 3900HBLR (136 gal).
• GVWR, 15,500 lb: shared with the 3800RK, 4002FB and 4003MB; of nine, three lower and two higher, nearest the 3990FL (15,375 lb) and the 3900HBLR (16,085 lb).
• Length, 42 ft 9 in: shared with the 3844QUAD, 3900HBLR and 4003MB; of nine, two shorter and three longer, nearest the 3480RL (38 ft 6 in) and the 4002FB (43 ft 5 in).

Next to the 4003MB, the nearest lighter floorplan by dry weight, the 3710HBFB is 40 lb heavier by dry weight, has 40 lb less cargo capacity, has a pin weight 395 lb heavier, stands 1 in taller, has a grey tank 4 gal larger and has a black tank 54 gal larger; the two publish the same GVWR, length and fresh tank.

Next to the 3800RK, the nearest heavier floorplan by dry weight, the 3710HBFB is 200 lb lighter by dry weight, has 200 lb more cargo capacity, is 1 ft 4 in shorter, stands 1 in taller, has a grey tank 4 gal larger and has a black tank 54 gal larger; the two publish the same GVWR, pin weight and fresh tank.

Sierra's published pin weights spread further than its dry weights do, and that is the fact worth carrying into a dealership: nine floorplans run 10,319 to 13,864 lb dry - a 3,500 lb band - while pin weight runs 1,560 to 2,825 lb, nearly doubling. Two Sierras a thousand pounds apart on the scale can be far apart at the pin too. Every plan on the roster ties out exactly against its published GVWR.

A full 50-gallon fresh tank is about 415 lb of water (water counts as cargo: 49 CFR 571.120 S10.4.2), 15% of the 3710HBFB’s 2,851 lb cargo capacity, leaving 2,436 lb. Across 9 Sierra floorplans the water share runs 14% to 19%, and 6 give up more than this one. Nearest on that share: Sierra 4003MB at 14% and Sierra 3900HBLR at 15%. Your own unit’s figure is on the label inside its entry door (49 CFR 571.120 S10.4.3).